Sandoz has decided not to pursue U.S. approval for its rituximab product (GP2013), a proposed biosimiliar of Rituxan/Mabthera.
GP2013 (Rixathon, Riximyo) is already approved outside the U.S.
Sandoz was seeking U.S. approval of GP2013 for all the same indications as the reference product—B-cell non-Hodgkin lymphoma, chronic lymphocytic leukemia, rheumatoid arthritis, granulomatosis with polyangiitis, microscopic polyangiitis, and pemphigus vulgaris.
The U.S. Food and Drug Administration (FDA) had accepted the biologics license application (BLA) for GP2013 in September 2017.
In May of this year, the FDA issued a complete response letter saying it could not approve GP2013. The agency also requested additional information to complement the BLA submission for GP2013.
At the time of the complete response letter, Sandoz said it was still committed to bringing GP2013 to the U.S. market. Now, the company’s position has changed.
“We appreciate the important conversations with the FDA, which have provided specific requirements for our potential U.S. biosimilar rituximab, but believe the patient and marketplace needs in the U.S. will be satisfied before we can generate the data required,” said Stefan Hendriks, global head of biopharmaceuticals at Sandoz.
“We are disappointed to have to make this decision and stand behind the safety, efficacy, and quality of our medicine, which met the stringent criteria for approval in the European Union, Switzerland, Japan, New Zealand, and Australia.”
The BLA for GP2013 was supported, in part, by the ASSIST-FL trial (NCT01419665), in which researchers compared GP2013 to the reference product. Results from this trial were published in The Lancet Haematology in July 2017.
The phase 3 trial included adults with previously untreated, advanced stage follicular lymphoma. Patients received 8 cycles of cyclophosphamide, vincristine, and prednisone with either GP2013 or reference rituximab. Responders then received GP2013 or rituximab monotherapy as maintenance for up to 2 years.
At a median follow-up of 11.6 months, the overall response rate was 87% (271/311) in the GP2013 arm and 88% in the rituximab arm (274/313). Complete response rates were 15% (n=46) and 13% (n=42), respectively.
Rates of adverse events (AEs) were 93% in the GP2013 arm and 91% in the rituximab arm. Rates of serious AEs were 23% and 20%, respectively. The rate of discontinuation due to AEs was 7% in both arms.
The most common AE was neutropenia, which occurred in 26% of patients in the GP2013 arm and 30% of those in the rituximab arm in the combination phase. Rates of neutropenia in the maintenance phase were 10% and 6%, respectively.