Ann: Clinical Trial Supply Agreement with Merck KGaA and Pfizer, page-192

Hey the key word you are missing is Pathologic Complete response.

Definition from here... https://www.cancer.gov/publications/dictionaries/cancer-terms/def/pathologic-complete-response

pathologic complete response: The lack of all signs of cancer in tissue samples removed during surgery or biopsy after treatment with radiation or chemotherapy. To find out if there is a pathologic complete response, a pathologist checks the tissue samples under a microscope to see if there are still cancer cells left after the anticancer treatment. Knowing if the cancer is in pathologic complete response may help show how well treatment is working or if the cancer will come back. Also called pathologic complete remission.