Eli Lilly and Co. (LLY) delivered some encouraging news on Sunday about its leukemia drug Jaypirca, which went head-to-head against Johnson & Johnson's (JNJ) established treatment Imbruvica. The Phase 3 BRUIN CLL-314 trial tested Jaypirca (pirtobrutinib) against Imbruvica (ibrutinib) in patients with chronic lymphocytic leukemia or small lymphocytic lymphoma who hadn't been treated before or had never received a BTK inhibitor.

Here's what matters: Jaypirca hit its primary goal of proving it's at least as good as Imbruvica. The overall response rate came in at 87.0% for Jaypirca versus 78.5% for Imbruvica in the intent-to-treat population. Not only did it clear the non-inferiority bar, but it actually showed numerically higher response rates across the board.

The progression-free survival data is still maturing, but the early trends look promising for Jaypirca. Among treatment-naïve patients—the group with the longest follow-up period—there was a 76% reduction in the risk of disease progression or death compared to Imbruvica. That's a pretty substantial difference if it holds up as more data comes in.

The trial tracked progression-free survival as a key secondary endpoint across different patient populations. The median follow-up times varied: 22.0 months for the overall intent-to-treat population, 18.4 months for relapsed/refractory patients, and 22.5 months for treatment-naïve patients. In every subgroup analyzed, the data trended in favor of Jaypirca over Imbruvica.

The safety story is straightforward. Jaypirca's safety profile in this trial matched what researchers have seen in previous studies, and the most common side effects were similar between both drugs. No major surprises on the safety front, which is exactly what you want to see.

The results were presented at the American Society of Hematology Annual Meeting and Exposition and published simultaneously in the Journal of Clinical Oncology.

For context, Imbruvica is a covalent BTK inhibitor that's been a standard treatment option for years. Jaypirca represents a non-covalent approach to targeting the same pathway, which could offer advantages in certain patient populations or treatment scenarios.

LLY Price Action: Eli Lilly shares were down 1.54% at $994.79 at the time of publication on Monday.