ASCO 2026: Spevatamig Opens a New Path in Pancreatic Cancer Immunotherapy

　　From May 29 to June 2,2026,the 62nd American Society of Clinical Oncology(ASCO)Annual Meeting was held at the McCormick Place Convention Center in Chicago.As the premier academic gathering in global oncology,the ASCO Annual Meeting has long been a bellwether for new drug development and clinical innovation.At this year's meeting,pancreatic cancer—the notorious"king of cancers"—became a major focus:targeted therapies,antibody-drug conjugates(ADCs)and immunotherapies advanced on three fronts simultaneously,forming a siege against pancreatic ductal adenocarcinoma(PDAC)for the first time.

　　1.An Expanding Treatment Map:Three Paths Advancing Together

　　Pancreatic cancer has long been one of the most difficult cancers to drug,with roughly 90%of patients harboring RAS gene mutations.Yet over the past two decades,no RAS-pathway targeted drug had produced clinically meaningful overall survival(OS)data in pancreatic cancer,and the few approved drugs serve narrow patient populations.At ASCO 2026,this deadlock was broken on multiple fronts at once.

　　2.Targeted Therapy:Landmark OS Data for the RAS Field

　　At the ASCO Plenary Session on May 31,Revolution Medicines presented full data from RASolute 302,a Phase III randomized controlled study of the pan-RAS inhibitor Daraxonrasib(RMC-6236),arguably one of the most watched studies of the meeting.Earlier in 2026,acquisition reports involving AbbVie and Merck had already set the tone for the year's RAS momentum.In previously treated metastatic PDAC patients,median OS reached 13.2 months with Daraxonrasib versus 6.7 months with chemotherapy,a 60%reduction in the risk of death.This doubling of median OS represents the strongest Phase III data ever reported for targeted therapy in pancreatic cancer.Meanwhile,a KRAS G12D inhibitor also drew wide attention:early Phase I data in 30 treatment-naive patients showed an objective response rate(ORR)of 63.3%and a disease control rate(DCR)of 93.3%,and a Phase III trial has been initiated.

　　3.ADCs:From Single-Agent Validation to Multi-Target Competition

　　ADCs are another class breaking the pancreatic cancer deadlock.At this year's ASCO,the competitive landscape shifted from single-agent validation to multi-target parallel development,with CLDN18.2 ADCs,B7H3 ADCs and CEACAM5 ADCs all achieving key clinical milestones and broadening options for advanced disease.

　　4.Immunotherapy Breakthrough:Spevatamig First-Line Data Unveiled

　　Compared with targeted drugs and ADCs,the immunotherapy advance may be even more exciting.On the morning of May 30,Phanes Therapeutics presented a poster at ASCO 2026 showing data for spevatamig combined with the GnP regimen(gemcitabine plus nab-paclitaxel)as first-line treatment for metastatic PDAC.As the world's first CLDN18.2/CD47 bispecific antibody to enter clinical development,spevatamig achieved an ORR of 52.4%and a DCR of 90.5%at the low dose of 2 mg/kg weekly plus GnP.In U.S.patients,median progression-free survival(PFS)reached 7.3 months and median OS reached 14.7 months(median follow-up 14.7 months),indicating a notable survival benefit.Efficacy data from the higher 3 mg/kg weekly dose cohort continue to mature,and this dose is expected to be the proposed regimen for a future Phase III registration trial.Notably,more than 90%of patients in this cohort were newly diagnosed metastatic cases,with baseline characteristics highly consistent with classic international Phase III populations,laying a solid foundation for further development.In terms of safety,spevatamig plus GnP was well tolerated,showing no meaningful additive toxicity over GnP alone,with a favorable therapeutic window supporting long-term combination use.

　　5.From Short-Term Control to Long-Term Stability:Immunotherapy"Guards the Gains"

　　If RAS-targeted drugs and ADCs deliver the precision strike,immunotherapy is tasked with guarding the gains.Targeted agents and ADCs act quickly on tumor lesions but cannot escape the core dilemma of resistance:nearly all patients eventually develop secondary resistance,leading to treatment failure and relapse,and long-term OS remains difficult to extend.Immunotherapy operates on an entirely different logic—rather than killing tumor cells directly,it activates and"trains"the patient's own immune system to recognize and eliminate tumor cells,building durable immune surveillance.Thanks to immune memory and the tail effect,once a response is achieved,residual immune cells continue to hunt remaining tumor cells,suppressing recurrence and metastasis and delivering long-term survival benefit.The Phase II data for spevatamig plus GnP in first-line metastatic PDAC—7.3-month median PFS and 14.7-month median OS in U.S.patients—provide strong evidence of long-term benefit for pancreatic cancer immunotherapy.Moreover,because immunotherapy does not heavily depend on specific mutations or antigen expression,it can be flexibly combined with chemotherapy,targeted drugs or ADCs,offering broader clinical applicability—especially valuable in"cold"tumors like pancreatic cancer,where multi-target,multi-mechanism combinations can maximize antitumor immune responses.

