Autologous stem cell transplantation for refractory or poor-risk relapsed Hodgkin's lymphoma: effect of the specific high-dose chemotherapy regimen on outcome

Targeting the DNA damage response in hematological malignancies

Deregulation of the DNA damage response (DDR) plays a critical role in the pathogenesis and progression of many cancers. The dependency of certain cancers on DDR pathways has enabled exploitation of such through synthetically lethal relationships e.g., Poly ADP-Ribose Polymerase (PARP) inhibitors for BRCA deficient ovarian cancers. Though lagging behind that of solid cancers, DDR inhibitors (DDRi) are being clinically developed for haematological cancers. Furthermore, a high proliferative index characterize many such cancers, suggesting a rationale for combinatorial strategies targeting DDR and replicative stress. In this review, we summarize pre-clinical and clinical data on DDR inhibition in haematological malignancies and highlight distinct haematological cancer subtypes with activity of DDR agents as single agents or in combination with chemotherapeutics and targeted agents. We aim to provide a framework to guide the design of future clinical trials involving haematological cancers for this important class of drugs.

Gemcitabine-based conditioning compared to BEAM/BEAC conditioning prior to autologous stem cell transplantation for non-Hodgkin lymphoma: No difference in outcomes

BACKGROUND

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) remains an effective treatment for non-Hodgkin lymphoma (NHL). The limited availability of carmustine has prompted the exploration of novel alternative conditioning regimens. This study aimed to compare the efficacy and safety profile of GBM/GBC (gemcitabine, busulfan, and melphalan or cyclophosphamide) conditioning compared with the standard BEAM/BEAC regimens (carmustine, etoposide, cytarabine, and melphalan or cyclophosphamide) for ASCT in patients with NHL.

METHODS

A retrospective analysis was conducted on 231 NHL patients, who underwent ASCT from October 2010 to October 2021 at the Institute of Hematology & Blood Disease Hospital, including both first-line and salvage settings. This resulted in the inclusion of 112 patients in the GBM/GBC arm and 92 in the BEAM/BEAC arm. Propensity score matching was employed to validate the results.

RESULTS

Disease subtype distribution was similar between the GBM/GBC and BEAM/BEAC groups, with diffuse large B-cell lymphoma being the most common (58.9% vs. 58.7%), followed by PTCL (17.0% vs. 18.5%) and MCL (14.3% vs. 14.1%). At 3 months post-ASCT, complete response (CR) rates were comparable (GBM/GBC 93.5% vs. BEAM/BEAC 91.1%; p = 0.607). The 4-year progression-free survival (78.4% vs. 82.3%; p = 0.455) and 4-year overall survival (88.1% vs. 87.7%; p = 0.575) were also similar. Both groups exhibited low non-relapse mortality at 4 years (GBM/GBC 1.8% vs. BEAM/BEAC 3.5%; p = 0.790) with no transplant-related mortalities reported. The GBM/GBC cohort demonstrated a higher incidence of grade 3/4 oral mucositis and hepatic toxicity, whereas the BEAM/BEAC group had more frequent cases of bacteremia or sepsis (13 cases vs. 5 in GBM/GBC).

CONCLUSIONS

The GBM/GBC regimen is effective and well-tolerated, offering outcomes that are highly comparable to those in NHL patients conditioned with BEAM/BEAC, as demonstrated in a prognostically matched cohort.

Safety and efficacy of high-dose cytarabine MEAM therapy and other treatments for auto-peripheral blood stem cell transplantation: A retrospective comparative study

AIM

The MEAM regimen consisting of ranimustine (MCNU), etoposide (ETP), cytarabine (Ara-C), and melphalan (MEL) is widely used before auto-peripheral blood stem cell transplantation (auto-PBSCT) for malignant lymphoma in Japan. The MEAM regimen generally consists of 200-400 mg/m² for 4 days, but we decided to increase the dosage of Ara-C from the standard to 2 g/m² for 2 days with the aim of increasing drug transferability to the central nervous system. We evaluate the safety and therapeutic efficacy of high-dose Ara-C MEAM therapy.

METHODS

The high-dose Ara-C MEAM protocol consisted of MCNU 300 mg/m² on day -7, ETP 200 mg/m² on days -6, -5, -4, -3 and Ara-C 2 g/m² on day -4 -3, and MEL 140 mg/m² on day -2. We retrospectively analyzed 37 cases of malignant lymphoma at our institution between May 2014 and July 2020.

RESULTS

All patients got engraftment and there were no cases of treatment-related mortality. In all cases, the 3-year overall survival (OS) and progression-free survival (PFS) after transplantation were 80.6% and 65.7%, respectively. Twenty-one cases of diffuse large B-cell lymphoma recurrence, for which there is proven usefulness of auto-PBSCT, showed good results after transplantation, with the 3-year OS and PFS after transplantation being 100% and 74.3%, respectively.

CONCLUSION

The safety and efficacy of high-dose Ara-C MEAM therapy were demonstrated, but the expected therapeutic effect on central nervous system lesions could not be fully evaluated owing to the small number of cases.

Pembrolizumab for the Treatment of Relapsed and Refractory Classical Hodgkin Lymphoma After Autologous Transplant and in Transplant-Naïve Patients

INTRODUCTION

Checkpoint inhibitors demonstrated significant efficacy in relapsed/refractory Hodgkin's Lymphoma (R/R cHL) resulting in high responses and prolonged progression free survival in patients, who relapse after or are ineligible for autologous stem cell transplantation (auto-SCT). We aimed to assess the efficacy and toxicity of Pembrolizumab before auto-SCT and in transplant naïve patients and calculate survival outcomes.

PATIENTS AND METHODS

Fifty-five patients with R/R cHL were included. Patients demographics, including age, sex, risk stratification, therapy received and details pertaining transplantation, were collected.

