PURPOSE
NCI-MATCH (EAY131) is a precision medicine trial using genomic testing to allocate patients with advanced malignancies to targeted treatments. Arm Y evaluated capivasertib, a pan AKT inhibitor, in patients with an
AKT1 E17K
–mutated tumor. Here, we report on the translational objectives of the study, a molecular and genomic analysis of specimens to identify potential biomarkers of response or resistance to capivasertib.
METHODS
Eligible patients had
AKT1 E17K
–mutated metastatic tumors that progressed with standard treatment and received capivasertib 480 mg orally twice daily for 4 days on and 3 days off weekly in 28-day cycles. The primary end point was objective response rate (ORR). We performed whole-exome sequencing, RNA sequencing, and gene set and pathway enrichment analysis on 25 pretreatment tissue samples and evaluated findings in responders (complete response [CR], n = 0, and partial response, n = 9) and nonresponders (stable disease, n = 13, and progressive disease, n = 3).
RESULTS
The ORR was 28.6% (10 of 35) in the reported primary trial and 36% (9 of 25) in this translational cohort. Mutations in the
TP53
gene were more frequent in responders, whereas the PI3K/AKT/mTOR pathway genes
TYRO3
,
SYNJ1
, and
CDIPT
were significantly altered in nonresponders. DNA repair, p53, E2F, and Wnt-beta catenin pathways were enriched in the responder group. Unsupervised clustering of gene expression identified five genes,
ANKRD30A
,
SUSD4
,
TTC6
,
POTEJ
, and
POTEI
, that were significantly higher in responders and lower in nonresponders. In addition, EGFR expression was significantly increased in nonresponders.
CONCLUSION
In patients with
AKT1 E17K
–mutated tumors, capivasertib achieved a clinically significant ORR.
TP53
mutations appear to be associated with response, whereas certain additional PI3K/AKT/mTOR pathway mutations and EGFR overexpression appear to be associated with nonresponse to capivasertib. Further investigation of predictive biomarkers is warranted.