In patients with AML with FMS-like tyrosine kinase 3 (FLT3) mutations, the significance of minimal residual disease (MRD) detected by PCR before allogeneic stem cell transplantation (SCT) on outcomes after transplant remains unclear. We identified 200 patients with FLT3-AML who underwent SCT at our institution. Disease status at transplant was: first or second complete remission (CR1/CR2, n = 119), high-risk CR (third or subsequent CR, marrow hypoplasia, or incomplete count recovery) (CR-HR, n = 31), and morphological evidence of active disease (AD, n = 50). The median follow-up was 27 months, and the 2-year overall and progression-free survival were 43% and 41%, respectively. Relapse was highest in the AD group (85%) and the CR-HR FLT3 MRD positive group (72%), followed by CR-HR FLT3 MRD negative (58%), CR1/CR2 FLT3 MRD positive (39%), and lowest in the CR1/CR2 FLT3 MRD negative group (23%). On multivariate analysis, independent factors influencing the risk of relapse were detectable morphological disease and FLT3 MRD by PCR pre-transplant. Factors that did not influence the relapse risk included: age, graft type, graft source, type of FLT3 mutation, or conditioning intensity. Morphologic and molecular remission status at the time of transplant were key predictors of disease relapse and survival in patients with FLT3-AML.

Lymphomas are not infrequently associated with the Epstein-Barr virus (EBV), and EBV positivity is linked to worse outcomes in several subtypes. Nanatinostat is a class-I selective oral histone deacetylase inhibitor that induces the expression of lytic EBV BGLF4 protein kinase in EBV+ tumor cells, activating ganciclovir via phosphorylation, resulting in tumor cell apoptosis. This phase 1b/2 study investigated the combination of nanatinostat with valganciclovir in patients aged ≥18 years with EBV+ lymphomas relapsed/refractory to ≥1 prior systemic therapy with no viable curative treatment options. In the phase 1b part, 25 patients were enrolled into 5 dose escalation cohorts to determine the recommended phase 2 dose (RP2D) for phase 2 expansion. Phase 2 patients (n = 30) received RP2D (nanatinostat 20 mg daily, 4 days per week with valganciclovir 900 mg orally daily) for 28-day cycles. The primary end points were safety, RP2D determination (phase 1b), and overall response rate (ORR; phase 2). Overall, 55 patients were enrolled (B-non-Hodgkin lymphoma [B-NHL], [n = 10]; angioimmunoblastic T-cell lymphoma-NHL, [n = 21]; classical Hodgkin lymphoma, [n = 11]; and immunodeficiency-associated lymphoproliferative disorders, [n = 13]). The ORR was 40% in 43 evaluable patients (complete response rate [CRR], 19% [n = 8]) with a median duration of response of 10.4 months. For angioimmunoblastic T-cell lymphoma-NHL (n = 15; all refractory to the last prior therapy), the ORR/CRR ratio was 60%/27%. The most common adverse events were nausea (38% any grade) and cytopenia (grade 3/4 neutropenia [29%], thrombocytopenia [20%], and anemia [20%]). This novel oral regimen provided encouraging efficacy across several EBV+ lymphoma subtypes and warrants further evaluation; a confirmatory phase 2 study (NCT05011058) is underway. This phase 1b/2 study is registered at www.clinicaltrials.gov as #NCT03397706.

BACKGROUND: Extra-Nodal natural killer/T-cell lymphoma (ENKL) is a rare lymphoma representing approximately 5-10% of T-cell non-Hodgkin lymphomas diagnosed in the United States each year. Patients with advanced stage III/IV ENKL and relapsed refractory ENKL have a poor prognosis even despite aggressive therapy and stem cell transplantation (SCT). We conducted a review of the management of 37 patients with advanced-stage and relapsed/refractory ENKL in a predominantly non-Asian cohort evaluating both chemotherapy and SCT outcomes. PATIENTS AND METHODS: We evaluated clinical outcomes in all patients treated for advanced stage III/IV or relapsed/refractory ENKL at MD Anderson cancer center between 2000-2014. Next, we collected stem cell transplant data from four transplant institutions to further evaluate outcomes of both allogeneic (allo-SCT) and autologous (auto-SCT) stem cell transplantation in ENKL. RESULTS: OS and PFS were 73% and 45% at one year, and 30% and 19% at 3-years, respectively. SMILE chemotherapy was more effective in maintaining a CR compared to CHOP (83% vs 17%). Only achievement of CR was prognostic for OS (HR 0.245, p=0.002) and PFS (HR 0.072, p) CONCLUSION: Our results suggest that achievement of a CR is imperative in patients with advanced ENKL, and is desirable for any patient for whom auto-SCT is utilized. SMILE-based chemotherapy appeared effective in attaining a CR, and was also an effective salvage regimen. For patients attaining a first CR, auto-SCT should be strongly considered, but should definitely be utilized in patients attaining CR2. For patients with refractory disease, allo-SCT can be considered in a selected group of patients.

Graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide (CY) after ablative HLA-matched bone marrow (BM) transplantation has been reported to have comparable rates of acute GVHD with an apparent reduction in chronic GVHD and infections when compared to historical prophylaxis with a calcineurin-inhibitor (CNI) and methotrexate (MTX). We conducted a phase II trial of post-transplantation CY (post-CY) after reduced-intensity conditioning (RIC) using intravenous busulfan (area under the curve of 4000 micromolar minute), fludarabine (40 mg/m(2)) for 4 days, and CY 50 mg/kg on days +3 and +4 after BM or peripheral blood (PB) transplantations from matched related (MRD) or unrelated donors (MUD). MUD recipients received antithymocyte globulin (ATG); however, a later amendment removed ATG. Forty-nine patients were treated (acute myeloid leukemia/myelodysplastic syndrome, 82%). Median age was 62 years (range, 39 to 72). Fifteen patients received an MRD (9 PB/6 BM); 34 had a MUD (2 PB/32 BM). The cumulative incidence of grade II to IV acute GVHD, III to IV acute GVHD, and chronic GVHD was 58%, 22%, and 18%, respectively. A matched cohort analysis compared outcomes to tacrolimus/methotrexate GVHD prophylaxis and indicated higher rates of acute GVHD grade II to IV (46% versus 19%; hazard ratio [HR], 2.8; P = .02) and treatment-related mortality (HR, 3.3; P = .035) and worse overall survival (HR, 1.9; P = .04) with post-CY. The incidence of chronic GVHD and CMV reactivation did not differ. This study suggests that post-CY should not be used as sole GVHD prophylaxis after a RIC transplantation from HLA-matched donors.

Background

High-dose, post-transplantation cyclophosphamide (PTCy) to prevent graft-versus-host disease (GVHD) has improved outcomes in haploidentical (HAPLO) stem cell transplantation (SCT). However, it remains unclear whether this strategy is effective in SCT from 1-antigen human leukocyte antigen (HLA)-mismatched unrelated donors (9/10 MUD) and how the outcomes of these patients compare with those of haploidentical transplantation recipients.

Methods

A parallel, 2-arm, nonrandomized phase 2 clinical trial was conducted of melphalan-based reduced-intensity conditioning with PTCy, tacrolimus, and mycophenolate mofetil to prevent GVHD in patients with high-risk hematologic malignancies who underwent HAPLO (n = 60) or 9/10 MUD (n = 46) SCT.

Results

The 1-year overall and progression-free survival rates were 70% and 60%, respectively, in the HAPLO arm and 60% and 47%, respectively, in the 9/10 MUD arm. The day +100 cumulative incidence of grade II to IV acute GVHD and grade III to IV acute GVHD was 28% and 3%, respectively, in the HAPLO arm and 33% and 13%, respectively, in the 9/10 MUD arm. The 2-year cumulative incidence of chronic GVHD was 24% in the HAPLO arm and 19% in the 9/10 MUD arm. The 1-year cumulative incidence of nonrelapse mortality was 21% in the HAPLO arm and 31% in the 9/10 MUD arm, and the 1-year relapse rate was 19% in the HAPLO arm and 25% in the 9/10 MUD arm.

Conclusions

Although this was a nonrandomized study and could not serve as a direct comparison between the 2 groups, the authors conclude that PTCy-based GVHD prophylaxis is effective for both HAPLO and 9/10 MUD SCTs. Prospective randomized trials will be required to compare the efficacies of alternative donor options for patients lacking HLA-matched donors. Cancer 2016;122:3316-3326. © 2016 American Cancer Society.