RESULTS

Median age was 28 years (range, 16-62 years). The median follow-up was 15.3 months and the median number of previous treatments was 3 (1-10). The best objective response was 74.5% (CR 32.7%, SD 5.5%) with reasonable safety profile. Twenty-nine of the responding patients received subsequent auto-SCT and 9 allogeneic stem cell transplantation (allo-SCT), 6 are currently alive with ongoing response. At the time of analysis, 6 patients remained on Pembrolizumab and the rest discontinued. The main reason for discontinuation was disease progression (n-49). Twelve-months overall survival and progression free survival (PFS) was 92% (95% CI: 76%-95%) and 51% (95% CI, 39%-67%) respectively. Twelve-month PFS for patients, who achieved CR or PR or PD was 88% (95% CI: 07%-75%); PR 60% (95% CI: 21%-29%) and 5% (95% CI: 5%-0%). Though the number of patients who received auto-SCT after Pembrolizumab was small (n-15), 12 months overall survival and PFS 100% and PFS 92%. 11 patients (20%) deceased during the follow-up and none was regarded to be treatment-related.

CONCLUSION

Checkpoint inhibitors are effective in heavily pretreated cHL patients with reasonable survival outcomes. The results supporting the concept of auto and/or allo-SCT after checkpoint inhibitors use.

Outcome of CBV (Carmustine, Cyclophosphamide, Etoposide) Conditioning Regimen for Autologous Stem Cell Transplant in Lymphoma: A Retrospective Study from a Tertiary Cancer Center in South India

Background In autologous stem cell transplant (ASCT) for lymphomas, no standard conditioning regimen has been defined so far. Thus, the choice is guided by the center's familiarity and experience with a particular regimen.

Objective To determine the response, toxicity, and survival outcomes in lymphoma patients who underwent ASCT with CBV (cyclophosphamide, carmustine, and etoposide) conditioning regimen.

Materials and Methods Between January 2013 and May 2019, 45 consecutive lymphoma patients who had ASCT with CBV conditioning regimen were included in this retrospective study. CBV consisted of cyclophosphamide (1.5 g/m2/day × 4 days), carmustine (300 mg/m2 × 1 day), and etoposide (125 mg/m2 twice daily × 3 days). Baseline characteristics, pre transplant response, apheresis, post-transplant toxicities, post-transplant response, and survival outcomes were collected. Endpoints were toxicity, response, event-free survival (EFS), and overall survival (OS).

Results The median age was 30 (range: 6–64) years. Diagnosis was Hodgkin lymphoma (HL) in 26 (58%) and non-Hodgkin lymphoma (NHL) in 19 (42%). Forty-three patients (95%) had chemosensitive disease; 22(49%) in CR, and 21 (46%) in PR. The median CD34 was 2.95 × 106/kg (range: 0.9–9.56). The median time to neutrophil engraftment was 11 days (9–23) and 13 (8–36) days for platelets. All patients had febrile neutropenia, clinically and/or microbiologically documented infection was seen in 75% of patients. The most common grade 3/4 toxicities were mucositis (n = 4, 9%), diarrhea (n = 4, 9%), and nausea/vomiting (n = 2, 4%). The average days of hospitalization was 18 (range: 10–37). Day 100 mortality was 6.6% (n = 3). The median follow-up was 44.8 months. The median EFS for the entire cohort was 23.8 months; for HL, the median EFS was not reached, and for NHL, it was 7.97 months (95% confidence interval [CI]: 1.57–14.37). The median OS for the entire cohort and for HL was not reached; for NHL, it was 24.3 months (95% CI: 0.56–48.11).

Conclusion CBV conditioning regimen was well tolerated with low grade 3/4 toxicities and efficacy comparable to literature data.

Autologous stem cell transplantation after anti-PD-1 therapy for multiply relapsed or refractory Hodgkin lymphoma

Autologous stem cell transplantation (ASCT) can be curative for patients with relapsed/refractory Hodgkin lymphoma (HL). Based on studies suggesting that anti-PD-1 monoclonal antibodies (mAbs) can sensitize patients to subsequent chemotherapy, we hypothesized that anti-PD-1 therapy before ASCT would result in acceptable outcomes among high-risk patients who progressed on or responded insufficiently to ≥1 salvage regimen, including chemorefractory patients who are traditionally considered poor ASCT candidates. We retrospectively identified 78 HL patients who underwent ASCT after receiving an anti-PD-1 mAb (alone or in combination) as third-line or later therapy across 22 centers. Chemorefractory disease was common, including 42 patients (54%) refractory to ≥2 consecutive systemic therapies immediately before anti-PD-1 treatment. Fifty-eight (74%) patients underwent ASCT after anti-PD-1 treatment, while 20 patients (26%) received additional therapy after PD-1 blockade and before ASCT. Patients received a median of 4 systemic therapies (range, 3-7) before ASCT, and 31 patients (41%) had a positive pre-ASCT positron emission tomography (PET) result. After a median post-ASCT follow-up of 19.6 months, the 18-month progression-free survival (PFS) and overall survival were 81% (95% CI, 69-89) and 96% (95% confidence interval [CI], 87-99), respectively. Favorable outcomes were observed for patients who were refractory to 2 consecutive therapies immediately before PD-1 blockade (18-month PFS, 78%), had a positive pre-ASCT PET (18-month PFS, 75%), or received ≥4 systemic therapies before ASCT (18-month PFS, 73%), while PD-1 nonresponders had inferior outcomes (18-month PFS, 51%). In this high-risk cohort, ASCT after anti-PD-1 therapy was associated with excellent outcomes, even among heavily pretreated, previously chemorefractory patients.

FDG PET for Assessment of Autologous Stem Cell Transplantation

The appropriate selection of patients to undergo hematopoietic stem cell transplant (HSCT) is critical due to the risk of treatment-related morbidity and mortality. The prognostic value of FDG-PET/CT in response assessment in hematologic malignancies is well-established and has led to numerous investigations into the role of FDG-PET/CT in the evaluation of patients in the setting of HSCT. This article discusses the most common indications for autologous stem cell transplant (autoSCT) in which FDG-PET/CT has been evaluated, including for lymphoma and multiple myeloma. For relapsed/refractory Hodgkin lymphoma, achieving a negative FDG-PET/CT scan, regardless of the number of the regimens, prior to autoSCT is an important prognostic factor for posttransplant outcome. The data in the pretransplant setting are more variable for non-Hodgkin lymphoma. For both Hodgkin and non-Hodgkin lymphoma, studies have primarily used a visual assessment for FDG-PET/CT interpretation, with the Deauville score the current standard criteria. Optimization of thresholds for specific regimens pretransplant as well as integration of additional semiquantitative parameters to assess response remain active areas of research. For multiple myeloma, FDG-PET/CT has emerged as the recommended imaging modality of choice for assessing response to treatment. Data suggest that FDG-PET/CT may provide prognostic and predictive value for assessing outcome after autoSCT.

