Breast Cancer Trials announced that its new CAPTURE clinical trial, led by Professor Sarah-Jane Dawson, is open to patients – https://www.breastcancertrials.org.au/current-clinical-trials/capture
The trial will recruit 140 patients at 20 participating institutions in Australia and sites currently open are: The Mater Hospital (SYD), The Calvary Mater Newcastle, South West Care (Warrnambool), Peter MacCallum Cancer Centre, Monash Medical Centre (Clayton) and the Royal Darwin Hospital (Darwin, NT).
The CAPTURE clinical trial is aimed at improving progression free survival rates for patients with metastatic breast cancer that is ER positive and HER-2 negative. Oestrogen-receptor positive (ER+) breast cancers account for 70% of all breast cancers and while treatment with a class of drugs called CDK4/6 inhibitors (eg: palbociclib and ribociclib) have been effective for some patients, others may be resistant to treatment.
It is thought that the PI3K pathway (important in cell growth and survival) can become very active in cancer cells because of mutations in the PIK3CA gene, and that this pathway may be important when resistance to CDK4/6 inhibitors and endocrine therapy develops. About 40% of ER-positive breast cancers have a PIK3CA mutation. PIK3CA mutations can be found by testing tumour tissue or blood. A blood test is easy to perform, safe, less invasive than a tumour biopsy and can be repeated regularly.
As a cancer grows, cancer cells die and are replaced by new ones. The dead cells get broken down and their contents, including DNA, are released into the bloodstream. This type of DNA is called circulating tumour DNA (ctDNA). ctDNA can be used to identify the PIK3CA mutation, which may also identify if treatment with a type of drug called a PI3K inhibitor will be effective.
The drug alpelisib is a class of drug called a PI3K inhibitor which can inhibit the growth and survival of cancer cells with a PIK3CA mutation. CAPTURE hopes to determine whether individuals with breast cancers that have the PIK3CA mutation will be more likely to benefit from treatment with alpelisib, in combination with fulvestrant, compared to standard treatment with capecitabine.
The CAPTURE clinical trial will screen approximately 400 patients with ER+, HER2 negative breast cancer via a blood test for the PIK3CA gene mutation in ctDNA. It is expected that approximately 260 (65%) of those tested will be negative for this mutation. Those participants who have a confirmed PIK3CA gene mutation (approximately 140 (35%)) will be randomised 1:1 to receive alpelisib and fulvestrant (Arm A) or the standard treatment capecitabine (Arm B).
Participants will have regular blood tests to see if the level of ctDNA changes during treatment. Participants will continue treatment until documented disease progression. The final study visit occurs 28 days after the last dose of study treatment. Treatment after the end of the study will be decided by the participant and their primary physician.
If successful, the trial will be an important step towards demonstrating the clinical utility of circulating tumour DNA testing in women with ER positive metastatic breast cancer.
“Rapid progress has been made in the development of ctDNA tests for use in cancer management. This trial will provide an important opportunity to understand how these tests may benefit women with metastatic breast cancer and hopefully bring us a step closer to routine incorporation of ctDNA testing in clinical practice,” said Professor Dawson.
Breast Cancer Trials is the largest, independent, oncology clinical trials research group in Australia and New Zealand. For over 40 years, Breast Cancer Trials has conducted a national clinical trials research program for the treatment, prevention and cure of breast cancer. For more information about Breast Cancer Trials, visit www.breastcancertrials.org.au.