Suzhou, China, August 14th, 2025 – CStone Pharmaceuticals (“CStone”, HKEX: 2616), an innovation-driven biopharmaceutical company focused on the research and development of anti-cancer therapies, today announced its 2025 interim results and recent business highlights.
Dr. Jason Yang, CEO, President of R&D, and Executive Director at CStone, remarked, “In the first half of 2025, CStone accelerated the development of its next-generation innovative products. Core Pipeline 2.0 assets progressed in clinical development at speed to explore their potential to reshape treatment paradigms. Lifecycle management for commercialized products advanced steadily and expanded our global reach extensively. Furthermore, as a key component of our strategic expansion into non-oncology therapeutic areas, we disclosed two novel bispecific antibody molecules for autoimmune and inflammatory diseases, opening up new long-term growth avenues. Looking ahead, CStone remains committed to driving the clinical advancement and value realization of our Pipeline 2.0 assets through sustained innovation, aiming to deliver more breakthrough therapies to patients worldwide while generating sustainable long-term returns for our investors.”
BUSINESS HIGHLIGHTS
For the six months ended June 30, 2025 and up to the date of this results announcement, we accelerated our global expansion strategy, advanced our differentiated pipeline, and strengthened our commercial footprint through strategic partnerships. Key achievements during this period include regulatory approvals, clinical advancements, and strategic collaborations, collectively reinforcing our position in developing innovative therapeutics.
Commercial Products
• CEJEMLY® (sugemalimab), anti-PD-L1 antibody
– Global expansion and regulatory approvals
Following sugemalimab’s approvals for stage IV non-small cell lung cancer (NSCLC) in the European Union (EU) and United Kingdom (U.K.) last year, we submitted a new indication application in March 2025 to the European Medicines Agency (EMA) for the treatment of patients with unresectable stage III NSCLC who have not progressed following concurrent or sequential platinum-based chemoradiotherapy(CRT). If approved, sugemalimab would address a critical unmet need in stage III NSCLC, where only one anti-PD-(L)1 antibody is currently approved in Europe.
– Global commercialization driven by strategic alliances
In January 2025, we entered into a partnership with SteinCares to commercialize sugemalimab across ten countries in Latin America (LATAM). This was followed by a partnership with Gentili in July 2025 to commercialize sugemalimab in 23 countries in Western Europe and the U.K. To date, four partnerships have been executed extending sugemalimab’s international footprint to over 60 countries around the world. Additional partnerships in Southeast Asia, Canada, and other markets are expected in the near future.
– Robust data reinforcing clinical impact
• Publications in top-tier journals: In February 2025, the results of the final progression-free survival (PFS) and overall survival (OS) for the GEMSTONE-303 study (for first-line gastric cancer/gastroesophageal junction cancer [GC/GEJC]) were published in JAMA (Journal of the American Medical Association). In June 2025, long-term survival data from the GEMSTONE-302 study (for first-line stage IV NSCLC) were published in The Lancet Oncology, marking the trial’s third publication in top-tier journals.
• Global guideline adoption: Sugemalimab has been incorporated into the Non-Oncogene-Addicted Metastatic NSCLC Living Guideline of the European Society for Medical Oncology (ESMO) in February 2025 and is recommended as a Level [I, A] first-line combination therapy for both squamous and non-squamous NSCLC.
• GAVRETO® (pralsetinib), rearranged during transfection (RET) inhibitor
– Localized production approved
In July 2025, the China NMPA approved the manufacturing localization application for GAVRETO® (pralsetinib, 100mg). Commencing in 2026, the Chinese market supply will transition gradually from imports to end to end domestic production, from active pharmaceutical ingredient to finished drug product, significantly enhancing cost efficiency and supply chain resilience.
– NRDL negotiation
In August 2025, pralsetinib passed the formality review for the 2025 NRDL negotiation.
• AYVAKIT® (avapritinib), KIT/PDGFRA inhibitor
– Domestic supply launch
Following the China NMPA approval for localization production of AYVAKIT® tablets (300 mg and 100 mg) in 2024, domestic supply of AYVAKIT® commenced in February 2025. This shift is projected to drive gross margin expansion.
