Dr. Mascarenhas on the MPD-RC 112 Study in PV and ET

John Mascarenhas, MD, associate professor of Medicine, Mount Sinai School of Medicine, discusses the results from the interim analysis of the MPD-RC 112 study, which compared frontline pegylated interferon-alpha-2a (Pegasys) with hydroxyurea in the treatment of patients with high-risk polycythemia vera (PV) and essential thrombocythemia (ET).

This randomized phase III study was conducted, explains Mascarenhas, because both physicians and patients are concerned that hydroxyurea is a leukemogenic drug, and many suspect that pegylated interferon-alpha-2a may be a superior agent. Preclinical studies have shown that pegylated interferon-alpha-2a has a direct effect on hematopoietic stem cells. Moreover, he says, early phase II studies have demonstrated an impressive overall response rate for the agent. These findings support the rationale to study the drug in the upfront setting for these patients.

In fact, he says, many institutions already hold the belief that pegylated interferon-alpha-2a is superior to hydroxyurea in the treatment of patients with high risk PV and ET. The MPD-RC 112 study set out to provide evidence-based recommendations that one of these drugs is superior to the other. It is particularly important to compare these 2 agents, says Mascarenhas, because of their different mechanisms of action and toxicity profiles.