MRK, Daiichi's ADC Drug Gets FDA Breakthrough Tag for Ovarian Cancer

Core Insights - Merck and Daiichi Sankyo received FDA Breakthrough Therapy Designation for R-DXd, aimed at treating platinum-resistant epithelial ovarian, primary peritoneal, or fallopian tube cancers expressing CDH6 in patients previously treated with Avastin [1][7][10] Group 1: FDA Breakthrough Therapy Designation - The FDA's Breakthrough Therapy Designation for R-DXd accelerates the development and review process for drugs addressing serious conditions, indicating potential significant improvement over existing treatments [2] - The designation was based on data from the ongoing phase II/III REJOICE-Ovarian01 study and a phase I study, with results expected to be presented at an upcoming medical conference [3][7] Group 2: Merck's Investment and Collaboration - Merck acquired global co-development and co-commercialization rights to R-DXd and two other ADCs from Daiichi Sankyo for a total potential consideration of up to $22 billion, while Daiichi Sankyo retains exclusive rights for development in Japan [5][8] - The collaboration has expanded to include MK-6070, a T-cell engager targeting DLL3, obtained from Harpoon Therapeutics [8] Group 3: ADC Market and Competition - ADCs are viewed as a disruptive innovation in the pharmaceutical industry, enhancing cancer treatment by delivering cytotoxic drugs directly to tumors [11] - Daiichi Sankyo is developing several ADCs across various cancers, including Enhertu, which is approved for multiple indications [12] - Pfizer has entered the ADC market through the acquisition of Seagen for $43 billion, adding four ADCs to its portfolio, which have significantly contributed to its revenues [13][14]