Avapritinib

CS2009 Achieved Key Clinical Validations for Efficacy and Safety As of August 2026, updated data further confirmed the favorable safety profile of CS2009 and demonstrated strengthened efficacy across multiple key cohorts compared with the data presented at ASCO in May 2026. With expanded patient enrollment and longer follow-up, improvements were observed in both the objective response rate (ORR) and duration of response (DOR): Compelling monotherapy efficacy in first-line non-small cell lung cancer (NSCLC) At the 30 mg/kg dose level, CS2009 achieved an ORR of 100% and a disease control rate (DCR) of 100% in patients with PD-L1 TPS ≥50%. In the broader PD‑L1 TPS ≥1% population, the ORR was 70.8% and DCR was 91.7%. Monotherapy efficacy in Immunotherapy (IO)-pretreated NSCLC and IO-nonresponsive "cold tumors" further validates CTLA-4 activity and efficacy In second-line NSCLC patients (all previously treated with IO plus chemotherapy), CS2009 monotherapy (30 mg/kg dose level) yielded an ORR of 38.5% and a DCR of 84.6%; In patients with heavily pretreated metastatic colorectal cancer (mCRC), CS2009 monotherapy (30 mg/kg dose level) achieved an ORR of 20% and a DCR of 93.3%; In patients with heavily pretreated soft tissue sarcoma (STS) and non-clear cell renal cell carcinoma (nccRCC), CS2009 monotherapy delivered ORR of 38.5% and 42.9%, respectively. CStone will present additional more mature Phase I/II clinical data for CS2009 in patients with advanced NSCLC and mCRC via two rapid oral presentations at ESMO 2026 in October. The Company also expects to reach consensus with global regulatory authorities including the U.S. Food and Drug Administration (FDA) and the Center for Drug Evaluation (CDE) of China National Medical Products Administration (NMPA), on the global Phase III registrational trial protocol in the fourth quarter of 2026. Pralsetinib Delivers Strong Sales Growth Following its effective inclusion in the National Reimbursement Drug List (NRDL) on January 1, 2026, pralsetinib's in-market sales volume increased by almost 500% year-over-year in the seven‑month period ending July 2026. Solid Cash Position As of June 30, 2026, cash and cash equivalents and time deposits totaled RMB1,560.2 million. SUZHOU, China, Aug. 27, 2026 /PRNewswire/ -- CStone Pharmaceuticals ("CStone," HKEX: 2616), an innovation-driven biopharmaceutical company focused on the research and development of therapies for oncology, immunology, inflammation, and other key disease areas, today announced its 2026 interim results and recent business highlights. Dr. Jason Yang, CEO, President of R&D, and Executive Director at CStone, commented, "In the first half of 2026, CStone entered a pivotal stage of transition from innovation-driven accumulation to global value realization. Our lead asset, CS2009, continues to advance rapidly through global clinical development. To date, we have accumulated clinical data from more than 300 patients, consistently demonstrating three key clinical validations: first, proof of safety; second, multidimensional confirmation of CTLA‑4 target activity and efficacy, evidenced by pharmacodynamic biomarkers and clinical activity in "cold tumors" and IO‑pretreated NSCLC; and third, broad‑spectrum and highly competitive antitumor efficacy across multiple tumor types. The most recent data show that CS2009's antitumor activity continues to deepen and strengthen with longer follow-up, exhibiting particularly competitive efficacy and a well-tolerated safety profile in key patient populations, including NSCLC and mCRC. These robust data provide strong support for the upcoming global Phase III registrational trials. We look forward to presenting additional more mature clinical data on CS2009 in oral presentations at the ESMO Congress this October. Beyond CS2009, other Pipeline 2.0 candidates are also progressing steadily toward clinical stage. CS5007, built on our proprietary ADC platform, has initiated a global Phase I clinical trial in both China and Australia. In addition, more than ten early-stage programs spanning next-generation ADCs, immunology & inflammation and other areas are advancing smoothly. The successive entry of these differentiated innovative assets into clinical development will serve as a critical driver for the Company's sustained growth and global expansion. On the commercial front, our three key products, sugemalimab, pralsetinib, and avapritinib, continued to achieve breakthroughs across domestic and international markets, contributing significant momentum