Experimental Drug: DeMizio v. JHH 2

The Appellate Court of Maryland recently examined the boundaries for expert witness medical testimony in medical malpractice cases. It issued an unreported opinion filed on May 8, 2026. The case was Deidre DeMizio, et al. v. Johns Hopkins Health System Corp., et al. (No. 2412, September Term, 2023). It centered upon a defense verdict in a medical malpractice action. The plaintiffs had alleged that a team of medical providers failed to timely diagnose and treat a patient suffering from cardiac amyloidosis prior to his sudden cardiac arrest death. In this Part 2 of a Blog series, I focus to the boundaries for expert witness testimony. Specifically, I analyze the appellate court’s affirmance of a pre-trial order. That order kept out the plaintiffs’ expert cardiologist testimony that an experimental drug (not yet approved by the Food and Drug Administration (FDA)) was the standard of care during the relevant period of treatment .

In Part 1 of the Blog series, I discussed the trial court’s denial of a motion to reopen discovery.

Factual Background

The procedural core of this dispute emerged from a pre-trial motion filed by the defendants. The motion sought to exclude or restrict the testimony of the plaintiffs’ designated expert witness, a board-certified cardiologist . The plaintiffs intended to introduce three distinct clinical opinions through this expert witness. These would prove both a breach of the standard of care and legal causation. The trial court ultimately allowed the expert witness to testify regarding two of his clinical conclusions. However, the primary conflict on appeal focused on his third opinion. The defendants had breached the medical standard of care by failing to treat the patient with the drug tafamidis. Or by failing to refer him to a center where he could get the drug.

The relevant treatment window a from February 2015 until the patient’s sudden death in December 2017. The FDA had not approved the drug tafamidis for any therapeutic use within the United States. The FDA did not officially grant regulatory approval for the drug until 2019.

Expert Testimony on Experimental Drug

At the pre-trial evidentiary hearing, the expert witness stated that despite the lack of domestic FDA approval, the European Union and Japan had already approved tafamidis for treating cardiac amyloidosis during 2015 and 2016. He said that clinical studies showed the medical community widely knew about the drug’s safety and effectiveness. They were accessible to American cardiologists at that time.

To bridge the regulatory gap, the expert witness maintained that patients of financial means could have traveled abroad to obtain the medication. Alternatively, he claimed that the patient could obtain the drug in the USA “off-label” through special “amyloid centers.” These were located at elite institutions like Harvard, Stanford, and Johns Hopkins via compassionate use or special prescribing protocols.

The expert witness said that a reasonably competent cardiologist operating between 2015 and 2017 had to either prescribe tafamidis off-label or immediately refer the patient to an amyloid specialist who could secure the drug. However, at the hearing, the expert witness failed to produce, cite, or reference a single peer-reviewed publication, clinical guideline, or objective data source. He did not show that American cardiologists had generally accepted this non-FDA-approved drug during the relevant time period.

Parties’ Arguments

On appeal, the plaintiffs contended that the trial court committed a reversible abuse of discretion by overly restricting the expert witness’s testimony. They argued that the expert firmly grounded his conclusions in decades of personal clinical experience, extensive active practice, and a comprehensive awareness of ongoing global medical literature.

The plaintiffs maintained that because the expert witness was a highly qualified, board-certified cardiologist who actively treated amyloidosis patients in his own practice, his insights into cutting-edge therapeutic options should have been presented to the jury. Barring this testimony, they argued, caused severe and fatal prejudice to their case. It entirely eliminated their ability to argue a primary theory of negligence: that a viable, life-extending treatment protocol existed and should have been pursued by the defendants.

The defendants argued that the trial court properly ruled in its role as a judicial gatekeeper. They maintained that the expert witness’s opinion regarding tafamidis was a classic example of speculation that lacked any objective factual or scientific foundation. The defendants claimed that under longstanding Maryland law, the standard of care is not formulated in a vacuum. It must reflect what a reasonably competent practitioner would do under similar circumstances within the domestic medical community.

