The 42-year-old woman had no evidence of cancer after receiving dostarimab, a drug still in early trials to treat a rare form of colorectal cancer.
advertisementCarrie Downey, a single mother with a 17-year-old son, was diagnosed with colon cancer a year ago, but after just six months of treatment with a new anti-cancer drug, she is now fully recovered.
The drug, dostarlimab, is currently in clinical trials and targets certain colorectal cancers that have genetic abnormalities in their cells. All patients have specific mismatch repair (MMR) gene mutations.
According to Swansea Bay University Health Board, this genetic defect is present in 3.5% to 5% of rectal cancers.
Ms Downey, 42, was told that depending on the location of the cancer, she might be left with a permanent stoma. A stoma is an opening in the abdomen through which the body’s waste products are expelled, collected in a small bag worn outdoors. body.
She was referred to oncologist Dr Craig Barrington on behalf of South West Wales Cancer Centre.
“He said something like, ‘What would you do if I told you that you could get the same results without having a permanent stoma or major surgery and no evidence of cancer?'” Downey said. said in a statement:
“He tested my biopsy and knew I had this rare mutation. He asked me if I wanted to go ahead with it.”
Downey received intravenous (IV) treatments of the drug three times a week for six months, with each treatment taking about 30 minutes.
“I was tired and had a rash here and there, but it was nothing compared to chemotherapy, radiation and surgery,” she said.
The tumor shrank during treatment and no evidence of disease remained at the end of the period.
Mr Barrington said in a statement: “We are the first country in the UK, and together with Italy, in the world, to routinely include it as a treatment option.”
“It doesn’t mean patients have to have it. It’s an additional tool in the toolbox, so to speak. But when a trial shows a 100 percent complete response, it’s hard to argue against that.”
Medicine is still in clinical trials, but data is limited
Dostarlimab has been prescribed to 10 patients in Wales, but its use in the treatment of these rare rectal cancers is still being analyzed.
The drug, sold by GlaxoSmithKline (GSK) as Gemperi, was first approved in the European Union in 2021 to treat the condition. endometrial cancer It is advanced and has the same genetic abnormality.
A small clinical trial of 12 patients with rectal cancer in the United States revealed that New England Medical Journal In 2022, all patients were found to have had a complete clinical response.
The study concluded that this type of rectal cancer, known as mismatch repair-deficient/high microsatellite instability (dMMR/MSI-H), is “highly sensitive” to drugs, but “symptomatically Longer-term follow-up is needed to evaluate.” Duration of reaction”.
There are further ongoing trials in the United States, but these are “single-arm trials” and therefore not randomized, which was cited as a cause for concern by U.S. authorities in February.
Nevertheless, the U.S. Food and Drug Administration (FDA) committee concluded that data from two single-arm trials “characterized the benefits and risks” of using this drug to treat advanced rectal cancer with genetic abnormalities. They voted that it was “enough to