AstraZeneca has announced enrolment of the first patient in the Phase III clinical programme for olaparib, an oral poly ADP ribose polymerase (PARP) inhibitor being investigated for the treatment of BRCA mutated ovarian cancer. 

The Phase III SOLO (Study of OLaparib in Ovarian cancer) programme is designed to determine the benefit, by progression-free survival, of olaparib as a maintenance monotherapy in BRCA mutated ovarian cancer patients. 

The SOLO 1 study is being conducted in collaboration with the Gynecologic Oncology Group and the SOLO 2 study with the European Network of Gynaecological Oncological Trial Groups. Both trials are randomised, double blind, placebo controlled studies that utilise the tablet formulation of olaparib at a dose of 300mg twice daily.

The initiation of these studies is based on the subgroup analysis by BRCA mutation status of the Phase II maintenance study in relapsed ovarian cancer, announced at the American Society of Clinical Oncology (ASCO) 2013 Congress, which demonstrated olaparib's potential as a maintenance treatment for platinum-sensitive relapsed patients with BRCA mutated ovarian cancer.

BRCA1 and BRCA2 are human genes that belong to a type of genes known as tumour suppressors. Mutation of these genes has been linked to hereditary breast and ovarian cancer and a woman's risk of developing breast and/or ovarian cancer is greatly increased if she inherits a BRCA1 or BRCA2 mutation. Only 15 per cent of ovarian cancers are found before the cancer has spread outside the ovary. Despite advances in treatment and diagnosis, for patients with ovarian cancer that has spread beyond the ovary the five-year survival rate is well below 50 per cent.