In an ongoing Phase 1 dose-escalation study, ACR-2316, Acrivon’s WEE1/PKMYT1 inhibitor, showed pharmacodynamic target engagement at the first two dose levels, with approximately dose-proportional pharmacokinetics and early clinical activity, including tumor shrinkage, at the third dose level. Separately, the company plans to share updated interim outcomes from its registrational‑intent Phase 2b study of ACR-368 (prexasertib) in endometrial cancer, along with an update on a newly opened biopsy‑independent Phase 2b arm and details of a planned confirmatory Phase 3.
The core development is a January 2026 webcast where Acrivon will consolidate program updates across its AP3-guided pipeline: new data reads from ACR-368 and ACR-2316 and the nomination of a new preclinical candidate in its cell‑cycle franchise. For ACR-368, the company has an FDA Fast Track for monotherapy in endometrial cancer using its OncoSignature assay to identify likely responders, and an FDA Breakthrough Device designation for that assay. The Phase 2b is framed as registrational‑intent, with a confirmatory Phase 3 in planning. For ACR-2316, enrollment through three dose levels is complete.
Strategically, the move reads as a dual‑track de‑risking exercise. On one track, Acrivon is leaning into an assay‑enriched path for ACR-368 that could support an accelerated filing if the interim Phase 2b readout shows a clean efficacy signal in OncoSignature‑positive patients. On the other hand, the company is opening a biopsy‑independent arm—an implicit acknowledgement of the operational drag and screen‑failure risk that fresh‑biopsy, mass‑spec–based selection can impose. If the drug demonstrates activity outside the assay gate, even at a lower magnitude, it could ease enrollment, broaden commercial optionality, and provide a hedge if the diagnostic’s clinical validation or scalability becomes a bottleneck. The confirmatory Phase 3 planning signals an intent to align early with regulators on endpoints, enrichment strategy, and diagnostic readiness—key issues for assay‑dependent oncology programs.
For stakeholders, the impact is practical. Sites running the OncoSignature workflow face added biopsy logistics, turnaround times, and sample chain‑of‑custody complexity; a biopsy‑independent cohort could improve throughput and reduce screen failures, but may require larger sample sizes and tighter monitoring to preserve power. CROs and central labs will need robust PD and PK sampling infrastructure, given Acrivon’s heavy reliance on mass spectrometry–based readouts and pharmacodynamic markers. Regulators will look for a consistent efficacy delta between OncoSignature‑positive and negative populations, analytical robustness, and inter‑site reproducibility of the assay, and a clear bridging plan if the assay evolves between Phase 2b and Phase 3. Within the DDR landscape, ACR-2316 enters an increasingly crowded WEE1 segment where hematologic and GI tolerability often dictate dose intensity; early signs of target engagement and activity are encouraging, but the recommended Phase 2 dose and dose‑limiting toxicities will determine whether the program can sustain monotherapy ambitions or must pivot to combinations.
Key watch items in January are the magnitude and durability of response for ACR-368 in OncoSignature‑selected endometrial cancer, comparative activity in the biopsy‑independent arm, and clarity on safety—particularly myelosuppression, given prexasertib’s historical profile. The Phase 3 blueprint will reveal whether Acrivon will anchor on ORR with a confirmatory PFS trial, and how tightly the assay will be tied to eligibility. For ACR-2316, establishing a tolerable RP2D and outlining expansion cohorts across AP3‑prioritized tumor types will signal the scale of near‑term investment and whether the company can advance as a monotherapy or must lean into rational DDR combinations. Execution risk centers on diagnostic scalability, enrollment velocity, and the ability to translate sophisticated PD readouts into operationally simple protocols across community and academic sites.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