Results of a completely outpatient autologous stem cell transplant program for lymphoma patients receiving reduced-intensity conditioning

Autologous stem cell transplantation (ASCT) is commonly an in-patient procedure. However, outpatient ASCT grows as a cost-effective and feasible option for patients with lymphoma and reports assessing it after reduced-intensity conditioning (RIC) are sparse. We report the outcome of 102 patients with lymphoma who underwent ASCT on a full outpatient basis in a single-center transplant program between 2010 and 2020. Forty-two percent of the cohort required transfusion support, 36.3% experienced a neutropenic fever episode, 25.5% mucositis, and 9.8% developed severe infection. At a median time of 5 days (range 1-28), only 22.5% of the cohort required admission within the first 100 days after the autograft, median length of hospital stay was 0 days (range 0-14) and neutropenic fever was the most common reason for hospitalization. Non-relapse mortality at 1 year was 5%. ASCT in a completely outpatient setting is feasible, safe, and highly effective to treat lymphoma patients.

The Evolving Role of Brentuximab Vedotin in Classical Hodgkin Lymphoma

The arrival of the CD30 directed antibody-drug conjugate, brentuximab vedotin (BV), has altered the approach to patients with classical Hodgkin lymphoma. Since initial approval in 2011, BV has been extensively studied in previously untreated and relapsed/refractory patients. Treatment indications for the antibody-drug conjugate have been expanded from the previously treated population to include maintenance therapy after autologous stem cell transplantation and recently, combination with chemotherapy in newly diagnosed advanced stage patients. This article will review the evolution of BV in classical Hodgkin lymphoma, detailing the studies that led to the approved indications and discussion of recent trials in combination with chemotherapy and immunotherapy.

Strategies to improve outcomes of autologous hematopoietic cell transplant in lymphoma

High-dose chemotherapy and autologous hematopoietic cell transplantation (HDT-AHCT) remains an effective therapy in lymphoma. Over the past several decades, HDT with BEAM (carmustine, etoposide, cytarabine, and melphalan) and CBV (cyclophosphamide, carmustine, and etoposide) have been the most frequently used preparatory regimens for AHCT in Hodgkin (HL) and non-Hodgkin lymphoma (NHL). This article reviews alternative combination conditioning regimens, as well as novel transplant strategies that have been developed, to reduce transplant-related toxicity while maintaining or improving efficacy. These data demonstrate that incorporation of maintenance therapy posttransplant might be the best way to improve outcomes.

Phase II Trial of High-Dose Gemcitabine/Busulfan/Melphalan with Autologous Stem Cell Transplantation for Primary Refractory or Poor-Risk Relapsed Hodgkin Lymphoma

We conducted a prospective phase 2 trial of gemcitabine, busulfan and melphalan (Gem/Bu/Mel) with autologous stem cell transplantation (ASCT) in patients with primary refractory or poor-risk relapsed Hodgkin lymphoma (HL) (ie, extranodal relapse or within 1 year of frontline therapy). The trial was powered to detect an improvement in 2-year progression-free survival (PFS) from a historical 50% using a BEAM regimen (carmustine/etoposide/cytarabine/melphalan) to 65%. We compared the study population with all other concurrent patients who were eligible for the trial but instead received the BEAM regimen at our center. No patient received post-ASCT maintenance therapy. The Gem/Bu/Mel trial enrolled 80 patients with a median age of 31 years, 41% with primary refractory HL and 59% with relapsed HL (36% extranodal relapses), and 30% with positron emission tomography (PET)-positive lesions at ASCT. The concurrent BEAM (n = 45) and Gem/Bu/Mel cohorts were well balanced except for higher rates of bulky relapse and PET-positive tumors in the Gem/Bu/Mel cohort. There were no transplantation-related deaths in either cohort. At a median follow-up of 34.5 months (range, 26 to 72 months), Gem/Bu/Mel was associated with better 2-year PFS (65% versus 51%; P = .008) and overall survival (89% versus 73%; P = .0003). In conclusion, our data show that Gem/Bu/Mel is safe, in this nonrandomized comparison yielding improved outcomes compared with a concurrently treated and prognostically matched cohort of patients with primary refractory or poor-risk relapsed HL receiving BEAM.

Pretransplant functional imaging and outcome in pediatric patients with relapsed/refractory Hodgkin lymphoma undergoing autologous transplantation

BACKGROUND

Pretransplant functional imaging (FI), particularly a negative positron emission tomography (PET), is a strong predictor of outcome in adults with relapsed or refractory Hodgkin lymphoma (HL), but data in pediatrics are limited.

METHODS

The medical records of 49 consecutive pediatric patients, who received autologous transplant at a single institution, were retrospectively analyzed. All patients had either gallium or PET scan before transplant and were conditioned with carmustine, etoposide, cytarabine, and melphalan (BEAM). Deauville scores were retrospectively assigned for patients with PET (score ≥ 4 positive).

RESULTS

Of the 49 patients (median age, 16.2 years), 41 (84%) were pretransplant FI negative and eight (16%) were pretransplant FI positive, after first- to fourth-line salvage therapy, and a median of two salvage cycles. Eighteen patients (37%) received posttransplant radiation. At a median follow up of 46 months, 45 patients (92%) were alive and disease free, and there were three nonrelapse deaths and only one relapse death (Deauville score of 5). The 4-year progression-free survival (PFS) for the entire cohort was 92% (95% confidence interval [CI]: 78-97), and PFS based on pretransplant disease status was 95% (95% CI: 82-99%) in the negative FI group versus 75% (95% CI: 31-93) if positive FI (P = 0.057).

CONCLUSION

Our analysis revealed outstanding outcomes for children and adolescents with relapsed/refractory HL. There were too few relapses to identify the predictive value of pretransplant metabolic status, but pediatric patients with relapsed/refractory HL and a negative pretransplant FI had excellent survival.

