Pirtobrutinib and Venetoclax in Waldenström Macroglobulinemia

This is a single-arm, open-label, Phase II study to evaluate the safety and efficacy of venetoclax combined with pirtobrutinib (VEN-P) in participants with symptomatic Waldenström Macroglobulinemia (WM) with previously treated disease. Pirtobrutinib blocks a type of protein called Bruton Tyrosine Kinase (BTK) that helps cells live and grow. Venetoclax blocks BCL-2, a protein essential for WM cells' survival. The U.S. Food and Drug Administration (FDA) has not approved pirtobrutinib for Waldenström Macroglobulinemia (WM), but it has been approved for other uses. The FDA has not approved venetoclax for Waldenström Macroglobulinemia (WM), but it has been approved for other uses. The FDA has not approved the combination of pirtobrutinib and venetoclax as a treatment for any disease. Study procedures include screening for eligibility, treatment visits, CT scans, blood tests, and bone marrow aspirates and biopsies. Participants will receive study treatment for up to 2 years and will be followed for up to 4 years or until they start a new therapy. It is expected that about 42 people will take part in this research study. Eli Lilly supports this research study by providing study drug pirtobrutinib and funding.