A phase 2 multicenter study of lenalidomide in relapsed or refractory classical Hodgkin lymphoma

Metronomic chemotherapy in hematology: Lessons from preclinical and clinical studies to build a solid rationale for future schedules

Metronomic chemotherapy (mCHEMO), based on frequent, regular administration of low, but pharmacologically active drug doses, optimizes antitumor efficacy by targeting multiple targets and reducing toxicity of antineoplastic drugs. This minireview will summarize preclinical and clinical studies on cytotoxic drugs given at weekly, daily, or at continuous metronomic schedules alone or in combination with novel targeted agents for hematological malignancies, including lymphoma, multiple myeloma, and leukemia. Most of the preclinical in vitro and in vivo studies have reported a significant benefit of both mCHEMO monotherapy and combinatorial regimens compared with chemotherapy at the maximum tolerated dose. However, the combination of mCHEMO with targeted drugs is still little explored in the hematologic clinical setting. Data obtained from preclinical studies on low dose metronomic chemotherapy in hematological malignancies clearly suggested the possibility to clinically investigate more tolerable and effective strategies for the treatment of patients with advanced hematological malignancies, or at least for those frail and elderly patients, who are not eligible or resistant to standard treatments.

Emerging immunotherapies in the Hodgkin lymphoma armamentarium

INTRODUCTION

Brentuximab vedotin and PD-1 inhibitors have improved outcomes for classic Hodgkin lymphoma (cHL), but better therapies are needed for patients who relapse after these agents. Based on an improved understanding of cHL biology, there is a robust pipeline of novel therapies in development. In this review, we highlight emerging immunotherapeutic agents and combinations for cHL.

AREAS COVERED

We review clinical trials of novel PD-1/PD-L1 inhibitors beyond FDA-approved agents, checkpoint inhibitors targeting CTLA-4, LAG-3, TIM-3, TIGIT, and CD47/SIRPα, PD-1 inhibitor combinations with immunomodulatory agents and epigenetic modifying therapies, antibody-drug conjugates, bispecific antibodies, and cellular therapies including anti-CD30 CAR-T and allogeneic NK cell therapy. We review the key safety and efficacy data from published phase 1-2 studies and highlight trials in progress, including the first phase 3 trial for PD-1 inhibitor-refractory cHL.

EXPERT OPINION

Many novel immunotherapies hold great promise in cHL. Rational combinations with existing agents and next-generation antibody and CAR-T constructs may improve response rates and durability. Identifying biomarkers of response to these immunotherapies and using more sensitive tools to assess response, such as circulating tumor DNA, may further inform treatment decisions and enable a precision medicine approach in the future.

A phase II study of interrupted and continuous dose lenalidomide in relapsed/refractory Hodgkin lymphoma

Not available.

Population pharmacokinetics of lenalidomide in Chinese patients with influence of genetic polymorphisms of ABCB1

Affected by differences in the pharmacokinetics (PK) of lenalidomide, the toxicity of lenalidomide varies among different patients, with serious toxicity leading to dose reduction or discontinuation. The differences in the PK of lenalidomide may be related to factors such as patients' physiological characteristics, pathological characteristics and gene polymorphisms etc., which may also affect its toxicity. The aim of this study is to establish a population pharmacokinetic (PPK) model of lenalidomide and explore factors associated with the adverse events (AEs) of lenalidomide from a PK perspective. Blood samples were collected by opportunistic blood collection. Drug concentrations were determined by using HPLC/MS and genotype of ABCB1 3435 C > T (rs1045642), ABCB1 1236 A > G (rs1128503) and ABCB1 2677 A > C/T (rs2032582) was tested by the first-generation DNA sequencing technology. NONMEM software and SPSS 26.0 software were used respectively to establish PPK model of lenalidomide and explore the correlation between PK parameters and the incidence of serious AEs of lenalidomide. 51 patients were enrolled in the PPK study, and one-compartment model with first-order absorption and elimination agreed well with the observed data. The significant covariate affecting lenalidomide apparent volume of distribution (V/F) were the gene polymorphism of ABCB1 3435 C > T and diet. Safety studies could be conducted in 39 patients. The V/F value in patients suffering from serious AEs was significantly higher than that in others ( median = 67.04 L vs 37.17 L, P = 0.033). According to the covariates screened, the incidence of serious AEs was higher in patients with genotype CT or TT at ABCB1 3435 C > T locus than that in patients with genotype CC (P = 0.039). Additionally, V/F value was the highest in patients carrying genotype TT with postprandial medication, in whom the incidence of serious AEs was higher than others (P = 0.037). In conclusion, the genotype of ABCB1 3435 C > T locus and diet had pharmacokinetically relevant impact on lenalidomide, which may also be related to the incidence of serious AEs. Patients with gene variants of CT or TT at ABCB1 3435 C > T locus may be more susceptible to serious AEs, and monitoring of adverse reactions should be particularly strengthened in patients who carried genotype TT with postprandial medication.

