# AKT1 E17K mutation

Source: https://onco.cc/biomarkers/akt1-e17k/  
OnCo record `akt1-e17k` (Biomarker). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

AKT1 E17K is a single hotspot mutation, in about 3 to 5 percent of hormone-receptor-positive breast cancers, that switches on the AKT kinase directly. It is one of the three alterations that qualify a patient for capivasertib.

## Summary

The E17K substitution in the pleckstrin homology domain sends AKT1 to the membrane without PIP3. Capivasertib (Truqap) is labelled with fulvestrant for HR-positive HER2-negative advanced breast cancer with one or more PIK3CA, AKT1 or PTEN alterations as detected by an FDA-approved test (CAPItello-291); FoundationOne CDx carries the three-gene claim. AKT1 E17K also appears in endometrial and rarer cancers, where it is a trial marker only.

## Fields

- Kind: Biomarker
- Last checked: 2026-09-23
- Also known as: AKT1 E17K; AKT1 mutation; E17K; AKT1-mutant
- Tags: biomarker; pi3k

## Sources

- TRUQAP prescribing information (DailyMed): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d698c106-2322-401e-b738-cbd83c843ecf

## Connected records

- biomarkers: [PIK3CA mutation](https://onco.cc/biomarkers/pik3ca-hotspot-mutation/), [PTEN alteration (sequencing) and PTEN loss (IHC)](https://onco.cc/biomarkers/pten-alteration/)
- cancers: [Endometrial cancer](https://onco.cc/cancers/endometrial/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/)
- drugs: [Capivasertib](https://onco.cc/drugs/capivasertib/), [FoundationOne CDx / Liquid CDx](https://onco.cc/drugs/foundationone-cdx/)
- terms: [Hyperglycaemia (PI3K/AKT inhibitor class effect)](https://onco.cc/terms/hyperglycaemia/)
- targets: [AKT](https://onco.cc/targets/akt/)

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JSON: https://onco.cc/api/v1/entities/akt1-e17k.json