Under the new partnership, MEI Pharma will amend its ongoing Phase 1b, dose-escalation trial (NCT02914938), which is already testing ME-401 alone and in combination with Rituxan (rituximab), to include a combination of ME-401 plus zanubrutinib.
ME-401 is a potent and selective inhibitor of the PI3K delta, a molecule whose levels are often increased in blood-related cancers and that plays a key role in promoting survival and proliferation of certain blood cancers.
Data presented in June at the ASCO 2018 meeting showed that 92% of patients responded a 60 mg dose of ME-401 (the lowest dose tested), including 42% complete responses. In CLL/SLL patients, all responded to the treatment, and half saw their tumors disappear.
Also, all 10 FL patients who progressed within two years of their first treatment with immunochemotherapy responded positively to ME-401.
Zanubrutinib inhibits BTK (Bruton’s tyrosine kinase), a key protein that helps B-cells stay alive and divide. By targeting BTK, zanubrutinib blocks survival signals in the cancerous B-cells, promoting their death and halting cancer progression.
Zanubrutinib is being tested in multiple B-cell cancers, alone and in combination with other products. In a Chinese Phase 1 trial including patients with relapsed or refractory Waldenström macroglobulinemia, chronic lymphocytic leukemia/small lymphocytic lymphoma, mantle cell lymphoma, marginal zone lymphoma, and follicular lymphoma, responses rates were very promising, ranging from 42% to 100%.
“We are excited to be working with BeiGene to explore the potential of ME-401 in combination with zanubrutinib,” Robert Mass, MD, chief medical officer of MEI Pharma, said in a press release.
“Combinatorial approaches to fighting difficult to treat cancers historically have proven to be important in the delivery of better treatments to patients, and we believe that the data observed to date for ME-401, with its unique pharmaceutical properties, and for zanubrutinib, support the evaluation of the combination for the treatment of patients with various B-cell malignancies,” Mass added.
“Zanubrutinib is a potentially differentiated BTK inhibitor that is being globally developed in a number of B-cell malignancies both as a monotherapy and in combination. We look forward to exploring this interesting combination in patients with B-cell malignancies,” said Jane Huang, MD, chief medical officer, hematology, at BeiGene.