Summit Therapeutics (NASDAQ: SMMT) says drug tops durvalumab on survival
Rhea-AI Filing Summary
Summit Therapeutics Inc. (SMMT) reported that its partner Akeso Inc. announced positive topline results from the Phase III HARMONi-GI1 trial in first-line advanced biliary tract cancer. Ivonescimab plus chemotherapy showed statistically significant and clinically meaningful superiority in the primary endpoint of overall survival versus durvalumab plus chemotherapy, and the study also met key secondary endpoints of progression-free survival and objective response rate in a pre-specified interim analysis. HARMONi-GI1 was conducted in China by Akeso, which generated, managed, and analyzed all data; detailed safety and efficacy results are expected at an upcoming medical congress and in a peer-reviewed journal. Ivonescimab (SMT112 in Summit’s territories) remains investigational and is not approved in Summit’s license regions, while a Biologics License Application for ivonescimab in NSCLC based on the HARMONi trial has been accepted by the FDA with a PDUFA goal date of November 14, 2026.
Positive
- Ivonescimab shows statistically significant overall survival benefit in Phase III BTC trial, with HARMONi-GI1 meeting its primary OS endpoint and key secondary endpoints (PFS and ORR) versus durvalumab plus chemotherapy in advanced biliary tract cancer.
- Five Phase III ivonescimab trials have read out positively to date, including four in NSCLC and one in biliary tract cancer, supporting a growing body of late-stage data for Summit’s key partnered asset.
- FDA accepted a Biologics License Application for ivonescimab in NSCLC based on the HARMONi trial, with a stated PDUFA goal date of November 14, 2026, providing a clear regulatory milestone.
Negative
- None.
Filing Explained
The filing adds interim China Phase III evidence, while ivonescimab remains investigational and unapproved in Summit’s U.S. and European territories.
On
The filing’s “positive topline” description is based on interim results: Akeso reported statistically significant and clinically meaningful superiority on overall survival, plus achievement of key progression-free-survival and objective-response-rate endpoints. All relevant data were generated, managed, and analyzed by Akeso.
The study was conducted in China and sponsored by Akeso, while detailed safety and efficacy results are expected at a future medical congress and in a peer-reviewed journal.
8-K Event Classification
2 items: 8.01, 9.01
2 items
Item 8.01
Other Events
Other
Voluntary disclosure of events the company deems important to shareholders but not covered by other items.
Item 9.01
Financial Statements and Exhibits
Exhibits
Financial statements, pro forma financial information, or exhibit attachments filed with this report.
Key Figures
PDUFA goal date: November 14, 2026
Phase III trials with positive readouts: 5 Phase III clinical studies
Patients treated with ivonescimab in clinical studies: Over 4,000 patients
+3 more
6 metrics
PDUFA goal date
November 14, 2026
FDA goal decision date for ivonescimab BLA based on the HARMONi NSCLC trial
Phase III trials with positive readouts
5 Phase III clinical studies
Number of ivonescimab Phase III trials reported with positive outcomes (four NSCLC, one BTC)
Patients treated with ivonescimab in clinical studies
Over 4,000 patients
Global clinical trial exposure to ivonescimab
Patients treated with ivonescimab commercially in China
Over 70,000 patients
Commercial use exposure in China as noted by Akeso
Phase III studies announced/ongoing/completed
16 Phase III clinical studies
Total ivonescimab Phase III program size cited, including Summit- and Akeso-sponsored
Ivonescimab half-life at steady state
Approximately 10 days
Half-life after first dose is 6 to 7 days, increasing to ~10 days at steady state
Key Terms
overall survival, progression-free survival, objective response rate, bispecific antibody, +2 more
6 terms
overall survival medical
"achieved statistically significant and clinically meaningful superiority in the primary endpoint of overall survival"
Overall survival is the average or median length of time patients remain alive after starting a treatment or entering a clinical study, measured regardless of cause of death. Investors care because it is a clear, hard measure of a therapy’s real-world benefit — like timing how long a new battery actually runs — and strong improvements in overall survival can drive regulatory approval, market adoption and revenue potential.