to revenue growth. Notably, following pralsetinib's first-time inclusion in the NRDL earlier this year, its in-market sales volume increased by almost 500% year-over-year during the first seven months of 2026, making it the primary driver of the Company's revenue growth in the first half of 2026. Looking ahead, CStone will focus on advancing the clinical value of its Pipeline 2.0 assets and actively pursue global partnerships to accelerate their development. Concurrently, the Company will continue to maximize the commercial potential of its marketed products through strategic partnerships and resource integration. Our goal is to foster a sustainable growth model where R&D and commercialization reinforce each other, creating a virtuous cycle between innovation and business operations." Business Highlights For the six months ended June 30, 2026 and up to the date of this results announcement, CStone made significant progress across both its proprietary Pipeline 2.0 portfolio and its commercial franchise, advancing the Company's strategy to build a fully integrated, globally competitive biopharmaceutical company. Clinical Stage Core Asset CS2009, PD-1/VEGF/CTLA-4 trispecific antibody Accelerating global clinical development toward Phase III registrational trials by year end The ongoing global Phase I/II trial has enrolled more than 300 patients across China and Australia, with U.S. Investigational New Drug (IND) clearance obtained in February 2026. CStone plans to initiate the first wave of global Phase III multi-regional clinical trials (MRCTs) for CS2009 by the end of 2026. Planned registrational studies include first-line non-small cell lung cancer (NSCLC) in combination with chemotherapy (versus pembrolizumab plus chemotherapy), and first-line mCRC in combination with chemotherapy (versus bevacizumab plus chemotherapy), with additional registrational studies planned for 2027 and following years. CS2009 validates its potential as a next-generation I/O backbone At the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, CStone presented comprehensive Phase I/II data from the ongoing global multicenter trial. As of the data cutoff date of August 2026, updated monotherapy efficacy data from the ongoing global Phase I/II trial of CS2009, reflecting a longer follow-up and larger sample size than the ASCO 2026 presentation continued to demonstrate robust and deepening antitumor activity across multiple tumor types. Three important key clinical validations are achieved from over 300 patient data: Proof of safety Across all dose levels, no dose-limiting toxicities (DLTs) were observed, and the maximum tolerated dose (MTD) was not reached. In the ASCO 2026, the incidence of Grade ­3 treatment-related adverse events (TRAEs) and immune-related adverse events (irAEs) were 24.6% and 12.7%, respectively. Notably, the incidence of Grade ­3 VEGF-related TRAEs was only 5.1%. No excessive toxicities typically associated with CTLA-4/PD-(L)1 combinations were observed. As of August 2026, the safety profile of CS2009 remained consistent with that presented at the 2026 ASCO Annual Meeting, with no new safety signals identified. Proof of CTLA-4 activities and efficacy Dose-dependent upregulation of ICOS on CD4+ T cells was observed as a pharmacodynamic biomarker of CTLA-4 blockade. Activity was also seen in "cold tumor" not sensitive to PD-(L)1 mAb: Later-line monotherapy for mCRC (30 mg/kg): the objective response rate (ORR) was 20.0% (3/15) and the disease control rate (DCR) was 93.3% (14/15). Later-line monotherapy for soft-tissue sarcoma (STS): the ORR was 38.5% (5/13) and the DCR was 69.2% (9/13). Later-line monotherapy for non-clear cell renal cell carcinoma (nccRCC): the ORR was 42.9% (3/7) and the DCR was 100.0% (7/7). Promising anti-tumor activity in later-line post immuno-oncology (IO) NSCLC monotherapy: ORR was 23.8% (5/21), DCR was 61.9% (13/21). Among patients who had previously received immunotherapy plus platinum-based chemotherapy (n=13), ORR was 38.5% (5/13) and DCR was 84.6% (11/13). Proof of broad efficacy Monotherapy and chemo-combination activity in first-line and later-line NSCLC: First-line NSCLC monotherapy (PD-L1 tumor proportion score [TPS]­ ≥1%; enrollment completed): ORR of 61.7% (29/47) and DCR of 93.6% (44/47), including ORR of 70.8% (17/24), DCR 91.7% (22/24) in patients treated at 30 mg/kg; in the PD-L1 TPS ≥­50% group (n=24), ORR was 83.3% (20/24) and DCR was 95.8% (23/24) (versus ORR of 81.3% [13/16] at the 2026 ASCO cutoff), including ORR of 100.0% (11/11) and DCR