US FDA declines to approve Atara’s therapy for rare blood cancer

Jan 12 (Reuters) – The U.S. Food and Drug Administration declined to approve Atara Biotherapeutics’ cell therapy for a rare form of blood cancer, the company said on Monday, sending its shares down 56% in early trading.

The FDA in its complete response letter said it is unable to approve the therapy’s application in its current form.

The letter said the company’s Allele trial, which was previously confirmed by the FDA as adequate to support the marketing application, was no longer considered adequate to provide evidence of effectiveness for an accelerated approval.

This comes as another setback to Atara after the FDA rejected approval for the therapy last year, citing observations made during an inspection of a third-party manufacturing facility.

The health regulator in its letter also stated that the trial’s interpretability is confounded due to the design, conduct and analysis of the trial.

The FDA’s new position is contrary to its prior guidance to Atara, the company said.

Atara’s partner Pierre Fabre Pharmaceutical said the decision is contrary to extensive dialogue with the agency over more than five years and added it “may have far-reaching consequences for the development of rare disease treatments”.

Atara was seeking approval for its CAR-T cell therapy, called tabelecleucel, in patients with Epstein-Barr virus positive post-transplant lymphoproliferative disease (EBV+ PTLD).

It is a form of rare and often fatal blood cancer that develops after organ or stem cell transplants.

There are no approved therapies for this disease in the U.S., but doctors often recommend chemotherapy alone or in combination with other cancer therapies such as rituximab, and surgery in rare cases.

Tabelecleucel is a T-cell immunotherapy designed to eliminate EBV-infected cells. It gained approval in Europe in 2022, under the brand name Ebvallo.

(Reporting by Sneha S K in Bengaluru; Editing by Sahal Muhammed, Shinjini Ganguli and Krishna Chandra Eluri)