Pirtobrutinib — Drug Monograph

Brand names: Jaypirca

Drug class: BTK Inhibitor

Mechanism of Action

Non-covalent (reversible) BTK inhibitor that maintains activity against the BTK C481S resistance mutation that commonly develops after covalent BTK inhibitors (ibrutinib, acalabrutinib, zanubrutinib). High selectivity for BTK with minimal off-target inhibition of EGFR, TEC family kinases, reducing cardiovascular toxicity compared with ibrutinib.

FDA Indications

• Relapsed or refractory mantle cell lymphoma (MCL) after at least 2 prior lines of therapy including a covalent BTK inhibitor (FDA approved January 2023; BRUIN MCL-321: 57.3% ORR)
• Relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) after at least 2 prior lines of therapy including a covalent BTK inhibitor and a BCL-2 inhibitor (BRUIN CLL-321)

Common Side Effects

• Fatigue (30%)
• Musculoskeletal pain (26%)
• Diarrhea (19%)
• Edema (18%)
• Dyspnea (17%)
• Neutropenia (17%)
• Bruising
• Cough

Clinical Pearl

Pirtobrutinib is the first non-covalent (reversible) BTK inhibitor FDA-approved, specifically designed to overcome BTK C481S resistance. Its lower cardiovascular toxicity profile (due to minimal EGFR and TEC kinase inhibition) distinguishes it from ibrutinib. Activity is preserved in both C481S and wild-type BTK settings.

Related Therapies & Mechanisms

• Acalabrutinib (Calquence) — BTK Inhibitor · Lymphoma
• Zanubrutinib (Brukinsa) — BTK Inhibitor · Lymphoma
• Bendamustine (Treanda) — Lymphoma
• Brexucabtagene autoleucel (Tecartus) — Lymphoma