Positive Phase III clinical trial results point to promise of capivasertib treatment

The clinical trial success moves a much-needed, new-therapeutic option one-step closer to reaching breast cancer patients who suffer a recurrence or disease progression following endocrine therapy. Notably, capivasterib is a first-in-class therapeutic originally discovered as part of a collaboration between the Institute of Cancer Research UK, Cancer Research Horizons and Astex Pharmaceuticals.  

Capivasterib targets Protein Kinase B (PKB), also known as AKT, an enzyme associated with the hallmark characteristics of a cancer cell including the promotion of survival and growth, cell proliferation and migration and even angiogenesis (the recruitment of blood vessels to ensure nourishment reaches an expanding cellular mass or tumour).  

Hormone receptor status directly influences the number of treatment options available to breast cancer patients.  As mentioned, trial participants demonstrated hormone receptor positive and human epidermal receptor 2 (HER2) negative, a genetic disposition associated with 70% of the breast cancer population. Broadening the therapeutics options for these patients, capivasterib is the first clinical asset to reach Phase III from a dedicated discovery platform for developing and commercialising novel small molecule inhibitors of PKB to use as anti-cancer agents. In 2005, AstraZeneca entered an alliance with Astex Pharmaceutical and licensed worldwide rights to PKB inhibitors discovered under Astex’s existing PKB drug discovery stem from collaboration with The Institute of Cancer Research and Cancer Research Technology, now Cancer Research Horizons.   

The AKT tumour survival pathways is frequently activated in tumours by disrupting PTEN, the cell’s tumour suppressor machinery. PTEN is known as tumour suppressor gene because the enzyme it expresses regulates cell growth and proliferation.   

Trial participants with hormone receptor positive and human epidermal receptor 2 (HER2) negative locally advanced or metastatic disease (following endocrine therapy) received either capivasterib in combination with Faslodex (fulvestrant), a standard treatment for metastatic breast cancer or Faslodex and placebo. The trial demonstrated a statistically significant improvement in progression-free survival in the group of patients treated with capivasterib, in comparison to the placebo group. The trial will continue till the assessment of overall survival is possible.

Read the press release from AstraZeneca here.