The US Food and Drug Administration approved pirtobrutinib (Jaypirca, Eli Lilly and Company) on October 2, 2026, for adult patients with previously untreated chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) with no known 17p deletion. The approval marks an expanded indication for pirtobrutinib, which had previously been authorized in the relapsed or refractory CLL/SLL setting.
Approval was based on results from the BRUIN CLL-313 trial, in which pirtobrutinib reduced the risk of disease progression or death by 80% compared with bendamustine plus rituximab in the first-line setting. Overall survival data were immature at the time of the primary analysis.
Key finding
In BRUIN CLL-313, pirtobrutinib demonstrated a hazard ratio of 0.20 (95% CI: 0.11, 0.37; p<0.0001) for progression-free survival versus bendamustine plus rituximab, with a median PFS not yet reached in the pirtobrutinib arm at a median follow-up of 28 months; however, overall survival data remained immature at the time of analysis.
Study Design
| Trial | BRUIN CLL-313 (NCT05023980) |
|---|---|
| Population | 282 adults with previously untreated CLL/SLL without deletion of chromosome 17p |
| Treatment | Pirtobrutinib 200 mg orally once daily until progression (n=141) vs. bendamustine plus a rituximab product for six cycles (n=141); randomized 1:1, open-label, active-controlled |
| Primary endpoint | Progression-free survival (PFS) as assessed by an independent review committee |
The trial was a randomized, open-label study with an estimated median follow-up for PFS of 28 months. The FDA used its Assessment Aid, a voluntary submission from the applicant, to facilitate its review; pirtobrutinib also received orphan drug designation for this indication.
Results and Safety
At the time of the primary PFS analysis, the median PFS was not estimable (95% CI: NE, NE) in the pirtobrutinib arm, compared with 33.5 months (95% CI: 32.7, NE) in the bendamustine-plus-rituximab arm. The hazard ratio was 0.20 (95% CI: 0.11, 0.37; p<0.0001). OS data were immature; the median OS was not reached in either arm, with a total of 13 deaths — three (2.1%) in the pirtobrutinib arm and 10 (7.1%) in the control arm. No response rate data were disclosed in the FDA’s approval communication.
The most common non-laboratory adverse reactions occurring in at least 20% of patients receiving pirtobrutinib were upper respiratory tract infections (27%), rash (22%), and COVID-19 (21%). The most common grade 3 or 4 laboratory abnormality was decreased neutrophil count. Serious adverse reactions occurred in 28% of patients in the pirtobrutinib arm.
The prescribing information carries warnings and precautions for infections, hemorrhage, cytopenias, cardiac arrhythmias, secondary primary malignancies, hepatotoxicity, and embryo-fetal toxicity. The recommended dose is 200 mg orally once daily, taken until disease progression or unacceptable toxicity.
Clinical Context
Pirtobrutinib is a non-covalent (reversible) BTK inhibitor, distinguishing it mechanistically from first-generation covalent BTK inhibitors such as ibrutinib and acalabrutinib that are already established in the frontline CLL/SLL setting. Its approval in the previously untreated population, although albeit restricted to patients without 17p deletion, adds a new first-line option and expands the drug’s labeled indications beyond the relapsed or refractory context.
Whether the observed PFS benefit translates into an overall survival advantage remains to be determined as follow-up matures. The trial’s exclusion of patients with 17p deletion also leaves open the question of pirtobrutinib’s role in that higher-risk subgroup in the frontline setting. Head-to-head comparisons with other approved frontline BTK inhibitors were not part of this trial design.
Sources
- US Food and Drug Administration. “FDA Approves Pirtobrutinib for Previously Untreated Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma.” Drug approval announcement. October 2, 2026. View source.
AI disclosure: This article was prepared with assistance from generative AI using the source material cited above. It was reviewed and edited by Brandon Twyford before publication.
