Phase I/II Study of Lenalidomide Combined with DA-EPOCH and Rituximab (DA-EPOCH-R²) in Primary Effusion Lymphoma in Patients with or without HIV

Primary effusion lymphoma (PEL) is a rare, aggressive B-cell neoplasm with a unique clinical profile that is most frequently associated with HIV infection. It generally presents with malignant effusions but may also present with extracavitary masses. It is caused by the gamma-herpesvirus Kaposi sarcoma herpesvirus (KSHV, also called human herpesvirus-8 [HHV-8]), which is also the etiologic agent of Kaposi sarcoma and the plasmablastic form of multicentric Castleman disease (KSHV-MCD). KSHV is known to cause cytokine related severe inflammation associated with elevated human interleukin (IL)-6 and IL-10. There have been no prospective studies in PEL and there is currently no standard therapy for this disease. The prognosis of PEL is poor compared to other HIV-associated lymphomas. PEL has a median survival of 10-22 months when treated with conventional chemotherapy regimens for non-Hodgkin lymphoma according to the most recent retrospective reports.

Lenalidomide, a derivative of thalidomide with immunomodulatory activity, has been shown to have in vitro antitumor effects in PEL cell lines. KSHV itself may cause downregulation of immune surface markers as a way to avoid immune detection. Lenalidomide can reverse this and enhance surface expression of major histocompatibility complex-1 and intercellular adhesion molecule-1 in PEL cell lines. Dose-adjusted infusional etoposide, vincristine, and doxorubicin with cyclophosphamide and prednisone (DA-EPOCH) is an anthracycline-based regimen that allows for personalization of dose-intensity, and prior anecdotal experience indicates it has activity in PEL. In combination with rituximab, an anti-CD20 monoclonal antibody, DA-EPOCH has been shown to be safe and effective for HIV-associated diffuse large B-cell lymphoma and Burkitt lymphoma. PEL is a CD20 negative tumor; however, many patients have concurrent KSHV-MCD for which rituximab is the standard treatment. In addition, rituximab may aid in eradication of the KSHV B-cell reservoir, a source of inflammatory cytokines that drive the natural history of PEL.

Patients of any HIV serostatus with both effusion and extracavitary presentations, including those with concurrent KSHV-associated diseases, such as Kaposi sarcoma and KSHV-MCD, are eligible. Patients with ECOG performance status of ≤4 are eligible for enrollment. The phase I portion of the study will evaluate the safety, tolerability, and maximum tolerated dose of lenalidomide combined with DA-EPOCH and rituximab (DA-EPOCH-R²). The phase II component will evaluate the activity and overall survival. Patients will receive 6, 21-day cycles of DA-EPOCH-R². Lenalidomide, initially at 25 mg, will be given on days 1 to 10. Patients will receive rituximab on day 1 and DA-EPOCH on days 1 to 5. Patients with HIV will be prescribed antiretroviral therapy as this is central to controlling HIV viremia and managing KSHV-associated malignancies. The lenalidomide dose will be de-escalated in a second dose group if 2 of 6 patients in phase 1 experience a dose-limiting toxicity. In the phase II portion of the study, 15 evaluable patients will be enrolled at the maximal tolerated dose of lenalidomide. At 12 months follow-up after the last patient has enrolled, a 1-tailed 0.10 alpha level test would have 80% power to determine if the overall survival curve would demonstrate a 1-year overall survival consistent with 45% or better and ruling out 20% or worse survival. Secondary outcomes include the evaluation of the pharmacokinetics of lenalidomide in blood, effusions, and CSF and the effect of DA-EPOCH-R²on concurrent KS, KSHV-MCD, and the KSHV-associated inflammatory cytokine syndrome. The study will also examine the effect of lenalidomide alone and in combination with rituximab and DA-EPOCH on the KSHV viral load, serum cytokines, lymphocyte subset reconstitution, HIV latency reversal, cellular measures of HIV, and the pharmacokinetics of tenofovir and tenofovir-diphosphate in plasma and peripheral blood mononuclear cells.

The study began enrollment in July 2017, and 5 patients have been enrolled on the phase I portion. All 5 patients have completed treatment without dose limiting toxicities.