Familial adenomatous polyposis (FAP) is rare condition that can often run in families, but it can also develop in people who do not have a family history of the condition. FAP causes hundreds or thousands of small growths called polyps to develop in the large bowel. These polyps are not cancerous, but if they are not treated some of them are likely to develop into cancer. If there is a family history of FAP, patients will have regular screening from a young age, usually done as a colonoscopy. Polyps usually appear when a person is in their teens if they have classical FAP, and around 10 years later if they have attenuated FAP. For patients with classical FAP, there is a nearly 100% risk of progression to colorectal cancer by 40 years of age if no treatment has been given. The only preventative treatment available for FAP is surgery to remove the colon and sometimes the rectum. After surgery, patients often need to go to the toilet more often, and may need to have a stoma (an opening in the abdomen allowing faeces to be collected in a bag).
Eflornithine in combination with sulindac is being developed as a treatment for FAP. Both these drugs slow down the growth of the polyps in different ways, and taking them together is thought to be potentially more effective than taking them alone. If licensed, this drug combination could reduce or delay the need for surgery or other major endoscopic procedures for people with FAP.
Olaparib belongs to a group of drugs called PARP enzyme inhibitors while bevacizumab is an anti-VEGF monoclonal antibody. Both drugs act in different but synergistic ways to kill tumour cells. It is thought that bevacizumab may increase the sensitivity of olaparib to killing the tumour cells. Olaparib administered orally as a monotherapy is already licensed as a maintenance therapy of advanced ovarian cancer. The addition of bevacizumab given by intravenous infusions may potentially improve treatment outcomes.