The optimal management of relapsed and refractory Hodgkin lymphoma: post-brentuximab and checkpoint inhibitor failure

The treatment landscape of classical Hodgkin lymphoma has changed dramatically over the past decade. Relapsed and refractory mainstay therapeutics such as brentuximab vedotin (BV) and checkpoint inhibitors (CPIs) are being moved to earlier lines of therapy. However, the treatment of patients who progress after BV and CPI remains a challenge. Allogeneic stem cell transplantation still plays an important role in this patient population as the only current treatment approach with curative potential. Unfortunately, not all patients are transplant candidates, and many will still relapse afterward. Cytotoxic chemotherapy and radiation may be used for symptom palliation or as a bridge to transplant. Targeted therapies, including the antibody drug conjugate, camidanlumab tesirine, and transcriptional agents such mammalian target of rapamycin and histone deacetylase inhibitors have shown some potential in patients with refractory disease. In addition, combination therapies with CPIs and novel agents may help overcome resistance to therapy. Clinical trials with cellular therapies, including chimeric antigen receptor T cells targeting CD30 and allogeneic natural killer cells combined with AFM13, a CD30/CD16a-bispecific antibody, have shown promising results. The availability of more therapeutic options for this patient population is eagerly awaited.

Optimizing Treatment for Relapsed/Refractory Classic Hodgkin Lymphoma in the Era of Immunotherapy

Most patients with classic Hodgkin lymphoma (cHL) are cured with combination chemotherapy, but approximately 10-20% will relapse, and another 5-10% will have primary refractory disease. The treatment landscape of relapsed/refractory (R/R) cHL has evolved significantly over the past decade following the approval of brentuximab vedotin (BV), an anti-CD30 antibody-drug conjugate, and the PD-1 inhibitors nivolumab and pembrolizumab. These agents have significantly expanded options for salvage therapy prior to autologous hematopoietic cell transplantation (AHCT), post-transplant maintenance, and treatment of relapse after AHCT, which have led to improved survival in the modern era. In this review, we highlight our approach to the management of R/R cHL in 2023 with a focus on choosing first salvage therapy, post-transplant maintenance, and treatment of relapse after AHCT. We also discuss the management of older adults and transplant-ineligible patients, who require a separate approach. Finally, we review novel immunotherapy approaches in clinical trials, including combinations of PD-1 inhibitors with other immune-activating agents as well as novel antibody-drug conjugates, bispecific antibodies, and cellular immunotherapies. Ongoing studies assessing biomarkers of response to immunotherapy and dynamic biomarkers such as circulating tumor DNA may further inform treatment decisions and enable a more personalized approach in the future.

Lenalidomide with or without dexamethasone for relapsed or refractory Hodgkin lymphoma post autologous stem cell transplant

Background

The prognosis of Hodgkin lymphoma (HL) relapsing post autologous transplant (AuSCT) is poor. Even with novel therapies, only approximately 20%-25% of patients attain complete remissions, with a median progression-free survival (PFS) of approximately 5-15 months. Lenalidomide has been shown to have activity in relapsed HL. We retrospectively analyzed the outcomes of patients with relapsed HL post AuSCT treated with lenalidomide alone or in combination with dexamethasone at our center.

Patients and methods

Records of 143 patients transplanted from November 2007 to October 2021 were reviewed. Of these patients, 41 (28%) relapsed, and 16 (39%) received lenalidomide alone or in combination with dexamethasone. Data collected included demographic, pathological, staging, and prior therapy details. Lenalidomide was administered at 10-25 mg/day on an intermittent or continuous schedule alone or in combination with dexamethasone (20-40 mg weekly). Response was assessed using PET-CT scan in accordance with Lugano criteria. Standard definitions were used for response, PFS, and overall survival (OS). Toxicities were graded using Common Terminology Criteria for Adverse Events version 5.0. Statistical analysis was done using SPSS Version 21.

Results

The median age of the patients was 25.5 years, and 10 were males. Eleven (69%) had advanced disease, and 7 (44%) were refractory to last systemic therapy. Nine patients received lenalidomide alone and 7 with dexamethasone. Four (25%) had complete response, and another four (25%) had partial response, with an overall response rate of 50%. The 3-year PFS and OS were 31% and 38%, respectively. Grade III/IV toxicities were only hematological, neutropenia and thrombocytopenia in four and three patients, respectively. No therapy-related deaths were recorded.

