(Reuters) - The U.S. Food and Drug Administration should be more transparent when granting accelerated approval for certain drugs, influential drug pricing body, Institute for Clinical and Economic Review (ICER), said in a report on Thursday.

The FDA's accelerated approval pathway speeds up authorization ‌of drugs for serious conditions with no approved treatments by using surrogate endpoints, markers that predict clinical benefit without directly measuring it, and significantly cutting the time needed to win the regulator's approval.

However, manufacturers whose drugs are approved under the accelerated approval pathway must still conduct confirmatory trials to verify the expected clinical benefit.

Drugs that obtained accelerated approval this year include Denali Therapeutics’ rare disease drug Avlayah and Rocket Pharmaceuticals' gene therapy Kresladi for ⁠a childhood disorder.

Expedited approval for drugs under the pathway have raised questions regarding the safety and efficacy of these treatments. For instance, in 2021, Biogen's Alzheimer's drug Aduhelm faced controversy over the FDA's accelerated approval without clear evidence of patient benefit. Three years later, the drugmaker dropped the treatment.