BACKGROUND Data are lacking on whether lenalidomide maintenance therapy prolongs the time to disease progression after autologous hematopoietic stem-cell transplantation in patients with multiple myeloma. METHODS Between April 2005 and July 2009, we randomly assigned 460 patients who were younger than 71 years of age and had stable disease or a marginal, partial, or complete response 100 days after undergoing stem-cell transplantation to lenalidomide or placebo, which was administered until disease progression. The starting dose of lenalidomide was 10 mg per day (range, 5 to 15). RESULTS The study-drug assignments were unblinded in 2009, when a planned interim analysis showed a significantly longer time to disease progression in the lenalidomide group. At unblinding, 20% of patients who received lenalidomide and 44% of patients who received placebo had progressive disease or had died (P<0.001); of the remaining 128 patients who received placebo and who did not have progressive disease, 86 crossed over to lenalidomide. At a median follow-up of 34 months, 86 of 231 patients who received lenalidomide (37%) and 132 of 229 patients who received placebo (58%) had disease progression or had died. The median time to progression was 46 months in the lenalidomide group and 27 months in the placebo group (P<0.001). A total of 35 patients who received lenalidomide (15%) and 53 patients who received placebo (23%) died (P=0.03). More grade 3 or 4 hematologic adverse events and grade 3 non-hematologic adverse events occurred in patients who received lenalidomide (P<0.001 for both comparisons). Second primary cancers occurred in 18 patients who received lenalidomide (8%) and 6 patients who received placebo (3%). CONCLUSIONS Lenalidomide maintenance therapy, initiated at day 100 after hematopoietic stem-cell transplantation, was associated with more toxicity and second cancers but a significantly longer time to disease progression and significantly improved overall survival among patients with myeloma. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00114101.)

IntroductionNatural killer (NK) cells are CD56 ϩ CD3 Ϫ large granular lymphocytes that comprise a key cellular compartment of the innate immune system. NK cells have been shown to exert antitumor activity against the malignant plasma cell clone in multiple myeloma (MM). 1-4 However, through several established mechanisms, the NK-cell versus MM effect is attenuated as the disease inexorably progresses. 5-9 MM is increasing in incidence and remains incurable despite the advent of potent novel therapies such as lenalidomide and bortezomib. 10 In fact, both lenalidomide and bortezomib have been shown to confer anti-MM activity, in part, through recovery or enhancement of the NK-cell versus MM effect. 11,12 The NK-cell versus MM effect is subject to modulation through intracellular signal transduction cascades initiated by activating and inhibitory receptors at the NK-cell surface interacting with ligands expressed on MM tumor cells. Programmed death 1 (PD-1), a member of the B7 family of cosignaling molecules, and its associated ligands PD-L1 and PD-L2 have been shown to play a key role in down-regulating the T-cell immune response. 13 The constitutive or inducible expression of PD-1 has been characterized on several immune cell subsets, including T, B, and dendritic cells; however, to date, comparatively little is known regarding PD-1 expression on NK cells and whether or not the PD-1/PD-L1 axis is involved in the NK-cell versus MM effect. 14 CT-011 (CureTech, LTD; previously CT-AcTibody or BAT) is a novel immunoglobulin G1 (IgG1) humanized monoclonal antibody (mAb) that modulates the immune response through interaction with PD-1, with previously demonstrated antitumor efficacy in experimental models of both solid and liquid tumors. [15][16][17] Several human malignancies, including MM, express cognate ligands for PD-1 (eg, PD-L1) and play a key role in tumor immunoevasion. 18,19 In a phase 1 clinical trial of patients with advanced hematologic malignancies including MM, CT-011 was demonstrated to be safe and well tolerated with evidence of single-agent clinical beneficial responses in 33% of the patients. 20 Given the results of this phase 1 study and the potential complementary mechanisms of action between CT-011 and lenalidomide, we hypothesized these agents in combination may represent a promising novel therapy for MM.Lenalidomide (Revlimid; Celgene) exerts efficacy in part through enhancement of the NK-cell versus MM effect, 11 an effect likely mediated through T-cell production of interleukin-2 (IL-2) in response to this agent. 21 The numbers of both T cells and NK cells are increased in patients receiving lenalidomide therapy 22 ; however, NK-cell killing is also enhanced, including antibodydependent cellular cytotoxicity and natural cytotoxicity. 23,24 Moreover, these events correlate with clinical responses to lenalidomide therapy in patients with MM. 22 In this report, we show that the PD-1/PD-L1 signaling axis mediates NK-cell activation and cytotoxicity against MM. We show that freshly isolated NK cells...

