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.

Long-term follow-up analysis after rituximab salvage therapy in adult patients with immune thrombocytopenia.

We report the long-term outcome results of 57 consecutive adult patients with immune thrombocytopenia after being treated with rituximab. According to the different period of therapy, patients received either standard dose (SD) rituximab (i.e., 375 mg/m(2) weekly for 4 weeks) or low dose (LD) rituximab (i.e., 100 mg flat dose weekly for 4 weeks). Overall (OR) and complete response (CR) rates were 60 and 40%, respectively. Patients' median follow-up was 52 months, 82 months in the SD, and 44 months in the LD group; 15 out of 34 responsive patients (44%) relapsed, with median response duration of 24 months (range 3-120). The estimated 4-years event-free survival (EFS, considering events the non response status at month 2 or relapses in responders) was 30%. Patients who received SD vs. LD rituximab had better outcome with regard to short term response (OR 66 vs. 52%, CR 50 vs. 28%), relapse rate (38 vs. 54%), probability to achieve and maintain long-term response (41 vs. 24%) and estimated 4-years EFS (35 vs. 23%). Patients with a longer interval between diagnosis and rituximab therapy had worse EFS [HR = 1.005; 95%IC: (1.002-1.009), P = 0.019]. Three patients developed short-term adverse events, two-serum sickness, and one interstitial pneumonia. Four cases of malignancies and two herpes zoster reactivations were registered during long-term follow-up; one patient died for cerebral bleeding. Rituximab SD appears a safe and active agent allowing in nearly 40% of cases to achieve long-term response and splenectomy sparing effect.

Dapsone salvage therapy for adult patients with immune thrombocytopenia relapsed or refractory to steroid and rituximab.

Dapsone is an antibacterial sulfonamide with anti-inflammatory property, which showed therapeutic activity in patients with immune thrombocytopenia (ITP); the activity in patients who showed refractoriness to rituximab is unknown. We evaluated the effect of dapsone in 20 consecutive adult patients, median age 51 years, with primary ITP previously treated at least with steroids and rituximab. Median baseline platelet count was 19 × 109/L, and the median interval between diagnosis of ITP and dapsone therapy was 46 months. Response (platelet count ≥ 30 × 109/L) and complete response (CR; platelet count ≥ 100 × 109/L) were 55 and 20%, respectively; median time to response (TTR) was 1 month. All responders were able to interrupt any other specific anti-ITP treatment. The median duration of dapsone therapy in responders and the median response duration were 31 and 42 months, respectively. None of responders lost response during treatment. One patient in CR interrupted dapsone after 9 months and still maintained the response after 48 months. None of the patients interrupted the treatment for toxicity. All the patients were screened for normal glucose-6-phosphate-dehydrogenase (G6PD); two patients showed mild increase of methemoglobin (MHb). These results highlight the therapeutic activity and good safety profile of dapsone in patients with ITP who previously failed rituximab treatment.

Monitoring of minimal residual disease by quantitative WT1 gene expression following reduced intensity conditioning allogeneic stem cell transplantation in acute myeloid leukemia.

WT1 is well-known to be a panleukemic marker that is expressed in 90% of acute myeloid leukemias (AML). Quantification of WT gene expression in bone marrow (BM) samples may be useful as a marker of minimal residual disease (MRD) during and after treatment for early prediction of relapse. We evaluated the validity of this AML-MRD marker after reduced intensity conditioning (RIC) allogeneic stem cell transplantation (SCT). The quantitative assessment of WT1 expression by real-time quantitative PCR (RQ-PCR) was measured in 25 patients (pts) with AML at diagnosis, at the time of RIC-SCT and after transplant at precise time points. All pts showed high WT1 levels at diagnosis with a mean of 4895 (SD 4462) and a median of 3679 (range 454-16,853) copies WT1/10(4) ABL. At transplant, 18/25 pts (72%) were in complete cytologic remission (CcR) and 7/25 (28%) had refractory AML. At the pre-SCT evaluation, BM samples from pts transplanted in CcR showed significantly lower WT1 expression levels compared to the samples from pts with refractory AML (p = 0.002). Median follow-up after RIC-SCT was 18 months (range 2-54). On 18 pts transplanted in CcR, those (17/18) who maintained CcR after RIC-SCT displayed a WT1 copy number persistently low during all the follow-up period. In patients who received RIC-SCT with active disease obtaining a sustained CcR after transplant (3/25), WT1 levels decreased to normal range in the first two months after RIC-SCT and remained low through the entire study period. All pts who relapsed after RIC-SCT (4/25) had a high WT1 copy number before the cytologic relapse. In 50% of these cases, an increase in WT1 expression was documented before molecular chimerism decreasing. With this experience, taking into account the limited number of pts, we confirmed a concordance between WT1 expression levels (measured by RQ-PCR at precise and sequential time points) and status of AML before and after RIC-SCT and we found a concordance between WT1 expression levels and hematopoietic chimerism status. Our data suggest that, in the RIC-SCT setting, the sequential and quantitative analysis of WT1 may be useful as a leukemia marker for monitoring MRD and as a predictor of overt AML cytologic relapse.