T.M. v. Janssen Pharmaceuticals, Inc. ( 2019 )


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  • J -A27012-18
    
    2019 Pa. Super. 217
    T.M. AND BRENDA TINKHAM                   IN THE SUPERIOR COURT OF
    PENNSYLVANIA
    APPELLANTS
    v.
    JANSSEN PHARMACEUTICALS INC.;
    JOHNSON & JOHNSON; JANSSEN
    RESEARCH & DEVELOPMENT, LLC;              No. 184 EDA 2018
    EXCERPTA MEDICA, INC.; AND
    ELSEVIER INC.,
    Appeal from the Judgment Entered December 4, 2017
    In the Court of Common Pleas of Philadelphia County Civil Division at
    No(s): 1076 May Term, 2013
    BEFORE: BOWES, J., STABILE, J., and McLAUGHLIN, J.
    OPINION BY BOWES, J.:                                  FILED JULY 16, 2019
    T.M. and his mother, Brenda Tinkham, ("Plaintiffs") appeal from the
    December 4, 2017 judgment entered in favor of Janssen Pharmaceuticals,
    Inc., Johnson & Johnson, Janssen Research & Development, LLC ("Janssen"),1
    following entry of a compulsory nonsuit in their action seeking damages for
    the drug manufacturer's failure to adequately warn of the risk of gynecomastia
    1   Defendants Excerpta Medica, Inc. and Elsevier, Inc. were dismissed from
    the case earlier and are not involved in the instant appeal.         "Janssen
    Pharmaceuticals, Inc. and Janssen Research & Development, LLC, are wholly
    owned companies of Johnson & Johnson." Pledger v. Janssen Pharms.,
    Inc., 
    198 A.3d 1126
    , 1130 n.1 (Pa.Super. 2018).
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    associated with Risperdal use in children.2 We vacate the judgment, reverse
    the order entering a compulsory nonsuit, and remand for a new trial.
    We glean the following from the evidence offered by Plaintiffs at trial.
    In 2004, T.M. was seven years old and living with his family in Wichita Falls,
    Texas.3 When he began acting out in school, his parents arranged for a mental
    health evaluation at the Rose Street Mental Health Clinic. Physician Assistant
    John Dewar diagnosed him with attention deficit hyperactivity disorder
    ("ADHD"), oppositional defiant disorder ("ODD"), and depression, and under
    the supervision of pediatric psychiatrists Harvey Martin, M.D. and Brian Wieck,
    M.D., prescribed Risperdal for T.M. Risperdal was not approved by the Food
    and Drug Administration ("FDA") for use in children, or for the indication for
    which it was prescribed. As approved, the drug was indicated only for adults
    with schizophrenia. Thus, Risperdal was prescribed for T.M. for an off -label
    2 Gynecomastia is "a condition where female breast tissue grows in males."
    Murray v. Janssen Pharmaceuticals, Inc., 
    180 A.3d 1235
    ,   1238
    (Pa.Super. 2018). This case is one of more than five thousand cases
    coordinated in Philadelphia's Complex Litigation Center under the caption In
    re Risperdal Litigation, involving males who allegedly developed
    gynecomastia as a result of taking the prescription drug Risperdal. Murray,
    supra at 1238.
    3 T.M. grew up in an Air Force family that moved from base to base throughout
    the United States. Although he was originally prescribed Risperdal in Texas,
    use of Risperdal continued when T.M. moved to the state of Washington. He
    was diagnosed with gynecomastia when he lived in Nebraska. The parties
    agree that Pennsylvania's procedural law governs this litigation, and that
    Texas's substantive law applies.
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    use.4 At the time, Risperdal was known to cause increased prolactin levels
    associated with gynecomastia and other endocrine disorders. T.M. remained
    on Risperdal for three and one-half years. In 2006, T.M. developed breasts.
    In May 2013, Plaintiffs filed the instant case against Janssen, the
    manufacturer and distributor of Risperdal, alleging negligent failure to provide
    adequate warnings of the known risk of gynecomastia associated with its
    drug,5 and fraud. A jury trial commenced on November 28, 2016.
    At trial, Plaintiffs offered the testimony of David Kessler, M.D, a
    physician specializing in pediatric medicine and public health, who served as
    the Commissioner of the FDA from 1990 through 1997, and who was formerly
    a biostatistics professor at the University of California and Dean of the Yale
    Medical School.    Dr. Kessler provided expert testimony establishing that
    4 "Off -label use" is the use of an FDA -approved drug for an unapproved use.
    Healthcare providers have the authority to prescribe a drug off -label, i.e., for
    an indication for which it has not received FDA approval.
    5 Texas law recognizes a products liability cause of action for failure to warn
    in a pharmaceutical case. However, the Texas Products Liability Act ("TPLA")
    provides that there is a rebuttable presumption that defendants are not liable
    if the warnings or information accompanying the product are FDA approved.
    The presumption may be rebutted by proving that, inter alia, the defendant
    withheld or misrepresented material information to the FDA that was causally
    related to the injury, or the defendant promoted or advertised or
    recommended the product for an indication that was not FDA approved, it was
    used as promoted, and the claimant's injury was causally related to the
    promoted use of the product. See Tex. Civ. Prac. & Rem. Code § 82.007,
    effective September 1, 2003.
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    Janssen had a duty to warn of the known risks of gynecomastia with Risperdal
    use, and that it breached that duty. Dr. Kessler traced the history of Risperdal,
    explaining that it was a second -generation antipsychotic drug manufactured
    and marketed by Janssen. It was first approved by the FDA in 1993 for the
    treatment of adults with psychotic disorders such as schizophrenia. In 1996,
    Janssen asked the FDA for permission to include dosing information for
    children on the label as it was "aware that Risperdal was being utilized in
    children in adolescence" for off -label uses such as ADHD.           Videotaped
    Deposition of David Kessler, M.D. 12/2/16, at 36.6 The FDA refused the
    request, citing "inadequate support for the changes sought." Id. at 40.
    Specifically, the FDA cited the "meager safety data" for Risperdal's pediatric
    use, and it feared that the proposed labeling would promote use in pediatric
    patients without justification.     Id. at 41-42; see also Plaintiffs' Exhibit 8
    (letter from Paul Leber, M.D. to Janssen, 9/17/97).
    Plaintiffs offered into evidence the 2002 package insert for Risperdal,
    often referred to as the "label." Plaintiffs' Exhibit 2. Dr. Kessler pointed to
    language therein that the drug's "[s]afety and effectiveness in children have
    not   been   established."    Id.       Under "Precautions," the label     listed
    "hyperprolactinemia," a condition in which one has higher than normal serum
    6 The videotaped deposition of David Kessler, M.D., was taken on May 19 and
    20, 2015, for use in the Risperdal litigation generally. It was played to the
    jury in this case commencing on December 2, 2016, and the page references
    are to the Designation Run Report.
