1cBio Licenses Preclinical PARP1 Inhibitor OC-3 to Lee's Pharm for Greater China and Southeast Asia in Deal Worth Up to $27 Million
核心洞察
1cBio (搜索) and Lee's Pharmaceutical Holdings (搜索) signed an exclusive licensing agreement covering development and commercialization of the preclinical PARP1 (搜索) inhibitor OC-3 in Greater China and parts of Southeast Asia.
The deal provides 1cBio (搜索) with up to US$27 million in upfront, development and sales milestone payments, plus royalties on future net sales of OC-3.
OC-3 is a PARP1 (搜索)-selective small molecule designed to spare PARP2 (搜索), which 1cBio (搜索) says may reduce hematologic toxicities seen with non-selective PARP inhibitors.
1cBio (搜索) and Lee's Pharmaceutical Holdings (搜索) Ltd. (HKEX: 00950) have entered an exclusive licensing agreement granting Lee's Pharm rights to develop, manufacture and commercialize 1cBio's lead PARP1 (搜索) inhibitor, OC-3, in mainland China, Hong Kong, Macau, Taiwan and certain Southeast Asian markets. The deal, announced Sept. 9, 2026, makes 1cBio eligible for up to US$27 million in upfront, development and potential sales milestone payments, as well as royalties on future net sales.
OC-3 is a next-generation, PARP1 (搜索)-selective small molecule that remains in preclinical development and has not yet entered clinical trials. It targets cancers with defects in DNA homologous recombination repair, including tumors carrying mutations in DNA repair genes such as BRCA1 (搜索), BRCA2 (搜索) or PALB2 (搜索) — predominantly prostate, ovarian, breast and pancreatic cancers. In preclinical models of cancers with this kind of DNA repair deficiency, OC-3 demonstrated potent anticancer activity, according to 1cBio (搜索).
Differentiation Through PARP2 Sparing
1cBio (搜索) describes OC-3 as a potential best-in-class PARP1 (搜索) inhibitor designed to spare PARP2 (搜索) at therapeutic exposures. The company said this selectivity may reduce the hematologic toxicities associated with non-selective PARP inhibitors. Lee's Pharm leadership framed the profile as a potential differentiator in both safety and efficacy.
"We believe that OC-3's PARP1 (搜索) inhibitor has the potential to become an important new treatment option for patients with cancer, with a differentiated profile that may offer meaningful improvements in both safety and efficacy," said Benjamin Li, Founder and Director of Lee's Pharm.
Division of Responsibilities and US Filing Plans
Under the agreement, Lee's Pharm's wholly-owned subsidiary, Lee's Pharmaceutical (HK) Limited, will be responsible for Good Laboratory Practice (GLP) 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 (搜索) 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 said the partnership will provide resources toward that filing. The near-term milestone for the program is completion of the GLP safety studies and manufacturing activities needed for Lee's Pharm to file for a clinical trial in its territory, while 1cBio separately advances toward a US IND submission.
"This agreement with Lee's Pharm provides 1cBio (搜索) a valued China-based drug development and commercialization partner for OC-3," said Andrew Protter, PhD, CEO of 1cBio. "With Lee's Pharm, 1cBio collaborates with a team that has a robust oncology group, strong manufacturing capabilities, and a proven ability to advance assets in various stages of development in Asia. This partnership will provide valuable resources as we work toward filing an IND in the U.S. and advancing OC-3 into clinical trials for patients with solid tumors."
A Familiar In-Licensing Template
The transaction 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 (搜索) valued at up to US$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 (搜索), indicating the company is building out an oncology portfolio through both in-licensing and internal development simultaneously.
Competitive Landscape in Selective PARP1 Inhibition
The PARP1 (搜索)-selective space is drawing significant investment. Eikon Therapeutics (搜索), which raised US$381 million in a February 2026 Nasdaq IPO, is already advancing two selective PARP1 inhibitors licensed from Impact Therapeutics (搜索) outside Greater China. EIK1003 and the CNS-penetrant EIK1004 (搜索) are both in Phase I/II development and, like OC-3, are designed to spare PARP2 (搜索) to potentially reduce hematologic toxicity. OC-3 remains the least advanced of these assets, with clinical entry still contingent on completion of GLP safety studies and manufacturing work.