A Study of the Pharmacokinetics and Safety of MK-8808 (MK-8808-002)

In Part A of the base study, participants are randomized to either MK-8808 or MabThera®. In Part B of the base study, participants are randomized to either MK-8808, MabThera®, or Rituxan®. Participants enrolled in Part A are not eligible to participate in Part B. In both Parts A and B, participants will receive one or two courses of therapy, with each course including two infusions of the study drugs. The extension portion of the study (Part C) will sequentially follow the base study beginning at Week 52 and continue for an additional 54 weeks. All participants who meet eligibility criteria and continue into the study extension will be treated with open-label MK-8808. Participants randomized to MK-8808 in the base study will remain on the same therapy. Participants randomized to rituximab (MabThera® or Rituxan®) in the base study will be switched to MK-8808 for the extension study.