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    levels of the hormone prolactin, the main function of which is to stimulate
    breast milk production after childbirth. The label also provided that "[a]s with
    other drugs that antagonize dopamine D receptors," elevated prolactin levels
    persisted "during chronic administration." Id. at 42. The label acknowledged
    that although disturbances such as galactorrhea (the expression of breast
    milk),     amenorrhea    (absence    of     menstrual      period),   impotence,   and
    gynecomastia (feminization of the male breast) had been reported with
    prolactin-elevating compounds, it stated that, "the clinical significance of
    elevated prolactin levels is unknown for most patients." Id. at 18, 21. The
    contents of the Risperdal label remained the same until 2006.
    Dr. Kessler testified that, in 2004, when Risperdal was prescribed off -
    label for T.M., Janssen was actively marketing the drug to physicians for off -
    label use in children. Janssen's July 29, 2002 business plan listed strategic
    initiatives associated with gaining acceptance of the usage of antipsychotics
    in child and adolescent psychology.             Plaintiffs' Exhibit 19.   This included
    "establishing    Risperdal   as   having    a    favorable risk/benefit     ratio" and
    "neutraliz[ing] safety and tolerability concerns." Id.; Videotaped Deposition
    of David Kessler, M.D., supra at 82.
    In 2006, the Risperdal label was changed. Pediatric use fell under the
    "Precautions" section of the 2006 label. The label indicated that Risperdal was
    approved by the FDA for use in children to treat irritability associated with
    autism, and that its safety and efficacy in treating children with schizophrenia
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    and bipolar mania had not been established.         It reported that Risperdal's
    safety and efficacy had been established in short-term clinical trials in autistic
    children ages five to sixteen; longer term studies in autistic children; and other
    short-term and long-term studies of children with other psychiatric disorders.
    For the first time, the label disclosed that Risperdal was associated with higher
    prolactin levels than other antipsychotic drugs in the same class. Again, it
    warned of hyperprolactinemia, and the conditions associated with it, including
    gynecomastia, but stated that the risk of such side effects was "rare."7
    Plaintiffs' Exhibit 3 (2006 Label). In 2007, the label was updated to warn that
    the incidence of gynecomastia with the use of Risperdal was 2.3 percent.
    Dr. Kessler then surveyed the studies and clinical trials Janssen had
    undertaken to test the safety and efficacy of Risperdal in young children and
    adolescents.   Janssen carried out two short-term double-blind studies of
    children and adolescents ages five to seventeen years of age, completed in
    2000, which demonstrated that forty-nine percent of the children who
    received Risperdal had elevated prolactin levels as compared to two percent
    of children who received a placebo. From the foregoing, the expert concluded
    that the results showed a statistically significant association between ingestion
    "Rare" was defined on the label as events "occurring in fewer than one in a
    thousand patients." Plaintiffs' Exhibits 2 and 3. "Infrequent" was defined as
    "occurring in more than one in a hundred patients, but less than one in one
    thousand patients. Id. "Frequent" meant that the risk occurred in at least
    one in one hundred patients. Id.
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    of Risperdal and higher prolactin levels and, further, that higher prolactin
    levels were known to be associated with certain conditions, including
    gynecomastia.
    Dr. Kessler explained that, in 2000, Janssen initiated an international
    study known as RIS-INT-41, which was intended to pay special attention to
    gynecomastia in boys and other prolactin-related events in children taking
    Risperdal. Risperdal was administered in two different doses to children with
    various levels of mental retardation and conduct disorder. The interim results
    showed that of the 266 males, ten were diagnosed with gynecomastia, an
    incidence rate of 3.75 percent. Sixteen of 319 patients had a prolactin-related
    adverse effect, a rate of 5 percent. In Dr. Kessler's opinion, this finding was
    a "red flag." Videotaped Deposition of David Kessler, M.D., supra at 56.
    The RIS-INT-41 study continued for another year. As of August 2001,
    there were twenty-six documented cases of prolactin-related adverse events
    in 504 children, an incidence of 5.15 percent. Twenty-four of the twenty-six
    children with prolactin-related adverse events had gynecomastia, and twenty-
    three of them were male. Dr. Kessler opined that there was an obligation on
    the part of Janssen "certainly by July 2001" to convey this information to
    physicians who were prescribing the drug off -label to children. Id. at 65.
    Janssen initiated a second study, RIS-INT-70, which was an extension
    of RIS-INT-41. Dr. Kessler reported that there were four additional cases of
    gynecomastia in children who participated in both studies, a risk of 8.3
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    percent. The children who participated only in RIS-INT-70 had an incidence
    of gynecomastia of 12.5 percent.8 Id. at 70.
    During the early 2000s, Janssen conducted eighteen clinical studies with
    pediatric patients, some of which were double-blind, i.e., involved a placebo,
    and others that were open -lab studies.      Six of the studies lasted up to six
    months.    RIS-INT-41 and RIS-INT-70 were the only long-term studies, and
    the only studies that paid special attention to prolactin-related adverse events
    such as gynecomastia.      The eighteen studies encompassed 1,885 subjects
    from five to eighteen years of age. In the double-blind studies, no children
    who received a placebo were diagnosed with gynecomastia.           Eight of nine
    cases of gynecomastia reported were related to the long-term studies. Dr.
    Kessler testified that the studies indicated that gynecomastia was manifested
    over time after exposure and that short-term studies did not capture the
    actual number of related cases.       Id. at 72-79; Plaintiffs' Exhibit 17.   Dr.
    Kessler informed the jury that, in January 2002, Janssen's own studies showed
    a   significant   association   of   4.4%   between    hyperprolactinemia     and
    gynecomastia in young males.
    In May 2002, Janssen conducted a post hoc analysis of data from five
    of the eighteen earlier studies.     RIS-INT-41 data was included; RIS-INT-70
    8 Dr. Kessler testified that, although the RIS-INT-70 results were known to
    Janssen in September 2002, they were not published in the Journal of Child
    and Adolescent Psychopharmacology until November 3, 2006. Videotaped
    Deposition of David Kessler, M.D., supra at 72.
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    data was not. Dr. Kessler opined that Janssen was attempting to prove that
    Risperdal was not related to elevated prolactin levels, but the data proved
    otherwise.    Analysis of the data showed a rate of 4.4% of gynecomastia.
    Plaintiffs' Exhibit 22. More importantly, he focused on one particular item of
    Janssen's supporting documentation, Table 21, which revealed that there were
    more prolactin-related side effects in Risperdal patients whose prolactin levels
    were higher.     Dr. Kessler explained that Table 21 demonstrated a causal
    correlation between high prolactin levels and "prolactin related adverse
    effects," called PRAE, one of which was gynecomastia.       He opined that the
    correlation was statistically significant, as there was a 98.5% likelihood that
    the side effects did not occur randomly. Internal Janssen emails confirmed,
    according to Dr. Kessler, that Janssen was aware of the significance of the
    findings.    Based on the foregoing evidence of a causal connection between
    Risperdal and elevated levels of prolactin, and higher levels of prolactin and
    gynecomastia, Dr. Kessler opined that Janssen had a duty to warn physicians
    who were prescribing the drug off -label to children and to notify the FDA. Id.
    at 121.
