- Regenxbio, facing regulatory delays for two of its gene therapy programs, has sued the Food and Drug Administration in hopes of overturning the agency's decision to halt enrollment into one study and stop dosing in a second.
- The lawsuit, filed Nov. 7 in federal district court, argues the FDA violated its own regulations in issuing the clinical hold orders and caused reputational harm to Regenxbio. The biotech delayed the start of a Phase 2b study testing the therapy in patients with age-related macular degeneration, a common eye disease, as a result of the hold.
- According to Regenxbio, the FDA's hold isn't tied directly to its therapy, but involves instead third-party surgical devices used to deliver the treatment into the eye. Shares in the biotech fell by nearly 4% the day following the news.
Suing the FDA over its regulatory actions is a long-shot attempt, but appears aimed at drawing out from the agency a fuller explanation of why the holds were instituted.
"Regenxbio filed a complaint against the FDA, as a procedural matter to preserve our rights," the company said in a statement to BioPharma Dive. "This action was taken on the recommendation from counsel as we continue to work with the FDA to address this matter."
The hold applies to two trials testing Regenxbio's retinal disease gene therapy RGX-314. One, a Phase 1/2 study, is testing RGX-314 as a treatment for wet age-related macular degeneration, while the second is focused on diabetic retinopathy.
As Regenxbio tells it, an FDA official informed the company by phone and email on Oct. 18 that both studies were placed on full clinical hold, meaning no new patients could be enrolled and already enrolled patients could not be treated further.
An email sent by another official a week later clarified that the wet AMD study was under only a partial clinical hold, which would pause enrollment but allow untreated patients already in the trial to undergo therapy.
So far, the FDA has only told Regenxbio its actions relate to "issues associated with [RGX-314's] delivery systems," according to the company's lawsuit.
"FDA's final agency action is contrary to law and arbitrary and capricious because it did not follow the statute or its own regulations, nor did FDA offer a reasoned explanation for issuing a clinical hold without advance warning," the company stated in its suit, which also names Health and Human Services Secretary Alex Azar and acting FDA Commissioner Brett Giroir as defendants.
While Regenxbio has sought further detail, the agency has said only that it will provide a full written explanation of the basis for the hold by Nov. 15, the end of the 30-day period which the FDA has to communicate its rationale.
"While it seems unlikely that the merits of the clinical hold will be resolved through the judiciary process in a helpful timeframe, the complaint has likely increased the chances that FDA will respond with a thorough explanation of its reason for the hold when it does provide the written basis," wrote Deborah Livornese, an attorney at the law firm Hyman, Phelps and McNamara in a post on the FDA Law Blog.
In its initial statement on the hold, Regenxbio said it anticipates a short delay for starting its planned Phase 2b study in wet AMD, and "believes there are readily available and suitable alternatives for these third-party devices, if needed."
Regenxbio intends to file the Initial New Drug Application in diabetic retinopathy, which it had withdrawn as a precaution, in the first quarter of next year.
The lawsuit also seeks to invalidate a section of the Food, Drug, and Cosmetic Act that allows the FDA to issue a clinical hold for reasons other than a determination on a drug's safety.