Cure IBM has been informed by Abcuro that the company has made the decision to close ABC008-IBM-202, the open-label long-term extension study of ulviprubart in people with inclusion body myositis.
This means that patients in the extension study will no longer have access to ulviprubart.
We know this will be very difficult news for some patients and families, especially for people who felt they were doing better while receiving ulviprubart or who hoped the extension study would continue. IBM is a progressive disease with no approved disease-modifying treatment, and news like this can be deeply disappointing.
What Was the Long-Term Extension Study?
The long-term extension study was the follow-up study for people who had completed the main ulviprubart trial. In the main trial, some participants received ulviprubart and others received placebo, and neither the patients nor the study doctors knew who was in which group.
In the extension study, participants could receive ulviprubart openly. Everyone knew they were receiving the drug. The extension study gave Abcuro a way to collect longer-term information about ulviprubart, including safety, tolerability, and possible effects over time. It also gave some patients continued access to ulviprubart after the main trial ended.
What Should Study Participants Do Now?
Abcuro has told Cure IBM that clinical trial sites have been notified, and that trial investigators will communicate directly with their patients.
Patients who are currently or recently enrolled in the extension study should contact their study physician or clinical trial site with medical or study-specific questions. Cure IBM cannot provide individual medical advice or answer questions about a person’s specific study participation.
What Happened in the Main trial?
This news follows Abcuro’s earlier report that the main ulviprubart trial did not show the benefit that the company, researchers, and patients had hoped to see. More specifically, Abcuro previously announced that its Phase 2/3 MUSCLE study of ulviprubart in IBM did not meet its primary endpoint or key secondary endpoints.
In that announcement, Abcuro stated that ulviprubart had a favorable safety and tolerability profile and reported signals suggesting possible slowing of disease progression in a pre-specified subgroup of patients with less severe disease.
What Might Happen Next?
Abcuro has indicated that it is still evaluating possible next steps for the ulviprubart program and the company. Abcuro also stated that it hopes a mechanism could eventually be put in place that would allow some patients who were previously in the study to restart therapy if they and their healthcare practitioner consider it to be in their best interest. However, Abcuro emphasized that this cannot be guaranteed at this time.
Cure IBM will share additional information when it is available and appropriate to do so.
Thank You to the Patients Who Participated
People who join IBM clinical trials take on real burdens: travel, testing, uncertainty, time, and hope. Cure IBM is grateful to every participant in this trial and its extension, as well as to their families, care partners, investigators, study coordinators, and clinical teams. This is not the result anyone wanted. But the patients who joined this study still helped answer important questions, and those answers will matter as researchers plan the next IBM studies.
Discussion of the ulviprubart main clinical trial results
General clinical trial information
by Kevin Dooley, MD
June 12, 2026