Hi cthornton , hi Catherine,
I read also about these findings, for example this asco abstract:
Baseline tumor size as an independent prognostic factor for overall survival in patients with metastatic melanoma treated with the anti-PD-1 monoclonal antibody MK-3475.
http://meetinglibrary.asco.org/content/134724-144
My sister has big ulcerated tumors on the left arm (try to imagine 2-3 oranges on the upper arm, plus other many smaller). She did not respond nor to Yervoy, neither to Nivolumab. The only successful drugs for her were Brafi, but she got resistant also first time and also during rechallenge. We recently asked the doctors in Brussels about the option of MK 3475, but they do not recommended it in her case. I trust this opinion as far as concern my sister. I know her disease by hard. It is not likely her tumors (too big and aggressive) will be shrunk by immunologic treatment. In the rest of the body she had no significant metastasis/tumors. But the problems which are coming from the arm tumors (pains, infections, bleeding, anemia, hypercalcemia) are enough to kill her.