Symphogen Publishes Final Rozrolimupab (SYM001) Phase 2 Trial Results in ITP in BLOOD Journal

COPENHAGEN, DENMARK — The hematology journal BLOOD published today a full-length article describing final Phase 2 data for Symphogen’s rozrolimupab, a novel human recombinant mixture of 25 antibodies which all are manufactured simultaneously from a single batch. The data demonstrates rozrolimupab’s favorable safety profile and its induction of a rapid increase in platelet counts in patients with Primary Immune Thrombocytopenia Purpura (ITP). Professor Tadeusz Robak, MD, University of Lodz, Poland, is the first author of the article entitled “Rozrolimupab, A Mixture of 25 Recombinant Human Monoclonal RhD Antibodies, in the treatment of Primary Immune Thrombocytopenia” which has been prepublished in First Edition of Blood and can be viewed on Blood Online at http://bloodjournal.hematologylibrary.org/content/early/recent.

The Phase 2 study was an open-label, multi-center clinical trial evaluating the efficacy, safety, and tolerability of rozrolimupab (SYM001) in adult, RhD positive, non-splenectomized ITP patients. A total of 61 patients were treated with single doses from 75µg/kg to 300µg/kg as single i.v. infusions of 15-20 minutes’ duration. The trial demonstrated that at 300µg/kg, 8 of 13 (62%) of patients responded at day 7. Already within 5 to 8 hours after rozrolimupab administration, 23% of the patients achieved platelet responses (≥ 30×10⁹/L and increase in platelet count by > 20×10⁹/L from baseline). Median time to response was 59 hours (approximately 2.5 days) and the median duration of response was 14 days.

The most common adverse events observed, were headache (20%), mostly mild or moderate, pyrexia (13%), chills (10%), and fatigue (8%). Four serious adverse events considered related to study drug were reported: decreased hemoglobin, extravascular hemolysis/dizziness and two cases of transient rise in D-dimer values without clinical symptoms.

According to Professor Robak, “These Phase 2 results suggest an efficacy and safety profile similar to that seen with plasma derived immunoglobulin products. It seems promising that rozrolimupab rapidly yields platelet responses. This unique recombinant human monoclonal antibody mixture, rozrolimupab can be produced indefinitely and may represent a novel and convenient replacement for blood-derived immunoglobulins with more limited supply.”

Kirsten Drejer, Symphogen chief executive officer, added, “Symphogen has reached an important milestone by generating clinical proof of concept for a product consisting of a mixture of 25 monoclonal antibodies. The multicenter study included involvement of the regulatory authorities of the USA, Europe and Asia, and we are confident that antibody mixtures represent a viable new class of antibody therapeutics offering well-characterized and potentially more efficacious alternatives to existing treatments.”