NEW YORK – Daiichi Sankyo on Thursday announced it had entered into a collaboration with AstraZeneca to evaluate the combination of its experimental HER3-directed DXd antibody drug conjugate, patritumab deruxtecan (U3-1402) in combination with AstraZeneca's TKI osimertinib (Tagrisso) in a two-part Phase I clinical trial for the treatment of patients with advanced or metastatic EGFR-mutated non-small cell lung cancer (NSCLC).
For its part of the partnership, Daiichi Sankyo will sponsor and conduct the Phase I trial, which will assess the targeted drug combination as both a first- and second-line treatment for patients with advanced or metastatic NSCLC who have EGFR exon 19 deletions or L858R mutations. The first part of the clinical trial will assess the safety of the combination and identify the maximum tolerated dose, and the second part, which will be segmented into the two cohorts based on line of treatment, will assess the treatment's anti-tumor activity while further evaluating its safety profile. The first-line cohort of patients will receive both drugs in combination, while the second-line cohort of patients will be randomized to receive either patritumab deruxtecan as a monotherapy or the combination of patritumab deruxtecan and osimertinib. The trial, which will be conducted in North America, Europe, and Asia, will enroll up to 258 patients.
Patritumab deruxtecan consists of an anti-HER3 antibody attached to a topoisomerase I inhibitor payload and is designed to deliver a targeted dose of chemotherapy to NSCLC cells that express HER3 antigens on their surface — which has been reported to be the case for as many as 75 percent of patients with EGFR-mutated NSCLC. There is evidence that HER3 expression may be associated with resistance to TKIs, meaning that the combination of drugs could potentially allow patients to overcome resistance to osimertinib. Currently, there are no approved HER3-targeted therapies for any cancer type, and Daiichi Sankyo is also evaluating patritumab deruxtecan in two other early-phase studies, both as a standalone therapy for previously treated patients with advanced or metastatic NSCLC and as a treatment for patients with HER3-expressing metastatic breast cancer.
"Clinical and preclinical data, as well as biomarker expression and resistance mechanism research support the further evaluation of patritumab deruxtecan and Tagrisso as a treatment combination for patients with EGFR-mutated NSCLC who have progressed after treatment with a TKI, typically Tagrisso," Gilles Gallant, Daiichi Sankyo's senior vice president and global head of oncology development, said in a statement. "Daiichi Sankyo is pleased to begin this focused collaboration with AstraZeneca on this important aspect of patritumab deruxtecan development