Revolutionizing Colorectal Cancer Treatment: Immunotherapy Breakthrough Offers Hope for a Cure

 

Revolutionizing Colorectal Cancer Treatment: Immunotherapy Breakthrough Offers Hope for a Cure

Colorectal cancer ranks among the most commonly diagnosed cancers in the United States. According to estimates from the American Cancer Society, this year will see over 150,000 new cases and more than 52,000 Americans succumbing to this disease. Early detection is key to successful treatment, as advanced stages, particularly when the cancer spreads, are associated with higher fatality rates.

Recent advancements in cancer treatment have emerged through the use of immunotherapies, a class of drugs that harness the body's own immune system to combat cancer. However, treating colorectal cancer with immunotherapies has posed a challenge, as they have proven largely ineffective for the majority of patients. Yet, a groundbreaking study published in the journal Oncogene offers new hope. In a small-scale study, patients were treated with an experimental immunotherapy before undergoing surgical tumor removal, resulting in an astonishing 80% to 90% reduction in cancer cells. This reduction indicates a decreased likelihood of cancer recurrence.

Pashtoon Kasi, the director of colon cancer research at Weill Cornell Medicine and the lead author of the study, described the rapid shrinkage of tumors as "like it had shriveled down to nothing" within weeks of treatment.

The study focused on 12 patients with advanced colon and rectal cancers that had not yet metastasized. These patients received a combination of two immunotherapies, botensilimab and balstilimab, developed by Massachusetts-based biotech company Agenus. These drugs target various mechanisms that cancer cells employ to evade the immune system, allowing the body to launch an effective attack. To mitigate the risk of infection post-surgery due to the inflammatory response triggered by these treatments, only half of the standard drug dose was administered.

Following surgery, the tumors were meticulously examined by Erika Hissong, a pathologist at Weill Cornell Medicine. While the study presents results for only two patients thus far, both experienced a remarkable "inside-out" response. This response involved the infiltration of inflammatory immune cells into tumor cells, effectively targeting and eradicating the disease.

Significantly, the analysis revealed that most surgically removed tumors primarily comprised inflammation and reactive tissue changes, rather than viable tumor cells. Additionally, the study indicated that the tumor was being "pushed out" of the bowel wall, a promising sign for preventing cancer recurrence compared to treatments that only target the tumor's surface.

What makes these findings even more remarkable is that the patients studied, like approximately 85% of colorectal cancer patients, had "mismatch repair proficient" cancers, typically unresponsive to immunotherapy. Based on these results, there is optimism that chemotherapy following surgery, a standard practice, may be reduced or eliminated.

It is important to note that this study has limitations, as it reports on only two of the 12 patients treated early in the research. Furthermore, it lacks comparisons with alternative treatments in a similar patient and setting context. Nevertheless, full results for all 12 patients are expected in the coming months, and more comprehensive analyses are planned for future trials. The preliminary results were published due to the impressive efficacy of the drug in these initial findings.

This study is not the sole instance of success with the immunotherapy combination in treating colorectal cancer. Earlier in the year, a phase 1 clinical trial reported nearly tripled one-year survival rates for patients with metastatic colorectal cancer. In June, Agenus announced that patients were experiencing prolonged survival compared to traditional standard care with lasting responses.

In April, the FDA granted fast-track designation to this treatment combination, expediting the approval process in medical areas with significant unmet needs. Larger clinical studies of this therapy are also underway. In August, Agenus announced its decision to prioritize the commercialization of the botensilimab/balstilimab combination, temporarily halting its other clinical pipeline endeavors.

"The observed clinical benefit in solid tumors underscores the program's game-changing potential," said Agenus CEO Garo Armen in a statement. "And our rapid progress towards a first filing in 2024 highlights the necessity for prioritization in every aspect of our operations."