They argued that a drug entirely lacking FDA approval during the years of treatment cannot be forced upon the medical community as a mandatory standard of care without objective evidence showing widespread domestic acceptance. Because the expert witness offered nothing but his own personal assertions (ipse dixit) to support his claim that off-label use was the expected standard, the defendants argued the testimony was properly excluded as unreliable.

Court’s Ruling on Experimental Drug Expert Testimony

The Appellate Court of Maryland reviewed the trial court’s decision under an abuse of discretion standard. It noted that a trial judge’s determination to admit or exclude expert testimony will not be disturbed unless the ruling is completely unsupported by logic, fact, or guiding legal principles. The appellate court affirmed the trial court’s exclusion. It held that the trial judge correctly applied the standards of Maryland Rule 5-702 and the Daubert-Rochkind reliability framework.

Under Maryland Rule 5-702(3), a court must determine whether a sufficient factual basis exists to support an expert’s testimony. That requires an evaluation of both the adequacy of the data and the reliability of the underlying methodology. To guide this assessment, courts utilize the ten non-dispositive Daubert-Rochkind factors. The appellate court walked through the trial judge’s factor-by-factor analysis. It balanced both the strengths and terminal deficiencies of the expert’s proffer.

Application of Factors

• Factors Weighing in Favor of Admissibility (Factors 6 and 10): The court acknowledged that the expert witness’s opinions grew naturally out of his independent clinical research and regular practice rather than developed solely for litigation (Factor 6). Furthermore, the court agreed that the field of cardiology is universally recognized as capable of reaching reliable results regarding medical standards of care (Factor 10) .
• Factors Compelling Exclusion (Factors 2, 5, and 7): Despite the expert’s qualifications, the court found fatal flaws under the remaining criteria. Under Factor 2 (peer review and publication), the court highlighted that the expert witness produced zero published literature stating that tafamidis was an accepted standard of care in the U.S. between 2015 and 2017. Under Factor 5 (general acceptance), the court observed that while the drug was “out there” or available globally, the expert provided no evidence of its widespread domestic acceptance among American practitioners during the relevant treatment years. Most critically, under Factor 7 (unjustified extrapolation), the court determined that because the drug entirely lacked FDA approval during the decedent’s lifetime, concluding that prescribing it was the mandatory standard of care constituted an impermissible leap.

The appellate court concluded that the expert witness failed to bridge the massive “analytical gap.” That gap was between the empirical data (global trials and localized experimental use) on one side. On the other was his sweeping conclusion (a nationwide standard of care). The opinion rested solely upon the ipse dixit—the uncorroborated word—of the expert. Thus, the appellate court held that the trial court properly exercised its discretion to exclude the testimony.

Commentary by Baltimore Medical Malpractice Lawyer Mark Kopec on Experimental Drug Expert Testimony

The Appellate Court of Maryland’s decision to affirm the restriction of the expert witness’s testimony was not surprising. Patients often face hurdles in gaining access to medical treatment that is available in other countries, but that the FDA has not approved for use in the USA. These hurdles can be at multiple stages. A patient may not be able to find a doctor who will consider such a treatment. In addition, the hurdle may be an insurance company that will not pay for the treatment.

In this case, the insurmountable hurdle was the legal system. Showing the availability of the treatment was not enough. Nor was showing wide acceptance in other places. The plaintiff’s expert had to establish that the medical community in the USA had widely accepted the treatment. For the patient in this case, that would not come until two years later, when it was too late.

Stay tuned for Part 3 of this series. I will analyze the trial court’s exclusion of the post-dated Cleveland Clinic medical article. I will also further explore the temporal constraints governing evidence in medical negligence actions.

Mark Kopec is a top-rated Baltimore medical malpractice lawyer. Contact us at 800-604-0704 to speak directly with Attorney Kopec in a free consultation. The Kopec Law Firm is in Baltimore and helps clients throughout Maryland and Washington, D.C. Thank you for reading the Baltimore Medical Malpractice Lawyer Blog.