Prevalence
10–15% of solid tumors
Across NSCLC, PDAC, glioblastoma, mesothelioma, bladder, and esophageal cancers — one of the most common deletions in oncology.
Deleted in 10–15% of all human cancers
The deletion you need to see.
Homozygous MTAP deletion may represent a clinically meaningful signal across solid tumors.
Understanding MTAP today and coordinating care can prepare for tomorrow's treatment landscape.
Why this biomarker, why now
A genetic vulnerability hiding in plain sight.
Homozygous deletion of the MTAP gene on chromosome 9p21 occurs in roughly 15% of all solid tumors — including non-small cell lung cancer, pancreatic ductal adenocarcinoma, glioblastoma, mesothelioma, bladder, and esophageal cancers.
When MTAP is lost, tumor cells become uniquely dependent on the PRMT5 methylation pathway — a synthetic lethal vulnerability that a new generation of investigational therapies is designed to exploit.
For pathologists and oncologists, the question is no longer whether to look for MTAP loss, but when.
When MTAP is lost, PRMT5 becomes the opening.
A passive deletion event becomes an active therapeutic target — but only for patients whose status is on the chart.
Vulnerability
PRMT5 synthetic lethality
MTAP loss elevates MTA, which sensitizes tumor cells to PRMT5 inhibition while sparing MTAP-intact normal tissue.
Actionability
Trials enrolling now
A new generation of MTA-cooperative PRMT5 inhibitors is in clinical development. Status determines eligibility.
The unmet need
The biology is solved. The workflow isn't.
~15%
of solid tumors carry homozygous MTAP deletion
0
PRMT5 inhibitors approved today — every eligible patient is a trial candidate
9p21.3
the locus where MTAP and CDKN2A are co-deleted and routinely missed in reports
Where to start
Four steps to operationalize MTAP testing.
01
Understand the biology
What MTAP does, why its loss creates PRMT5 dependency, and which tumor types are most often affected.
Read more
02
Choose the right test
IHC, FISH, and NGS — how each detects homozygous loss, with guidance on interpretation pitfalls.
Read more
03
Plan the clinical pathway
When to test, how to report, and how to coordinate molecular tumor boards around MTAP findings.
Read more
04
Connect patients to trials
Investigational PRMT5 inhibitors are recruiting now. Identify candidates before progression narrows options.
Read more
Clinical trials
When testing reveals an MTAP deletion, a trial may be the next conversation.
Investigational PRMT5 inhibitors are being studied in patients whose tumors carry homozygous MTAP loss. Refer eligible patients early — site activation, screening, and consent take time.
Search the trial directory