By Caroline Humer
(Reuters) – The U.S. Food and Drug Administration’s rejection of BioMarin Pharmaceutical Inc’s gene therapy for blood disease hemophilia A cited the need for long-term data, the drugmaker said on Wednesday, potentially pushing any approval to 2022.
BioMarin shares fell 31%, or $ 37, to $ 81.54 in morning trading.
The company, Wall Street, and doctors had expected the therapy to be approved this month, after it was shown in clinical studies that it reduced the blood speed of patients with the disorder, requiring or eliminating the treatment.
There are approximately 16,000 patients in the United States with haemophilia A who lack the factor VIII coagulation protein. The standard therapy requires that patients infuse factor proteins into their bloodstream several times a week for life, costing hundreds of thousands of dollars a year. It was hoped that the gene therapy could enable patients to give or reduce these infusions.
BioMarin had said that the gene therapy could be priced in the range of $ 1 million to $ 3 million, potentially making it the most expensive one-time treatment in the United States. Novartis AG’s spinal muscular atrophy gene therapy is priced at $ 2.1 million.
The company said on Wednesday that the FDA had changed its requirements for data in the application, to request the full two-year data from an ongoing study of the therapy to the late stage.
It received the request in a full response letter from the agency, which had to respond to the company about its request this week.
“We are surprised and disappointed that the FDA first introduced new expectations in the Complete Response Letter,” Chief Executive Officer Jean-Jacques Bienaimé said in a statement.
BioMarin has submitted its application based on three-year phase 1/2 data and interim analysis of phase 3 data. Phase 1/2 data had indicated that the effects of treatment decreased in the second year and continued to decrease in years three and four. The treatment is intended to enable patients with hemophilia A to produce the blood clotting protein that they would otherwise lack.
The FDA told BioMarin that the differences between the trials limited their ability to rely on phase 1/2 data in their analysis of how long the treatment would be effective.
The trial in the late phase completed enrollment in November of 2019, making the data available for resubmission in late 2021, and approval one year later, Stifel analyst Paul Matteis said in a research note.
The FDA had no immediate comment.
The FDA’s rejection limits the lead BioMarin’s valoctocogenic roxaparvovec, as ValRox, had on potentially rival treatments from Roche Holdings AG and Pfizer Inc / Sangamo Therapeutics Inc. Pfizer and Sangamo are due to start phase 3 this year, while Roche will not be thankful for his trial until next year.
It may benefit from Roche’s bispecific antibody Hemlibra which mimics the function of a missing blood clotting protein to restore the clotting process. It is expected to have sales of $ 2 billion this year.
(Report by Caroline Humer in New York, John Miller in Zurich and Manas Mishra in Bengaluru; Edited by Maju Samuel, Steve Orlofsky and Andrea Ricci)