    According to Dr. Kessler, Janssen breached its duty to disclose Table 21
    to the FDA, and withheld data showing the correlation between elevated
    prolactin levels and prolactin related adverse effects such as gynecomastia
    from its own endocrinologist and psychiatrist consultants.          The expert
    demonstrated how Janssen manipulated the study data in such a way as to
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    reduce the statistical significance of the association between Risperdal and
    boys with gynecomastia, and alleged that Janssen funded the publishing of a
    misleading article in the Journal of Clinical Psychiatry.9 Id. at 149.
    Plaintiffs also offered the expert testimony of Mark Solomon, M.D., a
    plastic surgeon with expertise in gynecomastia and diseases of the breast. He
    examined T.M., who was at the time was twenty-one years of age, and
    confirmed that T.M. suffered from true gynecomastia. After reviewing the
    medical literature about Risperdal, T.M.'s family history, his medical records,
    and ruling out other possible causes of T.M.'s gynecomastia, Dr. Solomon
    concluded, with a reasonable degree of medical certainty, that Risperdal was
    the cause of T.M.'s gynecomastia.      N.T. Trial (Jury), 12/7/16, at 71.    He
    explained that, although T.M.'s family physician in Nebraska only diagnosed
    him with gynecomastia on May 19, 2010, his breasts had started to develop
    in 2006.    Dr. Solomon opined that the timing was consistent with the
    development of breast tissue generally, and that T.M.'s early breast
    development could be seen in photographs from 2007.
    9 Dr. Kessler testified that Janssen manipulated the data by removing boys
    who were less than ten years of age from the figures on gynecomastia, but
    failed to make a commensurate reduction in the number of overall subjects in
    the study. Id. at 123. Consequently, when Janssen ran the numbers again
    in September 2002, instead of a 95 percent statistical significance, the smaller
    numbers resulted in only a 90 percent statistical significance. Videotaped
    Deposition of David Kessler, M.D., supra at 125-26.
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    When Plaintiffs attempted to elicit additional testimony from          Dr.
    Solomon about two studies he had reviewed and relied upon in reaching his
    opinions, Janssen objected to the testimony on the ground that Dr. Solomon
    had not identified them in his expert report.1° N.T. Trial (Jury), 12/7/16, at
    53. Janssen maintained that it lacked fair notice of Dr. Solomon's testimony
    in this regard. Plaintiffs countered that since Janssen had cross-examined Dr.
    Solomon in other trials and depositions regarding the same articles, there was
    no surprise and no prejudice. Moreover, Plaintiffs argued that Janssen had
    been afforded the opportunity to depose Dr. Solomon in this case, but had
    declined.   The trial court sustained Janssen's objection under Pa.R.C.P.
    4003.5, finding that the expert's testimony regarding the literature and
    studies he relied upon was beyond the fair scope of his expert report, and
    precluded the expert's testimony      in   this regard.   However, on cross-
    examination, Dr. Solomon testified that his opinion that Risperdal caused
    elevated prolactin levels was informed by his review of the literature, the
    package inserts, and Janssen's documents. N.T. Trial (Jury), 12/7/16, at 91.
    In addition to the foregoing proof regarding the inadequacy of the
    Risperdal label, Janssen's failure to accurately report the drug's role       in
    1° The court would not allow Dr. Solomon to discuss any of the Risperdal labels,
    even though they were exhibits entered into evidence, because he did not
    state in his report that he had reviewed them. The court ruled that it was
    improper for the expert to "comment on something he never indicates that he
    reviewed, never indicates that he relies upon[.]" N.T. Trial (Jury), 12/7/16,
    at 137.
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    elevating prolactin levels and gynecomastia, and ingestion of Risperdal as the
    cause of T.M.'s gynecomastia, Plaintiffs offered the following proof to rebut
    the presumption under the TPLA that the label was adequate. The prescribed
    use in T.M., a child, was off -label and not approved by the FDA. Furthermore,
    it was not FDA -approved for ADHD or conduct disorders.          Dr. Martin, Dr.
    Wieck, and Physician Assistant Dewar testified that Janssen had actively
    promoted the use of Risperdal      in    children, and that the marketing had
    influenced them to prescribe Risperdal for T.M. for an off -label use. Dr. Wieck,
    the psychiatrist who supervised the prescribing of Risperdal for T.M., attended
    a Janssen meeting, all expenses paid, in Miami Beach. In addition, just days
    before Dr. Wieck prescribed Risperdal for T.M., he had a visit from a Janssen
    representative, who talked about the use of Risperdal to treat younger children
    with agitation and anxiety and conduct disorders generally. The prescribers
    testified that if they had been aware that the real risk of gynecomastia with
    Risperdal was frequent rather than rare, and that Risperdal was linked to a
    greater elevation of prolactin levels than other antipsychotic drugs in the same
    class, they would have prescribed another medication instead.            Brenda
    Tinkham testified that she was not told of the risk of gynecomastia or breast
    development when Risperdal was recommended for T.M.            N.T. Trial (Jury),
    12/8/16, at 60. Had she known, she stated she would not have agreed to its
    administration to T.M. Id. at 44, 60.
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    On December 9, 2016, at the close of Plaintiffs' case, Janssen orally
    moved for a nonsuit. It alleged first that Plaintiffs failed to produce sufficient
    evidence to rebut the presumption under the TPLA that the FDA -approved
    warning was adequate. Specifically, Janssen maintained that Plaintiffs failed
    to prove that Janssen promoted or advertised Risperdal for an indication not
    approved by the FDA, or that plaintiff used it for an off -label use, and that
    Janssen's off -label promotion caused the prescriber to prescribe it for the off -
    label use.
    Second, Janssen argued that Dr. Solomon's opinions did not meet the
    general or specific causation requirements for scientific reliability under Texas
    law,   including   proof of two    epidemiological studies     demonstrating     a
    statistically significant doubling of the relative risk. Janssen maintained that
    the 2007 photographs of T.M. that Dr. Solomon testified showed budding
    breasts could not overcome the fact that T.M. stopped the medication in 2008
    and was first diagnosed with gynecomastia in 2010. Finally, Janssen argued
    that there was a complete failure of proof as to fraud.11
    11 After orally moving for a compulsory nonsuit, Janssen filed a written motion
    for compulsory nonsuit in which it advanced additional bases for nonsuit: (1)
    that Plaintiffs failed to establish that the warnings were inadequate and that
    the inadequate warnings were the proximate cause of T.M.'s injury; (2) that
    federal law preempted Plaintiffs' failure to warn claim; and (3) that Plaintiffs
    failed to introduce any evidence that Johnson & Johnson and Janssen Research
    & Development, LLC, were manufacturers or sellers under the Texas Products
    Liability Act.