Clinical Stage Core Assets
• CS5001, ROR1 ADC
– Global Phase Ib trial progress
The global multicenter clinical trial of CS5001 is actively enrolling patients across Australia, China and the United States of America (U.S.). Recruitment efforts are prioritizing combination therapy cohorts, including CS5001 in combination with R-CHOP (Rituximab + Cyclophosphamide + Hydroxydaunorubicin + Vincristine +Prednisone) for the first-line DLBCL, and CS5001 in combination with SoC for second-line DLBCL. No DLT was observed to date. Additionally, enrollment is ongoing for monotherapy cohorts targeting aggressive and indolent advanced lymphomas with potential to be expanded into a Phase II single-arm registrational study. CS5001 is also being studied both as a monotherapy and in combination with sugemalimab for advanced solid tumors, underscoring its clinical potential across oncological indications.
• CS2009, PD-1/VEGF/CTLA-4 trispecific antibody
– Global multicenter Phase I/II trial progress
The global multicenter Phase I/II study is rapidly enrolling patients in Australia and China, with planned expansion to the U.S. for Phase II enrollment. Phase Ia data including safety, pharmacokinetic (PK), pharmacodynamic (PD), and antitumor activity will be presented at ESMO Congress in October 2025.
– First-in-class (FIC)/best-in-class (BIC) potential and next-generation I/O backbone
The Phase Ia dose escalation study has evaluated five dose levels in patients with advanced and heavily pretreated solid tumors. Dose level 5 at 30 mg/kg, Q3W has just passed safety evaluation without identifying any DLT. The study is currently enrolling to establish a wide safety margin over potential recommended phase 2 dose (RP2D), while backfilling is ongoing for prior dose levels (1-30 mg/kg, Q3W). As of the date of this announcement, CS2009 is found to be well tolerated across all evaluated dose levels, with excellent PK profile supporting Q3W dosing, and with PD responses indicating both T cell activation and proliferation from PD-1 and CTLA-4 blockade and potent VEGFA neutralization. Anti-tumor activities have been observed from lower-dose cohorts in patients with “cold” tumors and PD-(L)1 pretreated tumors.
• Nofazinlimab, anti-PD-1 antibody
– Final analysis of CS1003-305
In July 2025, the final analysis of the global multicenter Phase III CS1003-305 study demonstrated a clinical compelling trend in OS for the nofazinlimab-lenvatinib combination compared to placebo-lenvatinib, indicating meaningful patient benefit despite not reaching statistical significance. In addition, clinically meaningful improvements in PFS and objective response rate (ORR) were achieved and no new safety signals were observed. We will engage with regulatory authorities to explore the registration pathway for this combination therapy.
Preclinical/IND (Investigational New Drug)-enabling Stage Programs and Proprietary ADC Platform
CStone’s preclinical pipeline compromises over nine promising candidates across multispecific antibodies, ADC etc. These programs focus on FIC/BIC profiles covering various therapeutic fields such as oncology, autoimmune and inflammatory diseases. We are dedicated to delivering clinical value through the development of these Pipeline 2.0 candidates, which will undergo international, multi-center clinical trials to maximize their global potential.
Our innovative in-house ADC technology platform features optimized proprietary linkers improving tumor-selective payload release. This platform supports multiple ADC products in Pipeline 2.0, including CS5007 (EGFR/HER3 bispecific ADC), CS5008(DLL3/SSTR2 bispecific ADC), CS5005 (SSTR2 ADC), CS5006 (ITGB4 ADC), CS5009 (B7H3/PD-L1 bispecific ADC), etc.
In May 2025, we presented preclinical data for CS2009 (PD-1/VEGF/CTLA-4 trispecific antibody), CS5007 (EGFR/HER3 bispecific ADC), CS2011 (EGFR/HER3 bispecific antibody), , CS5006 (ITGB4 ADC) and CS5005 (SSTR2 ADC) at the 2025 annual meeting of the American Association for Cancer Research (AACR).
In July 2025, we disclosed the targets of two autoimmune/inflammatory candidates, CS2013 (BAFF/ APRIL bispecific antibody) and CS2015 (OX40L/TSLP bispecific antibody).
Both have FIC/BIC potential, and IND-enabling studies with respect to both are expected to be initiated in the second half of 2025. These candidates reflect our strategic expansion into non-oncology therapeutic pipelines.
FUTURE AND OUTLOOK
Our mission is to deliver transformative therapies through scientific excellence and technological innovation, making high-quality treatments accessible worldwide to benefit patients and their families.
