Suzhou, China, July 8, 2025 - CStone Pharmaceuticals (“CStone,” HKEX: 2616), an innovation-driven biopharmaceutical company focused on oncology, today announced an exclusive partnership with Istituto Gentili (“Gentili”), a leading European biopharmaceutical company with a century-long heritage in oncology, to commercialize sugemalimab across Western Europe and the UK.

Under the terms of the agreement, Gentili will receive exclusive commercialization rights for sugemalimab in 23 European countries - including 18 EEA countries (Austria, Belgium, Cyprus, Denmark, Finland, France, Germany, Greece , Ireland, Italy, Liechtenstein, Luxembourg, Malta, the Netherlands, Norway, Portugal, Spain, and Sweden) - as well as the United Kingdom, Andorra, Monaco, San Marino, and Vatican City.

CStone is eligible to receive up to US$192.5 million in total consideration, comprising an upfront payment and payments tied to regulatory and commercial milestones. Additionally, CStone will supply sugemalimab and recognize close to 50% of net sales from the licensed territories as revenue, while Gentili will lead all local regulatory and commercial operations in the covered regions.

Dr. Jason Yang, CEO, President of R&D, and Executive Director at CStone, stated:

“Sugemalimab is the first anti-PD-L1 monoclonal antibody approved in the EU and UK for use in combination with chemotherapy for the first-line treatment of stage IV non-small cell lung cancer (NSCLC), regardless of histology or PD-L1 expression. The European Medicines Agency (EMA) has also accepted a supplemental marketing application for Stage III NSCLC, which, if approved, will make sugemalimab the second PD-(L)1 therapy in Europe for this indication.

Gentili’s deep oncology expertise, established commercial infrastructure, and commitment to patient-centric innovation make them an ideal partner to accelerate access to sugemalimab across Europe, especially during this critical time, as the ongoing dynamic pricing discussions in the US create uncertainty around the global availability and affordability of US market-weighted immunotherapy drugs. Therefore, it is more critical than ever to broaden access to high-impact therapies like sugemalimab.

To date, we have secured four major regional partnerships covering more than 60 countries and territories across Europe, the Middle East, Africa, and Latin America. Our global commercialization launch is underway, and we are working closely with our partners to integrate resources and maximize both the clinical and commercial value of sugemalimab. Meanwhile, we continue to pursue new collaborations in Southeast Asia, Canada, and other key markets, while advancing regulatory filings for additional indications.”

Alessandro Del Bono, CEO of Istituto Gentili, commented:

“At Gentili, we are committed to transforming oncology care by delivering innovative, high-quality treatments to patients. We are proud to partner with CStone to introduce sugemalimab—a well clinically validated innovative immunotherapy—to patients across Europe and the UK. Its compelling clinical profile in stage IV NSCLC and potential future indication in stage III disease will help address significant unmet needs in the region.

Sugemalimab is highly complementary to our current pipeline and strategic focus. Through this collaboration, we aim to accelerate patient access by establishing a robust and efficient commercialization pathway. Together with CStone, we look forward to driving therapeutic innovation and improving outcomes for patients across our markets. This agreement is another important step in our development strategy aimed at extending our pipeline in oncology and expanding Gentili’s presence in Europe.”