of 100.0% (11/11) in patients treated at 30 mg/kg. After median follow up of 6 months, median progression-free survival (PFS) and DOR have not been reached. Second-line or later NSCLC monotherapy (30 mg/kg): ORR of 28.0% (7/25) and DCR of 60.0% (15/25), with a 6-month DOR rate of 83.3% (versus ORR of 24.0% and a 6-month DOR rate of 80.0% at the 2026 ASCO cutoff). Across all evaluated dose levels (n=54), ORR was 16.7% (9/54) and DCR was 68.5% (37/54), with a 6-month DOR rate of 87.5% (versus 85.7% at the 2026 ASCO cutoff). Later-line NSCLC (second/third-line combination therapy, n=6): ORR of 66.7% (4/6), DCR of 100.0% (6/6). Data are as of the 2026 ASCO data cutoff and will be updated at ESMO 2026. First-line squamous NSCLC combination therapy (PD-L1-low/negative, TPS ≤5%, n=8): ORR of 75.0% (6/8), DCR of 100.0% (8/8); notably, the ORR reached 100.0% (4/4) in the PD-L1-negative subgroup. Data are as of the ASCO 2026 data cutoff and will be updated at ESMO 2026. Robust Chemo-combo efficacy in the first-line mCRC, mostly proficient mismatch repair or microsatellite stable (pMMR/MSS): First-line mCRC (with XELOX, n=6): ORR of 66.7% (4/6), DCR of 100.0% (6/6). Data as of 2026 ASCO cutoff, will be updated at ESMO 2026. Promising monotherapy activity observed in metastatic castration-resistant prostate cancer (mCRPC), ovarian cancer, triple-negative breast cancer, gastric cancer, esophageal cancer, as well as STS and nccRCC. Upcoming two oral presentations of CS2009 at ESMO 2026 The clinical research results of CS2009 have been accepted for two Rapid Oral presentations at the 2026 European Society for Medical Oncology (ESMO) Congress. The presentations will feature Phase I/II clinical data of CS2009 in patients with advanced NSCLC and mCRC. Other Clinical Stage Asset CS5007, EGFR/HER3 ADC Global Phase I trial initiated in China and Australia The Company initiated the Phase I first-in-human study in June 2026. This trial consists of dose-escalation and dose-expansion cohorts evaluating CS5007 as a monotherapy in patients with advanced solid tumors, and will be conducted concurrently in Australia and China. CStone presented preclinical data for CS5007 at the 2026 American Association for Cancer Research (AACR) Annual Meeting, further supporting its broad-spectrum anti-tumor potential. Commercial Products CEJEMLY ® (sugemalimab), anti-PD-L1 antibody Global regulatory and scientific recognition Following the initial marketing authorizations of sugemalimab in the European Union (EU) and the United Kingdom (U.K.) for Stage IV NSCLC, sugemalimab received additional approvals in the EU in November 2025 and subsequently in the U.K. in February 2026 as monotherapy for adults with unresectable Stage III NSCLC whose disease has not progressed following platinum-based chemoradiotherapy (CRT). Meanwhile, marketing authorization applications for sugemalimab have either been approved or are under active review in nearly 30 countries worldwide. In March 2026, CEJEMLY® (sugemalimab) was included in the ESMO Early and Locally Advanced NSCLC Living Guideline. Sugemalimab received a Level [I, A] recommendation for consolidation therapy in patients with unresectable Stage III NSCLC who have not progressed after concurrent or sequential chemoradiotherapy. Secured fifth international commercial partnership In June 2026, CStone entered into an exclusive commercialization agreement with Arrotex Pharmaceuticals Pty Ltd (Arrotex), Australia's largest privately owned pharmaceutical company with established oncology commercialization capabilities and distribution infrastructure across Australia and New Zealand. This milestone expands sugemalimab's global commercialization network to five strategic partnerships, covering more than 60 countries and regions across Europe, the Middle East and Africa, Latin America, and Oceania. Pralsetinib capsules, RET inhibitor NRDL inclusion and accelerated commercial growth Following the inclusion of pralsetinib capsules (100 mg) in China's NRDL in late 2025, effective January 1, 2026, patient access has improved significantly. In the seven‑month period ending July  2026, pralsetinib's in-market sales volume increased by almost 500% year-over-year. Localized manufacturing approval supporting commercial scalability Following the approval by China's NMPA of the manufacturing localization application for pralsetinib capsules (100 mg), the first batch of locally-manufactured pralsetinib was released in China in 2026. Preclinical/IND-enabling Stage Programs A balanced, differentiated