A Study of Elranatamab (PF-06863135) in Chinese Participants With Refractory Multiple Myeloma.

The purpose of this study is to understand the study medicine (called Elranatamab, or PF-06863135) as potential treatment for refractory multiple myeloma. Multiple myeloma is a form of cancer in the bone that forces healthy blood cells to go out. Sometimes, multiple myeloma does not respond to current therapy or quickly progresses, and this is called refractory multiple myeloma. Elranatamab is a study medicine that target multiple myeloma and activates the human body to fight against this disease. We are seeking Chinese participants to take part in this study. The study will be 2 parts, called part 1b and part 2. In part 1b, participants will receive Elranatamab at 2 steps priming and full dose as a sc (subcutaneous injection) therapy. We will monitor participants' safety and reactions to the study medicine. This will help us understand the dosage of Elranatamab to be used safely. In part 2 of the study, participants will receive Elranatamab and their multiple myeloma growth will be monitored. This will help us understand if Elranatamab, when used alone, may be a therapy for refractory multiple myeloma. Participants in this part of the study are expected to take part for about 2 years.