Lenalidomide in DLBCL: are we past the cell of origin?

Single-agent lenalidomide has modest activity in diffuse large B-cell lymphoma (DLBCL) and is thought to be more potent in activated B-cell (ABC) lymphomas, which are more treatment-resistant. However, the addition of lenalidomide to rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in randomized clinical trials has shown equivocal benefit, despite phase 2 studies that suggested otherwise. These equivocal results suggest that either the cell of origin (COO) has limited importance for prescribing lenalidomide, or that lenalidomide is not the optimal agent for exploiting the vulnerability of ABC lymphomas. As more recent analyses have shown that the genetic landscape of DLBCL is considerably more complex than the binary COO paradigm, the disappointing impact of lenalidomide is less surprising. In contrast to the marginal benefit from the addition of lenalidomide to R-CHOP, recent studies suggest that lenalidomide in combination with novel agents has potent activity. Lenalidomide was recently approved in combination with the anti-monoclonal B-cell antibody tafasitamab for patients with relapsed DLBCL after 1 to 3 previous treatments. This combination has led to surprisingly prolonged progression-free survival rates, along with possible cure in a subset of patients. In addition, early-phase single-arm trials are also showing deep and durable responses in relapsed patients when lenalidomide is combined with the novel agents ibrutinib and venetoclax. Although these drugs have limited single-agent activity in DLBCL, their pronounced activity in combination suggests a possible unique synergistic effect. Overall, recent studies suggest that lenalidomide will continue to be an active player in the treatment for DLBCL but likely in combination with other novel agents rather than in combination with chemotherapy.