-CStone to acquire exclusive rights for development and commercialization 
outside South Korea for LCB71, an ROR1 antibody drug conjugate 
-Agreement adds to CStone's pipeline a potential first-in-class/best-in-class 
drug candidate with monotherapy and combination applications for a range of 
cancer indications 
-LCB71 has demonstrated preclinical efficacy and reduced toxicity

CStone Pharmaceuticals ("CStone", HKEX: 2616) announced today a licensing 
agreement with LegoChem Biosciences, Inc. ("LCB", KOSDAQ:141080), for the 
development and commercialization of LCB71, a potential 
first-in-class/best-in-class antibody drug conjugate ("ADC"). 

Under the agreement, CStone obtains the exclusive global right to lead 
development and commercialization of LCB71 outside the Republic of Korea. LCB 
will receive an upfront payment of US$10 million, and up to US$353.5 million in 
cumulative milestone payments, plus tiered royalties. 

Frank Jiang, M.D., Ph.D., Chairman and Chief Executive Officer 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 pipeline, and bolsters 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 pre-clinical ADC entering into Investigational New Drug ("IND") 
enabling studies. It targets ROR1 (receptor tyrosine kinase-like orphan 
receptor 1), a high-potential ADC target for multiple solid and hematological 
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 across several 
preclinical cancer models, which may translate into a wide therapeutic index 
for a range of solid and hematologic malignancies. Additionally, it utilizes 
site-specific conjugation for a precise drug antibody ratio. This supports 
serum half-life and improves its pharmacokinetic profile, and also enables 
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 oncology 
expertise, especially in global clinical development. This partnership puts 
LCB71 on a path to development and commercialization for patients worldwide. We 
are convinced that CStone is the right partner to secure the future of this 
important drug."

About CStone 

CStone is a biopharmaceutical company focused on developing and commercializing 
innovative immuno-oncology and precision medicines to address the unmet medical 
needs of cancer patients in China and worldwide. Established at the end of 
2015, CStone has assembled a world-class management team with extensive 
experience in innovative drug development, clinical research, and 
commercialization. With a strategic emphasis on immuno-oncology combination 
therapies, the Company has built an oncology-focused pipeline of 15 drug 
candidates, including five late-stage candidates at pivotal trials or 
registration stages. With an experienced team, a rich pipeline, a robust 
clinical development-driven business model and substantial funding, CStone's 
vision is to become globally recognized as a leading Chinese biopharmaceutical 
company by bringing innovative oncology therapies to cancer patients worldwide. 
For more information about CStone, please visit: www.cstonepharma.com. 

About LegoChem Biosciences

LegoChem Biosciences (LCB) is a clinical-stage biopharmaceutical company 
focusing on the development of next-generation novel therapeutics utilizing its 
proprietary medicinal drug discovery technology LegoChemistry and ADC platform 
technology ConjuAll.  Since its foundation in 2006, LCB has focused on the 
research and development of Antibody-Drug-Conjugates (ADCs), antibiotics, 
anti-fibrotic and anticancer therapeutics based on proprietary platform 
technologies. For more information on LCB's robust pipeline, visit 
www.legochembio.com.

Forward-looking Statement 

The forward-looking statements made in this article relate only to the events 
or information as of the date on which the statements are made in this article. 
Except as required by law, we undertake no obligation to update or revise 
publicly any forward-looking statements, whether as a result of new 
information, future events or otherwise, after the date on which the statements 
are made or to reflect the occurrence of unanticipated events. You should read 
this article completely and with the understanding that our actual future 
results or performance may be materially different from what we expect. In this 
article, statements of, or references to, our intentions or those of any of our 
Directors or our Company are made as of the date of this article. Any of these 
intentions may alter in light of future development.

CSTONE INVESTOR CONTACT 
ir@cstonepharma.com  

Source: CStone Pharmaceuticals