Dostarlimab: Immune cell switch that fights rectal cancer

PD-1 is a protein found in T lymphocytes, which act as “switches” for another protein called PD-L1 (programmed death ligand 1), which works to prevent T cells from attacking healthy cells in the body. Unfortunately, some cancer cells similarly contain large amounts of PD-L1, which prevents the immune system from attacking them.

Dostarlimab is an immunotherapy drug commonly used for endometrial cancer, whose action is to prevent the binding of PD-1 with PD-L1, which allows cancer cells to be detectable by the immune system and subsequently eliminated.

In a recent study published by researchers at Sloan Kettering Memorial Cancer Center, twelve patients with stage II or III rectal adenocarcinoma with a deficiency in pairing error repair to a treatment of one dose of dostarlimab (priced at $11 each) every three weeks, over a sixmonth period. During the clinical trial, none of the volunteers received chemo or radiotherapy, nor did they have to undergo surgery to treat recurrences (conventional treatments for this type of cancer).

At the time of publication of the final report (June 2022), no cases of progression or recurrence have been reported during study follow-up, and no grade 3 or higher adverse events have been reported.

Despite the initial findings of the remarkable benefit of using dostarlimab as a treatment for rectal cancer, it is necessary to replicate the results published by the research group of Dr. Luis A. Díaz in a more extensive and diverse population, to further clarify whether the action of this drug is similar in different populations.

GlaxoSmithKline, which markets Dostarlimab under the name Jemperli, has acquired all outstanding shares of Sierra Oncology ($55 per share in cash), representing a total capital value of approximately $1.9 billion.

The price per share acquired represented a premium of roughly 39% to Sierra Oncology’s closing share price on April 12, 2022, and approximately 63% to Sierra’s volumeweighted average price during the last 30 trading days. With this, this pharmaceutical company seeks to strengthen its areas of therapies aimed at rare forms of cancer.

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Sources:

1. Cercek, A., Lumish, M., Sinopoli, J., Weiss, J., Shia, J., Lamendola-Essel, M., ...& Diaz Jr, L. A. (2022). PD-1 Blockade in Mismatch Repair–Deficient, Locally Advanced Rectal Cancer. New England Journal of Medicine.

2. ul Hussain, H., Burney, M. H., Rehan, S. T., & Hasan, M. M. (2022). Dostarlimab: A breakthrough in the field of oncology. Annals of Medicine and Surgery, 104046.

3. https://cincodias.elpais.com/cincodias/2022/04/13/companias/1649864997_678266.html