Conclusions

Lenalidomide alone or in combination with dexamethasone is a safe and effective therapy for relapsed HL post AuSCT and results in durable response and long-term survival in approximately one-third of the patients. However, these results needs verification in larger prospective studies.

Advances in the treatment of Hodgkin's lymphoma (Review)

Hodgkin's lymphoma (HL) is a unique B‑cell lymphoproliferative malignancy that has a critical pathogenesis characterized by a sparse population of Hodgkin and Reed‑Sternberg cells surrounded by numerous dysfunctional immune cells. Although systemic chemotherapy with or without radiotherapy, has significantly improved the prognosis of the majority of patients with HL, a subset of patients remains refractory to first‑line therapy or relapse after achieving an initial response. With the increased understanding of the biology and microenvironment of HL, novel strategies with notable efficacy and manageable toxicity, including targeted therapies, immunotherapy and cell therapy have emerged. The present review summarizes the progress made in developing novel therapies for HL and discusses future research directions in HL therapy.

Management of classical Hodgkin lymphoma: a look at up to date evidence and current treatment approaches

The treatment landscape of classical Hodgkin lymphoma (cHL) has undergone significant changes over the past 20 years. Gradual improvements have been made in the management of cHL patients, particularly in prolonging the survival rate for those in the relapsed setting. Most of these improvements came with the addition of brentuximab vedotin and PD1 blockade (nivolumab and pembrolizumab) into the current cHL treatment algorithms. On the other hand, the treatment approach to cHL has become more complex than ever before, with multiple ways to add and sequence therapies to achieve long-term remission. In this review, we will discuss the most up-to-date evidence on the management of cHL patients with the inclusion of ongoing clinical trials in cHL. We will provide a general overview of the current therapeutic landscape of cHL in light of these most recent data. We conclude with our perspective on how the approach to cHL treatment may evolve in the future.

Phase I/II clinical trial of temsirolimus and lenalidomide in patients with relapsed and refractory lymphomas

The PI3K/Akt/mTOR (PAM) axis is constitutively activated in multiple lymphoma subtypes and is a promising therapeutic target. The mTOR inhibitor temsirolimus (TEM) and the immunomodulatory agent lenalidomide (LEN) have overlapping effects within the PAM axis with synergistic potential. This multicenter phase I/II study evaluated combination therapy with TEM/LEN in patients with relapsed and refractory lymphomas. Primary endpoints of the phase II study were rates of complete (CR) and overall response (ORR). There were 18 patients in the phase I dose-finding study, and TEM 25 mg weekly and LEN 20 mg on day 1 through day 21 every 28 days was established as the recommended phase II dose. An additional 93 patients were enrolled in the phase II component with three cohorts: diffuse large B-cell lymphoma (DLBCL, n=39), follicular lymphoma (FL, n=15), and an exploratory cohort of other lymphoma histologies with classical Hodgkin lymphoma (cHL) comprising the majority (n=39 total, n=20 with cHL). Patients were heavily pretreated with a median of four (range, 1-14) prior therapies and one-third with relapse following autologous stem cell transplantation (ASCT); patients with cHL had a median of six prior therapies. The FL cohort was closed prematurely due to slow accrual. ORR were 26% (13% CR) and 64% (18% CR) for the DLBCL and exploratory cohorts, respectively. ORR for cHL patients in the exploratory cohort, most of whom had relapsed after both brentuximab vedotin and ASCT, was 80% (35% CR). Eight cHL patients (40%) proceeded to allogeneic transplantation after TEM/LEN therapy. Grade ≥3 hematologic adverse events (AE) were common. Three grade 5 AE occurred. Combination therapy with TEM/LEN was feasible and demonstrated encouraging activity in heavily-pretreated lymphomas, particularly in relapsed/refractory cHL (clinicaltrials gov. Identifier: NCT01076543).

NCCN Guidelines® Insights: Hodgkin Lymphoma, Version 2.2022

Hodgkin lymphoma (HL) is an uncommon malignancy of B-cell origin. Classical HL (cHL) and nodular lymphocyte-predominant HL are the 2 main types of HL. The cure rates for HL have increased so markedly with the advent of modern treatment options that overriding treatment considerations often relate to long-term toxicity. These NCCN Guidelines Insights discuss the recent updates to the NCCN Guidelines for HL focusing on (1) radiation therapy dose constraints in the management of patients with HL, and (2) the management of advanced-stage and relapsed or refractory cHL.

