Researchers at the London’s Institute of Cancer Research have conducted a clinical trial on a new drug – ONX-0801 – that is showing incredible promise for treatment of ovarian cancer.
The new drug mimics folic acid to enter cancer cells and attacks them by blocking thymidylate synthase causing irreparable DNA damage. Ovarian cancer cells have high numbers of folic acid receptors (alpha folate receptors) making them particularly susceptible to the treatment.
15 women with ovarian cancer took part in the small initial clinical trial, with half responding positively to the treatment with dramatic shrinkage of their tumors.
Dr Udai Banerji, leader of the study said, “It is rare to see such clear evidence of reproducible responses in these early stages of drug development.” The results have been called “highly unusual” and “very promising”.
Cancer treatments such as chemotherapy have many unwanted side effects, although treatment with ONX-0801 only resulted in minimal side effects as the drug leaves normal cells alone, only attacking cancer cells.
The researchers are naturally excited about the discovery, with Banerji saying the treatment could add “upward of 6 months to lives of patients.” If the treatment is given to women in the early stages of the disease, when treatments tend to be more effective, it is possible that the drug will have more impact on survival rates.
However, this is only one small trial and long-term outcomes have not been determined, so the results should be treated with caution. Shrinking tumors is important but it does not mean the new drug will be a cure for ovarian cancer. The results of the study are exciting, but they must be treated with caution.
Ovarian cancer has a five-year survival rate of just 45% and in the United Kingdom, more than a third of patients diagnosed with ovarian cancer die in the first year following diagnosis. 1,600 of the 14,000 women diagnosed with ovarian cancer in the UK died within a month of being diagnosed.
Any treatment that has the potential to increase the lives of patients by 6 months or more without any major side effects would make a big difference to patients and their families.
The success rate could be further improved by carefully selecting patients. Analysis of ovarian tumors would allow doctors to determine the level of folic acid receptors and therefore the likelihood of a positive response to treatment. The researchers suggest ONX-0801 could be used as a treatment for ovarian cancer in women who have stopped responding to other forms of cancer treatment.
The results of the trial were recently presented at the American Society of Clinical Oncologists Conference in Chicago.