Prothena announces AFFIRM-AL trial did not meet primary endpoint

Prothena (PRTA) announced the Phase 3 AFFIRM-AL clinical trial evaluating birtamimab in patients with AL amyloidosis did not meet its primary endpoint. Based on these results, the company will discontinue the development of birtamimab, including stopping the open label extension of the AFFIRM-AL clinical trial. In the Phase 3 AFFIRM-AL clinical trial, the primary endpoint of time to all-cause mortality was not met for patients treated with birtamimab. In addition, neither of the secondary endpoints were met: 6-minute walk test distance and Short Form-36 version 2 Physical Component Score. Birtamimab was generally safe and well-tolerated, consistent with its established safety profile. In June, the company expects to provide details of plans to reduce ongoing operating expenses. The results of the company’s review of its business options will be communicated as appropriate once the analysis and plans are finalized.