Daiichi Sankyo and Merck entered into a global development and commercialization agreement for three of Daiichi Sankyo’s DXd antibody-drug conjugate (ADC) candidates: patritumab deruxtecan (HER3-DXd), ifinatamab deruxtecan (I-DXd) and raludotatug deruxtecan (R-DXd). Daiichi Sankyo will be solely responsible for manufacturing and supply.
 
All three potentially first-in-class DXd ADCs are in various stages of clinical development for the treatment of multiple solid tumors both as monotherapy and/or in combination with other treatments. Patritumab deruxtecan was granted Breakthrough Therapy Designation by the U.S. FDA in December 2021 for the treatment of patients with EGFR-mutated locally advanced or metastatic non-small cell lung cancer (NSCLC) with disease progression. The submission of a biologics license application (BLA) in the U.S. is planned by the end of March 2024 for patritumab deruxtecan. 
 
Ifinatamab deruxtecan is currently being evaluated as monotherapy in a Phase 2 trial in patients with previously treated extensive-stage small cell lung cancer (SCLC). Raludotatug deruxtecan is currently being evaluated in a Phase 1 trial in patients with advanced ovarian cancer.
 
Each ADC leverages Daiichi’s DXd ADC technology to target and deliver a cytotoxic payload inside cancer cells that express a specific cell surface antigen.
 
Merck will pay $1.5 billion upfront for ifinatamab deruxtecan; $1.5 billion for patritumab deruxtecan, where $750 million is due upon execution and $750 million is due after 12 months; and $1.5 billion for raludotatug deruxtecan, where $750 million is due upon execution and $750 million is due after 24 months. Merck also will pay an additional $5.5 billion for each DXd ADC contingent upon the achievement of certain sales milestones. The total potential consideration across the three programs is as much as $22 billion.
 
Merck may opt out of the collaboration for patritumab deruxtecan and raludotatug deruxtecan. For raludotatug deruxtecan, Merck will be responsible for 75% of the first $2 billion of R&D expenses. Except as outlined above with respect to R&D expenses, the companies will equally share expenses and profits worldwide, except for Japan where Daiichi Sankyo retains exclusive rights and Merck receives a royalty based on sales.