Experimental Cancer Drug Removes Tumours In All Patients In Small Scale Trial

Tumours in all 12 patients with rectal cancer vanished at the end of the trial, the study says.

Dostarlimab is an experimental cancer drug.

(Photo: iStock)

In an unprecedented first of its kind, every single person in a 12-person group of people with cancer had their tumours vanish fully after being administered an experimental cancer treatment drug treatment called Dostarlimab.

The US Food and Drug Administration (FDA) had given the experimental drug Dostarlimab-gxly, a drug candidate created by GlaxoSmithKline, approval for use in patients with recurrent tumours, in August 2021.

The trial was performed at the Memorial Sloan Kettering Cancer Center in New York.

The study, published in the New England Journal of Medicine states:

"Single dose dostarlimab was administered every three weeks for six months in patients with mismatch repair–deficient stage II or III rectal adenocarcinoma. This treatment was to be followed by standard chemoradiotherapy and surgery."

"Patients who had a clinical complete response after completion of dostarlimab therapy would proceed without chemoradiotherapy and surgery," the study added.

All 12 patients underwent the course of treatment as well as six months of follow-up care. At the end of the period, tumours in all 12 patients had vanished completely.

In a statement to the New York Times, Dr Luis A Diaz J from the Memorial Sloan Kettering Cancer Center called it an unprecedented first in the history of cancer treatment.

The candidates who were selected had all undergone several other treatment procedures for colorectal cancer with little success.

After a period of 12 months, the patients were examined with positron-emission tomography (PET) scans, endoscopic evaluations, digital rectal examinations, and/or biopsy. In all 12 patients, no evidence was present of tumours.

In May 2022, another treatment procedure had been administered for the first time, with a genetically modified virus CF33-hNIS which would target, infect, and kill cancer cells while leaving healthy cells untouched.

The results of the trial could be revolutionary for cancer treatment if they can be replicated.

However, according to oncologist Hanna K. Sanoff, from the University of North Carolina, the full picture of dostarlimab's safety and effectiveness in cancer treatment will only become clearer once the full trial's results are out, which will include about 30 candidates.

Until such time, she adds, we need to treat the test's results "with both optimism and caution"

According to Sanoff, a clinical complete response to the treatment is not a surrogate for long-term cancer control, as even though checkpoint inhibitors like dostarlimab can have effects lasting years, cancer regrowth is generally expected to still occur in a minority of patients where tumors are managed non-operatively, let alone with an experimental treatment like this.