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    Plaintiffs countered that they could maintain the action as they had
    rebutted the presumption under Texas's Products Liability Act that the
    warnings were adequate by introducing proof that Janssen promoted Risperdal
    for an indication that was not approved by the FDA; that the drug was used
    as promoted; and that T.M.'s gynecomastia was causally related to the
    promoted off -label use of Risperdal.    See Tex. Civ. Prac. & Rem. Code §
    82.007(b)(3)(A-C).
    Plaintiffs argued that Texas law did not require proof of epidemiological
    studies to prove general or specific causation. Furthermore, they maintained
    that Texas's standards governing the reliability of scientific evidence of
    general or specific causation under Texas law were not substantive. They
    maintained that Pennsylvania adheres to Frye v. United States, 
    293 F. 1013
    (D.C. Cir. 1923), and that the issue was one of procedure and not a question
    governed by Texas substantive law.
    The trial court granted the nonsuit, finding that Texas law as enunciated
    in Merrell Dow Pharm. v. Havner, 
    953 S.W.2d 706
     (Tex. 1997), and Merck
    & Co. v. Garza, 
    347 S.W.3d 256
    , 266 (Tex. 2011), governed the issue of the
    sufficiency of expert scientific testimony regarding medical causation. It then
    construed Havner and Garza as strictly requiring Plaintiffs to introduce the
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    following proof of causation: 1) two epidemiological studies12 proving general
    causation, i.e., that exposure to a particular agent causes or increases the risk
    of the injury sustained; 2) that those studies demonstrated a doubling of the
    relative risk; and 3) that the plaintiff      is   similarly situated to the study
    participants. The trial court ruled that Dr. Solomon failed to introduce at least
    two epidemiological studies demonstrating a doubling of the risk for purposes
    of general causation and testify that T.M.'s circumstances were similar to
    those of the study subjects. The court reasoned that Plaintiffs could not rely
    upon Janssen's clinical trials, RIS-INT-41 and RIS-INT-70, to meet the
    requirement set forth in Havner because the studies did not show a doubling
    of the risk for gynecomastia or demonstrate that the subjects of those studies
    were similar to T.M. Thus, the court concluded that Plaintiffs' evidence was
    insufficient under Texas law to make out a prima facie failure to warn claim
    12 Epidemiology is defined as "[t]he study of the relationships between the
    various factors that determine the frequency and distribution of diseases in
    human and other animal population." Stedman's Medical Dictionary (26th ed.).
    Epidemiological studies are one type of scientific research used to evaluate
    whether there is a correlation or causal relationship between exposure to a
    substance and adverse health effects. Cohort and case -control studies are
    just two examples of types of epidemiological studies.                  See
    https://www.cdc.gov/csels/dsepd/ss1978/lessonl/section7.html.
    In addition to epidemiological studies, there are various types of clinical
    research and trials calculated to measure and test new medications. See
    https://www.fda.gov/forpatients/clinicaltrials/types/default.htm.         Meta -
    analysis is "a quantitative statistical analysis of several separate but similar
    experiments or studies in order to test the pooled data for statistical
    significance."   Merriam -Webster Dictionary, see https://www.merriam-
    webster.com/dictionary/meta-analysis.
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    as it lacked the scientific reliability to prove that exposure to Risperdal caused
    gynecomastia, and that T.M. developed gynecomastia due to his ingestion of
    Risperdal.
    Plaintiffs filed a post -trial motion, which the trial court denied. Plaintiffs
    appealed, both Plaintiffs and the trial court complied with Pa.R.A.P. 1925, and
    the matter is ripe for our review.
    1. Did the trial court improperly enter nonsuit given the evidence
    introduced at trial concerning causation?
    2. Did the trial court err by precluding Plaintiffs' causation expert
    from testifying about specific epidemiology studies under a
    "fair scope" of the expert report analysis?
    Appellants' brief at 4.
    Pennsylvania law is well settled that entry of a compulsory nonsuit is
    proper upon the motion of a defendant where, at the close of the plaintiff's
    case, the plaintiff has not introduced sufficient evidence to establish the
    necessary elements to maintain a cause of action.              Gigus v. Giles &
    Ransome, Inc., 
    868 A.2d 459
     (Pa.Super. 2005). On appeal, we review the
    evidence to determine whether the trial court abused its discretion or made
    an error of law. Baird v. Smiley, 
    169 A.3d 120
     (Pa.Super. 2017). Further,
    in making this determination, we must give the Plaintiffs the benefit of every
    fact and all reasonable inferences arising from the evidence and resolve all
    conflicts in the evidence in Plaintiffs' favor. Id. We will affirm the grant of
    compulsory nonsuit "only if no liability exists based on the relevant facts and
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    circumstances." Id. at 121. Otherwise, the compulsory nonsuit is removed
    and the matter remanded for a new trial. Id.
    The threshold issue before us is whether the trial court correctly applied
    Texas law in ruling on the sufficiency of Plaintiffs' expert scientific evidence
    for purposes of the compulsory nonsuit.       The trial court held that Havner
    required proof of two epidemiological studies showing a statistically significant
    doubling of the risk, evidence that T.M. was similarly situated to the patients
    in those studies, and that these requirements were "not merely procedural
    guideposts," but substantive under Texas law. Trial Court Opinion, 10/19/17,
    at 4. The court relied on Garza, supra at 266, in concluding that since
    Plaintiffs failed to meet that threshold, the case could not go to the jury. As
    this is a question of law, our standard of review is de novo and our scope of
    review is plenary.
    Plaintiffs contend first that the reliability and sufficiency of causation
    evidence is a question of procedure and that Pennsylvania law governs.
    Plaintiffs rely upon this Court's recent decision in Stange v. Janssen Pharm.,
    Inc., 
    179 A.3d 45
    , 53 (Pa.Super. 2018), in support of their assertion that
    "[e]vidence is procedural law as are the standards for reviewing and deciding
    dispositive motions." Plaintiffs' brief at 37. Plaintiffs maintain that the court
    erroneously applied Texas law to an issue that was procedural and governed
    by Pennsylvania law, specifically, Frye rather than Daubert v. Merrell Dow
    Pharm., Inc., 
    509 U.S. 579
     (1993). Under Pennsylvania law, they argue that
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    the evidence was admissible, reliable, and legally sufficient to go to the jury.
    Plaintiffs point out that Janssen could have challenged the admissibility of Dr.
    Solomon's testimony by filing a pretrial Frye motion pursuant to Pa.R.E. 702,
    as it did in Stange, supra, but it elected not to do so. Instead, Janssen
    successfully objected to Dr. Solomon testifying about studies that he reviewed
    and relied upon, waited for Plaintiffs to rest, and then moved for compulsory
    nonsuit, citing Dr. Solomon's failure to introduce two epidemiological studies
    supporting his opinion.
