Marengo Reports Phase 2 Breast Cancer Data at AACR

CAMBRIDGE, Mass., April 17, 2026

Marengo Therapeutics, Inc. announced late-breaking Phase 2 clinical results for its investigational immunotherapy invikafusp alfa in combination with TRODELVY®, demonstrating confirmed complete responses in heavily pretreated metastatic breast cancer patients. Presented at the AACR Annual Meeting 2026 in San Diego, the data highlight a novel immunotherapy-ADC combination strategy with the potential to address significant unmet needs in triple-negative (TNBC) and HR+/HER2− breast cancer subtypes.

Phase 2 Data Show Promising Responses in Difficult Cases

The STARt-002 Phase 1b/2a clinical trial revealed encouraging clinical activity, including confirmed complete responses in patients who had previously failed multiple lines of therapy, a population typically associated with poor outcomes. Notably, responses were observed across both triple-negative breast cancer (TNBC) and HR+/HER2− metastatic breast cancer, underscoring the broad applicability of the therapy.

The combination of invikafusp alfa with TRODELVY® (sacituzumab govitecan) leverages antibody-drug conjugate (ADC)-mediated tumor cell killing alongside precision T-cell activation, resulting in enhanced anti-tumor immune responses. Importantly, the treatment demonstrated a manageable safety profile consistent with the known profiles of the individual agents, with no unexpected toxicities reported.

Pharmacodynamic data further confirmed that invikafusp alfa maintains its mechanism of action in combination therapy, driving robust and selective expansion of Vβ6/Vβ10 T cells, which are critical for sustained anti-tumor immunity.

STAR Platform Drives Next-Generation Immunotherapy Innovation

Marengo also unveiled progress from its proprietary Selective T Cell Activation Repertoire (STAR) platform, including the advancement of a second clinical candidate, IPN01203/STAR0501, currently in Phase 1 development through a collaboration with Ipsen. This next-generation program was highlighted in the “New Drugs on the Horizon” session at AACR 2026, signaling strong scientific and clinical momentum.

The STAR platform represents a novel multi-specific antibody fusion approach, designed to selectively activate specific T-cell subsets using a non-clonal mechanism combined with co-stimulatory signals. This enables the expansion of diverse effector memory T cells, enhancing the immune system’s ability to target and eliminate cancer cells.

The IPN01203 candidate specifically targets Vβ6 T cells via TCR and IL-15 receptor pathways, offering a differentiated mechanism that could potentially transform treatment paradigms in solid tumors. The rapid progression of this program into clinical trials reflects the strength of Marengo’s platform and its strategic collaboration with Ipsen.

Advancing Oncology Pipeline Toward Broader Clinical Impact

The STARt-002 trial continues to enroll patients across North America, with completion expected later in 2026. The study includes dose expansion cohorts designed to further evaluate efficacy and determine the recommended Phase 2 dose (RP2D), supporting future late-stage development.

Marengo’s approach aligns with a broader industry trend toward combination therapies that integrate immunotherapy with targeted agents, aiming to overcome resistance mechanisms and improve long-term outcomes. The early clinical success of invikafusp alfa suggests it could become a key component of next-generation cancer treatment regimens, particularly for patients with limited therapeutic options.

With multiple programs advancing and strong clinical signals emerging, Marengo is positioning itself at the forefront of precision immuno-oncology, leveraging innovative science to address complex cancers.

The latest AACR 2026 data reinforce the potential of invikafusp alfa and the STAR platform to redefine cancer treatment through precision T-cell activation and combination therapy strategies. As Marengo continues to advance its clinical programs, these findings highlight a promising path toward more effective and durable therapies for metastatic breast cancer and beyond.

Source: Marengo Therapeutics press release