Mesenchymal stem cells (MSCs) are found in a variety of tissues, including human bone marrow; secrete hematopoietic cytokines; support hematopoietic progenitors in vitro; and possess potent immunosuppressive properties. We hypothesized that cotransplantation of culture-expanded MSCs and hematopoietic stem cells (HSCs) from HLA-identical sibling donors after myeloablative therapy could facilitate engraftment and lessen graft-versus-host disease (GVHD); however, the safety and feasibility of this approach needed to be established. In an open-label, multicenter trial, we coadministered culture-expanded MSCs with HLA-identical sibling-matched HSCs in hematologic malignancy patients. Patients received either bone marrow or peripheral blood stem cells as the HSC source. Patients received 1 of 4 study-specified transplant conditioning regimens and methotrexate (days 1, 3, and 6) and cyclosporine as GVHD prophylaxis. On day 0, patients were given culture-expanded MSCs intravenously (1.0-5.0 x 10(6)/kg) 4 hours before infusion of either bone marrow or peripheral blood stem cells. Forty-six patients (median age, 44.5 years; range, 19-61 years) received MSCs and HLA-matched sibling allografts. MSC infusions were well tolerated, without any infusion-related adverse events. The median times to neutrophil (absolute neutrophil count > or = 0.500 x 10(9)/L) and platelet (platelet count > or = 20 x 10(9)/L) engraftment were 14.0 days (range, 11.0-26.0 days) and 20 days (range, 15.0-36.0 days), respectively. Grade II to IV acute GVHD was observed in 13 (28%) of 46 patients. Chronic GVHD was observed in 22 (61%) of 36 patients who survived at least 90 days; it was extensive in 8 patients. Eleven patients (24%) experienced relapse at a median time to progression of 213.5 days (range, 14-688 days). The probability of patients attaining disease- or progression-free survival at 2 years after MSC infusion was 53%. Cotransplantation of HLA-identical sibling culture-expanded MSCs with an HLA-identical sibling HSC transplant is feasible and seems to be safe, without immediate infusional or late MSC-associated toxicities. The optimal MSC dose and frequency of administration to prevent or treat GVHD during allogeneic HSC transplantation should be evaluated further in phase II clinical trials.

• Lower GVHD after haploidentical transplant with posttransplant cyclophosphamide compared with HLA-matched unrelated donor transplant.• Comparable overall survival after haploidentical compared with matched unrelated donor transplant for AML.We studied adults with acute myeloid leukemia (AML) after haploidentical (n 5 192) and 8/8 HLA-matched unrelated donor (n 5 1982) transplantation. Haploidentical recipients received calcineurin inhibitor (CNI), mycophenolate, and posttransplant cyclophosphamide for graft-versus-host disease (GVHD) prophylaxis; 104 patients received myeloablative and 88 received reduced intensity conditioning regimens. Matched unrelated donor transplant recipients received CNI with mycophenolate or methotrexate for GVHD prophylaxis; 1245 patients received myeloablative and 737 received reduced intensity conditioning regimens. In the myeloablative setting, day 30 neutrophil recovery was lower after haploidentical compared with matched unrelated donor transplants (90% vs 97%, P 5 .02). Corresponding rates after reduced intensity conditioning transplants were 93% and 96% (P 5 .25). In the myeloablative setting, 3-month acute grade 2-4 (16% vs 33%, P < .0001) and 3-year chronic GVHD (30% vs 53%, P < .0001) were lower after haploidentical compared with matched unrelated donor transplants. Similar differences were observed after reduced intensity conditioning transplants, 19% vs 28% (P 5 .05) and 34% vs 52% (P 5 .002). Among patients receiving myeloablative regimens, 3-year probabilities of overall survival were 45% (95% CI, 36-54) and 50% (95% CI, 47-53) after haploidentical and matched unrelated donor transplants (P 5 .38). Corresponding rates after reduced intensity conditioning transplants were 46% (95% CI, 35-56) and 44% (95% CI, 0.40-47) (P 5 .71). Although statistical power is limited, these data suggests that survival for patients with AML after haploidentical transplantation with posttransplant cyclophosphamide is comparable with matched unrelated donor transplantation. (Blood. 2015;126(8):1033-1040

