The AKT inhibitor capivasertib (brand name Truqap) has been approved by the Medicines and Healthcare products Regulatory Agency (MHRA) for treating eligible patients with advanced breast cancer.
Capivasertib is indicated in combination with the hormone therapy fulvestrant for treating advanced hormone receptor (HR) positive, human epidermal growth factor receptor 2 (HER2) negative locally advanced breast cancer with specific biomarker alterations (PIK3CA, AKT1 or PTEN) following recurrence or progression on or after an endocrine-based regimen.
This follows the marketing authorisation of capivasertib by the European Commission (EC) in June 2024 for the same indication.
The first-in-class drug is taken orally at a starting dose of 400 mg twice a day for four days followed by three days of rest, then repeated.
Safety and efficacy of capivasertib
The MHRA and EC approvals were based on the results of the phase 3, randomised, double-blind CAPItello-291 trial, which included 708 patients with locally advanced or metastatic HR-positive, HER2-negative breast cancer. Of these, 289 patients (40.8%) had AKT pathway alterations.
Patients were randomised to receive either capivasertib or a placebo, both in combination with fulvestrant. The dual primary endpoint was investigator-assessed progression-free survival assessed both in the overall population and among patients with AKT pathway–altered (PIK3CA, AKT1, or PTEN) tumours.
In the overall population, the median progression-free survival was 7.2 months in the capivasertib–fulvestrant group, as compared with 3.6 months in the placebo–fulvestrant group (HR 0.60; 95% CI, 0.51 to 0.71; P<0.001).
In the AKT pathway–altered population, the median progression-free survival was 7.3 months in the capivasertib–fulvestrant group, as compared with 3.1 months in the placebo–fulvestrant group (HR 0.50; 95% CI, 0.38 to 0.65; P<0.001).
Potential side effects of capivasertib included high blood sugar, diarrhoea, rash and other skin drug reactions, urinary tract infection, low level of haemoglobin in blood, loss of appetite, nausea, vomiting, mouth sores or ulcers with gum inflammation, itching, and tiredness.
The most frequent adverse events of grade 3 or higher in patients receiving capivasertib–fulvestrant were rash (12.1% vs in 0.3% of those receiving placebo–fulvestrant) and diarrhoea (9.3% vs 0.3%).
Adverse events leading to discontinuation were reported in 13.0% of the patients receiving capivasertib and in 2.3% of those receiving placebo.
‘Exciting new targeted treatment’
Professor Nicholas Turner, professor of molecular oncology at The Institute of Cancer Research, London, and consultant medical oncologist at The Royal Marsden NHS Foundation Trust, who led the CAPItello-291 trial, said the MHRA approval is ‘wonderful development in the treatment of the most common type of advanced breast cancer’.
He added: ‘Around half of patients with this kind of breast cancer have mutations in one or more of the genes PIK3CA, AKT1 or PTEN, and for these patients, capivasertib provides an exciting, new targeted treatment which can keep their cancer from progressing for longer.
‘We hope NICE will recommend the use of capivasertib in combination with fulvestrant for patients on the NHS.’
Speaking about the EC marketing authorisation of this AKT inhibitor, Dr Mafalda Oliveira, senior clinical investigator of the Vall d’Hebron Institute of Oncology’s Breast Cancer Group in Barcelona, Spain, said: ‘Patients with advanced [HR]-positive breast cancer typically experience tumour progression or resistance with widely used endocrine-based treatment regimens, and there is an urgent need to provide them more time with their disease under control.
‘[This] approval is welcome news for approximately half of [HR]-positive breast cancer patients in Europe who have tumours with these biomarkers, and it is important for clinicians to test and identify eligible patients who may be able to benefit from this combination.’