Tandem Autologous Hematopoietic Cell Transplantation for Patients with Primary Progressive or Recurrent Hodgkin Lymphoma: A SWOG and Blood and Marrow Transplant Clinical Trials Network Phase II Trial (SWOG S0410/BMT CTN 0703)

Based on promising pilot data a phase II tandem autologous hematopoietic stem cell transplant (AHSCT) trial for relapsed/refractory Hodgkin lymphoma (HL) was performed in the US intergroup setting to determine if long-term progression-free survival (PFS) could be improved. Patients were enrolled after salvage therapy and stem cell collection. Sensitivity to salvage was defined by 1999 Standardized Response Criteria and did not include fluorodeoxyglucose-positron emission tomography. Cycle 1 consisted of melphalan 150 mg/m² with half of the stem cells. For stable disease or better, patients received cycle 2 consisting of single doses of etoposide 60 mg/kg and cyclophosphamide 100 mg/kg and either total body radiation 12 Gy in 8 fractions over 4 days or BCNU 150 mg/m²/day for 3 days with the remaining stem cells. Of 98 enrolled patients, 89 were eligible and treated: 82 completed both cycles of AHSCT, 47 (53%) had primary refractory HL, and 72 (81%) were resistant to salvage therapy. There were no treatment-related deaths in the first year after AHSCT. With a median follow-up of 6.2 years (range, 2 to 7.7) for eligible patients who remained alive, the 2-year and 5-year PFS were 63% (95% CI, 52% to 72%) and 55% (95% CI, 44% to 64%) respectively; the 2-year and 5-year overall survival were 91% (95% CI, 83% to 95%) and 84% (95% CI, 74% to 90%), respectively. Univariate Cox regression analysis showed Zubrod performance status and lactate dehydrogenase levels > 1 times upper limit of normal at the time of enrollment were significantly associated with PFS. The observed 5-year PFS of 55% suggests the tandem approach appears to be effective in treating HL patients demonstrated to have poor prognosis in prior single AHSCT trials. This trial was registered at www.clinicaltrials.gov as NCT00233987.

Prognostic Analysis of Absolute Lymphocyte and Monocyte Counts after Autologous Stem Cell Transplantation in Children, Adolescents, and Young Adults with Refractory or Relapsed Hodgkin Lymphoma

Previous studies in adults have shown that peripheral blood absolute lymphocyte and monocyte count ratio (ALC/AMC) after autologous stem cell transplantation (ASCT) can predict outcome in patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL). We retrospectively reviewed all of our children, adolescent, and young adult (CAYA) patients (age ≤26) who underwent transplantation for R/R HL between 2004 and 2015. Seventy-six patients (median age, 21; range, 10 to 26 years) who reached day 100 disease free were analyzed; 33% of them had positron emission tomography (PET)-positive tumors before ASCT. Patients received high-dose carmustine, etoposide, cytarabine, and melphalan (n = 40) or gemcitabine/busulfan/melphalan (n = 36). Median follow-up after day 100 was 3.9 years (95% confidence interval [CI], 2.8 to 4.9). A day 100 ALC/AMC ratio >2.1 correlated with lower risk of relapse (hazard ratio,  .097; 95% CI, .03 to .29; P <.0001). Patients with day 100 ALC/AMC ratios >2.1 and ≤2.1 had 4-year relapse-free survival rates of 93% and 33%, respectively (P = .0001) and 4-year overall survival rates of 96% and 76%, respectively (P = .0001). In addition, an ALC/AMC ratio increase >1.8 from day 15 to day 100 correlated with lower risk of relapse (hazard ratio, .24; 95% CI, .08 to 0.73; P = .01). Likewise, an ALC/AMC ratio change >.26 from day 30 to day 100 also correlated with a lower likelihood of relapse (hazard ratio, .20; 95% CI,  .081 to .51; P = .0007). Multivariate analysis showed that a positive PET scan at ASCT, day 100 ALC/AMC ratio ≤ 2.1, and an ALC/AMC ratio change either ≤1.8 from day 15 to day 100 or ≤.26 from day 30 to day 100 were independent adverse predictors. In conclusion, our analysis confirms in CAYA patients prior observations in adults indicating a major prognostic effect of peripheral lymphocyte and monocyte counts at day 100 and earlier post-ASCT time points in R/R HL.

The PARP inhibitor olaparib enhances the cytotoxicity of combined gemcitabine, busulfan and melphalan in lymphoma cells

The combination of gemcitabine (Gem), busulfan (Bu), and melphalan (Mel) is a promising regimen for autologous stem-cell transplantation (SCT) for lymphomas. To further improve the efficacy of [Gem + Bu + Mel], we added poly(ADP-ribose) polymerase (PARP) inhibitor olaparib (Ola). We hypothesized that Ola would inhibit the repair of damaged DNA caused by [Gem + Bu + Mel]. Exposure of J45.01 and Toledo cell lines to IC_10-20 of individual drug inhibited proliferation by 6-16%; [Gem + Bu + Mel] by 20-27%; and [Gem + Bu + Mel + Ola] by 61-67%. The synergistic cytotoxicity of the four-drug combination may be attributed to activation of the DNA-damage response, inhibition of PARP activity and DNA repair, decreased mitochondrial membrane potential, increased production of reactive oxygen species, and activation of the SAPK/JNK stress signaling pathway, all of which may enhance apoptosis. Similar observations were obtained using mononuclear cells isolated from patients with T-cell lymphocytic leukemia. Our results provide a rationale for undertaking clinical trials of this drug combination for lymphoma patients undergoing SCT.