We reaffirm our commitment to advancing a robust and differentiated pipeline by prioritizing internal discovery capabilities and sustained R&D investments, while executing strategic partnerships to unlock the global value of our in-market products. Critical catalysts for the second half of 2025 include:
• Clinical milestones:
– Progress CS5001 (ROR1 ADC) and CS2009 (PD-1/VEGF/CTLA-4 trispecific antibody) towards pivotal trials and in parallel pursue global partnerships to expedite development.
– Advance early-stage candidates into clinical stages.
• Commercial excellence:
– Maximize the value of AYVAKIT® and GAVRETO® through strategic collaborations and potential transactions.
– Continue to accelerate ex-China commercialization of sugemalimab via regional partnerships.
• Innovation and technology:
– Strengthen proprietary platforms (e.g., ADC technology) to sustain pipeline growth.
– Present key clinical data at major conferences (e.g., ESMO, American Society of Hematology (ASH)).
FINANCIAL HIGHLIGHTS
International Financial Reporting Standards (IFRS) Measures:
• Revenue was RMB49.4 million for the six months ended June 30, 2025. The revenue is composed of RMB20.2 million in sales of pharmaceutical products (avapritinib, pralsetinib), RMB17.9 million in license fee income and RMB11.3 million in royalty income of sugemalimab. Sales of pralsetinib decreased substantially period-on-period, which is primarily due to price adjustments of pralsetinib in preparation for the NRDL negotiation and related one-off channel compensation. If included in NRDL, benefit from sales ramp up of pralsetinib in 2026 and beyond is expected to overweigh short-term negative impact on revenue. License fee income also decreased substantially period-on-period, primarily due to the fact that we received a strong contribution from a one-time milestone payment for sugemalimab gastric cancer approval in China in the first half of 2024. A major out licensing agreement with Gentili in July 2025 is expected to contribute to license fee income for the second half of 2025.
• Cost of revenue was RMB142.2 million for the six months ended June 30, 2025, primarily due to inventory write-downs charged to cost of revenue and cost associated with an early billing of pralsetinib supply under the Patient Assistance Program covering the period through the first half of 2026 to mitigate customs clearance risks amid trade uncertainties.
• Research and development expenses were RMB105.2 million for the six months ended June 30, 2025, primarily due to increased costs for clinical trials.
• Administrative expenses were RMB43.5 million for the six months ended June 30, 2025.
• Selling and marketing expenses were RMB35.7 million for the six months ended June 30, 2025.
• Loss for the period was RMB270.2 million for the six months ended June 30, 2025.
• Cash and cash equivalents and time deposits were RMB652.8 million as of June 30, 2025.
Non-International Financial Reporting Standards (Non-IFRS) Measures:
• Research and development expenses excluding the share-based payment expenses were RMB102.1 million for the six months ended June 30, 2025, primarily due to increased costs for clinical trials.
• Administrative and selling and marketing expenses excluding the share-based payment expenses were RMB77.2 million for the six months ended June 30, 2025.
• Loss for the period excluding the share-based payment expenses was RMB265.1 million for the six months ended June 30, 2025.
2025 Interim Results Conference Call
The Company will host its 2025 interim results earnings call at 10:00 a.m. (Beijing Time) on Friday August 15, 2025. Please register for the conference in advance through the link: https://s.comein.cn/jt4d1gyp.
About CStone
CStone (HKEX: 2616), established in late 2015, is an innovation-driven biopharmaceutical company focused on the research and development of anti-cancer therapies. Dedicated to addressing patients’ unmet medical needs in China and globally, the Company has made significant strides since its inception. To date, the Company has successfully launched 4 innovative drugs and secured approvals for 16 new drug applications covering 9 indications. The company’s pipeline is balanced by 16 promising candidates, featuring potentially FIC/BIC ADCs, multispecific antibodies, immunotherapies and precision medicines. CStone also prides itself on a management team with comprehensive experiences and capabilities that span the entire drug development spectrum, from preclinical and translational research to clinical development, drug manufacturing, business development, and commercialization.
For more information about CStone, please visit: www.cstonepharma.com.
IR contact: ir@cstonepharma.com
PR contact: pr@cstonepharma.com
Forward-looking statements
The forward-looking statements made in this article only relate to events or information as of the date when the statements are made in this article. Except as required by law, we undertake no obligation to update or publicly revise 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. All statements in this article are made on the date of publication of this article and may change due to future developments.
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