    Janssen contends that medical causation, both general and specific, is
    an   essential element of Plaintiffs' failure to warn claim under Texas
    substantive law. It argues that in order to present a question of fact, Plaintiffs
    were compelled to provide the proof of causation required by Havner.
    Appellees' brief at 12. It cites Havner and Garza as imposing a black -letter
    requirement under Texas law that           a   plaintiff introduce at least two
    epidemiological studies showing a statistically significant doubling of the risk,
    and evidence that the plaintiff is similar to the subjects of the studies, in order
    present a question of fact for the jury in a failure -to -warn case.13 According
    13 Janssen relies upon Freeman v. AMF, Inc. (In re Asbestos Prods. Liab.
    Litigation), 
    2012 U.S. Dist. LEXIS 31650
     (E.D. Pa. 2012), for the proposition
    that Havner's standard for the reliability of epidemiological evidence is
    substantive. In that case, however, the parties agreed to apply Texas
    substantive law, and merely treated the issue as one governed by Texas law.
    We observe, however, that the trial court noted therein that no
    epidemiological studies were required under Texas law to prove general
    - 18 -
    J -A27012-18
    to Janssen, since Dr. Solomon, Plaintiffs' only "causation" expert, neglected
    to cite any medical literature or studies to support his opinions, Plaintiffs could
    not meet their burden of proof, and thus, the entry of a compulsory nonsuit
    was warranted. Id. at 16-17.
    Whether the sufficiency of causation evidence          is a   procedural or
    substantive issue governed by Pennsylvania or Texas law is critical to the
    disposition of this appeal. Under Pennsylvania law, experts who are qualified
    by their "scientific, technical or other specialized knowledge beyond that
    possessed by a layperson" routinely provide causation evidence. Pa.R.E. 702.
    Whether the expert witness is qualified is a determination left to the sound
    discretion of the trial court. Daniel v. Wyeth, 
    15 A.3d 909
    , 926 (Pa.Super.
    2011).   A qualified expert's causation testimony, rendered to a reasonable
    degree of medical certainty and adequately based            in fact, is   generally
    sufficient to make out a prima facie case of failure to warn. See Snizavich
    v. Rohm & Haas, Co., 
    83 A.3d 191
    , 195 (Pa.Super. 2013) (holding that an
    expert's testimony must be "based on more than mere personal belief," and
    "must be supported by reference to facts, testimony or empirical data").
    Where, however, a party seeks to introduce novel scientific evidence
    through the conclusions of an expert, Pennsylvania follows the standard set
    forth in Frye. Before novel science enters the courtroom, a party seeking to
    causation, and that Havner merely established the threshold for the scientific
    reliability of such evidence when it was relied upon.
    - 19 -
    J -A27012-18
    introduce it must demonstrate "that the relevant scientific community has
    reached general acceptance of the principles and methodology employed by
    the expert witness before the court will allow the expert witness to testify as
    to his conclusions."   Reading Radio, Inc. v. Fink, 
    833 A.2d 199
    , 208
    (Pa.Super. 2003) (citing Trach v. FeIlin, 
    817 A.2d 1102
    , 1108-09 (Pa.Super.
    2003) (en banc)). The expert's conclusions need not be generally accepted
    as long as they are derived from generally accepted principles and sound
    scientific research. Once the evidence crosses that threshold, Pennsylvania
    courts allow juries to assign to it whatever weight they feel is appropriate.
    The Frye rule has been incorporated into Pa.R.E. 702.
    On the other hand, the federal courts, as well as some states, apply the
    rule espoused in Daubert, supra, when determining whether proffered
    scientific evidence is sufficiently reliable to be admissible. Daubert involves
    a judicial evaluation of the validity of the underlying data relied upon by
    experts. Texas adopted its version of Daubert in E.I. du Pont de Nemours
    & Co. v. Robinson, 
    923 S.W.2d 549
     (Tex. 1995). In determining whether
    scientific evidence was sufficiently reliable to be admissible, the Robinson
    court identified a non-exclusive list of factors, now known as the Robinson
    factors, which trial courts should consider in making a preliminary admissibility
    determination under Texas Rule of Evidence 702:
    (1)   The extent to which the theory has been or can be tested;
    (2)   The extent to which the technique relies upon the subjective
    interpretation of the expert;
    - 20 -
    J -A27012-18
    (3)   Whether the theory has been subjected to peer review and
    publication;
    (4)   the technique's potential rate of error;
    (5)   Whether the underlying theory or technique has been
    generally accepted as valid by the relevant scientific
    community; and
    (6)   The non -judicial uses that have been made of the theory or
    technique.
    Havner, supra at 714 (quoting Robinson, 923 S.W.2d at 557).
    In Havner, the Texas Supreme Court expanded the role of the
    Robinson factors. Instead of being employed solely to determine whether
    scientific evidence was reliable enough to be admissible, the court mandated
    that those factors be reweighed and re-evaluated by the court when it
    conducted its sufficiency review. In essence, a court would make a sua sponte
    second reliability determination of the scientific evidence in determining
    whether it was sufficient to sustain the verdict. Texas courts call this a "no -
    evidence" review. Havner, supra at 721. Under Texas law, a court will find
    "no evidence" to sustain the verdict when "(a) there is complete absence of
    evidence of a vital fact, (b) the court is barred by rules of law or of evidence
    from giving effect to the only evidence offered to prove a vital fact, (c) the
    evidence offered to prove a vital fact is no more than a mere scintilla, or (d)
    the evidence conclusively establishes the opposite of the vital fact." Id.
    The facts in Havner are instructive. The Havners sued Merrell Dow for
    negligence, defective design, and defective marketing of its drug Bendectin, a
    - 21 -
    J -A27012-18
    drug prescribed to pregnant women to relieve morning sickness. It was not a
    failure to warn case. They alleged that mother's ingestion of Bendectin caused
    limb defects in their daughter in utero.
    At several stages of the litigation, Merrell Dow challenged the scientific
    reliability of the Havners' evidence that Bendectin ingested by pregnant
    women caused limb defects in their unborn children.       Immediately prior to
    trial, Merrell Dow filed motions in limine seeking to exclude the Havners'
    causation testimony.     Following a Robinson hearing, the motions were
    denied.   At the close of the Havners' case, the court denied Merrell Dow's
    motion for a directed verdict. At the conclusion of trial, the jury returned a
    verdict in favor of the Havners and awarded both compensatory and punitive
    damages. On appeal, a divided court of appeals affirmed the compensatory
    damages, but reversed the award of punitive damages. The Supreme Court
    of Texas granted Merrell Dow's application for writ of error that challenged
    both the legal sufficiency and admissibility of the Havners' causation evidence.
