FDA Grants accelerated approval to Pirtobrutinib for Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma with Prior Therapy

By: Dr. Anish Shah
Bronx-Lebanon Hospital; Bronx, NY

The U.S. Food and Drug Administration granted accelerated approval for Pirtobrutinib (Jaypirca) to be administered to adult patients diagnosed with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) on December 1, 2023. This approval applies to those patients who have undergone a minimum of two previous therapy lines, inclusive of a BTK inhibitor and a BCL2 inhibitor.

Study ID: NCT03740529

Approval was based on the BRUIN trial, an open-label, single-arm, multicohort, phase 1/2 study that included 108 patients with CLL/SL. The ongoing approval of this treatment might rely on proving its positive effects through a large-scale test called the BRUIN CLL-321 trial (NCT04666038). Pirtobrutinib was given orally at a dosage of 200 mg daily until disease progression or unacceptable toxicity.

Efficacy was established on overall response rate (ORR) and duration of response (DOR). The ORR was 72% (95% CI, 63%-80%), all of which were partial responses. The median time to response was 3.7 months (range, 1.7-27.9), and the median DOR was 12.2 months (95% CI, 9.3-14.7).

The medication led to side effects such as a new cancer, COVID-19, and a serious condition known as sepsis. Over half of the patients who took Pirtobrutinib experienced serious negative consequences. At least 5% of patients suffered from serious effects like lung infection, COVID-19, sepsis, and a condition characterized by fever and low white blood cell count. However, the study found that Pirtobrutinib could offer a novel method for targeting BTK, demonstrating clinical advantages for a significant number of CLL or SLL patients. These patients’ conditions had deteriorated after initial treatment with a BTK inhibitor and a BCL2 inhibitor.