progression-free survival medical
"The study also met the key secondary endpoints of progression-free survival and objective response rate"
Progression-free survival is the length of time during and after a treatment that a patient's disease does not get worse, measured from the start of treatment until the disease shows measurable signs of progression or the patient dies. Investors care because longer progression-free survival in clinical trials often signals that a drug is effective, improving chances of regulatory approval, market adoption, and revenue potential—think of it as a stopwatch showing how long a therapy can keep the illness at bay.
objective response rate medical
"The study also met the key secondary endpoints of progression-free survival and objective response rate"
The objective response rate (ORR) is the percentage of patients in a clinical trial whose tumors measurably shrink or disappear according to preset rules. Investors use it as a quick, objective signal of a drug’s ability to produce a clear treatment effect—like counting how many plants visibly respond after applying a new fertilizer—and higher ORR can improve odds of regulatory approval, commercial success, and company valuation.
bispecific antibody medical
"is a novel, potential first-in-class investigational bispecific antibody combining the effects"
A bispecific antibody is a specially designed protein that can attach to two different targets at the same time. Think of it as a custom-made connector that brings two things together—such as a disease cell and an immune system component—helping the body fight illnesses more effectively. For investors, understanding bispecific antibodies is important because they represent innovative therapies that could lead to new treatments and potentially lucrative market opportunities.
tetravalent structure medical
"specifically engineered tetravalent structure (four binding sites) enables higher avidity"
PDUFA regulatory
"which the FDA accepted for filing in January 2026; the goal Prescription Drug User Fee Act (PDUFA) date is November 14, 2026"
PDUFA is the Prescription Drug User Fee Act, the U.S. law under which drug companies pay fees that fund the FDA's review of new medicines. In company news the term usually appears as the PDUFA date, the target deadline by which the FDA aims to decide on a drug application; that date tells investors when to expect the approval or rejection decision for the product.
FAQ
What did Summit Therapeutics (SMMT) announce regarding the HARMONi-GI1 trial?
Summit reported that partner Akeso’s Phase III HARMONi-GI1 trial in advanced biliary tract cancer showed statistically significant and clinically meaningful overall survival superiority for ivonescimab plus chemotherapy versus durvalumab plus chemotherapy, and also met key secondary endpoints of PFS and ORR at an interim analysis.
Where was the HARMONi-GI1 study conducted and who ran it?
HARMONi-GI1 is a single-region, multi-center Phase III study conducted in China and was sponsored by Akeso, with all relevant data exclusively generated, managed, and analyzed by Akeso.
Is ivonescimab approved in Summit Therapeutics’ (SMMT) territories?
Ivonescimab remains an investigational therapy and is not approved by any regulatory authority in Summit’s license territories, including the United States and Europe. It was initially approved for marketing authorization in China in May 2024.
How extensive is the clinical and commercial experience with ivonescimab cited by SMMT?
Summit notes that over 4,000 patients have received ivonescimab in clinical studies globally and over 70,000 patients in commercial use in China, as reported by Akeso.
What major regulatory milestone did Summit Therapeutics (SMMT) highlight for ivonescimab in NSCLC?
Summit stated that a Biologics License Application for ivonescimab based on the Phase III HARMONi trial in NSCLC was accepted for filing by the FDA, with a goal PDUFA date of November 14, 2026.
How many Phase III ivonescimab trials have read out positively according to SMMT?
Summit reports that five Phase III ivonescimab trials have read out positively so far: four in NSCLC (including HARMONi, HARMONi-A, HARMONi-2, HARMONi-6) and one in biliary tract cancer (HARMONi-GI1).
AI-generated analysis. How Rhea-AI works. Not financial advice.
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934
Date of Report (Date of Earliest Event Reported): August 25, 2026
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Item 8.01 | Other Events. | ||||
On August 25, 2026, Summit Therapeutics Inc. issued a press release noting that its partner, Akeso, Inc., (“Akeso”) announced positive topline results from the randomized Phase III HARMONi-GI1 study (“HARMONi-GI1”) evaluating ivonescimab plus chemotherapy compared with durvalumab plus chemotherapy as a first-line treatment for patients with advanced biliary tract cancer. HARMONi-GI1 is a single-region, multi-center, Phase III study conducted in China and sponsored by Akeso, with all relevant data exclusively generated, managed, and analyzed by Akeso.
