Lenalidomide maintenance in patients with relapsed diffuse large B-cell lymphoma who are not eligible for autologous stem cell transplantation: an open label, single-arm, multicentre phase 2 trial.

BACKGROUND: Patients with relapsed diffuse large B-cell lymphoma (DLBCL) not eligible for autologous stem cell transplantation (ASCT) or having relapse after ASCT have a low likelihood of cure. Single-drug maintenance after salvage therapy might be an attractive strategy to prolong survival in these patients. Lenalidomide is a suitable candidate for long-lasting maintenance as it is an oral drug, active against DLBCL that can be taken for years with an acceptable toxicity profile. We designed a study to investigate safety and efficacy of lenalidomide maintenance in patients with chemosensitive relapse of DLBCL not eligible for ASCT or having relapse after ASCT. METHODS: In this open-label, single group, multicentre phase 2 trial, we recruited HIV-negative adults with de novo or transformed DLBCL and relapsed disease responsive to conventional rituximab-containing salvage therapy from 12 oncology-haematology centres in Italy. All patients were given oral lenalidomide 25 mg per day for 21 of 28 days until lymphoma progression or unacceptable toxicity (severely compromises organ function, quality of life, or both). Primary endpoint was 1-year progression-free survival. The estimated sample size was 47 patients; maintenance was deemed efficacious if at least 19 patients were progression-free survivors at 1 year. All enrolled patients were included in primary analyses, with the exception of patients who post-hoc objectively did not meet the eligibility criteria (modified intention-to-treat). This study is registered with clinicaltrials.gov registry, number NCT00799513. FINDINGS: Between March 24, 2009, and Dec 22, 2015, we recruited 48 patients. 46 of 48 enrolled patients were assessable (two patients had unconfirmed diagnoses). 36 (78%) of 46 patients had de novo DLBCL and ten (22%) of 46 patients had transformed DLBCL. At a median follow-up of 25 months (IQR 12-56), 556 lenalidomide courses had been delivered, with an average mean of 12 courses (range 3-41) per patient; 19 patients were still in treatment at a median follow-up of 25 months. Lenalidomide was well tolerated; with the exception of neutropenia, grade 3-4 toxicities were uncommon. We recorded ten severe adverse events in nine patients due to febrile neutropenia (n=4), diarrhoea (n=2), melena, stroke, vomiting, and intestinal infarction; all but one patient recovered, and six of these patients continued with lenalidomide treatment. The exception was the only death due to toxicity (intestinal infarction). At 1 year from trial registration, 28 patients were progression free, which was much higher than the predetermined efficacy threshold. During the whole observation period, 21 events occurred: progressive lymphoma in 19 patients, death due to toxicity in one, death while off therapy in one, 1-year progression-free survival was 70% (95% CI 57-83). INTERPRETATION: With the limitations of a non-randomised design, this trial supports the use of lenalidomide maintenance in patients with chemo-sensitive relapse of DLBCL who are not eligible for ASCT or who had relapse after ASCT. These results warrant further investigation of immunomodulatory drugs as maintenance in high-risk patients with DLBCL. FUNDING: Celgene Corp.

Rituximab, bendamustine, and low-dose cytarabine as induction therapy in elderly patients with mantle cell lymphoma: a multicentre, phase 2 trial from Fondazione Italiana Linfomi.

BACKGROUND: The combination of rituximab, bendamustine, and cytarabine (R-BAC) was highly active in a pilot trial of mantle cell lymphoma, but its use was restricted by high haematological toxicity. We aimed to assess the efficacy and safety of an R-BAC regimen with low-dose cytarabine (RBAC500). METHODS: In this multicentre, phase 2 trial, we recruited previously untreated patients with an established histological diagnosis of mantle cell lymphoma from 29 Fondazione Italiana Linfomi centres in Italy. Patients had to be older than 65 years and fit according to the comprehensive geriatric assessment, or aged 60-65 years if they were ineligible for high-dose chemotherapy plus autologous stem-cell transplantation and were fit or unfit. All patients received RBAC500 (rituximab 375 mg/m2 on day 1, bendamustine 70 mg/m2 on days 2 and 3, and cytarabine 500 mg/m2 on days 2-4; all administered intravenously) every 4 weeks for up to six cycles. Primary endpoints were the proportion of patients achieving complete response at the end of treatment and toxicity, defined as the occurrence of any of the stop treatment criteria or of any episode of relevant toxicity. All patients who started at least one cycle of RBAC500 were included in the primary and safety analyses. Using efficacy and toxicity as a composite primary endpoint, we considered the final conclusion positive if more than 28 of 57 patients achieve complete response and fewer than 18 of 57 patients report toxicities. This study is registered with EudraCT, number 2011-005739-23, and ClinicalTrials.gov, number NCT01662050, and is completed. FINDINGS: Between May 2, 2012, and Feb 25, 2014, we enrolled 57 patients (median age 71 years, IQR 67-75). 54 (95%) patients received at least four RBAC500 cycles (three discontinued because of toxicity), and 38 (67%) completed six cycles. Two (4%) had disease progression (one after the fourth cycle and one after the sixth cycle). All 52 (91%, lower limit of one-sided 95% CI 85%) remaining patients achieved complete response at the end of treatment. 23 (40%, upper limit of one-sided 95% CI 53%) of 57 patients had at least one episode of relevant toxicity. The most frequent grade 3-4 haematological toxicities were neutropenia (149 [49%] of 304 cycles) and thrombocytopenia (158 [52%]). Most treatment-related non-haematological adverse events were of grade 1-2, with the most frequent ones being fatigue (14 [25%] patients), nausea or vomiting (12 [21%]), and infusion-related reactions or tumour lysis syndrome (12 [21%]). 41 (72%) patients required a dose reduction. 12 patients died during the study, but no deaths were related to treatment. INTERPRETATION: RBAC500 is an effective treatment for elderly patients with mantle cell lymphoma and, despite not meeting our prespecified safety boundary, haematological toxicity was manageable with appropriate supportive care and dose reduction. Since maintenance therapy is not required, RBAC500 could be considered an option and should be studied in phase 3 trials. FUNDING: Fondazione Italiana Linfomi and Mundipharma.