Nivolumab discontinuation and retreatment in patients with relapsed or refractory Hodgkin lymphoma.

Immune checkpoint inhibitors (ICI) have demonstrated high therapeutic efficacy in relapsed or refractory classical Hodgkin lymphoma (r/r cHL). Nevertheless, despite the accumulated data, the question of the ICI therapy duration and efficacy of nivolumab retreatment remains unresolved. In this retrospective study, in a cohort of 23 adult patients with r/r cHL who discontinued nivolumab in complete response (CR), the possibility of durable remission achievement (2-year PFS was 55.1%) was demonstrated. Retreatment with nivolumab has demonstrated efficacy with high overall response rate (ORR) and CR (67% and 33.3% respectively). At the final analysis, all patients were alive with median PFS of 16.5 months. Grade 3-4 adverse events (AEs) were reported in 36% of patients, and there was no deterioration in terms of nivolumab retreatment-associated complications.

A Phase 2 Study of Nivolumab Using a Fixed Dose of 40 mg (Nivo40) in Patients With Relapsed/Refractory Hodgkin Lymphoma.

The introduction of nivolumab has changed the landscape of relapsed/refractory classical Hodgkin lymphoma (r/r cHL) treatment. Despite its clinical importance, this therapy may remain inaccessible for a significant number of patients worldwide, especially in low-income countries, due to its high cost. The results of pharmacokinetic analysis and clinical observations suggest the potential efficacy of low dose nivolumab in r/r cHL patients. The aim of this trial was to assess the efficacy and safety of nivolumab at a fixed dose of 40 mg in patients with r/r cHL. The study included 30 patients with r/r cHL, treated with 40 mg nivolumab every 2 weeks. The median dose of nivolumab per kilogram bodyweight was 0.59 mg/kg (0.4-1 mg/kg). Median follow up was 19.2 months (range 12.7-25.4). The objective response rate was 70%, with 13 (43.3%) patients achieving a complete response. Median PFS was 18.4 months (95% CI, 11.3 to 18.5 months) with 18-month PFS of 53.6% (95% CI, 32%-71%). At the time of analysis, 96.7% of patients were alive with a median OS not reached. Severe (grade 3-5) adverse events were observed in 4 patients (13.3%). Nivolumab in a fixed dose of 40 mg was efficient in patients with r/r cHL, independent from dose per kg bodyweight. The results of this study are in good agreement with previously reported data and create a rationale for further studies aimed to define the optimal dosing regimen of nivolumab for the treatment of r/r cHL. Registered at www.clinicaltrials.gov (NCT03343665).

A Study of Safety and Efficacy of Nivolumab and Bendamustine (NB) in Patients With Relapsed/Refractory Hodgkin Lymphoma After Nivolumab Monotherapy Failure.

This single-center prospective clinical trial evaluated the combination of nivolumab plus bendamustine (NB) as a salvage regimen in classical Hodgkin lymphoma patients after failure of nivolumab monotherapy. A total of 30 patients received nivolumab (3 mg/kg) on D1,14 and bendamustine (90 mg/m2) on D1, 2 of a 28-day cycle for up to 3 cycles. The ORR was 87% with 57% CR, 30% PR. With median follow-up of 25 months, the estimated 2-year OS was 96,7% (95% CI, 90.2%-100%), PFS was 23,3% (95% CI, 8.2%-38.4%) median PFS was 10.2 months (95% CI, 7.7-14.2 months) with median DOR 6.6 months (95% CI 3.9-11.6 months). Ten patients (33.3%) experienced grade 3 to 4 AE during therapy. Infections were most common AEs of the combined therapy. NB was a highly efficient salvage regimen in relapsed/refractory cHL with a manageable toxicity profile and modest potential for achievement of long-term remission. Registered at www.clinicaltrials.gov (#NCT0334365).

High prevalence of CD3, NK, and NKT cells in the graft predicts adverse outcome after matched-related and unrelated transplantations with post transplantation cyclophosphamide.

The predictive value of graft composition and plasma biomarkers on the outcome of allogeneic HSCT is well known for conventional GVHD prophylaxis based on calcineurin inhibitors with or without antithymocyte globulin. Currently, there is limited data whether these results could be translated to post transplantation cyclophosphamide (PTCy). The prospective extension cohort of NCT02294552 trial enrolled 79 adult patients with acute leukemia in CR. Twenty-six received matched-related bone marrow (BM) grafts with single-agent PTCy and 53 received unrelated peripheral blood stem cell graft (PBSC) with PTCy, tacrolimus, and MMF. The grafts were studied by the flow cytometry, and plasma samples were analyzed by ELISA. In the cluster and major component analysis, we determined that transplantation from donors with high content of CD3, NKT, and CD16-CD56 + subpopulations in the PBSC grafts was associated with poor immunological recovery and compromised event-free survival (50% vs. 80%, HR 2.93, p = 0.015) both due to increased relapse incidence and non-relapse mortality. The significant independent predictor of moderate and severe chronic GVHD was the high prevalence of and iNKT, Vß11, and double-positive cells in the PBSC grafts from young donors (HR 2.75, p = 0.0483). No patterns could be identified for BM grafts and for plasma biomarkers.