National Institutes of Health Hematopoietic Cell Transplantation Late Effects Initiative: The Subsequent Neoplasms Working Group Report

Subsequent neoplasms (SN) after hematopoietic cell transplantation (HCT) cause significant patient morbidity and mortality. Risks for specific SN types vary substantially, with particularly elevated risks for post-transplantation lymphoproliferative disorders, myelodysplastic syndrome/acute myeloid leukemia, and squamous cell malignancies. This document provides an overview of the current state of knowledge regarding SN after HCT and recommends priorities and approaches to overcome challenges and gaps in understanding. Numerous factors have been suggested to affect risk, including patient-related (eg, age), primary disease-related (eg, disease type, pre-HCT therapies), and HCT-related characteristics (eg, type and intensity of conditioning regimen, stem cell source, development of graft-versus-host disease). However, gaps in understanding remain for each of these risk factors, particularly for patients receiving HCT in the current era because of substantial advances in clinical transplantation practices. Additionally, the influence of nontransplantation-related risk factors (eg, germline genetic susceptibility, oncogenic viruses, lifestyle factors) is poorly understood. Clarification of the magnitude of SN risks and identification of etiologic factors will require large-scale, long-term, systematic follow-up of HCT survivors with detailed clinical data. Most investigations of the mechanisms of SN pathogenesis after HCT have focused on immune drivers. Expansion of our understanding in this area will require interdisciplinary laboratory collaborations utilizing measures of immune function and availability of archival tissue from SN diagnoses. Consensus-based recommendations for optimal preventive, screening, and therapeutic approaches have been developed for certain SN after HCT, whereas for other SN, general population guidelines are recommended. Further evidence is needed to specifically tailor preventive, screening, and therapeutic guidelines for SN after HCT, particularly for unique patient populations. Accomplishment of this broad research agenda will require increased investment in systematic data collection with engagement from patients, clinicians, and interdisciplinary scientists to reduce the burden of SN in the rapidly growing population of HCT survivors.

PD-1 blockade in Hodgkin's lymphoma: learning new tricks from an old teacher

INTRODUCTION

Classical Hodgkin's Lymphoma (cHL) is characterized by genetic reliance on the PD-1 pathway. Rapid accumulation of data describing the role and efficacy of PD-1 and its blockade warrants a focused review.

AREAS COVERED

In this article, we will review the unique biologic features that predispose cHL to PD-1 inhibition, current data regarding the safety and efficacy of PD-1 inhibitors in the treatment of cHL, biomarkers of immune response, ongoing clinical trials with PD-1 inhibitors, as well as areas of uncertainty. Expert commentary: The biologic and genetic underpinnings of cHL make it unique among all malignancies in its exquisite sensitivity to PD-1 inhibition. High response rates to single agent PD-1 inhibitors in early phase clinical trials serve as further proof of concept. These data strongly support continued clinical investigation of the evolving role of PD-1 inhibition in classical Hodgkin's lymphoma, including the optimal sequence, setting, and combination to best exploit the immunologic properties of this disease.

Risk factors predicting outcomes for primary refractory hodgkin lymphoma patients treated with salvage chemotherapy and autologous stem cell transplantation

We aimed to identify risk factors that predict functional imaging (FI) response to salvage chemotherapy and evaluate outcomes following autologous stem cell transplant (ASCT) in primary refractory Hodgkin Lymphoma (HL). From 1 October 1994 to 10 July 2015, 192 primary refractory HL patients were treated on sequential second line protocols. Event-free survival (EFS) and overall survival (OS) were calculated from the date of histological confirmation of refractory disease. Covariates were analysed for relationship with FI response and EFS. By intent-to-treat, the median EFS was 8·9 years and OS 10·4 years with 41% having positive post-salvage FI. On multivariate analysis, the presence of B symptoms and bulk ≥5 cm predicted for positive FI, with odds ratios of 2·15 and 2·03, respectively. For the 167 (87%) transplanted patients, 60% had a negative pre-ASCT FI. Median EFS and OS were not reached with at a median follow-up of 3·6 years in surviving patients. Both stage IV refractory disease and persistent FI abnormality pre- ASCT were associated with worse outcomes: 3-year EFS was 84%, 54% and 28% for zero, 1 and 2 risk factors, respectively (P < 0·001). Further studies are needed to validate our prognostic model and to determine optimal therapy for patients with multiple risk factors.

Double epigenetic modulation of high-dose chemotherapy with azacitidine and vorinostat for patients with refractory or poor-risk relapsed lymphoma

BACKGROUND

More active high-dose chemotherapy (HDC) regimens are needed for refractory lymphomas. The authors previously combined infusional gemcitabine with busulfan and melphalan (Gem/Bu/Mel) pursuing DNA damage repair inhibition. Subsequently, they combined Gem/Bu/Mel with vorinostat, which facilitates chemotherapy access to DNA. The resulting regimen was safe and synergistic. However, vorinostat induced DNA methyltransferase up-regulation, which could be preclinically abrogated by azacitidine, increasing tumor-cell kill. Those observations led to a clinical combination of azacitidine with vorinostat/Gem/Bu/Mel.

METHODS

Patients ages 12 to 65 years with refractory or poor-risk relapsed lymphomas were eligible. They received intravenous azacitidine on days -11 through -3 at doses from 15 to 35 mg/m(2) daily (dose levels 1-3), followed by oral vorinostat (1000 mg once daily on days -11 through -3), gemcitabine (2775 mg/m(2) over 4.5 × 2), busulfan (at an area under the receiver operating characteristic curve of 4000 daily × 4), and melphalan (60 mg/m(2) × 2). Patients who had tumors that were positive for CD20 (cluster of differentiation 20; B-lymphocyte antigen) received rituximab on day -9.

RESULTS

In total, 60 patients were enrolled, including 26 with diffuse large B-cell lymphoma (DLBCL) (10 double hit/double expressors), 21 with Hodgkin lymphoma, 8 with T-cell lymphoma, and 5 with other B-cell lymphomas. The median patient age was 41 years (range, 16-65 years), patients had received a median of 3 prior lines of chemotherapy (range, 2-7 lines of chemotherapy); and 32% of tumors were positive on positron emission tomography studies at the time of HDC. Two patients died from treatment complications (respiratory syncytial virus pneumonia and sepsis, respectively). The maximum tolerated dose of azacitidine was encountered at dose level 1 (15 mg/m(2) daily). The toxicity profile (mainly mucositis and dermatitis) was manageable and was identical to that of vorinostat/Gem/Bu/Mel. Neutrophils and platelets engrafted promptly. At a median follow-up of 15 months (range, 8-27 months), the event-free and overall survival rates were 65% and 77%, respectively, among patients with DLBCL; 76% and 95%, respectively, among patients with Hodgkin lymphoma; and 88% for both among patients with T-cell lymphoma.

CONCLUSIONS

Double epigenetic modulation of Gem/Bu/Mel with azacitidine/vorinostat is feasible and highly active in patients with refractory/poor-risk relapsed lymphomas, warranting further evaluation. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2680-2688. © 2016 American Cancer Society.

