With an FDA approval decision on treosulfan possibly more than a year off, the U.S. Patent and Trademark Office granted Medac GmbH a third one-year extension of its method-of-use patent covering the drug, which is being developed as a conditioning agent in allogeneic hematopoietic stem cell transplantation.
Despite prior marketing approvals in Europe and Canada, an effort to win FDA support for the bifunctional alkylating agent treosulfan has drawn a complete response letter (CRL) from the agency, the company's U.S. rights holder, Medexus Pharmaceuticals Inc., said.
Aptevo Therapeutics Inc.’s chief scientific officer, Jane Gross, told BioWorld that the sale of the firm’s marketed recombinant hemophilia B therapeutic, Ixinity, to Medexus Pharmaceuticals Inc. allowed for a “cleaner message” to Wall Street. “It was a little difficult to explain having a commercial asset and an R&D pipeline,” she said.