As scientific and technological capabilities continue to advance, the U.S. Food and Drug Administration (FDA) is easing a long-standing drug approval requirement for common diseases. Rather than requiring drugmakers to complete two separate, large-scale studies to demonstrate a new medication’s effectiveness, the agency will now accept single trials for many approvals.
Dropping the two-trial requirement reflects modern advances that have made drug research “increasingly precise and scientific,” according to FDA officials. They emphasize that while only one study may be required for most approvals, the agency will continue to maintain the highest standards for safety.
Powerful Alternatives
The move to single-trial approval, detailed by FDA Commissioner Marty Makary, MD, MPH, and his top deputy, Vinay Prasad, MD, MPH, is the latest in a series of efforts to streamline the regulatory process and shorten review timelines. Since the early 1960s, the agency has required two adequate and well-controlled investigations to prove a new medication is effective, with the second study intended to confirm the first. Going forward, the FDA’s default position will be to require only one rigorous study for new drugs and other innovative health products.
Dr. Makary has also directed the FDA to accelerate reviews in other ways, including mandating the use of artificial intelligence and offering one-month reviews for select medications that serve “national interests” and qualify for expedited approval.
“In this setting, overreliance on two trials no longer makes sense,” wrote Dr. Makary and Dr. Prasad. “In 2026 there are powerful alternative ways to feel assured that our products help people live longer or better than requiring manufacturers to test them yet again.”
The FDA has been moving toward this approach for decades. Since the 1990s, it has often accepted a single study for treatments targeting rare or life-threatening diseases, where recruiting enough participants for multiple trials is challenging.
Janet Woodcock, MD, who led the FDA’s drug center for about 20 years before retiring in 2024, noted that for cancer and rare disease treatments, “the agency has been approving those on a single trial already.”
Dr. Woodcock agreed that advances in science and medicine have made duplicate testing unnecessary in some cases. “The scientific point is well taken that as we move toward greater understanding of biology and disease, we don’t need to do two trials all the time,” she said.
Getting to Market
Over the last five years, approximately 60% of novel drugs have been approved based on a single study, signaling a notable shift — particularly for treatments targeting more common conditions. The updated policy is expected to further expand this approach.
The FDA’s move toward faster approvals represents a significant change in how new medicines may reach patients. By reducing the need for multiple, large-scale studies, the policy could lower development costs and timelines, potentially accelerating innovation and access.
What this policy change will not do, FDA officials emphasized, is compromise the safety of emerging drugs and therapies. Safety remains a top priority, and the agency still retains the authority to demand secondary or even tertiary studies if the initial data is not convincing.