　　6.Three Immune Barriers:Why Conventional Immunotherapy Fails

　　Developing immunotherapy for pancreatic cancer is extraordinarily difficult,and no broadly viable clinical regimen exists today.The root cause is a tumor microenvironment fortified by three immune barriers.First,a scarcity of immune cells:pancreatic cancer is a textbook"cold tumor,"with cytotoxic CD8+T-cell infiltration below 5%of the lesion,while PD-1/L1 inhibitors rely on activating pre-existing infiltrating T cells.Second,a physical penetration barrier:abundant activated pancreatic stellate cells and collagen fibers form a dense fibrotic stroma that severely impedes drug delivery.Third,an immunosuppressive barrier:lesions are enriched with M2 macrophages,myeloid-derived suppressor cells and other suppressive cells that continuously dampen antitumor immunity.For these reasons,conventional immunotherapy represented by PD-1/PD-L1 inhibitors has struggled in pancreatic cancer.What the disease needs is not incremental improvement,but a fundamentally new mechanistic path.

　　7.Innate Immunity Enhancer:A New Mechanism to Crack"Cold"Tumors

　　Spevatamig belongs to an emerging class of tumor immunotherapy drugs called innate immunity enhancers(I2E).Unlike widely used checkpoint inhibitors that kill cancer cells by activating T cells,I2Es activate macrophages and dendritic cells to recognize and eliminate cancer cells—a fresh alternative mechanism for turning the body's own immune system against tumors,particularly in"cold"tumors unresponsive to checkpoint blockade.In the data presented at ASCO,spevatamig showed positive results at the very first dose level in first-line pancreatic cancer,suggesting that innate immune activation may offer a new immunotherapy option for this cold tumor.

　　8.Dual-Target Design:Balancing Efficacy and Safety

　　Pancreatic cancer immunotherapy must address the tumor microenvironment with differentiated mechanisms and tailored combinations,making the field a high-barrier,fine-grained arena of hardcore innovation.The safety and controllability of spevatamig rest on its distinctive CLDN18.2/CD47 dual-target molecular design.Metastatic PDAC cells commonly overexpress both CLDN18.2 and CD47,yet single-target drugs each carry serious toxicity liabilities:CD47 programs were long hampered by severe hematologic toxicity—in 2024,Gilead's high-profile CD47 agent magrolimab was fully terminated over safety issues,with Grade 3 or higher drug-related adverse events reaching 76.4%,including neutropenia,anemia and thrombocytopenia—while CLDN18.2-targeted drugs can bind normal gastric mucosa and cause persistent nausea and vomiting.In early development,Phanes Therapeutics applied a dual proprietary molecular design:it screened PT240,a highly tumor-specific CD47 antibody that binds tumor cells strongly while markedly reducing red blood cell binding,avoiding hematologic toxicity at the source;and,using its in-house PACbody®and SPECpair®bispecific platforms,it built an asymmetric mono-arm architecture for spevatamig that retains only one CLDN18.2 arm and one CD47 arm,weakening nonspecific binding to normal tissues.The resulting molecule is a natural IgG-format antibody with strong developability,manufacturable through conventional monoclonal antibody processes,laying a solid foundation for commercial production.

　　9.Regulatory Designations and Global Development

　　Spevatamig is currently advancing through a Phase II study in patients with unresectable locally advanced or metastatic gastric cancer,gastroesophageal junction cancer,pancreatic cancer and biliary cancer.It received FDA Orphan Drug Designation for pancreatic cancer in June 2022 and FDA Fast Track Designation for metastatic CLDN18.2-positive pancreatic cancer in March 2024.Completing the orphan-drug-to-fast-track progression in under two years is uncommon for a pancreatic cancer drug,meaning spevatamig may qualify for priority review and rolling review at the NDA stage,potentially shortening the path from pivotal trial completion to approval.Its global development strategy accelerates enrollment while accumulating multi-regional,multi-ethnic data to validate efficacy across broader populations,paving the way for future registration and commercialization worldwide.

　　10.Conclusion:A Collective Update of Pancreatic Cancer Treatment Logic

　　Pancreatic cancer is undergoing a collective update in treatment logic.From fast-acting targeted drugs and ADCs to long-acting immunotherapies,the clinical treatment puzzle is,for the first time,showing signs of being completed.The"king of cancers"will not be dethroned overnight,but the direction of change is becoming clear:no longer single-point breakthroughs,but multiple paths advancing in parallel—each solving one piece of the pancreatic cancer treatment puzzle.