In June, a groundbreaking clinical trial revealed remarkable results for dostarlimab (brand name Jemperli), a programmed death receptor-1 (PD-1)-blocking antibody. This innovative treatment completely eradicated rectal cancer tumors in patients without the need for surgery, radiation, or chemotherapy. The results, which were published in The New England Journal of Medicine, could have life-changing implications for patients, particularly those with locally advanced rectal cancer. Traditional treatments for rectal cancer often lead to serious side effects, including loss of fertility and incontinence, making this new immunotherapy an exciting prospect for many.

The promise of dostarlimab lies in its potential to change the way rectal cancer is treated. “Today’s designation, which is based on the unprecedented 100% clinical complete response rate of dostarlimab reported to date, supports a path to help change the treatment paradigm for patients with locally advanced dMMR/MSI-H rectal cancer, who face long-term adverse quality-of-life effects,” said Hesham Abdullah, Senior Vice President of Research and Development at GlaxoSmithKline (GSK), in a December 2023 press release.

The Breakthrough Therapy Designation granted to dostarlimab by the U.S. Food and Drug Administration (FDA) is a crucial step in accelerating the approval process for promising new treatments. This designation is intended for drugs that address serious conditions for which no other effective treatment exists, helping to fast-track their review and development. In 2024, the FDA had received 1,516 requests for this designation, with only 587 being granted, highlighting the significance of dostarlimab’s breakthrough status.

The clinical trial results have garnered attention from oncologists worldwide, especially after the trial conducted at Memorial Sloan Kettering Cancer Center (MSK) showed extraordinary success. Dostarlimab was administered to patients with rectal cancer, and in each case, the tumors were completely eradicated, with patients remaining cancer-free. Initially reported on 24 patients, the trial was later updated to include 42 participants, all of whom are now in remission.

“Everyone on the clinical trial is doing great,” said Dr. Andrea Cercek, a gastrointestinal oncologist at MSK, in June. “So far, 42 people have completed treatment, and all of them have no evidence of disease. Side effects were quite mild and well-tolerated.” Dr. Cercek added that the treatment has proven to be durable, with most patients remaining cancer-free for at least a year. For some of the original participants, the treatment has been effective for up to four years and counting.

The “100% clinical complete response rate” is defined as having no detectable tumors, assessed through methods such as magnetic resonance imaging (MRI), endoscopy, and digital rectal exams. This level of success is unprecedented in the treatment of rectal cancer.

Dostarlimab’s Breakthrough Therapy Designation marks its second FDA designation for the treatment of locally advanced dMMR/MSI-H rectal cancer, following its Fast Track designation in January 2023. With both designations in place, the drug now enters a phase of accelerated testing and review. This could significantly shorten the timeline for dostarlimab’s availability to patients, potentially offering the treatment to the public up to three years sooner than if it were undergoing traditional approval processes.

In the U.S., approximately 46,220 people are diagnosed with rectal cancer each year, and up to 10% of these cases are classified as dMMR/MSI-H cancers, a subtype that is particularly difficult to treat. The success of dostarlimab in these trials offers a beacon of hope for these patients, who currently face limited treatment options and significant long-term side effects from traditional therapies.

With continued positive trial results, dostarlimab could revolutionize the treatment of rectal cancer, providing a more effective and less invasive option for patients and significantly improving their quality of life. As research progresses, it is hoped that this breakthrough will set a new standard for cancer treatment, not only for rectal cancer but potentially for other cancers as well.

In June, a groundbreaking clinical trial revealed remarkable results for dostarlimab (brand name Jemperli), a programmed death receptor-1 (PD-1)-blocking antibody. This innovative treatment completely eradicated rectal cancer tumors in patients without the need for surgery, radiation, or chemotherapy. The results, which were published in The New England Journal of Medicine, could have life-changing implications for patients, particularly those with locally advanced rectal cancer. Traditional treatments for rectal cancer often lead to serious side effects, including loss of fertility and incontinence, making this new immunotherapy an exciting prospect for many.

The promise of dostarlimab lies in its potential to change the way rectal cancer is treated. “Today’s designation, which is based on the unprecedented 100% clinical complete response rate of dostarlimab reported to date, supports a path to help change the treatment paradigm for patients with locally advanced dMMR/MSI-H rectal cancer, who face long-term adverse quality-of-life effects,” said Hesham Abdullah, Senior Vice President of Research and Development at GlaxoSmithKline (GSK), in a December 2023 press release.

The Breakthrough Therapy Designation granted to dostarlimab by the U.S. Food and Drug Administration (FDA) is a crucial step in accelerating the approval process for promising new treatments. This designation is intended for drugs that address serious conditions for which no other effective treatment exists, helping to fast-track their review and development. In 2024, the FDA had received 1,516 requests for this designation, with only 587 being granted, highlighting the significance of dostarlimab’s breakthrough status.

The clinical trial results have garnered attention from oncologists worldwide, especially after the trial conducted at Memorial Sloan Kettering Cancer Center (MSK) showed extraordinary success. Dostarlimab was administered to patients with rectal cancer, and in each case, the tumors were completely eradicated, with patients remaining cancer-free. Initially reported on 24 patients, the trial was later updated to include 42 participants, all of whom are now in remission.

“Everyone on the clinical trial is doing great,” said Dr. Andrea Cercek, a gastrointestinal oncologist at MSK, in June. “So far, 42 people have completed treatment, and all of them have no evidence of disease. Side effects were quite mild and well-tolerated.” Dr. Cercek added that the treatment has proven to be durable, with most patients remaining cancer-free for at least a year. For some of the original participants, the treatment has been effective for up to four years and counting.

The “100% clinical complete response rate” is defined as having no detectable tumors, assessed through methods such as magnetic resonance imaging (MRI), endoscopy, and digital rectal exams. This level of success is unprecedented in the treatment of rectal cancer.

Dostarlimab’s Breakthrough Therapy Designation marks its second FDA designation for the treatment of locally advanced dMMR/MSI-H rectal cancer, following its Fast Track designation in January 2023. With both designations in place, the drug now enters a phase of accelerated testing and review. This could significantly shorten the timeline for dostarlimab’s availability to patients, potentially offering the treatment to the public up to three years sooner than if it were undergoing traditional approval processes.

In the U.S., approximately 46,220 people are diagnosed with rectal cancer each year, and up to 10% of these cases are classified as dMMR/MSI-H cancers, a subtype that is particularly difficult to treat. The success of dostarlimab in these trials offers a beacon of hope for these patients, who currently face limited treatment options and significant long-term side effects from traditional therapies.

With continued positive trial results, dostarlimab could revolutionize the treatment of rectal cancer, providing a more effective and less invasive option for patients and significantly improving their quality of life. As research progresses, it is hoped that this breakthrough will set a new standard for cancer treatment, not only for rectal cancer but potentially for other cancers as well.

By Impact Lab