MTAP deletion

PRMT5 inhibitor activity is independent of TKI exposure, driver alteration, and SDMA expression and enhanced by addition of TKI. These findings support clinical evaluation of PRMT5 inhibitor + TKI combinations for advanced NSCLC.

After failure of gemcitabine/docetaxel chemotherapy, next-generation sequencing identified an IGFBP5-ALK fusion (breakpoint: IGFBP5 exon 1 - ALK exon 19), a TERT promoter mutation, and a homozygous CDKN2A/CDKN2B/MTAP deletion. This case highlights the first documented response to an ALK inhibitor in ALK-rearranged HG-ESS. The findings underscore the importance of comprehensive molecular profiling in identifying targetable alterations in rare sarcomas and support the use of iruplinalkib as an effective therapeutic option in this setting.

P1, N=36, Not yet recruiting, M.D. Anderson Cancer Center

P1, N=260, Recruiting, IDEAYA Biosciences | Not yet recruiting --> Recruiting

Analysis of consensus QSAR models identified two highly active PRMT5 inhibitor candidates (CHEMBL4539612 and CHEMBL4577464), with high affinity for binding (- 13.5 to - 13.7 kcal/mol) to the PRMT5 active site and interactions similar to those of the known clinical PRMT5 inhibitor ONAMETOSTAT...Network pharmacology analysis indicated that PRMT5 and its interacting partners are mainly associated with histone arginine methylation and spliceosomal assembly, processes that are frequently dysregulated in MTAP-deficient cancers. These findings suggest CHEMBL4539612 and CHEMBL4577464 as promising scaffolds for the development of selective PRMT5 inhibitors in epigenetic cancer therapy.

Furthermore, I-14 displayed acceptable pharmacokinetic properties and significant antitumor efficacy (TGI = 84.8% at 100 mg/kg) in an MTAP-null MDA-MB-231 xenograft model. Our findings suggest that I-14 is a promising lead compound for MTAP-null TNBC treatment.

MTA-cooperative PRMT5 inhibitors such as BMS-986504/MRTX1719 and AMG 193 target the PRMT5-MTA complex, while inhibitors of the SAM synthetase methionine adenosyl transferase 2A (MAT2A), such as IDE397, deprive PRMT5 of its methyl donor SAM. In this review article, we summarize the mechanisms of action, preclinical data, and clinical data available thus far for these novel classes of oncology precision medicine and discuss potential future directions relevant to MTAP deletion as a promising synthetic lethal vulnerability for cancer therapy.

This review summarizes current knowledge on the biological functions of MTAP, the mechanisms linking its loss to oncogenesis, and the evolving landscape of therapeutic strategies targeting MTAP-deficient cancers. Understanding these molecular dependencies offers novel opportunities for the development of precision-based therapies across diverse tumor types.

Leveraging the kinetic isotope effect, we generated methyl-d3 analog 16 which reduced the formation of M1 in vivo, resulting in acceptable safety margins and an improved pharmacokinetic profile. Our data suggest this strategy could be employed more broadly to reduce undesirable metabolism of methylated amines.

MTAP is a key biomarker in precision oncology; this work describes the clinical outlook for these patients within the community-oncology setting. These insights can inform future study design, as MTAP-directed therapies continue their development.

It demonstrates that targeting these lesions can yield outcomes that meet or exceed the benchmarks set by the NAPOLI-1 trial (liposomal irinotecan plus 5-fluorouracil and leucovorin), with a median overall survival of 6.2 months and progression-free survival of 3.1 months. Objective response rates reach 33% with adagrasib in KRAS G12C PDAC, 22% with olaparib maintenance in germline BRCA1/2 cancers, and over 50% with RET or NTRK inhibitors with fusion alterations; pembrolizumab produces durable benefit in the 1-3% of tumours that are MSI-H/dMMR. Emerging data highlight NRG1 fusions (overall response rate 42% with zenocutuzumab), HER2 amplification, MTAP deletion with PRMT5 dependency and variant-specific (MRTX1133) or pan-RAS (daraxonrasib) inhibitors as the next frontier...Taken together, these advances represent a substantive therapeutic progress in PDAC over the past decades, even though they currently apply to a minority of patients. These findings underscore the necessity of comprehensive next-generation sequencing for every patient with advanced disease, enabling identification of rare, yet clinically meaningful, targets and moving PDAC management towards a precision-oncology paradigm.

MTAP dels frequently co-occur with oncogenic driver alterations and can develop at time of osimertinib resistance. A patient with oncogenic driver-positive, MTAP-del NSCLC had a partial response to PRMT5 inhibitor treatment. This work could inform future trials of PRMT5 and MAT2A inhibitors.