Akeso reported that, at a pre-specified interim analysis, the ivonescimab-based regimen achieved statistically significant and clinically meaningful superiority in the primary endpoint of overall survival compared to the durvalumab-based regimen. The study also met the key secondary endpoints of progression-free survival and objective response rate. Detailed results from this first readout of HARMONi-GI1, including safety and efficacy data, are expected to be presented at an upcoming medical congress and published in a peer-reviewed journal.
A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated by reference herein.
| Item 9.01 | Financial Statements and Exhibits. | ||||
(d) Exhibits
Exhibit Number | Description | ||||
| 99.1 | Press Release, dated August 25, 2026 | ||||
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document) | ||||
SIGNATURE
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.
| SUMMIT THERAPEUTICS INC. | ||||||||
| Date: August 26, 2026 | By: | /s/ Manmeet S. Soni | ||||||
| Chief Operating Officer, Chief Financial Officer and Director | ||||||||
| (Principal Financial Officer) | ||||||||
1 Ivonescimab Plus Chemotherapy Demonstrates Statistically Significant Overall Survival Benefit Compared to Durvalumab Plus Chemotherapy in First-Line Advanced Biliary Tract Cancer in Single-Region Trial Conducted by Akeso in China HARMONi-GI1 Conducted in China by Akeso Is First Known Phase III Study in Advanced BTC to Demonstrate OS Superiority vs. Anti-PD-(L)1 Plus Chemotherapy First Phase III Ivonescimab Readout beyond NSCLC Demonstrates Significant OS Benefit Miami, Florida, August 25, 2026 – Summit Therapeutics Inc. (NASDAQ: SMMT) today noted that its partner Akeso Inc. announced positive topline results from the randomized Phase III HARMONi-GI1 study (AK112-309) evaluating ivonescimab plus chemotherapy compared with durvalumab plus chemotherapy as a first-line treatment for patients with advanced biliary tract cancer (BTC). HARMONi-GI1 is a single-region, multi-center, Phase III study conducted in China and sponsored by Akeso, with all relevant data exclusively generated, managed, and analyzed by Akeso. Akeso reported that, at a pre-specified interim analysis, the ivonescimab-based regimen achieved statistically significant and clinically meaningful superiority in the primary endpoint of overall survival (OS) compared to the durvalumab-based regimen. The study also met the key secondary endpoints of progression-free survival (PFS) and objective response rate (ORR). Detailed results from this first readout of HARMONi-GI1, including safety and efficacy data, are expected to be presented at an upcoming medical congress and published in a peer-reviewed journal. Akeso’s press release announcing these results can be found here. The HARMONi-GI1 study was conducted by Akeso in China, where ivonescimab is approved and commercially available for indications in non-small cell lung cancer (NSCLC). Ivonescimab remains investigational and is not approved by any regulatory authority in Summit’s license territories, including the United States and Europe. About Ivonescimab Ivonescimab, known as SMT112 in Summit’s license territories, North America, South America, Europe, the Middle East, Africa, and Japan, and as AK112 outside of Summit’s license territories, is a novel, potential first-in-class investigational bispecific antibody combining the effects of immunotherapy via a blockade of PD-1 with the anti- angiogenesis effects associated with blocking VEGF into a single molecule. By design, ivonescimab displays unique cooperative binding to each of its intended targets with multifold higher affinity to PD-1 when in the presence of VEGF. This design is intended to differentiate ivonescimab as there is potentially higher expression (presence) of both PD-1 and VEGF in tumor tissue and the tumor microenvironment (TME) as compared to normal tissue in the body. Summit believes ivonescimab’s specifically engineered tetravalent structure (four binding sites) enables higher avidity (accumulated strength of multiple binding interactions) in the TME (Zhong, et al, iScience, 2025). This tetravalent structure, the intentional novel design of the molecule, and bringing these two targets into a single bispecific antibody with cooperative binding qualities have the potential to direct ivonescimab to the tumor tissue versus healthy tissue. The intent of ivonescimab’s design, together with a half-life of 6 to 7 days after the first dose (Zhong, et al, iScience, 2025) increasing to approximately 10 days at steady state dosing, is to improve upon