early-stage portfolio spanning oncology and immunology/inflammation CStone's preclinical Pipeline 2.0 comprises innovative candidates across multispecific antibodies, ADCs and other next-generation modalities, with potential first-in-class (FIC) or best-in-class (BIC) opportunities spanning oncology, immunology, inflammation and other high-value therapeutic areas. The Company's proprietary ADC platform incorporates optimized linker technologies designed to enable tumor-selective payload release and supports multiple Pipeline 2.0 ADC candidates, including CS5007 (EGFR and HER3 bispecific ADC), CS5006 (ITGB4 ADC), CS5008 (DLL3 and SSTR2 bispecific ADC), etc. The Company is also exploring next-generation ADC technologies, including dual-payload ADCs (e.g., CS5009, a B7H3/PD-L1 bispecific dual-payload ADC, and CS5010, a HER2-targeting dual-payload ADC) and novel-payload ADCs (e.g., CS5012, a HER2-targeting novel-payload ADC). In April 2026, CStone presented preclinical data for CS5007, CS5006 and CS5008 at the 2026 AACR Annual Meeting, highlighting the breadth and differentiation of its next-generation ADC pipeline. Beyond oncology, CStone has expanded Pipeline 2.0 into immunology and inflammation by leveraging its proprietary multispecific antibody platform. The Company has developed CS2015 (OX40L/TSLP bispecific antibody) targeting Type 2 inflammatory diseases, CS2013 (BAFF/APRIL bispecific antibody) targeting B cell-mediated autoimmune diseases, CS2016 (TL1A/α4β7 bispecific antibody), and CS1016 (PD-1 agonist antibody). 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. Key catalysts for the second half of 2026 include: Clinical milestones Accelerate global development of CS2009 by advancing interactions with global regulatory authorities, including the U.S. FDA and the CDE of NMPA, on Phase III registrational trial design, with the first wave of global Phase III MRCTs planned to be initiated by the end of 2026, while continuing to pursue global partnerships. Advance clinical development of CS5007 (EGFR/HER3 bispecific ADC), CS5006 (ITGB4 ADC), CS5008 (SSTR2/DLL3 ADC) and other early-stage candidates. Innovation and technology Further strengthen proprietary technology platforms, including multi-specific antibody and next-generation ADC technologies, to support sustained expansion of the preclinical pipeline. Present key clinical data, including updated CS2009 data, at major international scientific conferences, including two Rapid Oral presentations of CS2009 Phase I/II data at the 2026 ESMO Congress. Financial Highlights International Financial Reporting Standards (IFRS) Measures: Revenue was RMB205.1 million for the six months ended June 30, 2026. The revenue is composed of RMB183.2 million from sales of pharmaceutical products (avapritinib, pralsetinib and sugemalimab), RMB6.9 million from license fee income and RMB15.0 million from royalty income of sugemalimab. The substantial revenue growth was primarily driven by a significant increase in sales of pharmaceutical products, particularly pralsetinib, following its successful inclusion in the NRDL effective from January 2026, which led to a marked sales ramp-up. Cost of revenue was RMB110.9 million for the six months ended June 30, 2026. Research and development expenses were RMB205.5 million for the six months ended June 30, 2026, primarily due to increased costs for clinical trials. Administrative expenses were RMB51.3 million for the six months ended June 30, 2026. Selling and marketing expenses were RMB73.1 million for the six months ended June 30,2026. Loss for the period was RMB252.3 million for the six months ended June 30, 2026. Cash and cash equivalents and time deposits were RMB1,560.2 million as of June 30, 2026. Non-International Financial Reporting Standards (Non-IFRS) Measures: Research and development expenses excluding the share-based payment expenses were RMB193.4 million for the six months ended June 30, 2026, primarily due to increased costs for clinical trials. Administrative and selling and marketing expenses excluding the share-based payment expenses were RMB115.2 million for the six months ended June 30, 2026. Loss for the period excluding the share-based payment expenses was RMB230.9 million for the six months ended June 30, 2026. 2026 Interim Results Conference Call The Company will host its 2026 Interim results earnings call at 9:00 a.m. (Beijing Time) on Friday August 28, 2026. Please register for the conference in advance through the link: . About CStone CStone (HKEX: 2616), established in late 2015, is an innovation-driven biopharmaceutical company focused on the research and development of therapies for oncology, immunology, inflammation, and other key disease areas. 