CStone Pharmaceuticals announced a licensing agreement with LegoChem Biosciences, Inc., for the development and marketing of LCB71, a possible first-class / best-in-class antibody drug conjugate ("ADC").

Under the agreement, CStone obtains the exclusive worldwide right to lead the development and commercialization of LCB71 outside the Republic of Korea. LCB will receive an initial payment of US $ 10 million, and up to US $ 353.5 million in accumulated milestone payments, plus basic entitlements.

Frank Jiang , MD, Ph.D., President and CEO of CStone, said: "We are very pleased to form this partnership with LCB, a leading ADC platform company, to obtain global rights to an asset with highly differentiated attributes in an exciting new field of oncology. The agreement adds the first ADC to CStone's development process, and reinforces our precision medicine franchise with a new modality. We look forward to harnessing its full potential and bringing it to patients around the world. "

LCB71 is a preclinical ADC entering New Drug Investigation (IND) allowing studies. It targets ROR1 (Receptor Tyrosine Kinase as Orphan Receptor 1), a high potential ADC target for multiple solid and hematologic malignancies. ROR1 protein expression is prevalent in a variety of cancers, including various forms of leukemia, non-Hodgkin lymphoma, and breast, lung, and ovarian cancers.

LCB71 has a proprietary tumor-activated pyrrolobenzodiazepine ("PBD") prodrug toxin that addresses the typical toxicity problem associated with traditional PBD payloads. It has demonstrated complete tumor inhibition in several preclinical cancer models, which can translate into a broad therapeutic index for a range of solid and hematologic malignancies. In addition, it uses site-specific conjugation for a precise ratio of drug antibodies. This supports the serum half-life and improves its pharmacokinetic profile, and also allows for homogeneous production and large-scale manufacturing.

Dr. Yong-Zu Kim, CEO and President of LCB, said: "We are pleased to have reached this agreement with CStone, which has demonstrated extensive experience in oncology, especially in global clinical development. This partnership puts LCB71 in a path to development and commercialization for patients around the world. We are convinced that CStone is the right partner to secure the future of this important drug. "