Eli Lilly's Jaypirca Outperforms J&J's Imbruvica in Leukemia Trial
Phase 3 study shows Lilly's next-generation cancer drug has a superior response rate and a better safety profile, posing a direct challenge to a blockbuster incumbent.
Eli Lilly and Co. (NYSE: LLY) has delivered a significant blow to a key oncology franchise at Johnson & Johnson (NYSE: JNJ), with its cancer drug Jaypirca demonstrating superiority over the blockbuster Imbruvica in a head-to-head clinical trial for the most common type of leukemia.
In a first-of-its-kind Phase 3 study, Jaypirca met its primary endpoint for treating chronic lymphocytic leukemia (CLL), showing a numerically superior overall response rate and a more favorable safety profile. The positive data further solidifies Eli Lilly’s position as a pharmaceutical powerhouse, adding a major win in oncology to its dominant franchise in diabetes and weight-loss treatments.
According to company-issued results, Jaypirca achieved an overall response rate of 87.0% compared to 78.5% for Imbruvica. Perhaps more critically for physicians and patients, the drug showed a significantly better cardiac safety profile. The rate of atrial fibrillation or flutter, a known side effect of this class of drugs, was just 2.4% for patients taking Jaypirca, substantially lower than the 13.5% rate observed in the Imbruvica arm.
“These data from BRUIN CLL-314 are both novel and clinically significant, demonstrating an improved overall response rate and a favorable trend in progression-free survival outcomes with pirtobrutinib compared to ibrutinib," said Dr. Jennifer A. Woyach, Director of the Division of Hematology at The Ohio State University Comprehensive Cancer Center and a lead investigator on the study.
The results position Jaypirca, a non-covalent BTK inhibitor, to aggressively compete for market share against Imbruvica, a covalent BTK inhibitor that has been a foundational treatment for CLL for years and has generated tens of billions in revenue for J&J and its partner AbbVie. Analysts project that Jaypirca could become the market leader among BTK inhibitors for this type of leukemia by 2032, potentially capturing nearly $3 billion in annual sales.
For Eli Lilly, a company whose market capitalization has surged to over $900 billion on the unprecedented success of its GLP-1 drugs Mounjaro and Zepbound, this oncology victory underscores the depth and diversification of its research and development pipeline. While the stock was trading down slightly at $993.10 in recent market activity, it remains near its 52-week high, reflecting broad investor confidence in the company's multi-faceted growth story.
The positive data follows the U.S. Food and Drug Administration's decision earlier in December to grant Jaypirca traditional approval for CLL patients who have previously been treated with other therapies. The results of this new head-to-head study could pave the way for an expanded approval as a first-line treatment, significantly increasing the drug's addressable market.
While progression-free survival data were not yet mature, the study noted a favorable trend for Jaypirca. In the subgroup of previously untreated patients, there was a 76% reduction in the risk of disease progression or death, a strong indicator of the drug's potential long-term benefit.
“These data... reinforce the medicine's potential to deliver meaningful benefit for people living with CLL or SLL across various disease settings," said Jacob Van Naarden, president of Lilly Oncology, in a statement. The full results of the BRUIN CLL-314 study were presented at the 2025 American Society of Hematology (ASH) Annual Meeting, a key event for showcasing advancements in cancer care.
The findings signal a potential changing of the guard in the lucrative market for CLL treatments, demonstrating Lilly's ability to innovate and challenge established standards of care across multiple, high-value therapeutic areas.