Current salvage therapies in Hodgkin lymphoma

Hodgkin lymphoma is a B-cell malignancy with approximately 85-95% complete remission rate following frontline therapy; however, relapsed/refractory disease occurs in roughly 10-30% of patients after treatment. Salvage therapy conventionally relies upon cytotoxic chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation. A considerable number of patients experience relapse after transplantation, and further salvage management has included the use of allogeneic transplantation and radiotherapy. In the past decade, novel therapies including, brentuximab vedotin, PD-1 inhibitors, and the incorporation of PET-imaging into management have changed the paradigm of relapsed/refractory disease care. Novel therapies have been investigated in both single and combination regimens with other novel therapies and traditional chemotherapies. There is promising early work into the utility of CD30.CAR-T cell therapy, AFM13, camidanlumab tesirine, novel PD-1 inhibitors, and JAK1/JAK2 inhibition in management. Herein, we will review current salvage therapies in Hodgkin lymphoma and future directions in relapsed/refractory disease management.

Human leukocyte antigen (HLA) alleles as predictive factors for benefit from lenalidomide in acute myeloid leukemia (AML)

OBJECTIVES

Lenalidomide is an active agent in acute myeloid leukemia (AML); response rates are about 15-30%. There are no well-defined predictive factors for benefit from lenalidomide in AML. One of the mechanisms of lenalidomide is natural killer (NK) cell activation; hence human leukocyte antigen (HLA) class I alleles (serving as killer immunoglobulin-like receptor ligands) could play a predictive role. We here evaluate the same when lenalidomide was used as a bridge to transplant.

METHODS

Consecutive AML patients started on lenalidomide as bridge to transplant between Aug-2013 to Aug-2018 were included in this single centre retrospective analysis. The starting dose and schedule of lenalidomide were at the discretion of the treating clinician. Lenalidomide was scheduled to be stopped about 2-4 weeks prior to planned transplant admission (or was stopped earlier if there was intolerance). For this study, event was defined as progression/relapse while on lenalidomide or within 4 weeks of stopping the drug. The primary endpoint was event free survival (EFS). Those who underwent transplant without an event were censored on the day of transplant. Toxicities and post-transplant outcomes were secondary endpoints.

RESULTS

Twelve patients (8 males, median age 29 years) were included. At start of lenalidomide, 7 had complete remission (CR)-1 (measurable residual disease or MRD by flow cytometry was positive in 3, negative in 3, and 1 unknown), 4 CR-2 (all MRD negative) and 1 active disease. In the whole cohort, median EFS was not reached with projected 3 year EFS being 80%. There was a significantly reduced risk of event with HLA A*24 (0% vs 75%, P=0.018) or with HLA B*40 (0% vs 60%, P=0.045). Only 1 patient needed discontinuation due to toxicities (cytopenias). Among patients who underwent transplant, grade II-IV acute graft versus host disease (GVHD) was seen in 83%.

CONCLUSIONS

This is first study to show that HLA alleles may have a bearing on the effect of lenalidomide in AML and could serve as predictive biomarkers. These findings need to be confirmed in larger prospective studies.

Romidepsin and lenalidomide-based regimens have efficacy in relapsed/refractory lymphoma: Combined analysis of two phase I studies with expansion cohorts

Romidepsin (histone deacetylase inhibitor), lenalidomide (immunomodulatory agent), and carfilzomib (proteasome inhibitor), have efficacy and lack cumulative toxicity in relapsed/refractory lymphoma. We performed two investigator initiated sequential phase I studies to evaluate the maximum tolerated dose (MTD) of romidepsin and lenalidomide (regimen A) and romidepsin, lenalidomide, and carfilzomib (regimen B) in relapsed/refractory lymphoma. Cohorts in T-cell lymphoma (TCL), B-cell lymphoma (BCL) were enrolled at the MTD. Forty-nine patients were treated in study A (27 TCL, 17 BCL, 5 Hodgkin lymphoma (HL)) and 27 (16 TCL, 11 BCL) in study B. The MTD of regimen A was romidepsin 14 mg/m² IV on days 1, 8, and 15 and lenalidomide 25 mg oral on days 1-21 of a 28-day cycle. The MTD of regimen B was romidepsin 8 mg/m² on days 1 and 8, lenalidomide 10 mg oral on days 1-14 and carfilzomib 36 mg/m² IV on days 1 and 8 of a 21-day cycle. In study A, 94% had AEs ≥Grade 3, most commonly neutropenia (49%), thrombocytopenia (53%), and electrolyte abnormalities (49%). In study B 59% had AEs ≥Grade 3, including thrombocytopenia (30%) and neutropenia (26%). In study A the ORR was 49% (50% TCL, 47% BCL, 50% HL). In study B the ORR was 48% (50% TCL, 50% BCL). For study A and B the median progression free survival (PFS) was 5.7 months and 3.4 months respectively with 11 patients proceeding to allogeneic transplant. The combinations of romidepsin and lenalidomide and of romidepsin, lenalidomide and carfilzomib showed activity in relapsed/refractory lymphoma with an acceptable safety profile.

