Acrivon's Precision Drug ACR-368 Shows Strong Signal in Endometrial Cancer

WATERTOWN, MA – January 23, 2026 – Acrivon Therapeutics is set to take center stage at a major European oncology conference next month, where it will present highly anticipated clinical data for its lead drug candidate, ACR-368, in patients with advanced endometrial cancer. The announcement of a late-breaking oral presentation at the European Society of Gynecological Oncology (ESGO) Annual Congress has focused attention on the biotechnology company and its precision medicine approach, which appears to be yielding particularly strong results in one of the most aggressive forms of the disease.

The presentation, scheduled for February 27th in Copenhagen, will feature interim data from the company's potentially registrational Phase 2 trial. It will be delivered by Dr. Panagiotis Konstantinopoulos, a renowned gynecological oncologist from the Dana-Farber Cancer Institute and Professor at Harvard Medical School, lending significant weight to the findings. This event is seen as a critical milestone for Acrivon, potentially validating its unique drug development strategy and offering new hope for a patient population with limited treatment options.

“We are very excited that Dr. Konstantinopoulos will be presenting ACR-368 clinical data at this prestigious event,” said Peter Blume-Jensen, M.D., Ph.D., chief executive officer, president, and co-founder of Acrivon. “We believe that the recent interim clinical data from our ongoing study provide a highly compelling clinical profile in a high unmet need patient population and look forward to Panos sharing the data and his insights with leading gynecological oncologists from around the world.”

A Targeted Strike Against a Difficult Cancer

ACR-368, also known as prexasertib, is a small molecule designed to inhibit CHK1 and CHK2, two key proteins that regulate the cell's response to DNA damage. In healthy cells, these checkpoints are crucial for maintaining genomic stability. However, many cancer cells hijack these pathways to survive the stress of rapid, uncontrolled division. By blocking CHK1 and CHK2, ACR-368 aims to push these cancer cells past a point of no return, leading to cell death.

While the concept is not new—other CHK1 inhibitors have been tested with mixed results—Acrivon's strategy is distinguished by its precision. The ongoing trial uses a proprietary companion diagnostic, the OncoSignature assay, to select patients whose tumors are predicted to be most sensitive to the drug.

Recent interim data from the study has been particularly encouraging. An analysis from December 2025 revealed an overall response rate (ORR) of 39% in patients identified as biomarker-positive. More strikingly, the drug demonstrated profound activity in a specific, hard-to-treat subtype: uterine serous carcinoma. In this group of patients, ACR-368 achieved a confirmed ORR of 67%. This aggressive subtype is known to have inherent deficiencies in other cell cycle checkpoints, making it theoretically more dependent on the CHK1/CHK2 pathway that ACR-368 targets, a hypothesis the clinical data now appears to support.

This level of efficacy in a pre-selected population has already garnered regulatory attention. The U.S. Food and Drug Administration (FDA) has granted Fast Track designation to ACR-368 for this indication and Breakthrough Device designation for the OncoSignature assay, underscoring the potential of this drug-diagnostic combination to address a significant unmet medical need.

The Brains Behind the Breakthrough: The AP3 Platform

At the heart of Acrivon's strategy is its proprietary Generative Phosphoproteomics AP3 platform. This technology moves beyond traditional genomics-based biomarker discovery by directly measuring how a drug affects thousands of proteins and their activity levels inside the living cancer cell. By analyzing these "phosphoproteomic" signatures, the platform creates a detailed map of the drug's true mechanism of action and identifies which cellular pathways are critical for its anti-cancer effects.

This deep biological insight allows Acrivon to build its OncoSignature tests, which are designed to mechanistically match a patient's tumor biology to the drug. For ACR-368, the AP3 platform was first used in preclinical screening to identify endometrial cancer as a highly sensitive tumor type. The platform then identified a complex biomarker signature based on protein activity that predicts this sensitivity, which was subsequently validated in blinded studies on archived patient tumor samples before being deployed in the current prospective trial.

This platform-driven approach represents a potential paradigm shift from both traditional trial-and-error drug development and more common AI-based methods that often focus on identifying a single target without fully understanding the complex network effects within the cell. By quantifying a drug's impact on the entire cellular protein network, Acrivon aims to de-risk and streamline clinical development, selecting the right patients for the right drug from the outset.

Navigating a Shifting Treatment Landscape

The upcoming data presentation comes at a time of rapid evolution in the treatment of endometrial cancer, the most common gynecologic malignancy in the developed world. While surgery is effective for early-stage disease, options for patients with advanced or recurrent cancer have historically been limited, often relying on chemotherapy regimens with modest efficacy.

In recent years, the landscape has been transformed by the approval of immune checkpoint inhibitors like Keytruda and Jemperli, often in combination with chemotherapy or other targeted agents like Lenvima. These therapies have provided significant benefit, particularly for patients whose tumors have specific genetic features.

However, a substantial unmet need remains for patients whose cancers do not respond to or progress after these treatments. Acrivon’s approach with ACR-368 and the OncoSignature test is designed to fill this gap, offering a highly personalized therapy based on the functional biology of a patient's tumor, rather than a single genetic mutation. This could prove crucial for patients with aggressive subtypes like uterine serous carcinoma, which often exhibit resistance to standard therapies.

A Pivotal Moment in Copenhagen

For Acrivon, the ESGO congress represents more than just a scientific presentation; it is a strategic inflection point. A strong showing of data for a drug in a registrational-intent study, presented by a key opinion leader at a conference attended by over 3,000 specialists, can significantly elevate a company's profile. Positive results could bolster investor confidence, attract potential partners for commercialization, and pave the way for regulatory submissions in the U.S. and Europe.

The company is already expanding its clinical trial for ACR-368 into the European Union, with enrollment expected to begin in the first quarter of 2026. The focus on a global development plan highlights Acrivon's ambition to establish ACR-368 as a new standard of care.

Furthermore, the success of ACR-368 serves as a powerful proof-of-concept for the underlying AP3 platform. Acrivon is already leveraging the technology to advance a broader pipeline, including ACR-2316, a novel WEE1/PKMYT1 inhibitor in Phase 1 trials that has shown initial activity in several solid tumors, and ACR-6840, a preclinical asset targeting CDK11. The data presented in Copenhagen will therefore be watched not only for its implications for endometrial cancer patients but also as a barometer for the future of Acrivon's entire precision oncology pipeline.