Doctor Who Provided New Cancer Drug Explains Why She Thinks It Worked

Oncologist Dr. Andrea Cercek, who was involved in a new trial which saw cancerous tumours 'vanish' in patients, has offered her thoughts on why the drug worked.

The breakthrough trial was detailed in a paper published in the New England Journal of Medicine on Sunday (5 June) and involved 18 participants who had been diagnosed with rectal cancer.

The patients were treated with an immunotherapy drug called dostarlimab, and following the trial the doctors found the rectal cancer had vanished in all 18 patients, so much so that it could not be detected by physical exam, endoscopy, PET scans or MRI scans.

Dr. Andrea Cercek, an oncologist at Memorial Sloan Kettering Cancer Center and a co-author of the paper, discussed the results with CNN after the study was published and admitted the doctors 'didn't expect it'.

"We'd certainly never seen this before, it's really what cancer doctors' dreams are made of," she continued.

Very proud of our study published in @NEJM. 100% clinical complete response with dostarlimab alone in mismatch repair-deficient locally advanced #RectalCancer. No radiation or surgery! @ASCO #ASCO22 @MSKCancerCenter https://t.co/sZypoHBtj7

— Andrea Cercek (@AndreaCercek) June 5, 2022

Dr. Cercek explained dostarlimab works by 'unlocking the body's natural immune system to fight cancer', and said this particular treatment works in 'specific cancer cells' which lack a gene which enables them to repair their DNA, ultimately leading to mutations.

She said: "When we give immunotherapy like dostarlimab it really just revs up the immune system so that it sees the cancer and gets rid of it. But what's so remarkable here is that it completely eliminated the cancer, the tumours just vanished."

The doctor went on to explain that such results are typically only visible in 10 percent of patients with advanced cancer, making the study's results even more 'striking'.

Dr. Luis A. Diaz Jr., another author of the paper, told The New York Times he believes 'this is the first time this has happened in the history of cancer'.

The inspiration for the study came from a clinical trial led by Dr. Diaz in 2017, which involved 86 people diagnosed with metastatic cancer which shared a gene mutation that prevented cells from repairing damage to DNA.

Patients from the earlier trial took a checkpoint inhibitor for up to two years, after which results revealed tumours shrank or stabilised in about one third to half of the patients and disappeared altogether in 10 percent of the participants.

The results led Dr. Cercek and Dr. Diaz to question what would happen if the drug were administered earlier in the course of the disease, resulting in the more recent successful trial.