Novartis’ Sandoz remains committed to further discussions with the US FDA after receiving a complete response letter (CRL) for its rituximab biosimilar candidate.

The Biologics Licensing Application (BLA) for Sandoz’ proposed biosimilar of Roche’s autoimmune disease drug Rituxan (rituximab) suffered a setback yesterday when the US Food and Drug Administration issued a CRL.

A Sandoz spokesperson told BioProcess Insider that the firm is “still evaluating the content” of the letter and specific details are not being divulged for now.

“The point I would stress is that we stand behind the robust body of evidence included in our regulatory submission and are committed to further discussions with FDA in order to bring this important medicine to US patients as soon as possible,” we were told.

Rituxan – known as Mabthera in Europe – clocked in sales of CHF 7.4 billion (US$7.4 billion) for Swiss biopharma firm Roche in 2017.

In Europe, the European Commission (EC) approved Sandoz’s rituximab under the name Rixathon in June 2017.

(Bio)Similar Complete Response Letters

Earlier this year, the FDA issued a CRL to Celltrion for its rituximab biosimilar. The rejection was directly related to a warning letter​ sent to the South Korean drugmaker in January highlighting “multiple poor aseptic practices” at its production site in Songdo, Incheon.

If approved that biosimilar will be commercialized in North America by Israel’s Teva Pharmaceutical Industries following a 2016 partnership worth $160 million.

And Sandoz’s CRL comes just weeks after fellow biosimilar developer Pfizer suffered a setback to its Herceptin (trastuzumab) biosimilar program. Pfizer told this publication the rejection was not related to manufacturing, unlike a CRL received for its version of Amgen’s anaemia drug Epogen (epoetin alpha) received in June 2017.