2 previously established efficacy thresholds, side effects, and safety profiles associated with prior approved drugs to these targets. Ivonescimab was engineered by Akeso Inc. (HKEX Code: 9926.HK) and is currently utilized in multiple Phase III clinical trials. Over 4,000 patients have been treated with ivonescimab in clinical studies globally and over 70,000 patients when considering those treated in a commercial setting in China, as noted by Akeso. There are currently 16 Phase III clinical studies that are either announced, ongoing, or have been completed studying ivonescimab, five of which are Summit-sponsored global studies, one of which is a multiregional study sponsored by a cooperative group, and 10 of which are being or have been conducted in China by Akeso. Summit began its clinical development of ivonescimab in NSCLC, commencing enrollment in 2023 in two multiregional Phase III clinical trials, HARMONi and HARMONi-3. In 2025, Summit began enrolling patients in HARMONi-7. Summit expanded its Phase III clinical development program into colorectal cancer (CRC) in the fourth quarter of 2025 by initiating enrollment in HARMONi-GI3. In 2026, Summit announced initiation of HARMONi-GU1, a Phase II/III study in urothelial carcinoma (bladder cancer) with global clinical trial site activations planned to begin by the fourth quarter of 2026. HARMONi is a Phase III clinical trial evaluating ivonescimab combined with chemotherapy compared to placebo plus chemotherapy in patients with EGFR-mutated, locally advanced or metastatic non-squamous NSCLC who were previously treated with a third-generation EGFR TKI (e.g., osimertinib). Detailed results of the study were provided in September 2025, and a Biologics License Application (BLA) was submitted to the United States Food and Drug Administration (FDA) for marketing authorization, which the FDA accepted for filing in January 2026; the goal Prescription Drug User Fee Act (PDUFA) date is November 14, 2026. HARMONi-3 is a Phase III clinical trial evaluating ivonescimab combined with chemotherapy compared to pembrolizumab combined with chemotherapy in patients with first-line metastatic, squamous or non-squamous NSCLC, irrespective of PD-L1 expression. The clinical trial is evaluating the two histologies as individual, separately powered cohorts with independent statistical powering. HARMONi-7 is a Phase III clinical trial evaluating ivonescimab monotherapy compared to pembrolizumab monotherapy in patients with first-line metastatic NSCLC whose tumors have high PD-L1 expression. HARMONi-GI3 is a Phase III clinical trial evaluating ivonescimab in combination with chemotherapy compared with bevacizumab plus chemotherapy in patients with first-line unresectable metastatic CRC. HARMONi-GU1 is a Phase II/III clinical trial evaluating ivonescimab plus the antibody drug conjugate (ADC) enfortumab vedotin (EV) compared to pembrolizumab plus EV as first-line therapy in patients with previously untreated locally advanced or metastatic urothelial carcinoma (la/mUC). ILLUMINE is a Phase III study being conducted by GORTEC, a cooperative group dedicated to Head and Neck Oncology, in recurrent / metastatic head and neck squamous cell carcinoma (r/m HNSCC). ILLUMINE is a three- arm Phase III clinical trial designed to evaluate ivonescimab monotherapy, as well as ivonescimab in combination with ligufalimab, Akeso’s proprietary anti-CD47 monoclonal antibody, compared to monotherapy pembrolizumab in patients with PD-L1 positive r/m HNSCC.
