Rectal Cancer Study Ends With Every Patient in Remission

The trial involved dostarlimab, a monoclonal antibody produced by the drug company GlaxoSmithKline. Twelve* patients with stage II or III rectal cancer were each administered dostarlimab once every three weeks for a total of six months. The original goal was to see if their tumors would shrink, then conduct traditional treatment involving chemoradiotherapy and surgery. By the end of the study, however, neither was required: all 12 patients had entered remission. The cancer was nowhere to be found, even after the patients underwent MRI, biopsies, endoscopies, and digital exams.

None of the patients experienced adverse reactions that could be considered “clinically significant,” either. While one in five patients taking a drug like dostarlimab (a checkpoint inhibitor) experience negative side-effects, about one in twenty experience severe muscle fatigue and difficulty eating.

The idea for the study came about during a separate trial, in which 86 patients with stage IV cancer received a checkpoint inhibitor called pembrolizumab. The patients were similar in that their cancers each had a genetic mutation preventing cellular DNA repair. Many of them found success with pembrolizumab; nearly half of their tumors shrank or stabilized, while one in ten patients entered remission. But the researchers wondered what the rate of remission would’ve been if the drug had been administered earlier in each patient’s disease progression.

Like pembrolizumab, dostarlimab is administered intravenously and targets programmed cell death protein 1. The drug helps the immune system recognize and destroy cancer cells—a hail Mary for patients whose cancer has resisted traditional treatment. Some of the patients involved in the dostarlimab study, for instance, had previously undergone chemotherapy, but their tumors had grown instead of shrunk.

The initial success of the dostarlimab study is exciting, and in the 25 months since the trial ended, none of the twelve patients have experienced recurrence or required additional treatment. Nevertheless, researchers are committed to monitoring the long-term effects of dostarlimab and testing it on larger groups of patients before declaring it a miracle drug.

*While The New York Times and other outlets have widely reported the number of patients as 18, Cercek et al’s paper states 12 patients were involved in the study.

Continue reading

5 Lupus Patients Are In Remission After CAR-T Cell Therapy

Their success offers a glimmer of hope for those with an otherwise incurable disease.