Julia Weisinger, MD: Obinutuzumab a Promising Option for Intolerant/Refractory iTTP

Obinutuzumab was effective in treating patients with Immune-Mediated Thrombotic Thrombocytopenic Purpura (iTTP) intolerant or refractory to rituximab with an acceptable safety profile, offering a potential option for this patient population.

These findings, from the largest cohort of patients with iTTP receiving obinutuzumab, were presented at the 66th American Society of Hematology (ASH) Annual Meeting and Exposition, held December 7-10, 2024, in San Diego, California, by Julia Weisinger, MD, a PhD candidate at Greater Paris University Hospitals.

“There are not many clinical studies in TTP because it's a rare disease, and also, if there were some clinical studies, usually they were performed long ago, before the routine use of rituximab. So, we need new treatment options, and hopefully in the future, new guidelines what to use in TTP,” Weisinger told HCPLive® during the meeting.

Weisinger and colleagues found that most patients (n = 51; 85%) reached an ADAMTS13 activity of at least 20% after treatment, 72% (n=43) reached a normal activity, and 15% (n=9) failed to improve ADAMTS13 activity. In 34 evaluable patients after obinutuzumab treatment, all had complete B-cell depletion within 2 months following treatment initiation. The investigators also found that patients with previous refractoriness to rituximab tended to have a higher risk of refractoriness (P = .052). There were no serious adverse events associated with obinutuzumab. After a median follow-up of 11 months (range, 1-44), 2 ADAMTS13 relapses and 1 clinical relapse occurred; 2 patients died: 1 patient had intracranial bleeding during a relapse of iTTP and another with a history of severe cardiac disease died in cardiac arrest.

This study is part of the TOLERATE project funded by the European Union under grant agreement #101072729.

REFERENCE

Weisinger J, Fadlallah J, Barbet C, et al. Obinutuzumab in Rituximab Refractory or Intolerant Immune-Mediated Thrombotic Thrombocytopenic Purpura. Presented at: ASH Annual meeting; December 7-10; San Diego, California. Abstract 139.