In the healthcare industry, there have been a lot of wonders lately as a new drug promises to cure rectal cancer. Are these claims realistic? Let’s find out more about it.

The cure rate of locally advanced rectal cancer caused by a deficiency in mismatch pair seems to be improving daily. The standard treatments for rectal cancer (stage 2 and stage 3) with deficient mismatch repair (dMMR) is grueling or exhausting and takes a toll on the patient’s body, causing long-term illnesses like infertility, bowel abnormalities, sexual dysfunction, and neuropathy. As MSK medical oncologist Andrea Cercek also says, “The standard treatment for rectal cancer with surgery, radiation, and chemotherapy can be particularly hard on people because of the location of the tumor.”

Recently, a clinical trial undertaken in the United States (US) revealed that every patient (diagnosed with dMMR rectal cancer) treated in the trial had their cancer completely gone into remission, which promises to be a rather hopeful advance for the treatment of rectal cancer. The drug which has led to this breakthrough is known as “dostarlimab,” retailed under the brand name Jemperli. It is an immunotherapy drug (a programmed death receptor-1 (PD-1)-blocking antibody) initially used for the treatment of endometrial cancer. Still, for the first time, doctors used it for the clinical investigation trial of rectal cancer, which appears to be successful.

Dr. A. Cercek et al. conducted a phase 2 trial on a small group of 12 patients diagnosed with locally advanced rectal cancer and tumors with deficient mismatch repair (dMMR). This study involved the use of dostarlimab, which was administered every 3 weeks for 6 months to patients. The method involved the treatment followed up by neoadjuvant chemoradiotherapy and surgical procedure. Besides, patients who achieved a complete clinical response with dostarlimab therapy did not need chemoradiotherapy or resection.

After the completion of the study, the results were astounding, as all 12 patients involved in the process showed complete clinical responses to the drug. Doctors assured the results after detecting no tumor cells by magnetic resonance imaging, F-fluorodeoxyglucose-positron-emission tomography (PET), endoscopic evaluation, digital rectal examination, and biopsy. No traces of the tumor were found in the rectum of the patients. Furthermore, no patient had received the standard procedure for the treatment, and further follow-up (6-25 months) had shown no relapse or continuation of the tumor cells, and neither were there any adverse events.

These results have raised hope for patients suffering from this disease as dostarlimab is possibly a potent drug for treating one of the most lethal cancers.

How does this drug work? Firstly, PD-1 is why a patient’s immune system doesn’t react against the tumor cells. The binding between PD-1 and PD-L1 is a group of checkpoint inhibitors that inhibits the immune system’s T-cells from producing antibodies against the tumor cells. Dostarlimab is a monoclonal antibody drug that binds, which inhibits the signaling pathways of the PD-1 receptors. As the signaling pathways become unable to produce further signals to inhibit the antibody production, T-cells activation or T-cell mediated immune response against tumor cells initiates, resulting in the eradication of tumor cells in the host body.

Now, the question is, will it work against all cancer types? It is yet unknown. While it showed promising results against PD-1 inhibition, its efficacy against other cancer types still needs to be tested. Dr. Luis A. Diaz J., head of the Division of Solid Tumor Oncology in Memorial Sloan Kettering’s Department of Medicine, said, ” I believe this is the first time this has happened in the history of cancer.”

Still, even if the results are promising, further research on a large group of patients is required to assess the response duration and state it as the “ultimate cure for cancer.”