Sanofi's BTK Inhibitor Disappoints In Phase 3 Autoimmune Disease Trial

Sanofi SA's SNY BTK inhibitor, rilzabrutinib, has flunked its first major clinical test.
Rilzabrutinib was Principia Biopharma Inc's one of the key candidates that Sanofi acquired last year for $3.68 billion.
Investigators randomized 131 newly diagnosed or relapsing moderate-to-severe pemphigus patients to take rilzabrutinib or placebo orally.
The primary endpoint looked at the number of patients in each arm who were in complete remission and taking 5 mg or less of corticosteroids a day from week 29 to week 37 of the study. By that yardstick, rilzabrutinib was no better than placebo.
Pemphigus is characterized by blisters and ulceration affecting the skin and mucous membranes.
Sanofi is yet to give up on the drug, in any case.
A Phase 3 trial in the rare blood disorder immune thrombocytopenia and a Phase 2 study in the autoimmune condition IgG4-related disease are continuing.
And Sanofi plans to start mid-phase trials in immunological diseases including asthma, atopic dermatitis, chronic spontaneous urticaria, and warm autoimmune hemolytic anemia by the end of the year.
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Price Action: SNY stock is down 1.56% at $49.34 during the market session on the last check Thursday.