Bristol-Myers Squibb has decided to return worldwide rights to investigational rheumatoid arthritis drug clazakizumab to Alder BioPharmaceuticals, despite the compound’s impressive mid-stage data.

The decision follows a “portfolio prioritisation” by BMS and Alder notes that  the move “is not based on any new or unexpected efficacy or safety data or technical issues”. Indeed, “we view BMS' decision as a significant opportunity,” said the latter’s chief executive Randall Schatzman.

He added that clazakizumab has strong data that were presented at the most recent American College Of Rheumatology and European League Against Rheumatism conferences. These data “demonstrate the potential for clazakizumab to fulfill the unmet need in patients with RA to achieve disease control and remission”, he stated.

A Phase IIb study has shown clazakizumab treatment arms, both as monotherapy and in combination with methotrexate, met the primary endpoint of ACR20 response at 12 weeks, compared to MTX alone. Also remission rates for Alder’s  human anti-interleukin (IL)-6 monoclonal antibody plus MTX were greater than for MTX plus AbbVie’s blockbuster Humira (adalimumab) - 23.3% vs 8.5%.

Mr Schatman said the firm is reviewing its options for clazakizumab “while maintaining our focus on the continuing development of ALD403 for migraine on the current timelines”, which is in Phase II.

The results of a Phase IIb trial of clazakizumab for psoriatic arthritis will be presented at the ACR meeting in Boston in November.