90 Cal.App.5th 776
Cal. Ct. App.2023Background:
- In 2008 the FDA required AstraZeneca to run SAVOR, a randomized placebo-controlled cardiovascular outcomes trial of saxagliptin (16,492 high-CV‑risk type 2 diabetes patients). SAVOR’s primary composite end point showed no effect, but a secondary end point found higher hospitalization for heart failure in the saxagliptin arm (3.5% v. 2.8%); authors cautioned this could be a false positive and urged replication.
- The FDA updated saxagliptin labels to warn of a potential increased risk of heart failure and to advise caution in patients at higher heart-failure risk; subsequent observational studies and pooled trial analyses did not replicate SAVOR’s finding.
- Plaintiffs in coordinated state and federal actions designated two general-causation experts: Dr. Parag Goyal (cardiologist, opined saxagliptin can cause heart failure using a Bradford Hill analysis) and Dr. Martin Wells (biostatistician, analyzed SAVOR and meta-analyses).
- Defendants moved to exclude Dr. Goyal; the trial court granted exclusion, finding his reliance on SAVOR alone and his application of multiple Bradford Hill factors were methodologically unreliable and that he improperly relied on animal data beyond his expertise.
- Defendants then moved for summary judgment on the ground plaintiffs lacked admissible expert proof of general causation; the court granted summary judgment and denied plaintiffs’ request for more time to substitute an expert. Plaintiffs appealed; the appellate court affirmed.
Issues:
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Did the trial court abuse its gatekeeping discretion in excluding Dr. Goyal? | Goyal reasonably emphasized SAVOR (an RCT) and could weigh evidence under Bradford Hill without the court reweighing evidence. | Goyal’s methodology was shifting, relied on SAVOR alone, misapplied Bradford Hill factors, and relied on animal data beyond his expertise. | No abuse: exclusion proper because Goyal’s methods were logically unsound and unreliable. |
| Does Dr. Wells’s testimony alone create a triable issue on general causation? | Wells’ statistical analyses of SAVOR and meta-analyses support an association sufficient for causation. | Wells is a biostatistician and disclaimed offering medical causation; he is not qualified to opine on general causation. | No: Wells alone was insufficient because he did not offer a qualifying medical causation opinion. |
| Can non‑expert materials (SAVOR, label changes, FDA/AHA statements) substitute for expert proof of general causation? | The label update and AHA/FDA statements recognize a heart‑failure risk and thus create triable issues. | Those materials rest on SAVOR and do not establish causation; causation requires competent expert proof. | No: non‑expert materials based on SAVOR do not establish general causation; expert testimony is required. |
| Did the trial court abuse discretion by denying a continuance to designate a new expert? | Plaintiffs sought more time after Goyal’s exclusion to substitute an expert. | Plaintiffs had ample opportunity during the general‑causation discovery phase and designating a replacement would prejudice defendants. | No abuse: denial proper given discovery schedule, plaintiffs’ strategic choice to designate only one expert, and potential prejudice. |
Key Cases Cited
- Sargon Enterprises, Inc. v. University of Southern California, 55 Cal.4th 747 (Cal. 2012) (trial courts serve a gatekeeping role to exclude unreliable expert testimony).
- Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (U.S. 1993) (principles/methodology, not conclusions, govern admissibility of expert evidence).
- Aguilar v. Atlantic Richfield Co., 25 Cal.4th 826 (Cal. 2001) (summary judgment burdens and proof requirements).
- Saelzler v. Advanced Group 400, 25 Cal.4th 763 (Cal. 2001) (standard for summary judgment regarding essential elements).
- Intel Corp. v. Hamidi, 30 Cal.4th 1342 (Cal. 2003) (de novo review of summary judgment rulings).
- Lockheed Litigation Cases, 115 Cal.App.4th 558 (Cal. Ct. App. 2004) (expert reliance on a single study may be inadmissible if the study does not reasonably support the opinion).
- Jones v. Ortho Pharmaceutical Corp., 163 Cal.App.3d 396 (Cal. Ct. App. 1985) (medical causation ordinarily requires competent expert testimony).
- Johnson & Johnson Talcum Powder Cases, 37 Cal.App.5th 292 (Cal. Ct. App. 2019) (expert proof required to show a product is capable of causing the disease at issue).
- Cooper v. Takeda Pharmaceuticals America, Inc., 239 Cal.App.4th 555 (Cal. Ct. App. 2015) (importance of considering a body of epidemiological studies rather than rejecting studies simplistically).
- San Francisco Print Media Co. v. The Hearst Corp., 44 Cal.App.5th 952 (Cal. Ct. App. 2020) (gatekeeping focuses on principles and methodology, not persuasiveness).