This is a Phase 1b/2, open-label, nonrandomized study that will be conducted in 2 stages. In the first stage, Part 1 of the study will determine the safety and preliminary efficacy of acalabrutinib and pembrolizumab in a limited group of B-cell malignancies. In the second stage, Part 2 allows for possible expansion cohorts into a wider range of B-cell malignancies, and Part 3 will evaluate the combination in subjects with myelofibrosis (MF).