Low dose continuous lenalidomide in heavily pretreated patients with relapsed or refractory classical Hodgkin lymphoma: a retrospective case series

Patients with relapsed or refractory (R/R) classical Hodgkin lymphoma (cHL) following autologous stem cell transplant (ASCT) remain a management challenge with few reliably effective treatments. Lenalidomide, an immunomodulatory drug approved for patients with myelodysplastic syndrome with del(5q), multiple myeloma, and mantle cell lymphoma, has demonstrated some activity in patients with R/R cHL, though the toxicity of traditional doses and schedules has been a barrier to consistent use. Low dose continuous (LDC) schedules have emerged as promising, with a more favorable safety profile. We report herein that LDC schedules are associated with a far more tolerable toxicity profile, and exhibit at least equivalent efficacy in this patient population. We report that patients diagnosed with R/R cHL who previously underwent, or were not candidates for, ASCT and/or clinical trials, were administered daily LDC lenalidomide (20 mg orally with dose reduction for toxicity). Among the 19 patients included in this analysis, 11% of patients achieved a partial response (PR), with no documented complete responses (CR). A total of 12 (63%) patients maintained stable disease (SD), with 7 patients (37%) remaining in SD for more than 6 months. The clinical benefit rate (comprised of CR, PR, and SD for greater than 6 months) was 47% (7 out of 19 patients). The median progression-free survival and overall survival of all patients were 9.4 months (range, 4.6–14.4 months) and 90 months (range, 63.6–166.8 months), respectively. In general, the treatment was well tolerated, with grade 3 or 4 adverse events consisting of neutropenia (n = 4), and one case each of thrombocytopenia, fatigue, rash, creatinine elevation, aspartate transaminase/alanine transaminase elevation, and treatment related secondary malignancy. In a heavily treated R/R cHL patient population, daily LDC lenalidomide was associated with a high disease control rate with a favorable toxicity profile.

Therapeutic Updates for Relapsed and Refractory Classical Hodgkin Lymphoma

Hodgkin lymphoma (HL) is a B-cell malignancy representing approximately one in ten lymphomas diagnosed in the United States annually. The majority of patients with HL can be cured with chemotherapy; however, 5-10% will have refractory disease to front-line therapy and 10-30% will relapse. For those with relapsed or refractory (r/r) HL, salvage chemotherapy followed by autologous stem cell transplant (ASCT) is standard of care, but half of patients will subsequently have disease progression. Relapse following ASCT has been associated with exceedingly poor prognosis with a median survival of only 26 months. However, in recent years, novel agents including brentuximab vedotin (BV) and programmed cell death protein 1 monoclonal antibodies (anti-PD-1, nivolumab and pembrolizumab) have been shown to extend overall survival in r/r HL. With the success of novel agents in relapsed disease after ASCT, these therapies are beginning to show clinically meaningful response rates prior to ASCT. Finally, a new investigation in r/r HL continues to produce promising treatment options even after ASCT including CD30 directed chimeric antigen receptor T-cell therapy. In this review, we will discuss the recent advances of BV and anti-PD-1 therapy prior to ASCT, novel approaches in r/r HL after ASCT, and review active clinical trials.

A Pilot Study of Lenalidomide Maintenance Therapy after Autologous Transplantation in Relapsed or Refractory Classical Hodgkin Lymphoma

