Eli Lilly's Jaypirca Matches Imbruvica in Head-to-Head BTK Inhibitor Trial

Eli Lilly's newest Bruton's tyrosine kinase (BTK) inhibitor, Jaypirca, has demonstrated its efficacy in a phase 3 trial, going head-to-head against the established market leader, Imbruvica, developed by AbbVie and Johnson & Johnson. The trial results mark a significant milestone in the competitive landscape of BTK inhibitors for the treatment of chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL).

Trial Results and Clinical Implications

The phase 3 trial, codenamed Bruin CLL-314, met its primary endpoint in patients with CLL or SLL who were either newly diagnosed or had never received BTK inhibitors. Jaypirca matched Imbruvica in overall response rate (ORR) for both subpopulations in the study, with data suggesting a nominal superiority for Jaypirca, although this was not part of the trial's statistical plan.

While progression-free survival (PFS) data were not yet mature, Lilly reported that the trends favored Jaypirca. The company plans to conduct a formal PFS analysis in the future, aiming to demonstrate superiority over Imbruvica.

Jacob Van Naarden, Lilly's oncology chief, emphasized the ambitious nature of Jaypirca's development program, stating, "We launched the [Jaypirca] randomized development program with an ambitious suite of clinical trials, including head-to-head studies against modern standards of care and examinations of patient populations that reflect real world use, such as BTK inhibitor-pretreated patients."

Market Position and Future Prospects

Jaypirca, which gained accelerated FDA approval in 2023 for CLL, SLL, and mantle cell lymphoma after at least two prior lines of therapy, stands out as a non-covalent, or reversible, BTK inhibitor. This unique characteristic allows it to be used after treatment with other BTK inhibitors in the class, including Imbruvica, AstraZeneca's Calquence, and BeiGene's Brukinsa.

In 2024, Jaypirca generated sales of $337 million, a promising start for the newest entrant in the BTK inhibitor market. However, it still trails behind its competitors, with Calquence reaching $3.1 billion in sales, Brukinsa at $2.6 billion, and the market leader Imbruvica generating $6.4 billion in the same year.

Lilly is awaiting results from another trial, Bruin CLL-313, which compares Jaypirca to chemoimmunotherapy in treatment-naïve CLL/SLL patients. The outcomes of this study, expected later this year, will be crucial for Lilly's plans to seek global approvals for Jaypirca in these indications.