Eli Lilly has shared positive top-line results from a head-to-head study of its non-covalent Bruton’s tyrosine kinase (BTK) inhibitor Jaypirca (pirtobrutinib) in patients with chronic lymphocytic leukaemia or small lymphocytic lymphoma (CLL/SLL).
The phase 3 BRUIN CLL-314 trial has been comparing the drug against Johnson & Johnson and AbbVie’s covalent BTK inhibitor Imbruvica (ibrutinib) in both treatment-naïve patients and those who had been previously treated but not with a BTK inhibitor.
The study achieved its primary endpoint of non-inferiority on overall response rate in both the pre-treated and intent-to-treat populations, with data showing a nominal superiority for Lilly’s drug.
Data on progression free survival (PFS), a key secondary endpoint, also demonstrated a trend favouring Jaypirca, but this was not mature at the time of the analysis.
A formal PFS analysis testing for superiority is planned, Lilly said, adding that “no detriment” was observed for overall survival and the overall safety profile of Jaypirca was similar to previously reported trials.
CLL is one of the most common types of leukaemia in adults, with approximately 23,690 cases of the disease expected to be diagnosed in the US this year.
CLL and SLL are essentially the same disease and treated in the same way, but are named depending on the location of the patients’ cancer cells. In CLL, the cancer cells are present in the blood and bone marrow, while in SLL they appear in the lymph nodes.
The BTK enzyme is a validated molecular target found across numerous B-cell leukaemias and lymphomas, including CLL and SLL.
Jaypirca has already been granted accelerated approval in the US to treat CLL/SLL patients who have received at least two prior lines of therapy, including a BTK inhibitor and a BCL-2 inhibitor, as well as a subset of mantle cell lymphoma patients.
Jacob Van Naarden, executive vice president and president of Lilly Oncology, said: “This data marks the second positive phase 3 study in the [Jaypirca development] programme, as we continue to build evidence supporting the potential role of [the drug] in treating people with CLL/SLL and hopefully enabling future regulatory approvals that allow physicians to use the medicine in various disease settings, whether treatment-naïve or BTK inhibitor-pretreated.”