For patients with relapsed or refractory classical Hodgkin lymphoma (cHL), salvage chemotherapy followed by consolidation with autologous stem cell transplant (ASCT) remains the standard of care. Even with this aggressive treatment strategy, 5-year progression-free survival is ≤50%, and there remains interest in maintenance strategies to improve long-term disease-free survival. Lenalidomide is an immunomodulatory agent with demonstrated activity in multiple subtypes of lymphoma including cHL, and has also been shown to improve both progression-free and overall survival as maintenance therapy after ASCT in multiple myeloma. This multicenter study evaluated maintenance lenalidomide after ASCT for patients with cHL. Patients were enrolled 60 to 90 days post-transplant and received oral lenalidomide on days 1 to 28 of 28-day cycles for a maximum of 18 cycles. Lenalidomide was started at 15 mg daily and increased to maximum of 25 mg daily if tolerated. The primary objective of this study was to assess the feasibility of this regimen, with a goal <30% rate of discontinuation at or before cycle 12 for drug-related reasons. Twenty-seven patients were enrolled and 26 received at least 1 dose of lenalidomide. With a median follow-up of 51.3 months (range, 12.2 to 76.2 months), 23 of 26 patients were alive. Median event-free survival was 9.4 months and median progression-free survival had not been reached, with 17 of 26 patients (65.4%) remaining in remission at last follow-up. Excluding 4 patients who discontinued therapy for progression and 2 who discontinued due to noncompliance, the discontinuation rate at or before cycle 12 was 52%. Treatment was complicated by a high frequency of hematologic adverse events, with 15 patients (58%) experiencing grade 3 to 4 hematologic toxicity and 5 (19%) experiencing grade 4 hematologic toxicity. We conclude that the regimen of maintenance lenalidomide explored in this study is not feasible for patients with cHL immediately following ASCT. An alternative lenalidomide dose or schedule may be better tolerated following ASCT for patients with relapsed or refractory cHL.

Hodgkin Lymphoma, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology for Hodgkin Lymphoma (HL) provide recommendations for the management of adult patients with HL. The NCCN panel meets at least annually to review comments from reviewers within their institutions, examine relevant data, and reevaluate and update their recommendations. Current management of classic HL involves initial treatment with chemotherapy alone or combined modality therapy followed by restaging with PET/CT to assess treatment response. Overall, the introduction of less toxic and more effective regimens has significantly advanced HL cure rates. This portion of the NCCN Guidelines focuses on the management of classic HL.

Immunotherapy in Hodgkin and non-Hodgkin lymphoma: Innate, adaptive and targeted immunological strategies

Since the clinical introduction of anti-CD20 monoclonal antibodies into lymphoma treatment, immunologic approaches in lymphoma have made substantial progress. Advances in our understanding of tumor immunology have led to the development of strategies to overcome immunologic barriers responsible for an ineffective immune response. Specifically, therapeutic agents have been developed and tested against molecules that are responsible for T-cell exhaustion. The use of monoclonal antibodies against immune checkpoints in the adaptive immune system, such as programmed cell death-1 and cytotoxic T-lymphocyte-associated protein 4, has changed the landscape of cancer therapy including the treatment of lymphoma. This achievement has recently been accompanied by the development of novel immune checkpoint inhibitors targeting the innate immune system, including the CD47-SIRPα signaling pathway, and this approach has yielded promising results. To overcome impaired antigen presentation, antibody-based cytotoxic strategies, namely antibody-drug conjugates (polatuzumab vedotin and brentuximab vedotin) and bispecific T-cell or NK-cell engagers (blinatumomab, REGN1979, RG6206, and AFM13), have rapidly evolved with promising clinical activity. As additional tools become available for lymphoma treatment, formulation of safe, rational combination strategies to combine them with standard therapy will be of paramount importance. A successful approach to the treatment of lymphoma may require both an optimized anti-tumor immune response as well as effective depletion of malignant lymphoid cells.

Optimizing outcomes in relapsed/refractory Hodgkin lymphoma: a review of current and forthcoming therapeutic strategies

The outcome of patients with relapsed/refractory classical Hodgkin lymphoma (rr-cHL) has improved considerably in recent years owing to the approval of highly active novel agents such as brentuximab vedotin and Programmed Death-1 (PD-1) inhibitors. Although no randomized trials have been conducted to provide formal proof, it is almost undisputable that the survival of these patients has been prolonged. As autologous stem-cell transplantation (SCT) remains the standard of care for second-line therapy of most patients with rr-cHL, optimization of second-line regimens with the use of brentuximab vedotin, or, in the future, checkpoint inhibitors, is promising to increase both the eligibility rate for transplant and the final outcome. The need for subsequent therapy, and especially allogeneic SCT, can be reduced with brentuximab vedotin consolidation for 1 year, while pembrolizumab is also being tested in this setting. Several other drug categories appear to be active in rr-cHL, but their development has been delayed by the appearance of brentuximab vedotin, nivolumab and pembrolizumab, which have dominated the field of rr-cHL treatment in the last 5 years. Combinations of active drugs in chemo-free approaches may further increase efficacy and hopefully reduce toxicity in rr-cHL, but are still under development.

