Jaypirca: what changed in the evidence · Jaypirca · 2023 – 2026
What stayed the same across Jaypirca's approvals?
The drug's description and dose: a noncovalent BTK inhibitor at 200 mg once daily in every label. What changed in the label's warnings was a class-wide liver warning added in 2024.
EphemerisX Research · Published · 6 source documents · 1 min read
Short answer
The mechanism and the dose. Every label from January 2023 to October 2026 describes pirtobrutinib as a small-molecule, noncovalent inhibitor of BTK and recommends 200 mg once daily. The mantle cell lymphoma indication's accelerated-approval wording is also unchanged. A hepatotoxicity warning, applied to BTK inhibitors as a class, was added in 2024.
What the evidence shows
Mechanism, January 2023: Pirtobrutinib is a small molecule, noncovalent inhibitor of BTK
FDA · Jan 27, 2023 · p. 10; October 2026: Pirtobrutinib is a small molecule, noncovalent inhibitor of BTK
FDA · Oct 2, 2026 · p. 15. Lilly's filings call it non-covalent (reversible)
8-K · Feb 6, 2025.
Dose, in both labels: The recommended dosage of JAYPIRCA is 200 mg orally once daily until disease progression or unacceptable toxicity
FDA · Jan 27, 2023 · p. 3. The 2023 review noted significant limitations to determine if 200 mg daily is the optimal dosing regimen
FDA · Jan 27, 2023 · p. 72, and the December 2023 letter required a trial of at least two different dosages of pirtobrutinib not to exceed 200 mg once daily
FDA · Dec 1, 2023 · p. 4, which the 2025 letter lists as still open
FDA · Dec 3, 2025 · p. 3.
The warning added in 2024: Hepatotoxicity, including severe, life-threatening, and potentially fatal cases of drug-induced liver injury (DILI), has occurred in patients treated with Bruton tyrosine kinase inhibitors, including JAYPIRCA
FDA · Oct 2, 2026 · p. 5.
The mantle cell lymphoma indication, October 2026: This indication is approved under accelerated approval based on response rate
FDA · Oct 2, 2026 · p. 3. Back to the spine: What changed in the evidence behind Jaypirca's FDA approvals?
Follow the thread
- What uncertainty did the FDA's reviewers record when they approved Jaypirca in 2023?The 200 mg dose
- What evidence supported Jaypirca's accelerated approval in CLL/SLL?A trial of lower doses
- What evidence allowed the FDA to convert Jaypirca's CLL/SLL approval to traditional approval?A requirement “still open”
- Where does the confirmatory trial for Jaypirca's first indication stand?Unchanged accelerated wording
The documents, by date
The passages quoted
FDA-approved label, January 27, 2023 · page 3
The recommended dosage of JAYPIRCA is 200 mg orally once daily until disease progression or unacceptable toxicity.Open at the source →
FDA-approved label, January 27, 2023 · page 10
Pirtobrutinib is a small molecule, noncovalent inhibitor of BTK. BTK is a signaling protein of the B-cell antigen receptor (BCR) and cytokine receptor pathways. In B-cells, BTK signaling results in activation of pathways necessary for B-cell proliferation, trafficking, chemotaxis, and adhesion. Pirtobrutinib binds to wild type BTK and BTK harboring C481 mutations, leading to inhibition of BTK kinase activity.Open at the source →
FDA Multi-discipline Review, January 27, 2023 · page 72
the Applicant’s exposure-response analyses had significant limitations to determine if 200 mg daily is the optimal dosing regimenOpen at the source →
FDA approval letter, December 1, 2023 · page 4
4557-2 Conduct a randomized trial to characterize the safety and further assess the serious risks including infections, cytopenias, and hemorrhage, of at least two different dosages of pirtobrutinib not to exceed 200 mg once daily in patients with CLL or SLL.Open at the source →
Lilly Form 8-K, filed February 6, 2025
Positive Phase 3 results from the BRUIN CLL-321 trial evaluating pirtobrutinib, a non-covalent (reversible) Bruton's tyrosine kinase (BTK) inhibitor in adult patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) previously treated with a covalent BTK inhibitor;Open at the source →
FDA approval letter, December 3, 2025 · page 3
We have reviewed your submission and conclude that the above requirement was fulfilled. We remind you that there is postmarketing requirement listed in the December 1, 2023, approval letter that is still open.Open at the source →
FDA-approved label, October 2, 2026 · page 3
JAYPIRCA® is indicated for the treatment of adult patients with relapsed or refractory mantle cell lymphoma (MCL) after at least two lines of systemic therapy, including a BTK inhibitor. This indication is approved under accelerated approval based on response rate [see Clinical Studies (14.1)]. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.Open at the source →
FDA-approved label, October 2, 2026 · page 5
Hepatotoxicity, including severe, life-threatening, and potentially fatal cases of drug-induced liver injury (DILI), has occurred in patients treated with Bruton tyrosine kinase inhibitors, including JAYPIRCA.Open at the source →
FDA-approved label, October 2, 2026 · page 15
Pirtobrutinib is a small molecule, noncovalent inhibitor of BTK. BTK is a signaling protein of the B-cell antigen receptor (BCR) and cytokine receptor pathways. In B-cells, BTK signaling results in activation of pathways necessary for B-cell proliferation, trafficking, chemotaxis, and adhesion. Pirtobrutinib binds to wild type BTK and BTK harboring C481 mutations, leading to inhibition of BTK kinase activity.Open at the source →