French healthcare company Sanofi S.A. (Euronext Paris:SAN) (Nasdaq:SNY) announced on Tuesday that Japan's Ministry of Health, Labour and Welfare has granted marketing and manufacturing authorisation for Wayrilz (rilzabrutinib), an oral reversible Bruton's tyrosine kinase inhibitor (BTKi), to treat persistent or chronic immune thrombocytopenia (ITP) in patients who respond inadequately to other therapies or have tolerability issues.

Wayrilz is designed to address the underlying causes of the disease through multi-immune modulation targeting key immune system pathways.

The approval is supported by the Phase 3 LUNA 3 study, which met its primary and secondary endpoints and demonstrated improvements in sustained platelet counts and other symptoms. Among 202 adults with persistent or chronic ITP, Wayrilz achieved a 23% durable platelet response at week 25 versus 0% for placebo, reduced the time to first platelet response to 36 days versus not reached for placebo, and extended the duration of platelet response to a least square mean of seven weeks versus 0.7 weeks.

Patients receiving Wayrilz also reported a 10.6-point improvement in overall quality of life compared with a 2.3-point increase for placebo, although this analysis was descriptive and not powered for statistical significance. The most common adverse reactions were diarrhoea, nausea, headache, abdominal pain, and COVID-19.

Wayrilz is also under investigation for IgG4-related disease (IgG4-RD), warm autoimmune haemolytic anaemia (wAIHA), and sickle cell disease, with those indications not yet approved by regulatory authorities. Japan has granted the therapy orphan drug designation for ITP, IgG4-RD, and wAIHA.