This Study is Assessing the Safety and Efficacy of Immune Inhibition as a Treatment to Prevent Primary Graft Dysfunction

Lung transplant recipient survival lags other solid organ recipients, with the main early cause of death being primary graft dysfunction (PGD). PGD occurs in up to 1/3 of all recipients, is driven by the body's innate immune response, and has no known medical therapies for treatment or prevention. Investigators have recently shown that Natural Killer (NK) cells, a key innate immune cell, are critical in causing PGD. Importantly, the investigators found that Maraviroc, an FDA-approved drug that works to inhibit these immune cells, prevented lung injury in mouse models of PGD. The goal of this clinical trial is to learn if Maraviroc works to treat PGD in Lung Transplant patients who are above the age of 18 and have a PGD risk score greater than 50%. The objectives the study hopes to address are: To address the safety and tolerability of Maraviroc. To test a strategy for PGD enrichment in a lung transplant population. To measure the efficacy and biological efficacy of using Maraviroc. To study the biochemical, physiologic, and molecular effects of the drug on the body. This will be a double blind study where patients will either get the Maraviroc drug or a placebo. Researchers will then compare the two groups to address the above objectives. Participants will: Take drug Maraviroc or a placebo every 12 hours for 3 days post surgery. Follow up will occur during the entire length of stay at UCSF, about 16 days, with a single 12 month follow up once released.