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 21 new drug applications covering 9 indications. The company's pipeline is balanced by 13 promising innovative candidates, featuring antibody-drug conjugates (ADCs), mono-/multi-specific 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: . 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. Disclaimer: only for communication and scientific use by medical and health professionals, it is not intended for promotional purposes. SOURCE CStone Pharmaceuticals 21% more press release views with Request a Demo

Cancer treatments often show early promise: tumors shrink and symptoms ease. But in many cases, the disease comes roaring back, driven by treatment-resistant cells. Part of what makes cancer so difficult to cure is that cells within a tumor are not cookie-cutter – they vary widely. Cancer cells within a tumor exist in multiple distinct malignant states, a property called “heterogeneity.” These states can also switch into one another, a property called “plasticity” — like a phone moving between airplane mode, power-saving mode, or full-performance mode. The cells share the same lineage and DNA, yet may develop into different states depending on which regulatory proteins are active in each cell, much like the normal cells in our body can have widely different states and yet carry the same DNA. Drugs used to treat a tumor are often effective only for a few of the specific states, so cells in other states remain and repopulate, making the tumor difficult to eradicate. Researchers at Biohub and collaborators from Columbia University and other institutions have developed a novel AI-based system to model how individual cells within a tumor behave and interact with drugs. The work, published in a pair of papers in Nature Genetics, supports a new hypothesis the team calls “cancer quantum biology” — that tumors of the same type have virtually identical sets of cell states across patients, and that those states interact in ways that defeat treatment. In the pancreatic cancer study, the team showed that cancer cell states can spontaneously reprogram themselves into one another, allowing tumors to evade drugs targeting any single state. In the Diffuse Midline Glioma (DMG) study, the team went further: using AI to predict drugs that target each individual state, validating those predictions experimentally, and showing that drug combinations targeting multiple states simultaneously produced synergistic effects, doubling the survival achieved by individual drugs. The method worked across two difficult-to-treat cancers: pancreatic ductal adenocarcinoma, the most common type of pancreatic cancer, and DMG, a rare brain tumor that occurs most frequently in children between the ages of five and 10. “These tumors often kill the patient within nine months,” says study co-author Andrea Califano, head of Biohub, New York. “There is a desperate need for new ways to target these malignancies.” The work, published in a pair of papers in Nature Genetics (April 2026 and August 2026), represents the first time researchers have successfully shown that cancer cell states and their vulnerabilities, known as “Master Regulators,” are ultraconserved across patients and predicted drugs that target them in each of the coexisting cancer cell states, leading to effective combination therapies. A central Biohub goal is understanding how to engineer immune cells to detect cancer as it arises, and to precisely target diseased cells as early as possible. Tumors themselves are exceptional immune-cell engineers, leveraging various cell states to create microenvironments that ward off immune attacks. By mapping the regulatory proteins that govern these cell states, the new research brings the field closer to this goal — and the authors had previously shown that targeting the Master Regulators of a tumor greatly improves response to immunotherapy. First, the researchers needed to map how many and what types of cell states were present in each form of cancer. They did this by tracking which Master Regulator proteins governed the state of each single cell. Using single-cell RNA sequencing data from patient tumors, researchers identified these Master Regulators with two state-of-the-art AI-based algorithms developed in Califano’s lab and now used across Biohub to analyze single-cell data: ARACNe