The recent approval by the Food and Drug Administration (FDA) of Jaypirca (pirtobrutinib) for adults with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) who have received at least two prior lines of therapy, including a BTK inhibitor and a BCL-2 inhibitor, offers s necessary new treatment option for members of this patient population, as one expert explained.
“Once patients with CLL or SLL have progressed to covalent BTK inhibitors, such as (Imbruvica [ibrutinib]), (Calquence [acalabrutinib]) and (Brukinsa [zanubrutinib]) or BCL-2 inhibitors such as (Venclexta [venetoclax]), treatment options are limited and outcomes are generally poor,” Dr. Juan Alderuccio, clinical site disease group leader in the lymphoma section at Sylvester Comprehensive Cancer Center, part of UHealth – University of Miami Health System, told CURE.
“The approval of a non-covalent BTK inhibitor such as (Jaypirca [pirtobrutinib]) represents a meaningful advance and a much-needed new treatment option for these patients,” Alderuccio said. “This approval offers a new treatment option and a different approach to targeting the BTK pathway, providing clinical benefit for many patients with CLL or SLL.”
The approval was based on findings from the BRUIN trial, which included 108 patients with CLL or SLL who had been previously treated with at least two, and a median of five, lines of prior therapy, and 77% of those patients had discontinued their last BTK inhibitor due to refractory or progressive disease, according to the FDA.
Jaypirca, administered at 200 mg orally until disease progression or until unacceptable toxicity, elicited an overall response rate (ORR; patients whose disease responded partially or completely to treatment) of 72%, with a median duration of response of 12.2 months, according to the FDA, which also reported that all responses to treatment were partial — meaning none of the patients’ diseases disappeared completely.
“This drug is filling a gap in this specific population,” said Alderuccio.
Unmet needs remain, however, including the risk of Richter’s Transformation, also known as Richter’s Syndrome, an aggressive lymphoma that’s been shown to develop in some patients.
“All patients with CLL and SLL have risk of about 0.5% to 1% a year to transform to an aggressive lymphoma that’s called Richter’s Transformation,” Alderuccio said. “And unfortunately, this event is usually associated with poor outcomes. Emerging data has demonstrated that (Jaypirca) seems to provide promising activity (and) efficacy in this population, and also there is promising data when we combine (Jaypirca) with bi-specifics. Many of those studies are currently in progress.”
Earlier this year, Jaypirca was approved by the FDA for the treatment of patients with relapsed or refractory mantle cell lymphoma, an aggressive form of non-Hodgkin lymphoma.
Speaking at the recent CURE® Educated Patient® CLL Summit, Dr. Adam Kittai, an assistant professor at The James Cancer Center at The Ohio University Cancer Center, explained what distinguishes Jaypirca, a non-covalent BTK inhibitor.
“Covalent BTK inhibitors bind to the BTK protein (on cancer cells) in a very specific way,” Kittai explained. “(Jaypirca) is the next version of BTK inhibitor … it binds differently. This drug was designed to work specifically for patients who’ve already received those first-generation BTK inhibitors.”
Jaypirca, Kittai explained, is more selective in the way that it binds to the BTK molecule, and is less likely to interact with other nearby molecules and cause side effects.
Among the patients enrolled in BRUIN, the most common side effects experienced by at least 20% of participants included fatigue, bruising, cough, musculoskeletal pain, COVID-19, diarrhea, pneumonia, abdominal pain, dyspnea (labored breathing), hemorrhage, edema (swelling), nausea, pyrexia (fever) and headache, while grade 3 or 4 laboratory abnormalities experienced by more than 10% of patients included decreased neutrophil (a type of white blood cell) counts, anemia and decreased platelet counts, 32% of patients experienced serious infections and 10% had fatal infections, according to the FDA.
“With the prior BTK inhibitors, there was the risk of hypertension, bleeding, heart arrhythmias,” said Alderuccio. “With (Jaypirca) … the safety profile seems to appear more favorable compared to the prior BTK inhibitors.”
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