A Third Circuit panel recently affirmed the Western District of Pennsylvania’s dismissal of a claim that Novartis Pharmaceuticals failed to provide adequate warning to doctors that its drugs Aredia and Zometa contribute to the risk of developing the bone disease osteonecrosis of the jaw (“ONJ”). Bock v. Novartis Pharmaceuticals Corp. No. 15-3696, 2016 WL 5799663 (3d Cir. Oct. 5, 2016).

Aredia and Zometa are intravenously administered bisphosphonates, drugs that inhibit bone resorption (high-blood-calcium) in patients suffering from hypercalcemia of malignancy (“HCM”), a serious complication of cancer. Scientific studies began to suggest a link between bisphosphonate therapy and the development of ONJ in some patients in 2003. In 2003 and 2004, Novartis revised the packaging of Aredia and Zometa to include a notice that cases of ONJ had been reported and to advise caution with respect to dental procedures for patients on these medications. Novartis also sent out a “Dear Doctor” letter in 2004 to apprise the medical community that the package inserts for both drugs had been amended to contain warnings regarding ONJ. Id. at *1. In May 2005, Novartis sent out a second “Dear Doctor” letter reminding doctors of the changes to the package inserts for Aredia and reiterating the warning that during treatment, invasive dental procedures should be avoided if possible. Id. at *2.

The plaintiff, Mr. Bock, had a history of prostate and colon cancer and was diagnosed with multiple complications, including multiple myeloma and HCM, in early September 2005. To treat his HCM, his oncologist at the time, Dr. Islam, prescribed Aredia. Dr. Islam was on Novartis’s list of “Dear” Doctor” letter recipients, and he testified at his deposition that he was aware back in 2005 that ONJ was a potential side effect of Aredia. He believed he would have discussed this potential side effect with Mr. Bock, consistent with his regular practice. Id. at *2. He also testified that it was the standard of care in 2005 to prescribe Aredia or Zometa to treat patients with multiple myeloma and, if he were treating a patient similar to Mr. Bock today, he would still prescribe one of these drugs to that patient. Id. at *2.

In September 2005, Mr. Bock began seeing a hematologist, Dr. Agha, for his multiple myeloma. Dr. Agha was also on Novartis’s list of “Dar Doctor” letter recipients and testified that by September 2005, he was prescribing bisphosphonates for all of his patients with multiple myeloma consistent with the standard of care, which remains the same today. Dr. Agha’s records from March 23, 2006 indicated that he “explained in detail” to Mr. Bock that if he had any problems with his teeth, he needed to inform the doctor right away and that dental surgery can cause necrosis of the jaw, “which is rare, but he may need to be on prophylactic antibiotics.” Id. at *2. Dr. Agha testified that although ONJ is a serious complication of bisphosophonate treatment, bisphosphonates are critically important and he would not discontinue therapy for fear of ONJ. He explained his usual practice was to discontinue the drug for one month preceding any dental procedures and to restart the drug after the procedure. Id. After a period of not seeing Mr. Bock, on May 26, 2009, Dr. Agha noticed that Mr. Bock had a lesion and noted that he had undergone a dental extraction “without telling anybody.” Id. at *3.

As it turned out, Dr. Kent Galey had performed two dental extractions on Mr. Bock in 2008 and 2009, along with two other dental surgeries. Dr. Galey testified that he was aware Mr. Bock was taking Zometa but was not familiar with the drug when he began treating him. Although he had no specific memory of warning the patient in this case, his general practice would have been to look the drug up and discuss the potential risk of ONJ with Mr. Bock. He testified that regardless of the recommendation to avoid extraction in patients taking bisphosphonates, he believed it appropriate to perform Mr. Bock’s extractions because leaving the tooth in could pose more serious risks than taking it out, particularly in a cancer patient. Id. at *3. After discovering the lesion, Dr. Agha referred Mr. Bock to an osteonecrosis specialist, Dr. Kail. Id. at *3. Dr. Kail’s 2009 records indicated that he diagnosed Mr. Bock with ONJ, that Mr. Bock needed subsequent oral procedures, and that Dr. Kail planned to confer with Dr. Agha about placing Mr. Bock’s Zometa treatment on hold. Dr. Kail opined that Mr. Bock’s bisphosophonate treatment was a component in him developing ONJ. Id.

In 2010, Mr. Bock sued Novartis for strict liability, negligent manufacture, negligent failure to warn, and breach of express and implied warranties. The strict liability and warranty claims were disposed of on a motion to dismiss and the remaining claims on summary judgment. Plaintiff’s estate appealed only the District Court’s dismissal of the failure to warn claim.

The court noted that in failure to warn prescription drug cases, Pennsylvania applies the learned intermediary doctrine. Therefore, proximate causation may be shown through evidence that, if properly warned, the doctor either would have declined to prescribe a particular drug or would have detailed the known risks for the patient, who would have declined the medication. Id. at *4. The District Court granted summary judgment in favor of Novartis after finding that plaintiff could not demonstrate causation. Mr. Bock’s death precluded any testimony that he would have declined to take bisphosphonates if he had received more or different information about the risk of ONJ. And his treating physicians testified that they were “well aware” of the risk of ONJ at the time they prescribed the drugs, would have discussed that risk with Bock, and would still prescribe the drug to a patient like Bock today because, in their medical judgment, the benefits of the drug significantly outweigh the risks. Id. at *5.

The appellate court agreed that this evidence precluded a showing of proximate causation: not only did plaintiff fail to make the requisite showing that Mr. Bock would have received a different treatment had the warnings provided by Novartis been more detailed, but “the evidence mustered paint[ed] the opposite picture, particularly the fact that Mr. Bock, though informed by Dr. Agha of the risks of dental procedures and the concomitant need to inform his doctor of the need for any dental work, scheduled tooth extractions without consulting Dr. Agha.” Id. at *5. The court also found compelling the testimony that the considerable threat of infection rendered the dental procedures unavoidable and that if presented with the same set of facts the doctors would not have managed Mr. Bock’s treatment any differently. Id.

To overcome these proximate causation deficiencies, plaintiff’s estate argued that additional evidence, including expert testimony, was warranted to determine if the contents of the warning were adequate and whether the risks of Zometa are actually greater than is presently known. The court rejected this argument because, under Pennsylvania law, a warning cannot be considered improper due to subsequent revelations. Id. at *6. Therefore, “speculation” that evidence might exist that would have altered Mr. Bock’s doctors’ prescribing practices could not defeat summary judgment. Id.

Both the district and appellate courts in this case remained true to the fundamentals of the learned intermediary doctrine. Proximate causation, an essential element of a failure-to-warn claim, was lacking because the plaintiff could not establish a reasonable likelihood that an adequate warning would have prevented him from receiving the drug. If accepted, the argument advanced by plaintiff’s estate—that expert testimony was needed to test the adequacy of the warnings—would render the physicians’ causation testimony meaningless. It would also open the floodgates to failure-to warn-drug cases based solely on speculation that the current state of knowledge regarding a drug’s risks may change or develop further. While understandable on a personal level that a person who suffers a rare complication of a drug may question the accuracy of statistics concerning the incidence rate, altering the framework of the failure-to-warn theory of liability in the manner suggested by the plaintiff’s estate here would set a dangerous precedent and was rightfully rejected by the Third Circuit.