Adults newly diagnosed with chronic lymphocytic leukemia or small lymphocytic lymphoma can now start treatment with pirtobrutinib, after the Food and Drug Administration approved Eli Lilly’s Jaypirca for previously untreated disease on Oct. 2, 2026. The first-line indication carries one built-in limit: it applies only to patients with no known 17p deletion, a chromosomal abnormality tied to resistance to chemotherapy.
The approval rests on BRUIN CLL-313, a 282-patient randomized trial in which the drug cut the risk of progression or death by 80 percent compared with bendamustine plus rituximab, a standard chemoimmunotherapy pairing. Median follow-up was about 28 months, and the FDA notice describes overall survival data as immature, so the label rests on delayed progression.
The Indication and Its 17p Limit
Under the FDA’s approval notice, Jaypirca is indicated for adults with previously untreated chronic lymphocytic leukemia or small lymphocytic lymphoma without a known 17p deletion, at 200 mg by mouth once daily until the disease progresses or toxicity becomes unacceptable. The notice records orphan drug designation and notes that the review used the FDA Assessment Aid, a voluntary submission from the applicant. Pirtobrutinib was already on the market: Lilly’s release says the December 2025 approval covered relapsed or refractory disease after a covalent BTK inhibitor, and a mantle cell lymphoma indication exists under accelerated approval.
Lilly describes pirtobrutinib as the first and only approved non-covalent BTK inhibitor, meaning it blocks the same enzyme as covalent BTK inhibitors but binds without forming a permanent chemical bond with it. Jacob Van Naarden of Lilly Oncology said the approval expands the drug’s potential “to reach more patients who may benefit.” The release also records that the National Comprehensive Cancer Network lists pirtobrutinib as a Category 2A option for treatment-naive patients without del(17p), and that BRUIN CLL-313 was published in the Journal of Clinical Oncology.
BRUIN CLL-313 Against Chemoimmunotherapy
BRUIN CLL-313 randomized 282 previously untreated patients without 17p deletion, 141 to pirtobrutinib and 141 to six cycles of bendamustine plus a rituximab product, according to the FDA. The primary endpoint was progression-free survival as judged by an independent review committee. At a median follow-up of about 28 months, median progression-free survival had not been reached in the pirtobrutinib arm and was 33.5 months with chemoimmunotherapy, for a hazard ratio of 0.20 (95 percent confidence interval 0.11 to 0.37, p below 0.0001).
AJMC’s coverage of the December 2025 American Society of Hematology presentation adds that the 24-month progression-free survival rate was 93.4 percent with pirtobrutinib and 70.7 percent with bendamustine plus rituximab. Wojciech Jurczak of the Maria Sklodowska-Curie National Research Institute of Oncology in Warsaw presented the data and said they “may be considered a potential new standard of care for patients with untreated CLL.” Lilly’s release lists the overall response rate at 94 percent versus 81 percent, with complete responses in 13 percent versus 21 percent, so the control arm produced more complete remissions even though progression came much sooner.
Overall survival data were immature at the primary analysis. Thirteen patients had died, three on pirtobrutinib (2.1 percent) and ten on the control regimen (7.1 percent), and median overall survival was not reached in either arm. OncLive notes that control-arm patients could cross over to pirtobrutinib after confirmed progression, and 18 did.
Safety Profile and the Missing Head-to-Head
The FDA lists upper respiratory tract infections (27 percent), rash (22 percent) and COVID-19 (21 percent) as the most common non-laboratory adverse reactions, with decreased neutrophil count the most frequent grade 3 or 4 laboratory abnormality. Serious adverse reactions occurred in 28 percent of pirtobrutinib patients. Warnings cover infections, hemorrhage, cytopenias, cardiac arrhythmias, second primary malignancies, hepatotoxicity and embryo-fetal toxicity. Lilly’s release reports pneumonia, at 5 percent, as the only serious reaction reaching 3 percent, dose reductions in 3.6 percent and permanent discontinuation in 4.3 percent; atrial fibrillation or flutter occurred in 1.4 percent.
Patients with significant cardiovascular disease were excluded from the trial, according to Lilly, which matters for reading the arrhythmia figures above. The comparator also matters. BRUIN CLL-313 tested pirtobrutinib against chemoimmunotherapy, and Lilly’s materials state that no trial data compare it directly with covalent BTK inhibitors, the older class of enzyme blockers. Jennifer Woyach of Ohio State University, quoted in the Lilly announcement, said doctors “can now consider pirtobrutinib for appropriate patients when initial therapy is needed.”
She also noted, per CancerNetwork’s report, that many patients diagnosed today “may only receive 1 or 2 lines of therapy,” which raises the stakes of the first choice. Overall survival remains the unresolved endpoint. AJMC reports a favorable trend at later follow-up (hazard ratio 0.257), but the primary analysis is the one the FDA acted on: the 13 deaths recorded at the primary analysis are too few to separate the arms.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
More from Morning Overview
- Lake Powell sank to a record 3,517 feet, nearing the level that stops Glen Canyon Dam’s turbines
- Seven of Earth’s nine planetary boundaries are breached, and all seven are worsening
- The NSA says three phone features should be off whenever you aren’t using them
- Hurricane Hunter radar shows four warning signs that a tropical cyclone is about to strengthen, a University of Miami study found
