Eli Lilly Moves to Expand Use of Blood Cancer Drug Jaypirca

Eli Lilly is seeking to broaden the application of its blood cancer medication, Jaypirca (pirtobrutinib), following promising results from a recent clinical trial. The BRUIN CLL-313 study indicates that Jaypirca could improve treatment outcomes for patients with chronic lymphocytic leukaemia (CLL) or small lymphocytic lymphoma (SLL) when used as a first-line therapy.

The trial demonstrated that Jaypirca, a reversible BTK inhibitor, significantly enhances progression-free survival when compared to standard chemoimmunotherapy (CIT) in previously untreated patients without 17p deletions. While overall survival (OS) data is not yet fully mature, indications suggest a favorable trend for the drug, although it has not reached statistical significance. Eli Lilly described the improvement over CIT, specifically with bendamustine plus rituximab, as “one of the most compelling effect sizes ever observed for a single agent BTK inhibitor in a front-line CLL study.”

Regulatory Approval and Market Performance

In March 2023, Lilly achieved a significant milestone by securing FDA approval for Jaypirca as a third-line treatment for CLL/SLL and mantle cell lymphoma (MCL). This approval was particularly noteworthy as the drug was designed to target patients who develop resistance to existing BTK inhibitors, which include AbbVie and Johnson & Johnson’s Imbruvica (ibrutinib), AstraZeneca’s Calquence (acalabrutinib), and BeiGene’s Brukinsa (zanubrutinib).

The market performance of Jaypirca has been steadily improving, with sales reaching $337 million last year and contributing $123 million in the second quarter of this year alone. This figure represents an impressive 85% increase in total prescription numbers compared to the same period in 2024. Despite this progress, Jaypirca still has a considerable way to go to rival its competitors. Calquence generated over $3.1 billion in sales last year, while Imbruvica, although in decline, still reported $3.4 billion. Brukinsa, which is also rapidly growing, achieved sales of $2 billion.

The results from the BRUIN CLL-313 trial will be combined with data from an earlier trial, BRUIN CLL-314, which found that Jaypirca was as effective as Imbruvica in patients who had not previously received treatment for CLL/SLL. This data will be part of a regulatory filing aimed at expanding the label for Jaypirca later this year.

Expert Insights on Potential Impact

Jacob Van Naarden, head of Lilly Oncology, commented on the findings, stating, “The results from BRUIN CLL-313 are striking and provocative, across both PFS and OS endpoints, further demonstrating the potential of pirtobrutinib to be a meaningful treatment option for people with untreated CLL/SLL.” He emphasized that the company is committed to building clinical evidence for the role of pirtobrutinib in various treatment settings, including those that are treatment-naïve, BTK inhibitor-naïve, and BTK inhibitor-exposed.

As Eli Lilly continues to develop Jaypirca’s clinical profile, the anticipated findings from the upcoming trials and the potential for expanded use could significantly impact treatment options for patients battling these challenging blood cancers.