3 Five Phase III ivonescimab clinical trials have read out to date, all five with positive data. Four of these five studies are in NSCLC and one is in biliary tract cancer (BTC). In addition to Summit’s positive HARMONi study, Akeso has had positive read-outs in three single-region (China), randomized Phase III clinical trials, HARMONi-A, HARMONi- 2, and HARMONi-6, for ivonescimab in NSCLC, including a statistically significant overall survival benefit in both the HARMONi-A and HARMONi-6 studies. Akeso has also reported a positive read-out (statistically significant OS) in the single-region (China), randomized Phase III HARMONi-GI1 trial in advanced BTC. HARMONi-A was a Phase III clinical trial which evaluated ivonescimab combined with chemotherapy compared to placebo plus chemotherapy in patients with EGFR-mutated, locally advanced or metastatic non-squamous NSCLC who have progressed after treatment with an EGFR TKI. HARMONi-2 is a Phase III clinical trial evaluating monotherapy ivonescimab against monotherapy pembrolizumab in patients with locally advanced or metastatic NSCLC whose tumors have positive PD-L1 expression. HARMONi-6 is a Phase III clinical trial evaluating ivonescimab in combination with platinum-based chemotherapy compared with tislelizumab, an anti-PD-1 antibody, in combination with platinum-based chemotherapy in patients with locally advanced or metastatic squamous NSCLC, irrespective of PD-L1 expression. HARMONi-GI1 is a Phase III clinical trial evaluating ivonescimab in combination with chemotherapy compared with durvalumab plus chemotherapy as a first-line treatment for patients with advanced BTC. Akeso is actively conducting additional Phase III clinical studies in settings outside of NSCLC and biliary-tract cancer, including triple-negative breast cancer, head and neck squamous cell carcinoma, small cell lung cancer, colorectal cancer, and pancreatic cancer. Ivonescimab is an investigational therapy that is not approved by any regulatory authority in Summit’s license territories, including the United States and Europe. Ivonescimab was initially approved for marketing authorization in China in May 2024. About Summit Therapeutics Inc. Summit Therapeutics Inc. is a biopharmaceutical oncology company focused on the discovery, development, and commercialization of patient-, physician-, caregiver- and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. Summit was founded in 2003 and the company’s shares are listed on the Nasdaq Global Market (symbol "SMMT"). Summit is headquartered in Miami, Florida, with additional offices in Palo Alto, California, Princeton, New Jersey, Dublin, Ireland, and Oxford, UK. For more information, please visit https://www.smmttx.com and follow Summit on X @SMMT_TX. Summit Forward-Looking Statements Any statements in this press release about the Company’s future expectations, plans and prospects, including but not limited to, statements about the clinical and preclinical development of the Company’s product candidates, entry into and actions related to the Company’s partnership with Akeso Inc. and other collaborations, the intended use of the net proceeds from the private placements, the Company's anticipated spending and cash runway, the therapeutic potential of the Company’s product candidates, the potential commercialization of the Company’s product candidates, the timing of initiation, completion and availability of data from clinical trials, the potential
4 submission of applications for marketing approvals, the expected timing of BLA submissions or FDA decisions, potential acquisitions, statements about the previously disclosed At-The-Market equity offering program (“ATM Program”), the expected proceeds and uses thereof, the Company’s estimates regarding stock-based compensation, and other statements containing the words "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "target," "would," and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the Company’s ability to sell shares of our common stock under the ATM Program, the conditions affecting the capital markets, general economic, industry, or political conditions, including the effects of geopolitical developments, domestic and foreign trade policies, and monetary policies, the results of our evaluation of the underlying data in connection with the development and commercialization activities for ivonescimab, the outcome of discussions with regulatory authorities, including the Food and Drug Administration, the uncertainties inherent in the initiation of future clinical trials, availability and timing of data from ongoing and future clinical trials, the results of such trials, and their success, global public health crises, that may affect timing and status of our clinical trials and operations, whether preliminary results from a clinical trial will be predictive of the final results of that trial or whether results of early clinical trials or preclinical studies will be indicative of the results of later clinical trials, whether business development opportunities to expand the Company’s pipeline of drug candidates, including without limitation, through potential acquisitions of, and/or collaborations with, other entities occur, expectations for regulatory approvals, laws and regulations affecting government contracts and funding awards, availability of funding sufficient for the Company’s foreseeable and unforeseeable operating expenses and capital expenditure requirements and other factors discussed in the "Risk Factors" and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” sections of filings that the Company makes with the Securities and Exchange Commission. Summit defines a “positive study” as a clinical study with one or more prespecified primary endpoints in which one of those endpoints achieves a statistically significant benefit according to the protocol or statistical analysis plan. Any change to our ongoing trials could cause delays, affect our future expenses, and add uncertainty to our commercialization efforts, as well as to affect the likelihood of the successful completion of clinical development of ivonescimab. Accordingly, readers should not place undue reliance on forward-looking statements or information. In addition, any forward-looking statements included in this press release represent the Company’s views only as of the date of this release and should not be relied upon as representing the Company’s views as of any subsequent date. The Company specifically disclaims any obligation to update any forward-looking statements included in this press release. Summit Therapeutics’ Media & Investor Contacts: Nathan LiaBraaten Senior Director, Investor Relations Tracy Jones Director, Media & Public Relations investors@smmttx.com media@smmttx.com Summit Therapeutics and the Summit Therapeutics logo are registered trademarks of Summit Therapeutics Inc. and/or its affiliates. Copyright 2026, Summit Therapeutics Inc. All Rights Reserved.