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The optimal regimen intensity before allogeneic hematopoietic cell transplantation (HCT) is unknown. We hypothesized that lower treatment-related mortality (TRM) with reduced-intensity conditioning (RIC) would result in improved overall survival (OS) compared with myeloablative conditioning (MAC). To test this hypothesis, we performed a phase III randomized trial comparing MAC with RIC in patients with acute myeloid leukemia or myelodysplastic syndromes. Patients and MethodsPatients age 18 to 65 years with HCT comorbidity index # 4 and , 5% marrow myeloblasts pre-HCT were randomly assigned to receive MAC (n = 135) or RIC (n = 137) followed by HCT from HLAmatched related or unrelated donors. The primary end point was OS 18 months post-random assignment based on an intent-to-treat analysis. Secondary end points included relapse-free survival (RFS) and TRM. ResultsPlanned enrollment was 356 patients; accrual ceased at 272 because of high relapse incidence with RIC versus MAC (48.3%; 95% CI, 39.6% to 56.4% and 13.5%; 95% CI, 8.3% to 19.8%, respectively; P , .001). At 18 months, OS for patients in the RIC arm was 67.7% (95% CI, 59.1% to 74.9%) versus 77.5% (95% CI, 69.4% to 83.7%) for those in the MAC arm (difference, 9.8%; 95% CI, 20.8% to 20.3%; P = .07). TRM with RIC was 4.4% (95% CI, 1.8% to 8.9%) versus 15.8% (95% CI, 10.2% to 22.5%) with MAC (P = .002). RFS with RIC was 47.3% (95% CI, 38.7% to 55.4%) versus 67.8% (95% CI, 59.1% to 75%) with MAC (P , .01). ConclusionOS was higher with MAC, but this was not statistically significant. RIC resulted in lower TRM but higher relapse rates compared with MAC, with a statistically significant advantage in RFS with MAC. These data support the use of MAC as the standard of care for fit patients with acute myeloid leukemia or myelodysplastic syndromes.

A phase II clinical trial with single-agent decitabine was conducted in older patients (≥60 years) with previously untreated acute myeloid leukemia (AML) who were not candidates for or who refused intensive chemotherapy. Subjects received low-dose decitabine at 20 mg/m 2 i.v. over 1 h on days 1 to 10. Fifty-three subjects enrolled with a median age of 74 years (range, 60-85). Nineteen (36%) had antecedent hematologic disorder or therapy-related AML; 16 had complex karyotypes (≥3 abnormalities). The complete remission rate was 47% (n = 25), achieved after a median of three cycles of therapy. Nine additional subjects had no morphologic evidence of disease with incomplete count recovery, for an overall response rate of 64% (n = 34). Complete remission was achieved in 52% of subjects presenting with normal karyotype and in 50% of those with complex karyotypes. Median overall and disease-free survival durations were 55 and 46 weeks, respectively. Death within 30 days of initiation of treatment occurred in one subject (2%), death within 8 weeks in 15% of subjects. Given the DNA hypomethylating effect of decitabine, we examined the relationship of clinical response and pretreatment level of miR-29b, previously shown to target DNA methyltransferases. Higher levels of miR-29b were associated with clinical response (P = 0.02). In conclusion, this schedule of decitabine was highly active and well tolerated in this poor-risk cohort of older AML patients. Levels of miR-29b should be validated as a predictive factor for stratification of older AML patients to decitabine treatment.methylation | microRNA | azanucleoside

with leukemia or lymphoma and no suitable related donor. Reduced intensity conditioning (RIC) was used with either unrelated double umbilical cord blood (dUCB) or HLA-haploidentical related donor bone marrow (Haplo-marrow) transplantation. For both trials, the transplantation conditioning regimen incorporated cyclophosphamide, fludarabine, and 200 cGy of total body irradiation. The 1-year probabilities of overall and progression-free survival were 54% and 46%, respectively, after dUCB transplantation (n ‫؍‬ 50) and 62% and 48%, respectively, after Haplomarrow transplantation (n ‫؍‬ 50). The day ؉56 cumulative incidence of neutrophil recovery was 94% after dUCB and 96% after Haplo-marrow transplantation. The 100-day cumulative incidence of grade II-IV acute GVHD was 40% after dUCB and 32% after Haplo-marrow transplantation. The 1-year cumulative incidences of nonrelapse mortality and relapse after dUCB transplantation were 24% and 31%, respectively, with corresponding results of 7% and 45%, respectively, after Haplomarrow transplantation. These multicenter studies confirm the utility of dUCB and Haplo-marrow as alternative donor sources and set the stage for a multicenter randomized clinical trial to assess the relative efficacy of these 2 strategies.