    The Texas Supreme Court reviewed the record and noted that thirty
    million women worldwide had taken Bendectin from 1957 to 1983. The FDA
    investigated a possible association between the drug and birth defects, but
    concluded that there was no increased risk shown.14           More than thirty
    14 The Havner court showed deference to the FDA's evaluation of a drug. It
    suggested that courts follow the lead of the FDA, which rejected "isolated case
    reports, random experience, and reports lacking the details which permit
    scientific evaluation," and promulgated regulations "that detail the
    - 22 -
    J -A27012-18
    published and peer -reviewed studies on a possible association between
    Bendectin and birth defects failed to demonstrate an increased risk of limb
    defects. The Havner court observed that no plaintiff had ever prevailed in
    federal court in a Bendectin case, and that in some cases, causation evidence
    provided by the same experts who testified on behalf of the Havners had been
    held inadmissible or legally insufficient. The issue before Texas's highest court
    was "whether the Havners' evidence is scientifically reliable and thus some
    evidence to support the judgment in their favor." Havner, supra at 711.
    In making that determination, the court analyzed the epidemiological
    evidence to determine whether it was reliable. While it acknowledged that
    epidemiological studies may shed light on whether there is an association
    between a disease or condition and some drug or agent suspected of causing
    that disease or condition, it noted that such studies could not establish specific
    causation, i.e., that a particular individual contracted the disease or condition
    due to exposure to the drug or agent. After examining how other courts had
    determined what evidence was admissible or, in some cases sufficient, to
    establish scientifically reliable causation, the Havner court concluded that
    "properly designed and executed epidemiological studies may be part of the
    evidence supporting causation in a toxic tort case," but that there must be a
    showing of more than a doubling of the risk. Havner, supra at 717. The
    requirements for clinical investigations of the safety and effectiveness of
    drugs." Merrell Dow Pharm., Inc. v. Havner, 
    953 S.W.2d 706
    , 721 (Tex.
    1997) (citing 21 C.F.R. § 314.126(e) (1996)).
    - 23
    J -A27012-18
    court explained that if a condition occurs in six out of 1,000 people who are
    not exposed to a certain drug, and studies show that nine out of 1,000 people
    who take the drug manifest the condition, it is still more likely than not that
    causes other than the drug were responsible. It reasoned that, in order to
    prove that a condition was statistically more likely than not caused by a drug,
    a study would have to show that at least twelve people out of 1,000 took the
    drug and developed the condition. This is a relative risk of two, and relevant
    in proving general causation, i.e., "whether a substance is capable of causing
    a particular injury or condition in the general population." Id. at 714. The
    court acknowledged that while such a study could shed some light on the
    association between the drug and the condition, it would not suffice to prove
    specific causation, i.e., that "a substance caused a particular individual's
    injury." Id. at 714.     In most cases, the court concluded, expert medical
    testimony would be required to bridge that gap. Id.
    The Havner court ruled that, "[t]he use of [two] scientifically reliable
    epidemiological studies and the requirement of more than a doubling of the
    risk strikes a balance between the needs of our legal system and the limits of
    science." Id. at 718.15     In addition, the court held that to survive legal
    sufficiency review, a plaintiff must show that he is similar to those in the
    15 The Havner court expressly rejected the notion "that a relative risk of more
    than 2.0 is a litmus test" as, in some cases, "[t]here may be no causal
    relationship even if the relative risk is high." Id.
    - 24 -
    J -A27012-18
    studies, i.e., exposed to similar levels of the same substance, and that the
    timing of onset is consistent with that experienced by others in the study, and
    introduce expert testimony ruling out other plausible causes.16
    Thus, the court reaffirmed that medical causation evidence must be
    reliable as measured against the Robinson factors. For instance, the court
    made it clear that the bare opinion of a physician that, to a reasonable degree
    of medical certainty, the limb defect was caused by her mother's ingestion of
    Bendectin while pregnant, was not scientifically reliable.                It approved,
    however, of evidence negating other plausible causes of the condition with
    reasonable certainty, i.e., the differential diagnosis methodology employed by
    Dr. Solomon herein. It concluded that "courts must make a determination of
    reliability from all the evidence,     .    .   .    assuming it passes muster under
    Robinson," in determining whether there is legally sufficient evidence to
    support a judgment. Id. at 720. In addition, however, the court set forth an
    evidentiary standard for the reliability of epidemiological studies used to prove
    medical causation. Epidemiological proof that did not meet that standard was
    unreliable and no evidence at all.
    After    identifying   "statistical           shortcomings"   in   the   Havners'
    epidemiological evidence, and noting that it had not been subjected to peer
    review or publication, both of which the court regarded as significant indicia
    16 In Merck & Co. v. Garza, 
    347 S.W.3d 256
    , 266 (Tex. 2011), the court
    acknowledged that usage in a study did not have to match the claimant's
    usage exactly. Rather, the conditions of the study only had to be substantially
    similar to the claimant's circumstances.
    - 25 -
    J -A27012-18
    of reliability, the court disregarded that evidence when it conducted its no -
    evidence sufficiency determination. Since there was no scientifically reliable
    evidence of causation that would support the verdict, the court reversed the
    judgment.
    The upshot of Havner is that, even if scientific evidence is held to be
    admissible, Texas courts will re-examine the scientific reliability of the
    evidence when subsequently making a sufficiency determination. Where the
    admitted scientific evidence is found lacking, Texas courts treat it as no
    evidence at all in determining whether the evidence is sufficient to support the
    verdict rendered by the jury.
    More recently, in Garza, following a jury verdict in favor of plaintiffs in
    a defective design/failure to warn death case involving the drug Vioxx, the
    Texas Supreme Court held, citing Havner, that epidemiological evidence that
    did not show a doubling of the risk was not reliable proof of causation and
    could not be used to support the verdict. The court dismissed as unreliable
    Merck's own VIGOR study relied upon by the plaintiffs to show general
    causation, as it examined persons who took much larger doses of Vioxx for a
    substantially longer time than the decedent. Meta -analysis of cardiovascular
    data that combined results of many different studies, involved differing
    dosages, durations, and comparison drugs, was deemed unreliable as it
    showed a relative risk of only 1.19 percent when the VIGOR results were
    removed from the analysis. The APPROVe study relied upon by plaintiffs was
    not sufficiently similar as it only showed statistically significant differences in
    - 26 -
    J -A27012-18
    the incidence of cardiovascular death after eighteen months of use, and
    decedent took Vioxx for only twenty-five days. Although the VICTOR study
    showed statistically significant results for confirmed "thrombotic events" with
    a relative risk exceeding 3.0, the court noted that it was only one study, not
    the required two studies. Thus, the Garza Court concluded "the totality of
    the evidence cannot prove general causation if it does not meet the standards
    for scientific reliability established by Havner." Id. at 268.
