Drug combination shows exciting results in ovarian cancer in early trial

A study published recently in the Annals of Oncology and reported by the Institute of Cancer Research has shown exciting results that could offer hope to thousands of women with recurrent, platinum-resistant advanced stage ovarian cancer. We take a look at the study, and what the results could mean for women with the disease. 

What do we know so far?

Previous research has shown that increased levels of p-S6K in patients with ovarian cancer leads to them becoming resistant to standard platinum-based chemotherapy. 

Every year 7,400 women are diagnosed with the disease and a high percentage will suffer a relapse that is resistant to standard platinum treatments. Survival rates in this group are very poor, but inhibiting p-S6K in these patients could help improve outcomes.

What does this new study show?

The study looked at combining weekly paclitaxel chemotherapy, a drug commonly used to treat ovarian cancer, with a drug called Vistusertib. Based at the Institute of Cancer Research, the Royal Marsden, and nine other sites across the UK, the study included 25 patients who had advanced stage, platinum-resistant ovarian cancer. It also included a further 40 patients who had non-small cell lung cancer. 

Vistusertib works to inhibit proteins called mTOR1 and 2, which turn on an enzyme called p-S6K. p-S6K helps cancer cells to grow and resist chemotherapy, so inhibiting mTOR1 and 2 can prevent this.

The study found that just over half of the ovarian cancer patients saw the size of their tumour shrink by at least 30%. It also saw an average of nearly six months progression-free survival, meaning there was no further tumour growth in this period of time. These outcomes are particularly significant as previously this type of ovarian cancer would have been resistant to all types of standard treatment.

The study also found that although there were side effects to the treatment, they were manageable and did not significantly impact on the patient’s quality of life.

What does this mean and what happens next? 

Effective treatments for advanced stage, recurrent, and platinum-resistant ovarian cancer are very limited, so the results of this phase one study are hugely encouraging. 

The last few years have seen the development and approval of PARP inhibitors such as Olaparib and Niraparib for patients who have a platinum-sensitive ovarian cancer recurrence. This news potentially offers hope to a whole new group of patients who are platinum-resistant, and who currently find their treatment options extremely limited.

Treatments that can help slow down the progression of ovarian cancer with minimal side effects are essential. They allow women longer between treatments, fewer hospital visits, and more time to spend with family and friends while they feel well.

A phase two trial of this study has already begun. It will include more ovarian cancer patients and hopes to give more conclusive results about the effectiveness of Vistusertib combination therapy in treating advanced stage platinum-resistant ovarian cancer.