Complete response letters

The FDA recommended that REGENXBIO run a new study, treat more patients and include a placebo arm to support a resubmission for the gene therapy RGX-121.
Corcept’s relacorilant was rejected for hypercortisolism late last year—a decision which CEO Joseph Belanoff expressed surprise with at the time.
The DC-based biopharma disputed the FDA’s conclusions regarding the data provided in its supplemental application for Hetlioz and promised to keep pushing for an approval.
Last month, the FDA declined to approve Sanofi’s tolebrutinib for a specific form of multiple sclerosis. In a recently published complete response letter, the agency detailed its reasoning behind the rejection.
Both companies received agency requests for more evidence of the effectiveness of their therapies.
Biohaven is proposing troriluzole for the treatment of spinocerebellar ataxia, a group of rare, genetic diseases that lead to the progressive loss of control over movement.
Despite the rejection, analysts saw Regeneron’s use of an alternate filler for Eylea HD as a positive development, with BMO Capital Markets noting that this could signal the end of manufacturing troubles for the franchise.
As with recent rejections for Biogen and Scholar Rock, manufacturing issues stymied a regulatory bid from Fortress Biotech and Sentynl Therapeutics. Fortress said the FDA did not flag problems with the drug’s safety or efficacy.
FDA
By publishing complete response letters as soon as they are issued to drug sponsors, the FDA is expanding transparency in a way that, while positioned as a public health measure, also grants investors greater visibility into regulatory decisions. Experts question whether this is the agency’s proper remit.
The regulatory action marks the second rejection for a spinal muscular atrophy therapy this week after Scholar Rock’s apitegromab was issued a complete response letter on Tuesday, similarly on manufacturing grounds.
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