    Havner reaffirmed the vitality of the Robinson factors in determining
    whether scientific evidence is relevant and reliable.    In addition, the court
    defined what constitutes scientifically -reliable epidemiological evidence.
    However, under Texas law, epidemiological studies are not required to prove
    general causation. Havner and Garza stand for the proposition that where
    such studies are the only evidence of general causation, or relied upon by
    experts in support of their general causation opinions, unless there are at least
    two studies that reveal at least a doubling of the risk, the evidence is too
    speculative to permit a jury to find causation.'' Thus, the issue is one of the
    scientific reliability of evidence.
    17 In making its determination whether scientific evidence of causation is
    reliable enough to support the verdict, a Texas court looks at the totality of
    the evidence, including all evidence introduced by the defense as well as that
    of the plaintiff. See Centocor Inc. v. Hamilton, 
    310 S.W.3d 476
     (Tex. App.
    2010), rev'd on other grounds, 
    372 S.W.3d 140
     (Tex. 2012), (finding evidence
    of general and specific causation sufficient where: Centocor's own package
    - 27 -
    J -A27012-18
    As noted above, the parties agree that, in this matter, Pennsylvania law
    governs procedure and Texas substantive law applies. However, under settled
    Pennsylvania law, the law of the forum governs the issue of whether a matter
    is substantive or procedural. Foley v. Pittsburgh -Des Moines Co., 
    68 A.2d 517
     (Pa. 1949).     In Sheard v. J.J. DeLuca Co., Inc., 
    92 A.3d 68
    , 76
    (Pa.Super. 2014), this Court explained the difference between procedural and
    substantive law as follows: "Substantive law is the portion of the law which
    creates the rights and duties of the parties to a judicial proceeding, whereas
    procedural law is the set of rules which prescribe the steps by which the parties
    may have their respective rights and duties judicially enforced." Recently, in
    Hammons v. Ethicon, Inc., 
    190 A.3d 1248
    , 1285 (Pa.Super. 2018), we
    relied upon this language in Sheard in concluding that remittitur was
    procedural, and that Pennsylvania law, as the law of the forum, governed.
    See also Commonwealth v. Sanchez, 
    716 A.2d 1221
    , 1223 (Pa. 1998)
    (holding that in conflicts cases involving matters of procedure, we apply our
    own procedural laws when we are the forum state); see also Murray, supra
    insert, approved by the FDA, described clinical trial findings prior to FDA
    approval that some patients may rarely suffer from lupus -like syndrome as a
    result of Remicade; Centocor's own witness testified that if a risk associated
    with a drug's treatment is included on the package insert, that risk           is
    "reasonably associated" with the treatment; Centocor's expert testified that
    there was a 0.25% risk of the syndrome in women of child-bearing age, that
    recent Remicade trials showed a two to three percent increase in the incidence
    of the syndrome, and that lupus is a recognized complication of Remicade).
    - 28 -
    J -A27012-18
    at 1252 (finding Maryland damages cap to be a substantive limitation
    governed by Maryland law).
    Texas law similarly provides that the law of the forum governs the issue
    of whether a matter is substantive or procedural. See Penny v. Powell, 
    347 S.W.2d 601
    , 602 (Tex. 1961) (applying Texas rules of construction to
    determine   that Louisiana     Direct Action   Statute   was    procedural   and
    unenforceable in Texas); see also Penn Well Corp. v. Ken Assocs., 
    123 S.W.3d 756
    , 764 (Tex. App. 2003) (holding what is a matter of substance and
    what is a matter of procedure is determined by the law of the forum state);
    accord Brandon v. Ivie, 2018 Tex. App. LEXIS 7417, *3 (Tex. App. 2018)
    (applying Texas statute of limitation as they are procedural under Texas law);
    Owens-Corning Fiberglas Corp. v. Martin, 
    942 S.W.2d 712
     (Tex. App.
    1997) (declining to apply Alabama's unanimous -verdict rule upon finding it
    procedural under Texas law).
    Questions of evidence are governed by the           law   of the forum.
    Greenwood v. Hildebrand, 
    515 A.2d 963
    , 964 (Pa.Super. 1986). Whether
    evidence, once admitted, is sufficient to support a verdict or survive a nonsuit
    is similarly a procedural inquiry. Our Supreme Court held in Foley, supra
    that "[t]he law of the forum also controls all questions as to burden of proof
    and whether there     is   sufficient evidence of negligence and proximate
    causation to entitle the plaintiff to have the case submitted to the jury." Id.
    at 521 (citing Sudol v. Gorga, 
    31 A.2d 119
    , 120 (Pa. 1943); Restatement
    - 29 -
    J -A27012-18
    Conflict of Laws § 595, comments a and b); see also Ryan v. Adam Scheidt
    Brewing Co., 
    197 F.2d 614
    , 615 (3d Cir. 1952) (relying upon Foley, supra,
    in holding that "the issue as to the quantum of proof necessary to take the
    case to the jury is procedural rather than substantive, and therefore must be
    decided in accordance with the law of the forum"). The Restatement (Second)
    of Conflicts of Law § 135, provides that, with some exceptions not pertinent
    herein, "The local law of the forum determines whether a party has introduced
    sufficient evidence to warrant a finding in his favor on an issue of fact." Based
    on the foregoing, we conclude that whether the scientific evidence of causation
    was reliable enough to survive a compulsory nonsuit was a procedural inquiry
    that should have been governed by Pennsylvania law.1-8
    We find that a compulsory nonsuit was improperly entered applying
    Pennsylvania procedural law. "A compulsory non -suit       .   .   . may be entered
    only in cases where it is clear that the plaintiff has not established a cause of
    action[.]" Portside Investors, L.P. v. Northern Ins. Co., 
    41 A.3d 1
    , 14
    18 We find misplaced Janssen's reliance upon Freeman v. AMF, Inc. (In re
    Asbestos Prods. Liab. Litigation), 
    2012 U.S. Dist. LEXIS 31650
     (E.D. Pa.
    2012), for the proposition that Havner's standard for the reliability of
    epidemiological evidence is substantive. In that case, the parties simply
    agreed to apply Texas substantive law, and then treated that issue as
    substantive without any discussion or analysis. We also observe, however,
    that the court noted that no epidemiological studies were required under
    Texas law to prove general causation, and that Havner merely established
    the threshold for the scientific reliability of epidemiological evidence when it
    was relied upon.
    - 30 -
    J -A27012-18
    (Pa.Super. 2011) (quoting Reading Radio, Inc. v. Fink, 
    833 A.2d 199
    , 209-
    210 (Pa.Super. 2003). In making that determination, the plaintiff is entitled
    to the "benefit of all reasonable inferences arising from the evidence." Id. A
    non -suit is proper only if the plaintiff has not introduced sufficient evidence to
    establish the necessary elements to maintain a cause of action. /d.19 Viewing
    all of the evidence in the light most favorable to the Plaintiffs, we conclude the
    evidence was sufficient to make out a prima facie failure -to -warn case based
    on Texas substantive law.
