How effective is pitobrutinib treatment?

On December 1, 2023, the U.S. Food and Drug Administration has accelerated approval of pitobrutinib (Jaypirca, manufactured by Eli Lilly and Company) for the treatment of adult patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL). These patients must have received at least two prior therapies, including a BTK inhibitor and a BCL-2 inhibitor.

The efficacy of pittobrutinib was evaluated in theBRUIN (NCT03740529) trial. This is an open-label, international, single-arm, multi-short-term clinical trial involving 108 patients with CLL or SLL. These patients had received at least two prior therapies, including a BTK inhibitor and a BCL-2 inhibitor, and 77% of patients discontinued their last BTK inhibitor due to refractory or disease progression. In the trial, patients received 200 mg of pitobrutinib orally once daily until disease progression or unacceptable toxicity.

The trial's primary efficacy endpoints include overall response rate (ORR) and duration of response (DOR). As assessed by the independent review committee using 2018 iwCLL criteria, the ORR was 72% (95% CI: 63, 80), and the median DOR was 12.2 months (95% CI: 9.3, 14.7). It is important to note that all responses are partial.

Some common adverse reactions have been documented while using Pitoplutinib. In addition to laboratory terms, the most common adverse reactions (≥20%) included fatigue, bruising, cough, musculoskeletal pain, COVID-19, diarrhea, pneumonia, abdominal pain, dyspnea, bleeding, edema, nausea, pyrexia, and headache. In addition, more than 10% of patients developed grade 3 or 4 laboratory abnormalities, such as decreased neutrophil count, anemia, and decreased platelet count. Serious infections occurred in 32% of patients, of which 10% were fatal.

The prescribing information specifically mentions warnings and precautions regarding infection, bleeding, cytopenias, cardiac arrhythmias, and secondary primary malignancies. For patients taking Pitobrutinib, the recommended dose is 200 mg orally once daily until disease progression or toxicity becomes unacceptable.

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Reference: https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-pirtobrutinib-chronic-lymphocytic-leukemia-and-small-lymphocytic