Research we fund

Our laboratory and those of others discovered highly recurring mutations in the gene MYD88 which are found in patients with various B-cell cancers including Waldenstrom’s Macroglobulinemia (95-97%), ABC Subtype of Diffuse B-cell Lymphoma (30-40%), Primary Central Nervous Lymphoma (80%), Marginal Zone Lymphoma (10%) and Chronic Lymphocytic Leukemia (5-10%). Our laboratory and those of others showed that mutated MYD88 triggers BTK, which is the target of BTK-inhibitors like ibrutinib, acalabrutinib and zanubrutinib though complete remissions are rare with these agents largely in part because other pro-survival molecules are activated by mutated MYD88 such as HCK and IRAK1. In these studies, we will develop potent and selective inhibitors to HCK and IRAK1, including PROTACs which inhibit and degrade these molecules, using lead molecules and scaffolds whose target selectivity and activity we previously validated. We will also investigate the mechanisms underlying the inactivation of the Inhibitor of BTK (IBTK) as a potential new target for development of inhibitors for use in MYD88 mutated lymphomas.

In up to half of patients with hematologic malignancies undergoing allogeneic stem cell transplantation, the trajectory of a smooth recovery toward cure is disrupted by acute graft-versus-host disease (aGVHD). Inspired by the role of intestinal microbial communities in aGVHD pathogenesis, we recently completed the largest fecal microbiota transplantation (FMT) trial to date in transplant recipients. We established the safety of standardized third-party FMT and characterized FMT effects on the microbiota, leading to the proposed randomized, placebo-controlled phase 2 trial of FMT to prevent aGVHD.

CD19 targeting chimeric antigen receptor (CAR) T cell therapies (CAR19) are effective treatments for patients with non-Hodgkin Lymphoma (NHL), however, the majority of these patients will relapse. We have now evaluated a CD22 targeting CAR T cell therapy (CAR22) in patients who have large B cell lymphoma who have relapsed after CAR19 therapy and found that this therapy is both safe and effective resulting in a high rate of durable complete responses. We will now test this promising CAR22 for the first time in patients with other non-Hodgkin Lymphoma subtypes including mantle cell lymphoma, follicular lymphoma, and other CD22-expressing lymphomas.

Inhibition of a tumor-triggered immune exhaustion pathway, termed PD-1 blockade, enables immune effector cells to attack cancers. In classic Hodgkin Lymphoma (cHL), PD-1 blockade is now a standard treatment for relapsed disease and a component of experimental frontline therapy. We have identified a major population of monocyte/macrophages in patients with cHL that inhibit tumor cell killing and limit the efficacy of PD-1 blockade. Our goal is to fully characterize these tumor-specific monocytes/macrophages and target their immunosuppressive and tumorigenic program for therapeutic benefit in patients with cHL and other lymphoid malignancies.

This research will investigate blood stem cell mutations associated with progression of myeloproliferative neoplasm (MPN) to secondary acute myeloid leukemia (sAML). Our preliminary data suggest that pre-leukemic cells with particular mutations may have a selective advantage in a background of certain MPN subtypes. We will confirm this by utilizing mouse models and both MPN and sAML primary patient samples. Ultimately, we will examine and test inhibition of mechanisms which drive MPN to sAML.

Inhibition of the PD-1 exhaustion pathway enables the immune system to attack cancers. PD-1 blockade is now a standard treatment for relapsed classic Hodgkin Lymphoma (cHL) and a component of experimental frontline therapy. In patients with cHL, a newly identified population of monocytes/macrophages limits the efficacy of PD-1 blockade. We will characterize and target these tumor-programmed monocytes/macrophages for therapeutic benefit in patients with cHL and other lymphoid malignancies.

The microbiome is increasingly recognized as contributing to chronic graft-versus-host disease (cGVHD). I hypothesize that microbial antigens drive the devastating complication of bronchiolitis obliterans syndrome (BOS). To determine if such antigen targets are at the heart of BOS pathology, I will integrate spatial transcriptomic approaches, immunopeptidome analysis, and direct antigen specificity testing of TCRs from biospecimens collected from preclinical models and patient biospecimens.

MLL1/KMT2A rearranged leukemias are the most common blood cancer occurring in children characterized by dismal prognosis. Given the importance of fusion proteins in driving the disease, I will determine factors affecting the fusion protein stability through a CRISPR/Cas9 screening approach in an innovative model system where the MLL fusions are endogenously tagged with a fluorescent protein. This will facilitate development of molecular glue degraders specifically targeting the MLL fusions.

GATA2 deficiency is an inherited pediatric syndrome with a high rate of progression to myeloid malignancy, the mechanisms of which remain largely undefined. Here, we will use our recently generated mouse model, Gata2R396Q, to determine the effects of GATA2 deficiency on hematopoietic function and identify novel drivers of myeloid malignancy via focused CRISPR screens. Our work will provide further insight into the mechanisms driving leukemic progression of this syndrome.

The development of acute myeloid leukemia (AML) is preceded by a “preleukemic” phase in which mutated hematopoietic stem cells expand due to a fitness advantage. Our work uses prospective models and analysis of patient samples to study how the duration of preleukemia and how the preleukemic clonal burden affect progression to AML. Results of our studies will shed new light on AML pathogenesis and help guide clinical management of preleukemic conditions such as clonal hematopoiesis.