Advances in Therapy for Relapsed or Refractory Hodgkin Lymphoma

PURPOSE OF REVIEW

The landscape of relapsed or refractory (R/R) Hodgkin lymphoma (HL) treatment has changed significantly since the FDA approval of brentuximab vedotin in 2011. In this review, we summarize the recent advances in the therapy for R/R classical Hodgkin lymphoma (cHL).

RECENT FINDINGS

Immunotherapies with pembrolizumab, nivolumab, and ipilimumab, and chimeric antigen receptor (CAR) T cell therapies have shown promising results in early phase trials. Other novel agents under investigation include targeted therapies with histone deacetylase inhibitors, Janus kinase 2 inhibitors, and immunomodulators. While further studies with larger populations and longer follow-up times are needed to determine the safe and effective combinations, these novel approaches represent a growing list of treatment options that are on the horizon to improve the cure rate and increase duration of remission for R/R HL patients.

A phase II study of etoposide, methylprednisolone, high-dose cytarabine, and oxaliplatin (ESHAOx) for patients with refractory or relapsed Hodgkin's lymphoma

We assessed the efficacy and toxicity of etoposide, methylprednisolone, high-dose cytarabine, and oxaliplatin (ESHAOx) combination chemotherapy in patients with refractory or relapsed Hodgkin's lymphoma (HL). This was an open-label, non-randomized, multi-center phase II study. The ESHAOx regimen consisted of intravenous (i.v.) etoposide 40 mg/m² on days 1 to 4, i.v. methylprednisolone 500 mg on days 1 to 5, i.v. cytarabine 2 g/m² on day 5, and i.v. oxaliplatin 130 mg/m² on day 1. Cycles (up to six) were repeated every 3 weeks. In an effort to identify prognostic markers, the serum levels of cytokines including tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and vascular endothelial growth factor (VEGF) were measured at the time of study entry. A total of 37 patients were enrolled, and 36 were available for evaluation of tumor response. The overall response rate was 72.2% (26/36) (complete response, 33.3% [12/36]; partial response, 38.9% [14/36]). The median time to progression was 34.9 months (95% confidence interval, 23.1-46.7 months). The most common grade 3 or 4 hematological adverse events were neutropenia (16/37, 43.2%), followed by thrombocytopenia (10/37, 27.0%). Grade 3 or 4 non-hematological adverse events were nausea (3/37, 8.1%), anorexia (2/37, 5.4%), mucositis (1/37, 2.7%), and skin rash (1/37, 2.7%). There were no treatment-related deaths. High levels of TNF-α and CRP were significantly associated with poorer overall survival (p = 0.00005 for TNF-α, p = 0.0004 for CRP, respectively). The ESHAOx regimen exhibited antitumor activity and an acceptable safety profile in patients with refractory or relapsed HL. Trial Registration: ClinicalTrials.gov. Registered February 21, 2011, https://clinicaltrials.gov/ct2/show/NCT01300156.

Analysis of Relapsed/Refractory Hodgkin Lymphoma Treated with Autologous Transplantation: A Single-Center Experience

Introduction: Hodgkin lymphoma (HL) is one of the common lymphomas with high cure rate. Aims: The aim was to study the outcome of relapsed/refractory HL treated with autologous transplantation. Objectives: The objective was to study the overall survival, overall response, and disease-free survival of the relapsed/refractory HL after autologous transplantation. Methods: It was a retrospective study conducted over a period of 8 years in our center using computer-based database and medical records as the data source. Results: A total of 22 patients were diagnosed with relapsed/refractory HL of which majority of cases were male patients (59%) with a mean age of 29 years (range: 15–57 years) and were Stage 4A (40.9%), with nodular sclerosis (54.5%). The overall response rate was 81.8% with 9.1% complete response, 72.7% partial response, and 4.5% stable disease; the overall survival was 77.92 ± 6.65 months, and disease-free survival was 69.66 ± 8.13 months. Conclusion: Autologous stem cell transplant plays an integral role in the treatment of patients with relapsed/refractory Hodgkin lymphoma.

Novel agents and immune invasion in Hodgkin lymphoma

The approval of brentuximab vedotin (BV) and the PD-1 inhibitors nivolumab and pembrolizumab has dramatically improved outcomes for patients with relapsed or refractory (R/R) classic Hodgkin lymphoma (HL). With the goal of increasing long-term disease control rates and decreasing late toxicities, these agents are currently being tested in earlier phases of treatment in combination with chemotherapy agents. In the R/R setting, our expanding understanding of HL's various mechanisms of immune evasion and treatment resistance has spurred a growing number of rationally designed combination trials. Beyond BV and PD-1 blockade, other novel therapies have demonstrated encouraging preliminary results, including targeted agents, like the CD25 antibody-drug conjugate ADCT-301, and cellular therapies, including CD30 chimeric antigen receptor T cells and Epstein-Barr virus (EBV)-directed cytotoxic T cells. These trials, coupled with the rapid development of prognostic and predictive biomarkers, should drive additional breakthroughs that promise safer and more effective therapies for patients with HL in the future.