    Under Texas law, drug manufacturers are subject to liability for failure
    to warn. See Tex. Civ. Prac. & Rem. Code § 82.007; see also n.5 supra.
    However, there is a statutory presumption that the drug manufacturer is not
    liable if the "warnings or information that accompanied the product in its
    distribution were those approved by the Federal Drug Administration." Id. at
    § 82.007(a)(1). That presumption may be rebutted by evidence that (1) "the
    defendant   .   .   .   withheld from or misrepresented to the [FDA] required
    information that was material and relevant to the performance of the product
    and was causally related to the claimant's injury[,]" or 2) "the defendant
    19 Pennsylvania trial and appellate courts do not conduct anything akin to
    Texas's no -evidence review of the reliability of scientific evidence when ruling
    on whether evidence is sufficient to sustain a verdict. We do not re-examine,
    reweigh, or disregard properly -admitted scientific evidence. Rather, we
    consider all evidence that was actually received without consideration of
    whether the evidence was properly admissible. See Commonwealth v.
    Gray, 
    867 A.2d 560
    , 567 (Pa.Super. 2005) (reaffirming that appellate
    sufficiency determination is not conducted on a diminished record).
    - 31 -
    J -A27012-18
    recommended, promoted, or advertised the pharmaceutical product for an
    indication not approved" by the FDA, and the claimant used the product as
    recommended, promoted, or advertised, resulting in his injury.         Id. at §
    82.007(b)(1), (3).
    It is undisputed that the FDA approved the warning accompanying
    Risperdal. However, Plaintiffs offered evidence that Janssen promoted the use
    of Risperdal for two off -label uses: for use in children, when it was not FDA -
    approved for children; and for treating ADHD in children, when it was not
    approved for the treatment of ADHD. In addition, Plaintiffs' expert Dr. Kessler
    testified that Janssen withheld and/or misrepresented material information to
    the FDA that was causally related to the incidence of gynecomastia in children,
    especially young males. We find there was sufficient evidence adduced by
    Plaintiffs to rebut that presumption.
    Furthermore, in any failure -to -warn case under Texas law, a plaintiff
    must show that the warning was defective and that it was the producing cause
    of the plaintiff's injury. Wyeth-Ayerst Lab. Co. v. Modrano, 
    28 S.W.3d 87
    ,
    94-95 (Tex.App. 2000) (citing Rolen v. Burroughs Wellcome Co., 856
    A.W.2d 607 (Tex.App. 1993).         In situations involving a pharmaceutical
    product, the manufacturer fulfills its duty by providing an adequate warning
    to the learned intermediary who prescribes the drug, who then assumes the
    duty to pass the necessary warnings on to the end users. Centocor, Inc. v.
    Hamilton, 
    372 S.W.3d 140
     (Tex. 2012) (extending the learned intermediary
    - 32 -
    J -A27012-18
    doctrine adopted in Alm v. Aluminum Co. of Am., 
    717 S.W.2d 588
    , 590-92
    (Tex. 1986), to manufacturers of pharmaceutical products). If, however, the
    warning to the prescribing physician is inadequate or misleading, then the
    drug manufacturer remains liable for injuries sustained by the end user. Id.
    at 157.    In establishing causation, the plaintiff must prove that a proper
    warning would have changed the decision of the intermediary to prescribe the
    product.
    We find there was sufficient evidence introduced by Plaintiffs to make
    out a prima facie failure -to -warn case against Janssen under Texas
    substantive law. Plaintiffs' scientific evidence, much of which was based on
    Janssen's own clinical trials and studies, the results of which were published
    in   scientific journals and peer -reviewed, showed a statistically significant
    relationship between ingestion of Risperdal, elevated prolactin levels, and
    gynecomastia in young males like T.M.2° Dr. Kessler pointed to these studies
    and others, and opined, based on his education, knowledge, and experience,
    that the precautions and warnings on both the 2002 and 2006 Risperdal labels
    were inadequate and misleading, as they understated the known risk of
    gynecomastia from Risperdal.      Dr. Kessler specifically stated that the label
    reported the risk of gynecomastia as "rare" when Janssen's own test results
    20 Dr. Kessler stated that the FDA leaves it up to drug manufacturers to design
    and conduct studies on the safety and efficacy of their drugs. Those results
    are submitted to the FDA, in accordance with applicable regulations.
    - 33 -
    J -A27012-18
    showed that it was "frequent;" and that its label misrepresented Janssen's
    knowledge of the risks of Risperdal in children and adolescents. Dr. Kessler
    also pointed out that Janssen resisted the suggestion that the label contain a
    recommendation that the prolactin levels of Risperdal patients be monitored,
    although its tests showed a correlation of a higher incidence of prolactin-
    related adverse effects in subjects with higher prolactin levels. In sum, Dr.
    Kessler opined that Janssen promoted the drug for off -label use in children
    and adolescents, misrepresented its safety, and did not adequately warn
    physicians of the risks.
    T.M.'s prescribing psychiatrists testified that they would not have
    prescribed the drug for him had they known the true nature of the risk. Mrs.
    Tinkham told the jury that she did not know about the risk of gynecomastia,
    and that she would not have agreed to its administration to T.M. had she
    known. Dr. Solomon conducted a physical examination of T.M., and confirmed
    an earlier diagnosis of gynecomastia. After review of T.M.'s personal and
    family medical histories, his medical records, and ruling out other possible
    causes of gynecomastia, he rendered his opinion, to a reasonable degree of
    medical certainty, that Risperdal caused T.M.'s gynecomastia.
    Viewing the foregoing evidence in the light most favorable to the
    Plaintiffs, we find it was legally sufficient under Pennsylvania law to make out
    a prima facie case for the jury under Texas substantive law governing failure
    - 34 -
    J -A27012-18
    to warn. Accordingly, we find that a nonsuit was improperly entered, and
    remand for a new trial is warranted.
    Based on our disposition, we do not reach Plaintiffs' second issue
    involving the propriety of the trial court's ruling precluding Dr. Solomon from
    testifying about the studies he relied upon in arriving at his expert causation
    opinions because he did not specifically reference those studies in his expert
    report.21
    Judgment vacated. Order entering compulsory nonsuit reversed. Case
    remanded for a new trial. Jurisdiction relinquished.
    Judgment Entered.
    Jseph D. Seletyn,
    Prothonotary
    Date: 7/16/19
    21 We remind litigants, however, that where a ruling precludes evidence, the
    proponent of that evidence must make an offer of proof on the record to
    preserve the issue, unless the substance of the evidence is apparent from the
    record. See Pa.R.E. 103(a)(2) (providing that a party may claim error in a
    ruling to exclude evidence only if "the party informs the court of its substance
    by an offer of proof, unless the substance was apparent from the context").
    - 35 -