Are you on Herceptin/trastuzumab or Keytruda/pembrolizumab (or both)? These are different antibodies against different things.

Herceptin is against HER2, and Keytruda is against the immune inhibitor PD-1. Jemperli/dostarlimab is a different company's antibody against PD-1, and would be expected to have about the same effects as Keytruda. Jemperli is approved for dMMR endometrial cancers.

Thank you for sharing your journey and the helpful links. Love the foreign travel. Up yours, cancer! You go girl. Carpe Diem!
If you are dmmr have you seen the big news article from Sloan Kettering that was in the New England Journal of Medicine? It was on regular news outlets, too. The problem with the mismatch repair allowed the drug to target and strip cancer cells of protection and be DESTROYED. Here's the article . Dostarlimab is the drug they used.
The New England Journal of Medicine published a paper on April 27, 2025, that presents exciting new results from a clinical trial led by Memorial Sloan Kettering Cancer Center (MSK) gastrointestinal oncologists Andrea Cercek, MD, and Luis Diaz Jr., MD, that demonstrates how immunotherapy alone can help patients with MMRd cancers avoid surgery and preserve their quality of life. The results, presented simultaneously at the 2025 American Association of Cancer Research (AACR) Annual Meeting, showed that 80% of patients with several types of cancer treated with immunotherapy did not require surgery, radiation, or chemotherapy after six months of treatment with immunotherapy alone. Swim Across America awarded grants for the early-stage research and continues to award grants for the ongoing clinical trial.

Andrea Cercek, M.D., gastrointestinal oncologist and co-director of the Center for Young Onset Colorectal and Gastrointestinal Cancer at Memorial Sloan Kettering Cancer Center
Mismatch repair deficiency (MMRd) in cancer refers to a situation where tumor cells have defective mismatch repair (MMR) proteins, essential for correcting DNA errors during cell replication. This deficiency leads to the accumulation of mutations, including microsatellite instability (MSI), making tumors more prone to be recognized by the immune system. MMRd status is a significant factor in cancer treatment, particularly for immunotherapy, as it can predict response to immune checkpoint inhibitors.

The standard of care for many cancers that have this specific MMRd genetic mutation has been surgery, radiation, and chemotherapy. Still, the patients who responded positively to this clinical trial did not require surgery to remove an organ and did not experience chemotherapy or radiation, which improved their quality of life. This trial is the first time that immunotherapy has been shown to replace surgery for a variety of solid tumors.

“This study shows that immunotherapy can replace surgery, radiation and chemotherapy for mismatch repair-deficient solid tumors, which could help patients preserve their organs and avoid the harsh side effects of chemo and radiation,” said Andrea Cercek, M.D., gastrointestinal oncologist and co-director of the Center for Young Onset Colorectal and Gastrointestinal Cancer at Memorial Sloan Kettering Cancer Center. “Preserving a patient’s quality of life, while also successfully achieving positive results in eliminating their cancer, is the best possible outcome. They can return to their daily routines and maintain their independence.”

Luis Diaz, M.D., gastrointestinal oncologist and Head of the Division of Solid Tumor Oncology at Memorial Sloan Kettering Cancer Center
This phase 2 trial is an extension of a groundbreaking study, also funded in part by Swim Across America, in which all rectal cancer patients treated with the immunotherapy dostarlimab experienced a complete clinical response, meaning their tumors disappeared. This was the first time ever that a clinical trial had a 100% positive response rate.