Researchers from The Memorial Sloan Kettering Cancer Center (MSK) made a groundbreaking discovery. They have successfully completed a trial study with 100% of patients recovering fully from rectal cancer. Their only roadblock is the FDA’s approval. Their discovery? A type of immunotherapy that uses the compound dostarlimab (marketed as Jemperli). Produced by GSK they have caught the FDA’s attention.
On December 16, 2024, they received the FDA’s “Breakthrough Therapy Designation” which was an acknowledgment of their potential to revolutionize the treatment and eradication of rectal cancer completely.
A Paradigm Shift in Treatment
Designed to “expedite the development and review of drugs that are intended to treat a serious condition,” the FDA’s designation has displayed clinical data which shows “substantial improvement over available therapy.” Focusing on immunotherapy, this trial was conducted on patients with tumors that were categorized as mismatch repair-deficient (MMRd) or microsatellite instability-high (MSI).
Rectal cancer has traditionally been treated with radiation, chemotherapy, and sometimes surgery and the long-lasting side effects were life threatening. These long-lasting side-effects ranged from infertility to incontinence. “Everyone on the clinical trial is doing great,” shared Dr. Andrea Cercek, MSK’s gastrointestinal oncologist who played a major role. Co-leading the miraculous trial.
Exceptional Results and Mild Side Effects
Results were updated and shared in June of 2024, revealing a groundbreaking 42 successfully treated patients completing their treatment, left with zero remaining disease. “Side effects were quite mild and well tolerated,” noted Dr. Cercek. More importantly, the side effects have been reported to be minimal and durable. Most patients have remained cancer-free for a minimum of a year. Even more astonishing is the fact that the first trial of patients has remained healthy for up to four years. “The success rate remains 100%,” she added.
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Transforming Global Cancer Practices
Dr. Cercek presented her findings at ASCO 2024, America’s premier cancer conference. 2022’s trial results were additionally published in the New England Journal of Medicine. This has further garnered global attention which has swayed and influenced cancer treatment guidelines significantly. “Doctors worldwide have adopted this approach, and I receive letters of gratitude from countries like Australia, Ireland, and the U.S.,” said Dr. Cercek.
The National Comprehensive Cancer Network which sets and guides cancer treatment standards has since updated their guidelines following the remarkable trial results. Even insurers have been swayed into covering the treatment which allows access to so many more patients. Not only has the trial been successful, but t’s sparked a baby boom among trial patients. “Three women have had healthy babies post-treatment,” said Dr. Cercek. This proves the potential fertility preservation benefits of using Jemperli Dostarlimab.
A Life-Changing Phone Call
Sascha Roth was the trial’s first participant and she reported her life-changing moment. She was 6 months into her immunotherapy treatment and the next step was radiation. This was when she received a phone call from Dr. Cercek. “She said my tests showed no evidence of cancer,” Sascha shared. “I was stunned and ecstatic.”
The trial’s intended purpose was to explore whether immunotherapy treatments using dostarlimab could treat patients with a specific genetic mutation present in their tumors. “Dr. Cercek told me a team of doctors examined my tests and found no signs of cancer, so there was no need for radiation therapy,” Sascha said.
100% Remission Achieved
All 42 patients remarkably went into full remission. Celebrating this milestone in her research, Dr. Cercek weighed in. “It’s incredibly rewarding to receive joyful emails and tears from patients who realize they’ve retained their normal body functions.” Her co-investigator, Dr. Luis Diaz, Jr., also expressed his enthusiasm. “This is a significant step forward for patients.”
Harnessing Immunotherapy Against Genetic Mutations
Dr. Cercek and Diaz utilized two key premises while conducting their research. They first singled out candidates who would mostly benefit from immunotherapy. This would ensure effective treatment with Dostarlimab. These patients had MMRd or MSI tumors which only make up 5-10% of rectal cancer patients in total. “These tumors’ genetic mutations stimulate the immune system, which attacks the cancer cells,” explained Dr. Diaz.
The second requirement was aiming toward the lessened need for traditional treatment therapies. “Our first duty is to save lives, but standard treatments often lead to severe side effects,” Dr. Cercek noted. This is where immunotherapy was more likely to bypass the accompanying side effects of radiation, surgery, or chemotherapy.
The Science Behind Immunotherapy
Traditionally, cancer evades one’s immune system by activating certain immune checkpoints. This in turn suppresses immune responses. This is where dostarlimab comes in handy. It effectively releases these inhibitors, which then allow the immune system to attack these cancer cells. “MMRd tumors, with their numerous mutations, are especially vulnerable to this approach,” Dr. Cercek explained.
Astonishing Patient Outcomes
The rapid success of the trial astonished the researchers. “The tumors shrank faster than expected,” said Dr. Cercek. Within just two to three treatments, patients were experiencing serious relief from their symptoms such as pain and bleeding ceasing altogether. “It’s incredible to see patients feel normal again,” she added.
Sascha was the shining hope the trial aimed for. “Before MSK, doctors recommended chemo, radiation, and surgery. Immunotherapy felt like a cakewalk by comparison,” she shared. Dr. Diaz expressed his enthusiasm growing as each patient went into remission, describing it as remarkable.
Expanding Access and Applications
As time passes, the trial is continuing to enroll patients while making the public aware of the importance of testing for MMRd tumors. “If you have rectal cancer, get tested,” urged Dr. Diaz. Lynch syndrome for example is hereditary and is heavily linked to rectal cancer. The trial has also uncovered an alarming rise in younger colorectal cancer diagnoses. MSK’s Center for Young Onset Colorectal and Gastrointestinal Cancer which is co-led by Dr. Cercek is heavily focusing on this specific demographic.
Hope for Other Cancers
Dr. Diaz hopes that broader applications will arise for “immunoablative” therapy. MSK is exploring how effective Dostarlimab could potentially be for gastric, prostate, and pancreatic cancers. “This method replaces surgery, chemotherapy, and radiation to remove cancer,” he explained. Reflecting on her journey, Sascha has remained cancer-free for four years. “MSK’s care is years ahead of others. This trial saved my life.”
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