Acalabrutinib, Venetoclax and Durvalumab for the Treatment of Richter Transformation From Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

Inclusion Criteria: * Age \>= 18 years willing to provide consent and follow-up * Diagnosis of CLL according to the International Workshop on Chronic Lymphocytic Leukemia (IWCLL) 2018 criteria (Hallek et al., 2018) or small lymphocytic lymphoma (SLL) according to the World Health Organization (WHO) 2008 criteria (Harris, 1999). This includes previous documentation of: * Biopsy-proven SLL according to WHO 2008 criteria, or * Diagnosis of CLL according to IWCLL 2018 criteria as evidenced by all of the following: * 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 ) * Immunophenotyping consistent with CLL defined as: * 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.) * Clonality as evidenced by kappa or lambda light chain expression (typically dim immunoglobulin expression) or other genetic method (e.g. immunoglobulin heavy chain variable \[IGHV\] analysis) * NOTE: Splenomegaly, hepatomegaly, or lymphadenopathy are not required for the diagnosis of CLL * Before diagnosing CLL or SLL, mantle cell lymphoma must be excluded by demonstrating a negative fluorescence in situ hybridization (FI…