The U.S. Food and Drug Administration has authorized OGT's CytoCell KMT2A Breakapart FISH Probe Kit PDx as a companion diagnostic for Syndax's menin inhibitor revumenib (Revuforj), marking a significant advancement in precision oncology for patients with KMT2A-rearranged acute leukemia. The FDA granted the De Novo Classification Request on September 22, 2025, enabling rapid identification of patients eligible for treatment with the first-in-class therapeutic.
Diagnostic Technology and Clinical Impact
The CytoCell KMT2A Breakapart FISH Probe Kit PDx detects clinically relevant rearrangements in patients with acute leukemia, providing what OGT describes as "a robust, accessible, rapid turnaround test for KMT2Ar detection that will maximize the ability for clinicians to quickly identify patients who may be eligible for treatment with Revuforj."
The diagnostic addresses a critical need in acute leukemia care, as it is estimated that more than 95% of patients with KMT2A-rearranged acute leukemia have a KMT2A translocation—a type of rearrangement that occurs when part of one chromosome breaks and fuses to a different chromosome.
"Accurately identifying acute leukaemia patients with KMT2Ar is a key factor in selecting appropriate therapeutic options for a group of patients who have traditionally had a very poor prognosis," said Adrian Smith, CEO of OGT.
Regulatory Achievement and Classification
The companion diagnostic received Class II device classification, which Steve Chatters, OGT's EVP of Regulatory and Medical Affairs, noted as significant: "Our strong foundation in haematology diagnostics has been a key factor in our success bringing the KMT2Ar CDx to market as a Class II device, as opposed to the more common Class III classification for companion diagnostics."
This classification reflects OGT's decades of experience developing regulated FISH products, gained from prior development of IVDR-certified and FDA-cleared FISH probes, combined with extensive customer partnerships in hematology laboratories across the United States.
Disease Background and Patient Population
KMT2A rearrangements represent a particularly challenging subset of acute leukemia cases. The KMT2A gene at 11q23.3 is commonly rearranged in acute leukemias, especially in infant leukemia. KMT2A rearrangements can be detected in approximately 70%-80% of infants with acute lymphoblastic leukemia (ALL) and in 5-10% of pediatric and adult ALLs.
The rearrangements are also found in more than 50% of infants with acute myeloid leukemia (AML) and are seen in 10% of adolescents and 3-10% of adults with AML. More than 90 partner genes have been identified to date, with the most common partner genes being AFF1 (4q21), MLLT3 (9p22) and MLLT1 (19p13.3).
Revumenib Clinical Data
Revumenib received FDA approval in November 2024 for relapsed or refractory acute leukemia with a KMT2A translocation in adult and pediatric patients one year and older. The approval was supported by data from the phase 1/2 AUGMENT-101 trial, where revumenib demonstrated a complete remission with partial hematologic recovery (CR+CRh) rate of 21.2% (95% CI, 13.8%-30.3%) among patients with relapsed/refractory AML or ALL harboring KMT2A rearrangements. The median CR+CRh duration was 6.4 months (95% CI, 2.7-not estimable).
Precision Medicine Partnership
Dr. Leila Luheshi, VP of Pharma Partnering at OGT, emphasized the significance of the authorization: "The development and subsequent authorization of this new CDx is an important demonstration of the skill and commitment of our clinical scientists and regulatory specialists to deliver safe and effective diagnostics for patients with one of the most devastating forms of leukaemia."
The emergence of precision therapies like revumenib, described as an oral inhibitor of the menin-KMT2A interaction, offers new therapeutic avenues for patients with these challenging acute leukemia cases, representing a shift toward more targeted treatment approaches in hematologic malignancies.
