**Sanofi has presented promising results from a phase 3 study of its investigational oral Bruton’s tyrosine kinase (BTK) inhibitor rilzabrutinib in patients with immune thrombocytopenia (ITP).**
Data from the late-stage LUNA 3 study, which has been evaluating the drug in adults and adolescent patients with persistent or chronic cases of the rare autoimmune disorder, were presented at this year’s American Society of Hematology (ASH) annual meeting.
Affecting approximately 9.5 per 100,000 people in the US, ITP is characterised by low platelet counts resulting from both increased platelet destruction and decreased platelet production.
The disease can cause bruising and bleeding, which can include potentially life-threatening episodes such as intracranial haemorrhage, as well as arterial or venous thrombosis.
LUNA 3 met its primary endpoint, with twice-daily rilzabrutinib demonstrating durable platelet response in 23% of ITP adult patients compared to 0% in the placebo arm. This was defined as the proportion of patients able to achieve platelet counts at or above 50,000/μL for at least eight out of the last 12 weeks of the 24-week blinded treatment period in the absence of rescue therapy.
Platelet response was achieved in 65% of rilzabrutinib-treated patients compared to 33% of patients on placebo and, for the combined 24-week double-blind and 28-week open-label periods, durable response was achieved in 29% of those in the rilzabrutinib group as of the data cutoff.
Significant improvements were also observed with rilzabrutinib versus placebo in reduced bleeding, the need for rescue therapy use, and improved physical fatigue and quality of life measures.
Dietmar Berger, chief medical officer, global head of development at Sanofi, said: “This new data supports the potential of rilzabrutinib to provide robust and durable platelet response in ITP, offering hope for patients with limited treatment options.
“Based on its ability to target BTK, an enzyme that plays a critical role in many types of immune cells, we believe rilzabrutinib also has the potential to improve patient outcomes in multiple rare blood and autoimmune disorders.”
Beyond ITP, rilzabrutinib is being studied across a variety of immune-mediated diseases, including warm autoimmune haemolytic anaemia, asthma and chronic spontaneous urticaria.