Lee's Pharmaceutical Holdings (HKEX: 00950) has licensed exclusive rights to develop, manufacture, and commercialize OC-3, a preclinical selective PARP1 inhibitor, from San Francisco Bay Area-based 1cBio, Inc. for mainland China, Hong Kong, Macau, Taiwan, and certain Southeast Asian markets. Under the agreement, 1cBio said it stands to receive up to USD 27 million in upfront, development, and sales milestone payments, with royalties also included.
OC-3 is described by 1cBio as a next-generation, PARP1-selective small molecule targeting cancers with defects in DNA homologous recombination repair, including tumors carrying mutations in BRCA1, BRCA2, or PALB2. The company said preclinical models have demonstrated anticancer activity and that OC-3 is designed to spare PARP2 at therapeutic exposures, which 1cBio said may reduce the hematologic toxicities associated with non-selective PARP inhibitors. The asset has not yet entered clinical trials.
Lee's Pharm's wholly-owned subsidiary Lee's Pharmaceutical (HK) Limited will be responsible for good laboratory practice safety studies, manufacturing activities, and regulatory filings required for approval in the licensed territory. The agreement also includes a drug supply manufacturing arrangement between the parties. 1cBio retains the right to use data generated under the agreement to support its own planned US FDA investigational new drug (IND) application for OC-3, and the company said the partnership will provide resources toward that US filing.
The deal extends Lee's Pharm's established pattern of in-licensing Western-originated assets for Greater China and Southeast Asia development. The company has pursued a similar structure repeatedly, including an oncology license for TG02 in Greater China and Southeast Asia in 2015 and, more recently, an exclusive license and supply agreement with Ashlins Pharmaceuticals valued at up to USD 31 million, announced in July 2026. The OC-3 deal comes roughly six weeks after Lee's Pharm received NMPA acceptance of an IND application for its proprietary antibody-drug conjugate ZK2401, indicating the company is building out an oncology portfolio through both in-licensing and internal development simultaneously.