Synergistic cytotoxicity of busulfan, melphalan, gemcitabine, panobinostat, and bortezomib in lymphoma cells

DNA alkylators busulfan (B) and melphalan (M) act synergistically with gemcitabine (G) against lymphoma cells. To further improve the cytotoxicity, we combined them with the histone deacetylase inhibitor panobinostat (P) and proteasome inhibitor bortezomib (V). Lymphoma cell lines U937 and J45.01, and patient-derived cell samples were exposed to these drugs and the effects on cell proliferation and apoptosis were quantified. The combination BMGPV was found to exert strong synergistic cytotoxicity. Drug exposure to these cells activated the ATM pathway and modified histones at the epigenetic level. Cell death was triggered by the production of reactive oxygen species (ROS), permeabilization of the mitochondrial membrane, upregulation of proapoptotic factors, and activation of caspases. Downregulation of anti-apoptotic proteins c-MYC, MCL-1, and BCL-2 and inhibition of the prosurvival PI3K-AKT-mTOR pathway, culminated in apoptosis. The results of this study support a clinical trial using BMGPV as a possible pre-transplant conditioning regimen for relapsed/refractory lymphoma patients.

Prognostic value of pretransplant FDG-PET in refractory/relapsed Hodgkin lymphoma treated with autologous stem cell transplantation: systematic review and meta-analysis

This study aimed to systematically review the prognostic value of pretransplant ¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in refractory/relapsed Hodgkin lymphoma treated with autologous stem cell transplantation (SCT). MEDLINE was systematically searched for appropriate studies. Included studies were methodologically appraised. Results of individual studies were meta-analyzed, if possible. Eleven studies, comprising a total of 745 refractory/relapsed Hodgkin lymphoma patients who underwent FDG-PET before autologous SCT, were included. The overall methodological quality of these studies was moderate. The proportion of pretransplant FDG-PET positive patients ranged between 25 and 65.2 %. Progression-free survival ranged between 0 and 52 % in pretransplant FDG-PET positive patients, and between 55 and 85 % in pretransplant FDG-PET negative patients. Overall survival ranged between 17 and 77 % in pretransplant FDG-PET positive patients, and between 78 and 100 % in FDG-PET negative patients. Based on five studies that provided sufficient data for meta-analysis, pooled sensitivity and specificity of pretransplant FDG-PET in predicting treatment failure (i.e., either progressive, residual, or relapsed disease) were 67.2 % (95 % confidence interval [CI] 58.2–75.3 %) and 70.7 % (95 % CI 64.2–76.5 %), respectively. Based on two studies that provided sufficient data for meta-analysis, pooled sensitivity and specificity of pretransplant FDG-PET in predicting death during follow-up were 74.4 % (95 % CI 58.8–86.5 %) and 58.0 % (95 % CI 49.3–66.3 %), respectively. In conclusion, the moderate quality evidence suggests pretransplant FDG-PET to have value in predicting outcome in refractory/relapsed Hodgkin lymphoma patients treated with autologous SCT. Nevertheless, a considerable proportion of pretransplant FDG-PET positive patients remains disease free and a considerable proportion of pretransplant FDG-PET negative patients develops disease relapse after autologous SCT.

Immunotoxin - a new treatment option in patients with relapsed and refractory Hodgkin lymphoma

Background

Even though Hodgkin lymphoma is a highly curable disease, some of the patients have either a refractory disease or experience a relapse following a successful primary therapy. Durable responses and remissions in patients with relapsed or refractory disease may be achieved in approximately one-half with salvage chemotherapy followed by high dose chemotherapy (HDT) and autologous hematopoietic cell rescue (SCT). On the other hand, patients who relapse after HDT and autologous SCT or those who have failed at least two prior multi-agent chemotherapy regimens and are not candidates for HDT have limited treatment options.

Conclusions

A new treatment option in this population is an immunotoxin Brentuximab vedotin composed of a CD30 directed antibody linked to the antitubulin agent monomethyl auristatin E. It has demonstrated a substantial effectiveness and an acceptable toxicity. In the pivotal study, the overall response rate was 75% with 34% of complete remissions. The median durations of response were 20.5 and 6.7 months for those with complete remission and all responding patients, respectively. The median overall survival was 40.5 months (3-years overall survival 54%) and the median progression-free survival 9.3 months. The most common non-hematologic toxicities were peripheral sensory neuropathy, nausea, and fatigue while the most common severe side effects were neutropenia, thrombocytopenia, anemia, and peripheral sensory neuropathy.

Improved outcome of patients with relapsed/refractory Hodgkin lymphoma with a new fotemustine-based high-dose chemotherapy regimen

High-dose chemotherapy (HDT) with autologous stem cell transplantation is the standard of care for relapsed/refractory (RR) Hodgkin lymphoma (HL). Given that HDT may cure a sizeable proportion of patients refractory to first salvage, development of newer conditioning regimens remains a priority. We present the results of a novel HDT regimen in which carmustine was substituted by a third-generation chloroethylnitrosourea, fotemustine, with improved pharmacokinetics and safety (FEAM; fotemustine, etoposide, cytarabine, melphalan) in 122 patients with RR-HL accrued into a prospective registry-based study. Application of FEAM resulted in a 2-year progression-free survival (PFS) of 73·8% [95% confidence interval (CI), 0·64-0·81] with median PFS, overall survival and time to progression yet to be reached. The 2-year risk of progression adjusted for the competitive risk of death was 19·4% (95% CI, 0·12-0·27) for the entire patient population. Most previously established independent risk factors, except for fluorodeoxyglucose ((18) (F) FDG)-uptake, were unable to predict for disease progression and survival after FEAM. Although 32% of patients had (18) (F) FDG-positrin emission tomography-positive lesions before HDT, the 2-year risk of progression adjusted for competitive risk of death was 19·4% (95% CI; 0·12-0·27). No unusual acute toxicities or early/late pulmonary adverse events were registered. FEAM emerges as an ideal HDT regimen for RR-HL patients typically pre-exposed to lung-damaging treatments.