and VIPER/metaVIPER. By combining network modeling with computational analysis, these tools make it possible to determine how individual cells maintain different states within a tumor. ARACNe reconstructs gene-regulatory networks by identifying direct links between transcription factors and their target genes. It uses information theory, a branch of mathematics, to produce a map of how the cell is controlled. VIPER then identifies the cell’s master regulators — proteins that control a cell’s behavior and regulate which state it is in — based on the differential expression of their target genes. The team found that the same malignant cell states were virtually identically conserved across all patients in multiple cohorts representing the same tumor: across cohorts representing more than a hundred pancreatic cancer patients and fourteen diffuse midline gliomas. Though the fraction of cells in each state varied, every patient with glioma, for example, had cells in the same seven states. In pancreatic cancer, virtually all cells with high-quality data fell into the same six cell states. This was a significant finding — and a clarifying one. The field has long assumed that the internal variety of tumors was essentially limitless and different in every person, driving the push toward personalized medicine. This work suggests the opposite may be closer to the truth. With the cell states and their master regulators now known, it was time to test approved drugs to see which might work against each tumor cell state. For this step, the team focused on DMG. They screened 372 clinically relevant oncology drugs and analyzed how the cells responded to each drug after 24 hours. Instead of simply measuring whether cells died, the researchers analyzed how each drug changed the activity of master regulators within the cells, revealing whether a drug disrupted the regulatory networks that maintain specific tumor cell states. The team then fed these drug profiles into two other clinical-grade computational tools—OncoTarget and OncoTreat—that predict which drugs can best switch off the master regulators that keep each tumor cell state alive. One of these network-based algorithms identifies drugs that directly inhibit a key regulator, and the other flags those that can reverse the broader regulatory program sustaining a given cell state. Both have been tested in a large preclinical study and are now being applied clinically to guide cancer treatment. Using these technologies, the team systematically identified drugs capable of reversing individual cell states in DMG, achieving roughly 90% predictive accuracy and specificity in single-cell state depletion assays, which measure the proportion of cells remaining in a specific state after treatment. Next, those drug predictions needed to be validated. In a mouse model of DMG, in which the tumor was under the skin, eight out of nine drugs tested precisely depleted the predicted target states. “That is pretty remarkable, because we started with 372 possible drugs, virtually all those that are currently clinically relevant in oncology,” says Califano. With that success, the team then started combining drugs to target two states at once, and found that some drug combinations increased survival. Across these experiments, four out of six drug combinations tested showed much stronger benefit than single-drug treatments. The team then tested the drugs in a second mouse model, in which the tumor was in the brain. Here, they noticed a clear pattern: When a drug depleted one cell state, other, non-targeted states became more dominant, meaning that the tumors shifted toward cells that were able to survive the treatment, the very nature of drug resistance. Drug combinations were tested in DMG orthotopic models. This confirms why combination therapy is often needed across various cancers – eliminating only one cell state allows the others to take over. In the case of DMG, a combination of two drugs, avapritinib and ruxolitinib, offered the greatest survival gains. While FDA-approved for other conditions, these drugs have not previously been used to treat DMG. To directly apply their findings to human health, the Biohub team is now working with partners to build a clinical trial for the newly discovered DMG drug regimen. “Targeting different cell states simultaneously or sequentially would appear to be the only way forward,” says Califano. “Every tumor we’ve seen is made up of multiple states, and unless you hit more than one at a time, the cancer finds a way back.”