FDA approves new first-line pill for CLL and SLL

The FDA has approved Jaypirca (pirtobrutinib) as the first treatment option for adults with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) who lack a 17p deletion, a genetic marker tied to faster disease progression. This marks the first time a noncovalent Bruton tyrosine kinase (BTK) inhibitor has been approved for upfront therapy in these cancers, expanding its use beyond later-stage treatment.

CLL and SLL are slow-growing blood cancers originating in white blood cells. CLL primarily affects the blood, while SLL targets lymph nodes. A 17p deletion—missing genetic material on chromosome 17—appears in 5% to 8% of patients at diagnosis and indicates a higher progression risk.

The decision follows findings from the BRUIN CLL-313 trial, a global phase 3 study comparing Jaypirca to bendamustine plus Rituxan, a standard chemoimmunotherapy regimen. After a median follow-up of 28 months, Jaypirca reduced the risk of disease progression or death by 80%. The hazard ratio for progression-free survival (PFS) stood at 0.20, meaning patients on Jaypirca faced far lower cancer advancement during the study.

At analysis, median PFS for Jaypirca remained unreached, meaning over half of patients stayed progression-free, while the chemo group reached 33.5 months. Overall response rates were 94% for Jaypirca versus 81% for bendamustine plus Rituxan. Complete responses, where no detectable cancer remained, occurred in 13% of Jaypirca patients compared to 21% with the older treatment.

How Jaypirca’s Noncovalent Mechanism Differs

Unlike existing covalent BTK inhibitors such as Imbruvica (ibrutinib) or Brukinsa (zanubrutinib), Jaypirca operates as a noncovalent inhibitor. This distinct binding method may yield different safety or effectiveness outcomes, though no head-to-head trials have directly compared these approaches in untreated patients.

The BRUIN CLL-313 trial enrolled 282 adults with untreated CLL or SLL, randomly assigning them to Jaypirca or bendamustine plus Rituxan. Patients took Jaypirca as a 200-milligram daily pill until progression or unacceptable side effects, while the chemo group received standard dosing. The study prioritized progression-free survival, with secondary measures including response rates and safety.

Jaypirca patients stayed on treatment for a median of 32 months, with 92% continuing beyond two years. Dose reductions occurred in 3.6% of cases, and 4.3% permanently discontinued due to side effects. Serious adverse events affected 28%, including 5% with pneumonia. Common any-severity side effects included upper respiratory infections (27%), rash (22%), and COVID-19 (21%), with some cases progressing to pneumonia.

Blood test abnormalities improved over time for most patients, though 48% experienced lowered neutrophil counts and 30% showed raised bilirubin levels, signaling liver strain. Atrial fibrillation or flutter, irregular heart rhythms, occurred in 1.4% of patients. The trial excluded those with significant heart disease, including uncontrolled arrhythmias.

Broader Trials and Future Comparisons

Results were presented at the American Society of Hematology Annual Meeting and published in the Journal of Clinical Oncology. Jaypirca is now under evaluation in additional phase 3 trials, including BRUIN CLL-314, which directly compares it to Imbruvica.

Dr. Jennifer A. Woyach, director of hematology at The Ohio State University, stated that the approval allows oncologists to consider Jaypirca earlier in treatment. “Given the efficacy and tolerability of modern targeted therapies, coupled with factors like age or [other health conditions], many people diagnosed with CLL or SLL today may only receive one or two lines of therapy, making initial treatment choices critically important.”

The drug’s label includes warnings for infections, bleeding, low blood counts, heart rhythm disorders, secondary cancers, liver damage, and fetal harm. Its expanded approval reflects a broader shift in oncology toward targeted therapies that delay progression while reducing the harsh side effects of traditional chemotherapy.

Safety Profile and Reversible Binding

Researchers highlighted that Jaypirca’s noncovalent binding mechanism may explain its distinct safety profile. Unlike covalent inhibitors, which form permanent bonds with the BTK protein, Jaypirca’s reversible interaction allows for more predictable drug levels.

Study Design and Eligibility Restrictions in the BRUIN CLL-313 Trial

The BRUIN CLL-313 trial was conducted as an open-label study, meaning both patients and their treating physicians were aware of which treatment each participant received. This design differs from blinded trials, where participants or researchers may not know the assigned therapy to reduce bias.

The approval was based on data from the trial’s primary analysis, with additional evaluations ongoing in later-stage studies. The drug’s label now reflects these safety considerations, ensuring patients and providers are informed of possible risks before use.