This phase II trial tests whether acalabrutinib, venetoclax, and durvalumab work in treating patients with Richter transformation from chronic lymphocytic leukemia or small lymphocytic lymphoma. Richter transformation is a rare condition in which chronic lymphocytic leukemia or small lymphocytic lymphoma changes into a fast-growing type of lymphoma. Acalabrutinib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Venetoclax is in a class of medications called B-cell lymphoma-2 (BCL-2) inhibitors. It may stop the growth of cancer cells by blocking Bcl-2, a protein needed for cancer cell survival. Immunotherapy with monoclonal antibodies, such as durvalumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Giving acalabrutinib, venetoclax, and durvalumab may help improve survival in patients with Richter transformation.
Age >= 18 years willing to provide consent and follow-up
Biopsy-proven SLL according to WHO 2008 criteria, or
Peripheral blood B cell count of >= 5 x 10^9/L consisting of small to moderate size lymphocytes (If there are enough evidence to document the prior diagnosis of CLL, it is not required to meet the criteria of peripheral blood B cell count more than 5 x 10^9/L )
The predominant population of lymphocytes share both B-cell antigens (CD19, CD20 [typically dim expression], or CD23) as well as CD5 in the absence of other pan-T-cell markers (CD3, CD2, etc.)
Symptomatic arrhythmias
Congestive heart failure
Myocardial infarction =< 3 months prior to registration
Any class 3 or 4 cardiac disease as defined by the New York Heart Association functional classification