Impact of Polymorphic Variations of Gemcitabine Metabolism, DNA Damage Repair, and Drug-Resistance Genes on the Effect of High-Dose Chemotherapy for Relapsed or Refractory Lymphoid Malignancies

The goal of this study was to determine whether single nucleotide polymorphisms (SNPs) in genes involved in gemcitabine metabolism, DNA damage repair, multidrug resistance, and alkylator detoxification influence the clinical outcome of patients with refractory/relapsed lymphoid malignancies receiving high-dose gemcitabine/busulfan/melphalan (Gem/Bu/Mel) with autologous stem cell support. We evaluated 21 germline SNPs of the gemcitabine metabolism genes CDA, deoxycytidine kinase, and hCNT3; DNA damage repair genes RECQL, X-ray repair complementing 1, RAD54L, ATM, ATR, MLH1, MSH2, MSH3, TREX1, EXO1, and TP73; and multidrug-resistance genes MRP2 and MRP5; as well as glutathione-S-transferase GSTP1 in 153 patients with relapsed or refractory lymphoma or myeloma receiving Gem/Bu/Mel. We studied the association of genotypes with overall survival (OS), progression-free survival (PFS), and nonhematological grade 3 or 4 toxicity. CDA C111T and TREX1 Ex14-460C>T genotypes had a significant effect on OS (P = .007 and P = .005, respectively), and CDA C111T, ATR C340T, and EXO1 P757L genotypes were significant predictors for severe toxicity (P = .037, P = .024, and P = .025, respectively) in multivariable models that adjusted for clinical variables. The multi-SNP risk score analysis identified the combined genotypes of TREX1 Ex14-460 TT and hCNT3 Ex5 +25A>G AA as significant predictors for OS and the combination of MRP2 Ex10 + 40GG/GA and MLH1 IVS12-169 TT as significant predictor for PFS. Polymorphic variants of certain genes involved in gemcitabine metabolism and DNA damage repair pathways may be potential biomarkers for clinical outcome in patients with refractory/relapsed lymphoid tumors receiving Gem/Bu/Mel.

Salvage treatment for relapsed/refractory Hodgkin lymphoma: role of allografting, brentuximab vedotin and newer agents

INTRODUCTION

Second-line, salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation (AUTO-SCT) is the standard of care for patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL). Approximately 50% of patients relapse after AUTO-SCT and their prognosis is generally poor. Brentuximab Vedotin (BV) has demonstrated efficacy in this setting and allogeneic (ALLO)-SCT represents an option with curative potential in this subgroup of patients.

AREAS COVERED

A systematic review has been conducted to explore the actual knowledge on ALLO-SCT, BV and newer agents in R/R HL.

EXPERT OPINION

The introduction of BV in clinical practice has significantly improved the management of post-AUTO-SCT relapses and the drug can induce durable remissions in a subset of R/R HL. Allografting select patients has been used to improve clinical outcomes and recent case series have begun to explore BV as a potential 'bridge' to allo-SCT, even though the optimal timing of ALLO-SCT after BV response remains undetermined. However, reduced tumor burden at the time of ALLO-SCT is a key factor to decrease relapse risk. Based on the unique composition of the tumor, more recently new agents such as PD-1 inhibitors have been developed. The potential role of PD-1 inhibitors with ALLO-SCT remains to be explored.

Checkpoint inhibitors in Hodgkin's lymphoma

Hodgkin's lymphoma is unusual among cancers in that it consists of a small number of malignant Hodgkin/Reed-Sternberg cells in a sea of immune system cells, including T cells. Most of these T cells are reversibly inactivated in different ways and their reactivation may induce a very strong immune response to cancer cells. One way of reactivation of T cells is with antibodies blocking the CTLA-4 and especially with antibodies directed against PD-1 or the PD-L1 ligand thereby reversing the tumor-induced downregulation of T-cell function and augmenting antitumor immune activity at the priming (CTLA-4) or tissue effector (PD-1) phase. Immune checkpoint inhibitors have been evidenced as an additional treatment option with substantial effectiveness and acceptable toxicity in heavily pretreated patients with Hodgkin's lymphoma. Particularly, PD-1 blockade with nivolumab and pembrolizumab has demonstrated significant single-agent activity in this select population.

Vorinostat Combined with High-Dose Gemcitabine, Busulfan, and Melphalan with Autologous Stem Cell Transplantation in Patients with Refractory Lymphomas

More active high-dose regimens are needed for refractory/poor-risk relapsed lymphomas. We previously developed a regimen of infusional gemcitabine/busulfan/melphalan, exploiting the synergistic interaction. Its encouraging activity in refractory lymphomas led us to further enhance its use as a platform for epigenetic modulation. We previously observed increased cytotoxicity in refractory lymphoma cell lines when the histone deacetylase inhibitor vorinostat was added to gemcitabine/busulfan/melphalan, which prompted us to clinically study this four-drug combination. Patients ages 12 to 65 with refractory diffuse large B cell lymphoma (DLCL), Hodgkin (HL), or T lymphoma were eligible. Vorinostat was given at 200 mg/day to 1000 mg/day (days -8 to -3). Gemcitabine was infused continuously at 10 mg/m(2)/minute over 4.5 hours (days -8 and -3). Busulfan dosing targeted 4000 μM-minute/day (days -8 to -5). Melphalan was infused at 60 mg/m(2)/day (days -3 and -2). Patients with CD20(+) tumors received rituximab (375 mg/m(2), days +1 and +8). We enrolled 78 patients: 52 DLCL, 20 HL, and 6 T lymphoma; median age 44 years (range, 15 to 65); median 3 prior chemotherapy lines (range, 2 to 7); and 48% of patients had positron emission tomography-positive tumors at high-dose chemotherapy (29% unresponsive). The vorinostat dose was safely escalated up to 1000 mg/day, with no treatment-related deaths. Toxicities included mucositis and dermatitis. Neutrophils and platelets engrafted promptly. At median follow-up of 25 (range, 16 to 41) months, event-free and overall survival were 61.5% and 73%, respectively (DLCL) and 45% and 80%, respectively (HL). In conclusion, vorinostat/gemcitabine/busulfan/melphalan is safe and highly active in refractory/poor-risk relapsed lymphomas, warranting further evaluation. This trial was registered at ClinicalTrials.gov (NCI-2011-02891).

