Pirtobrutinib granted FDA approval for the treatment of R/R MCL

On January 27, 2023, it was announced that the U.S. Food and Drug Administration (FDA) had granted approval to pirtobrutinib, a non-covalent Bruton’s tyrosine kinase (BTK) inhibitor, for the treatment of adult patients with relapsed/refractory mantle cell lymphoma (MCL) after ≥2 prior lines of systemic therapy, including a previous BTK inhibitor.¹

Pirtobrutinib was granted approval under the FDA's Accelerated Approval pathway based on key data from the phase I/II BRUIN trial (NCT03740529). Data was obtained from a subset of 120 patients with MCL, treated with pirtobrutinib 200 mg once daily until disease progression or unacceptable toxicity. The key efficacy outcomes were:

• 50% overall response rate
• 13% complete response rate
• 38% partial response rate
• median time to response of 1.8 months
• median duration of response of 8.3 months

Serious adverse reactions occurred in 38% of patients. The most commonly reported serious adverse reactions were:

• pneumonia (14%)
• COVID-19 (4.7%)
• musculoskeletal pain (3.9%)
• hemorrhage (2.3%)
• pleural effusion (2.3%)
• sepsis (2.3%)

The approval of pirtobrutinib provides a new treatment option for patients with relapsed/refractory MCL, including those who have received prior covalent BTK inhibitors.