• Encouraging Phase 2 clinical activity with confirmed complete responses observed in heavily pretreated metastatic breast cancer across both TNBC and HR+/HER2- subtypes
• First public disclosure of clinical stage Ipsen-partnered STAR program IPN01203

CAMBRIDGE, Mass., April 17, 2026 /PRNewswire/ — Marengo Therapeutics, Inc., a clinical-stage biotechnology company pioneering precision immunotherapies for oncology and inflammation and immunology (I&I), today announced multiple presentations that highlight clear progress for key assets at the 2026 American Association for Cancer Research (AACR) Annual Meeting taking place April 17-22, 2026 in San Diego, CA.

Findings to be shared include late-breaking interim Phase 2a clinical results from Marengo’s ongoing STARt-002 Phase 1b/2a trial of invikafusp alfa plus TRODELVY® as part of a collaboration with Gilead Sciences and the first public disclosure of its second precision T cell activator from the STAR program, IPN01203/STAR0501, being advanced in partnership with Ipsen in the prestigious New Drugs on the Horizon session.

“Combining invikafusp alfa with ADC-mediated immunogenic tumor killing is a scientifically compelling approach, and it is exciting to see this translate into meaningful clinical responses in patients with metastatic breast cancer,” said Kevin Chin, M.D., Chief Medical Officer of Marengo Therapeutics. “The observation of confirmed complete responses in heavily pretreated breast cancer patients that did not respond to any prior therapy further reinforces our confidence in this novel combination. As enrollment progresses rapidly, we look forward to reporting additional data that both validate our platform and potentially offer a critical new treatment option in a disease with high unmet need.”

The initial Phase 2a data build on results presented at the 2025 San Antonio Breast Cancer Symposium, demonstrating encouraging clinical activity with invikafusp alfa plus TRODELVY® (sacituzumab govitecan-hziy) in heavily pretreated metastatic breast cancer patients, including confirmed complete responses, across both metastatic triple-negative breast cancer (TNBC) and HR+/HER2- breast cancer.

To date, invikafusp alfa with TRODELVY® has shown a safety profile consistent with the known profiles of the individual agents. Pharmacodynamic analyses further confirmed that invikafusp alfa maintains its mechanism of action in a combination regimen, driving robust and selective expansion of Vβ6/Vβ10 T cells. The STARt-002 Phase 1b/2a trial is actively enrolling patients at select cancer centers across North America, with enrollment expected to be completed later this year.

“In a heavily pretreated metastatic breast cancer population, the observation of confirmed complete responses is notable and warrants attention,” said Erika Hamilton, M.D., Chief Development Officer, Late Phase and Director of Breast Cancer Research. “While these are early data, the activity observed across both TNBC and HR+/HER2− subtypes, along with a safety profile consistent with the individual agents, supports further clinical evaluation of this combination.”

In parallel, Marengo will highlight the continued advancement of the STAR platform through its collaboration with Ipsen. The next clinical candidate, IPN01203/STAR0501, has been selected for an oral presentation during the New Drugs on the Horizon session.

“Together with Marengo, we are advancing a novel precision T cell activation approach with the potential to transform treatment paradigms in solid tumors,” said David Jenkins, Senior Vice President, Head of Research and External Innovation at Ipsen. “The rapid progression of this program into the clinic underscores the strength of our collaboration and the quality of scientific execution, and we look forward to exploring its clinical potential.”

“We are excited to see the second STAR program advance into the clinic with Ipsen and to share these important data with the scientific community,” said Zhen Su, M.D., MBA, Chief Executive Officer of Marengo Therapeutics. “This milestone reflects both the strength of our platform and the productivity of our collaboration as we work together to bring novel immunotherapies to patients with solid tumors.”

Additional presentation details are as follows:

• Presentation: Initial clinical and translational results and selection of recommended phase 2 dose (RP2D) from START-002: A Phase 1b/2 study of invikafusp alfa, a first-in-class dual T-cell agonist, in combination with sacituzumab govitecan in metastatic triple-negative or HR+/HER2- breast cancer
  • Abstract Number: LBA045 / 5
  • Session: First-in-Human Phase I Clinical Trials
  • Date/Time: Monday April 20, 9:00 AM – 12:00 PM PT
• Presentation: Development of IPN01203, a dual T cell agonist activating Vβ6/Vβ10 TCR-expressing T cells
  • Abstract Number: ND12
  • Session: New Drugs on the Horizon: Part 3
  • Date/Time: Monday, April 20, 10:15 AM – 11:45 AM PT

About Marengo Therapeutics
Marengo Therapeutics, Inc., a clinical-stage biotech company, develops novel TCR-targeting antibodies that selectively modulate common and disease-specific T cell subsets of the germline TCR repertoire to provide lifelong protection against cancer and autoimmune diseases. With a passionate team of dedicated scientists experienced in immunology and oncology, and three proprietary platforms: Selective T Cell Activation Repertoire (STAR), Trispecific T Cell Engager (Tri-STAR) and T cell Depletor (MSTAR), Marengo is working to selectively target the right T cells in the right patients to create a world in which everyone’s immune system can defeat cancer and autoimmune diseases. To learn more, visit marengotx.com.

About the STAR™ Platform
Marengo’s STAR™ Platform is a multi-specific antibody-fusion platform derived from Marengo’s proprietary library of antibodies targeting germline-encoded variable Vβ regions of the TCR fused to different T cell co-stimulatory moieties. Combining a novel non-clonal mode of TCR activation with a T cell co-stimulator in the same molecule promotes a distinct mechanism of action that promotes durable anti-tumor Vβ T cell responses.

About Invikafusp alfa (STAR0602)
Invikafusp alfa (STAR0602) is the lead candidate from Marengo’s STAR™ platform. It is designed to selectively activate a common Vβ T cell subset found in all cancers by combining a non-clonal mode of TCR activation with a T cell co-stimulatory signal in a single molecule. This innovative approach promotes the expansion of clonally diverse, effector memory Vβ T cells, enhancing anti-tumor immunity and enabling durable tumor clearance. Extensive preclinical studies demonstrate STAR0602’s potent anti-tumor activity in both mouse and human ex vivo models via a novel mechanism of action.

About the STARt-002 Clinical Study
STARt-002 (NCT06827613) is a Phase 1b/2, open-label, multicenter study investigating the combination of invikafusp alfa and TRODELVY® in patients with unresectable, locally advanced, or metastatic breast cancer. The trial consists of a safety lead-in phase followed by two dose expansion cohorts: one in triple-negative breast cancer (mTNBC) and one in HR+/HER2−metastatic breast cancer. More information is available at clinicaltrials.gov.

About STAR0502 / IPN01203
IPN01203 is a first-in-class T cell activator which selectively activates a group of Vβ6 T cells through the TCR and IL-15R pathways, enhancing their ability to recognize and target tumors. IPN01203 was generated by Marengo’s Selective T Cell Activation Repertoire (STAR) platform, a multi-specific fusion protein library that targets specific TCR Vβ variants fused to different co-stimulate moieties to develop potent T cell activators. A Phase I/II dose escalation and expansion trial is ongoing sponsored by Ipsen.

Marengo Contacts:
Media I Peg Rusconi I peg.rusconi@deerfieldgroup.com
Investors| bd@marengotx.com

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