AFT-50 EndoMAP: A phase IB/II multicohort study of targeted agents and/or immunotherapy for patients with recurrent or persistent endometrial cancer (EC).
Authors: Evelyn Cantillo, Tyler J. Zemla, John William Moroney, Edwin A Alvarez, Jigna Shah, Yvonne Gail Lin, Gillian DiLallo, Joyce F. Liu, Haider Mahdi, Angeles Alvarez Secord, Andrew B. Nixon, Sumithra J. Mandrekar, Ursula A. Matulonis, David E. Kozono, Brian M. Slomovitz
Journal: Journal of Clinical Oncology (2024)

TPS5642 Background: The landscape in the management of recurrent or persistent endometrial cancer (EC) continues to evolve. Anti-PD-1/PD-L1 immune checkpoint inhibitors (ICI) as monotherapy or when combined with the VEGF-targeted tyrosine kinase inhibitor, lenvatinib, have demonstrated promising response rates in patients (pts) with microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) and MS-stable (MSS)/MMR-proficient (MMRp) EC, respectively. Recent studies have also shown a benefit with adding ICI to standard of care chemotherapy in the frontline setting. Pts with MSI-H/dMMR tumors seem to derive the greatest benefit. Approximately, 30% of recurrent EC pts fall into this category. Pairing ICI with targeted therapies carries the potential to elicit prolonged anti-tumor effects. Atezolizumab (Atezo) is a humanized monoclonal PD-L1 inhibitor that has demonstrated monotherapy antitumor activity in relapsed recurrent EC, and other solid tumors (e.g. NSCLC, HCC) as monotherapy and as part of combinatorial therapy. The AFT-50/EndoMAP study is a phase IB/II non-randomized, multicenter, 2-arm, multi-cohort platform trial designed to evaluate the efficacy and safety of biomarker-driven combination regimens, both with Atezo (AFT-50A) and without Atezo (AFT-50B) with biomarker-defined targeted agents in pts with recurrent or persistent EC. Methods: Eligible pts have recurrent or persistent EC with no more than 2 prior lines of therapy. FoundationOne CDx (F1CDx) NGS assay will be used for genomic tumor profiling. In AFT-50A, pts may be eligible for one of the following doublets: Atezo+talazoparib (tumors with genomic loss of heterozygosity (gLOH ≥16%), Atezo+Trastuzumab emtansine (ERBB2/HER2 mutated or amplified tumors), and Atezo+Tiragolumab (MSI-H and/or TMB-H). The Atezo+bevacizumab (biomarker unmatched) and Atezo+ipatasertib (PIK3CA/PTEN/AKT1-altered tumors) cohorts have completed accrual. Each cohort will enroll ~20 pts with potential adjustment to account for statistical and clinical considerations. AFT-50A pts will receive Atezo in addition to a targeted agent (per study-approved dosing schedule) until progression, unacceptable toxicity, pt withdrawal, death, or study termination. AFT-50B pts will be eligible for inavolisib (PIK3CAm/PTEN and AKT1wt-altered tumors) + letrozole or giredestrant + abemaciclib (RB1wt, estrogen receptor positive tumors). The primary endpoint for AFT-50A is confirmed overall response rate (ORR) for each arm, and for AFT-50B is 6-month progression free survival. Secondary endpoints include disease control rate, duration of response, OS, safety and tolerability. As a platform study, additional arms may be added, as supported by evolving understanding of EC and molecular targets. EndoMAP is actively enrolling at 20 sites in the US with a target of 25 sites nationwide. Clinical trial information: NCT04486352 .