Role of cytotoxic therapy with hematopoietic cell transplantation in the treatment of Hodgkin lymphoma: guidelines from the American Society for Blood and Marrow Transplantation

The role of hematopoietic cell transplantation (HCT) in the therapy of Hodgkin lymphoma (HL) in pediatric and adult patients is reviewed and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are included and were reached unanimously by a panel of HL experts. Both autologous and allogeneic HCT offer a survival benefit in selected patients with advanced or relapsed HL and are currently part of standard clinical care. Relapse remains a significant cause of failure after both transplant approaches, and strategies to decrease the risk of relapse remain an important area of investigation.

Impact of conditioning regimen on outcomes for patients with lymphoma undergoing high-dose therapy with autologous hematopoietic cell transplantation

There are limited data to guide the choice of high-dose therapy (HDT) regimen before autologous hematopoietic cell transplantation (AHCT) for patients with Hodgkin (HL) and non-Hodgkin lymphoma (NHL). We studied 4917 patients (NHL, n = 3905; HL, n = 1012) who underwent AHCT from 1995 to 2008 using the most common HDT platforms: carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM) (n = 1730); cyclophosphamide, BCNU, and etoposide (CBV) (n = 1853); busulfan and cyclophosphamide (BuCy) (n = 789); and total body irradiation (TBI)-containing treatment (n = 545). CBV was divided into CBV(high) and CBV(low) based on BCNU dose. We analyzed the impact of regimen on development of idiopathic pulmonary syndrome (IPS), transplantation-related mortality (TRM), and progression-free and overall survival. The 1-year incidence of IPS was 3% to 6% and was highest in recipients of CBV(high) (hazard ratio [HR], 1.9) and TBI (HR, 2.0) compared with BEAM. One-year TRM was 4% to 8%, respectively, and was similar between regimens. Among patients with NHL, there was a significant interaction between histology, HDT regimen, and outcome. Compared with BEAM, CBV(low) (HR, .63) was associated with lower mortality in follicular lymphoma (P < .001), and CBV(high) (HR, 1.44) was associated with higher mortality in diffuse large B cell lymphoma (P = .001). For patients with HL, CBV(high) (HR, 1.54), CBV(low) (HR, 1.53), BuCy (HR, 1.77), and TBI (HR, 3.39) were associated with higher mortality compared with BEAM (P < .001). The impact of specific AHCT regimen on post-transplantation survival is different depending on histology; therefore, further studies are required to define the best regimen for specific diseases.

Classical Hodgkin's lymphoma: the Lymphoma Study Association guidelines for relapsed and refractory adult patients eligible for transplant

The Hodgkin's Lymphoma Committee of the Lymphoma Study Association (LYSA) gathered in 2012 to prepare guidelines on the management of transplant-eligible patients with relapsing or refractory Hodgkin's lymphoma. The working group is made up of a multidisciplinary panel of experts with a significant background in Hodgkin's lymphoma. Each member of the panel of experts provided an interpretation of the evidence and a systematic approach to obtain consensus was used. Grades of recommendation were not required since levels of evidence are mainly based on phase II trials or standard practice. Data arising from randomized trials are emphasized. The final version was endorsed by the scientific council of the LYSA. The expert panel recommends a risk-adapted strategy (conventional treatment, or single/double transplantation and/or radiotherapy) based on three risk factors at progression (primary refractory disease, remission duration < 1 year, stage III/IV), and an early evaluation of salvage chemosensitivity, including (18)fluorodeoxy glucose-positron emission tomography interpreted according to the Deauville scoring system. Most relapsed or refractory Hodgkin's lymphoma patients chemosensitive to salvage should receive high-dose therapy and autologous stem-cell transplantation as standard. Efforts should be made to increase the proportion of chemosensitive patients by alternating non-cross-resistant chemotherapy lines or exploring the role of novel drugs.

High-dose therapy followed by stem cell transplantation in Hodgkin's lymphoma: past and future

Hodgkin's lymphoma (HL) has been a fascinating challenge for physicians and investigators since its recognition during the 19th century. However, many questions still remain unanswered. One issue regards high-dose therapy followed by autologous stem cell transplantation (ASCT), which has yet to find its place among several guidelines. Other topics are still controversial with respect to transplantation for HL, including its role for newly diagnosed patients with advanced stage disease, the optimal timing of transplantation, the best conditioning regimen and the role of allogeneic/haploidentical SCT. Moreover, the potential use of localized radiotherapy or immunologic methods to decrease post-transplant recurrence, the role of novel agents such as brentuximab vedotin and their positioning in the treatment algorithm of resistant/relapsed HL patients, either before transplant to boost salvage therapy or after transplant as consolidation/maintenance, are burning questions without an answer. In this review, the authors try to give an answer to some of these dilemmas.

Peripheral blood stem cell yield calculated using preapheresis absolute CD34+ cell count, peripheral blood volume processed, and donor body weight accurately predicts actual yield at multiple centers

BACKGROUND

Accurate prediction of stem cell yield is important for planning leukapheresis procedures. A formula has been published (Pierelli et al., Vox Sang 2006;91:126-34) to estimate the CD34+ dose collected on the first day of leukapheresis that was based on the preapheresis peripheral blood (PB) CD34+ counts, the blood volume processed, and the donor's weight. The aim of this study was to assess the predictive value of this formula.

STUDY DESIGN AND METHODS

Data were retrospectively collected on 1126 consecutive PB stem cell harvests conducted at five institutions. Information on age, sex, diagnosis, weight, preapheresis absolute peripheral CD34+ count, total blood volume processed, and CD34+ cells harvested per kilogram of body weight on the first day of apheresis was collected.

RESULTS

Among donors at least 18 years old, Pearson's correlation coefficient (r) between actual yield (AY) and predicted yield (PY) was 0.76. To characterize this correlation, AY and PY were classified as being within the conventionally acceptable CD34+ doses (>2 × 10(6) -5 × 10(6) cells/kg), below this range (≤2 × 10(6) cells/kg), or above it (>5 × 10(6) cells/kg). The positive predictive value (PPV) of PY was estimated considering the distribution of AY as the "gold standard." PPV was relatively high for PY of more than 5 × 10(6) cells/kg (85%), moderate for PY of not more than 2 × 10(6) cells/kg (72%), and low for PY more than 2 × 10(6) to 5 × 10(6) cells/kg (56%). A consistent pattern was observed within institutions.

CONCLUSION

The formula of Pierelli et al. is associated with a PPV that is high, moderate, and relatively low for the corresponding predicted CD34+ doses.