As the 21st Century Cures Act cleared the U.S. Senate last week, many attendees of the annual World Stem Cell Summit (WSCS) here took a victory lap. The meeting assembled some of the lawyers, analysts, and activists who have long pushed for reform of how the U.S. Food and Drug Administration (FDA) handles regenerative medicine. And the behemoth biomedical bill predicted to get a presidential signature this week could allow some stem cell products a faster and more flexible premarket approval process.
“For the first time, I would submit to you, in the United States, regenerative medicine is taking its place,” said Bernard Siegel, executive director of the Regenerative Medicine Foundation, the nonprofit advocacy group that organizes the annual meeting, said of the bill in his 6 December welcome address.
The allure of stem cells—their ability to repair the body by multiplying and differentiating into more mature cells—has inspired researchers to try out hundreds of therapeutic applications, from grafting them onto damaged skin to infusing them into fetuses with bone disease. But because many of these therapies have yet to prove their clinical value and clinics around the world are selling untested treatments that may pose risks to patients, Congress’s push for faster approval of stem cell therapies is also causing anxiety. The Cures language on regenerative medicine, added during final negotiations last month between House of Representatives and Senate representatives, salvages certain aspects of a highly controversial Senate bill known as REGROW (Reliable and Effective Growth for Regenerative Health Options that Improve Wellness), first introduced in March by senators Mark Kirk (R–IL) and Joe Manchin (D–WV). That bill outlined a “conditional approval” system for stem cell therapies that would have spared their sponsors the large, costly, and time-consuming phase III clinical trials designed to confirm efficacy. Instead, once safety was generally shown in smaller trials, sponsors would get marketing approval and then could collect such evidence through follow-up studies of customers—once they were also collecting revenue. The bill was meant to stimulate investment in the field and get potential treatments to desperate patients faster. But both academic societies and trade groups panned it, arguing that it would compromise FDA’s standards and allow useless or even dangerous drugs onto the market.
The relevant Cures language is undeniably gentler: It lets companies apply to FDA for a new designation, “regenerative advanced therapy” that makes them automatically eligible for several existing types of special treatment, provided that their product targets a serious disease and, based on preliminary clinical evidence, has the “potential to address unmet medical needs.” Among the most enticing of these existing FDA perks is a pathway called accelerated approval, which allows a drug to reach the market based on what are called intermediate or surrogate clinical trial endpoints—measures like imaging data or markers in blood that are predictive of longer term disease outcomes like survival. Compared with the standard approval pathway, that can mean fewer, shorter, or smaller trials.
That’s an exciting prospect for Joanne Kurtzberg, a pediatric transplant researcher at Duke University in Durham, North Carolina, who presented at the meeting, and who is preparing a clinical trial that gives young cerebral palsy patients infusions of umbilical cord blood containing stem cells. Kurtzberg is considering seeking accelerated approval for the therapy, but has worked with drug sponsors who sought that designation before and were denied. “In my view as a clinician, the data was strong enough and compelling enough, and the need was compelling enough,” she says of those cases. To date, no stem cell treatment has been granted accelerated approval—and none has yet been approved by FDA via any pathway. The new bill “at least opens the door for some conversations that have not been possible up to now,” Kurtzberg says.