Risk-adapted GVHD prophylaxis with post-transplantation cyclophosphamide in adults after related, unrelated, and haploidentical transplantations.

INTRODUCTION: Although a number of studies were published on the efficacy of post-transplantation cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis, no large studies prospectively evaluated this strategy in related, unrelated, and haploidentical grafts. METHODS: In this study, GVHD prophylaxis for 57 matched bone marrow (MBM) grafts consisted of single-agent PTCy, for 88 matched PBSC grafts (MPBSC) consisted of PTCy, tacrolimus, and mycophenolate mofetil (MMF) 30 mg/kg, and for 55 mismatched grafts (MMGs) consisted of PTCy, tacrolimus and MMF 45 mg/kg. RESULTS: The study met the primary endpoint to demonstrate equivalent rates of acute GVHD grade II-IV (11%, 17%,19%, P = .46), III-IV (7%, 2%, 6%, P = .41), and moderate and severe chronic GVHD (22%, 11%, 15%, P = .23). There was also no differences in non-relapse mortality (11% vs 15% vs 17%, P = .75), overall survival (63% vs 71% vs 56%, P = .72), event-free-survival (51% vs 66% vs 48%, P = .32) for MBM, MPBSC, and MMG groups, respectively. Toxicity was comparable between groups except higher incidence of nephrotoxicity in combination arms (P = .0005) and higher incidence of graft failures in MMG group (P = .004). CONCLUSION: The suggested risk-adapted PTCy-based prophylaxis is feasible and is associated with low GVHD incidence and mortality in all types of grafts. The study was registered on clinicaltrials.gov (NCT02294552).

Graft-versus-Host Disease Prophylaxis in Unrelated Peripheral Blood Stem Cell Transplantation with Post-Transplantation Cyclophosphamide, Tacrolimus, and Mycophenolate Mofetil.

Clinical efficacy of post-transplantation cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis has been demonstrated in haploidentical and HLA-matched bone marrow but not in unrelated peripheral blood stem cell (PBSC) transplantations. Also, no direct comparisons have been published with current standard of care, combination of antithymocyte globulin (ATG), calcineurin inhibitors, and either methotrexate or mycophenolate mofetil (MMF). Eighty-six adult patients (median age 34 years; range, 18 to 59) with acute myeloblastic and lymphoblastic leukemia underwent unrelated PBSC transplantation with PTCy, tacrolimus, and MMF as GVHD prophylaxis in the single-center trial (clinicaltrial.govNCT02294552). The control group comprised 125 consecutive historical control patients who received ATG, tacrolimus, and methotrexate or MMF. Cumulative incidences of grades II to IV acute (19% versus 45%, P = .0003), grades III to IV acute (4% versus 27%, P < .0001), and chronic GVHD (16% versus 65%, P < .0001) were significantly lower in the PTCy compared with the ATG group. PTCy-based prophylaxis was associated with reduced incidence of nonrelapse mortality (16% versus 36%, P = .005; HR, .55; 95% CI, .34 to .89) and improved overall survival (69% versus 40%, P = .0007; HR, .43; 95% CI, .26 to .70), event-free survival (65% versus 38%, P = .0006; HR, .49; 95% CI, .31 to .78), and GVHD relapse-free survival (52% versus 12%, P < .0001). PTCy-based prophylaxis also had a better safety profile compared with ATG with reduced incidence of veno-occlusive disease, cytomegalovirus reactivation, invasive mycosis, and reduced severity of mucositis. In this study we demonstrated that PTCy in combination with tacrolimus and MMF is a safe and effective GVHD prophylaxis for unrelated PBSC transplantation. Although there are several limitations of the historical control approach, this study suggests the superiority of a PTCy-based approach over an ATG-based prophylaxis.

An inter-laboratory comparison of PNH clone detection by high-sensitivity flow cytometry in a Russian cohort.

OBJECTIVES: Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal stem cell disorder characterized by partial or absolute deficiency of glycophosphatidyl-inositol (GPI) anchor-linked surface proteins on blood cells. A lack of precise diagnostic standards for flow cytometry has hampered useful comparisons of data between laboratories. We report data from the first study evaluating the reproducibility of high-sensitivity flow cytometry for PNH in Russia. METHODS: PNH clone sizes were determined at diagnosis in PNH patients at a central laboratory and compared with follow-up measurements in six laboratories across the country. Analyses in each laboratory were performed according to recommendations from the International Clinical Cytometry Society (ICCS) and the more recent 'practical guidelines'. Follow-up measurements were compared with each other and with the values determined at diagnosis. RESULTS: PNH clone size measurements were determined in seven diagnosed PNH patients (five females, two males: mean age 37 years); five had a history of aplastic anemia and three (one with and two without aplastic anemia) had severe hemolytic PNH and elevated plasma lactate dehydrogenase. PNH clone sizes at diagnosis were low in patients with less severe clinical symptoms (0.41-9.7% of granulocytes) and high in patients with severe symptoms (58-99%). There were only minimal differences in the follow-up clone size measurement for each patient between the six laboratories, particularly in those with high values at diagnosis. CONCLUSIONS: The ICCS-recommended high-sensitivity flow cytometry protocol was effective for detecting major and minor PNH clones in Russian PNH patients, and showed high reproducibility between laboratories.