The Food and Drug Administration has delayed reviews of several drugs in a Trump-backed fast-track program after internal scientists raised safety, efficacy, and data concerns. These FDA drug review delays are slowing approvals meant to take one to two months, documents reviewed by Reuters show.
Fast-Track Program Slows as Scientists Flag Risks
The delays affect the FDA’s Commissioner’s National Priority Voucher program, a pilot initiative designed to sharply shorten drug review timelines for treatments aligned with U.S. national health priorities. Under the program, standard reviews of ten to twelve months could be compressed into one or two months.
Internal documents show that FDA scientists questioned whether some applications met evidentiary standards needed for approval. Reviewers raised concerns about trial design, statistical reliability and potential safety risks, prompting extensions of review timelines.
The pilot program currently includes sixteen drugs. In December, Merck & Co. cholesterol treatment Enlicitide decanoate and cancer therapy Sacituzumab Tirumotecan were selected for the program. If finalized, they would become the seventeenth and eighteenth drugs admitted, according to the documents.
The FDA has said from the outset that participation does not guarantee accelerated approval. Agency staff retain authority to extend reviews if applications are incomplete, manufacturing issues are identified or further analysis is deemed necessary.
Specific Drugs Face Added Scrutiny and Delays
Among the drugs affected is Bitopertin, an experimental treatment from Disc Medicine Inc. for Erythropoietic Protoporphyria, a rare blood disorder causing extreme sensitivity to sunlight. FDA drug review delays have postponed a decision by about two weeks, moving it to Feb. 10.
Regulators questioned whether “pain-free time in the sun,” a secondary clinical trial endpoint, was a statistically reliable measure of effectiveness. Reviewers also examined whether biomarker data could support approval.
In addition, FDA staff who evaluate drugs with abuse potential were asked to assess whether Bitopertin posed risks of misuse or addiction, adding another layer to the review.
Sanofi’s Tzield, used in late-stage type one diabetes, also saw its review delayed by more than a month. Documents cited by Reuters point to adverse event reports, including seizures, blood-clotting issues and what regulators described as a treatment-related death.
The FDA’s public adverse-event database references a September 2025 case involving a thirty-year-old man who experienced a seizure and other complications after treatment.
A Sanofi spokesperson said the company “carefully evaluates all serious adverse events and continues to work closely with the FDA” on the expanded-use application.
Other timelines have slipped as well. A decision on lung cancer drug Zongertinib from Boehringer Ingelheim is now expected in mid-February. Eli Lilly said its weight-loss pill Orforglipron could receive a decision in the second quarter, with FDA drug review delays guidance pointing to an April 10 target date.
Lawmakers, Experts Question Speed and Transparency
Two regulatory experts told Reuters the delays were reassuring. They said the program’s aggressive timelines raised concerns about whether reviews could remain thorough without compromising safety.
“Extremely compressed review periods increase the risk that important signals could be missed,” one expert said, adding that extensions suggest scientific standards are being maintained.
Democratic lawmakers have also criticized the program. Rep. Frank Pallone and Sen. Bernie Sanders said in a statement that the initiative lacks transparency and could invite favoritism.
They warned that rushed reviews “risk undermining public confidence in the FDA’s gold-standard approval process” if safety concerns are perceived as secondary to speed.
Market reaction reflected investor uncertainty. Shares of Disc Medicine fell sharply in premarket trading Thursday, while shares of Eli Lilly and Sanofi edged lower.
The FDA has not publicly commented on individual FDA drug review delays but has emphasized that patient safety and data integrity remain central to all approval decisions, regardless of review speed.