Relapsed and Refractory Classical Hodgkin Lymphoma: Keeping Pace With Novel Agents and New Options for Salvage Therapy

The management of relapsed and refractory classic Hodgkin lymphoma (HL) has changed substantially since the approval of brentuximab vedotin (BV) and the checkpoint inhibitors nivolumab and pembrolizumab. For patients progressing after frontline treatment, second-line therapy followed by consolidation with autologous stem cell transplant (ASCT) remains the standard of care; however, although traditional combination chemotherapy regimens previously represented the only options for salvage, BV is now routinely incorporated into second-line therapy, and studies are evaluating checkpoint inhibitors in this setting as well. After ASCT, BV maintenance improves progression-free survival for patients at higher-risk, and studies are evaluating the role of post-ASCT maintenance with checkpoint inhibitors. Management of HL that progresses after ASCT remains a challenge. Although many patients achieve prolonged disease control with checkpoint inhibitors, the majority eventually progress and require additional therapy. Newer approaches, including CD30-directed chimeric antigen receptor-T-cell therapy, appear promising. Furthermore, allogeneic stem cell transplant remains an important consideration. Altogether, BV and checkpoint inhibitors have improved survival for patients with relapsed and refractory HL. However, the ideal place for these drugs in the treatment course of HL is still under investigation. Ongoing studies testing novel combinations and assessing for prognostic and predictive markers will ultimately define the optimal setting for these drugs in the treatment of relapsed and refractory HL.

Current advances in Hodgkin's lymphoma

Hodgkin's lymphoma is a highly treatable malignancy. It has high cure rates yet there are many patients who relapse or are refractory to treatment. Traditionally, treatment has been with conventional chemotherapy; however, the development of brentuximab vedotin and immune checkpoint inhibitors has revolutionized the care of Hodgkin's lymphoma. This is a review of the current advances in the management of Hodgkin's lymphoma and a review of ongoing clinical trials in the field.

Hodgkin lymphoma in elderly patients

PURPOSE OF REVIEW

We aim to summarize the current knowledge on the treatment of elderly Hodgkin lymphoma patients with a focus on evidence from clinical trials and novel drugs.

RECENT FINDINGS

For elderly Hodgkin lymphoma patients above 60 years without precluding comorbidities a curative treatment approach is warranted. Early favorable stage patients should receive two cycles of multiagent chemotherapy followed by 20 Gy localized radiotherapy. Early unfavorable stage patients should receive four cycles of multiagent chemotherapy followed by 30 Gy localized radiotherapy. For advanced stage patients six cycles of multiagent chemotherapy can be recommended and should be followed by localized radiotherapy on residual disease manifestations. Relapsed or refractory patients should be treated in an individually tailored approach that considers both the patient's objectives and comorbidities. The antibody-drug conjugate brentuximab vedotin is a very effective option for elderly patients with a high response rate albeit limited durability. Anti-programed cell death protein 1 antibodies might also be effective in elderly Hodgkin lymphoma patients with a mechanism of action distinct from chemotherapy.

SUMMARY

In conclusion, the goal of treatment in newly diagnosed elderly Hodgkin lymphoma patients is curative whenever possible and prospective and retrospective evidence has shown that this is feasible for all disease stages with a variety of multiagent chemotherapy regimen. Relapsed and refractory elderly Hodgkin lymphoma patients can mostly only be treated with the goal of palliation. However, it remains to be seen if novel substances and new combination regimen are able to change that.

Novel Therapies and Approaches to Relapsed/Refractory HL Beyond Chemotherapy

Although Hodgkin lymphoma (HL) is highly curable with first-line therapy, relapses occur in approximately 10–20% of patients with early stage disease and 30–40% of patients with advanced stage disease. The standard approach for relapsed or refractory disease is salvage therapy, followed by consolidation with high dose therapy and autologous stem cell transplant (ASCT). Patients who achieve a complete response to salvage therapy prior to ASCT have better outcomes, thus recent studies have focused on incorporating newer agents in this setting. Major challenges in the management of relapsed patients remain how to choose and sequence the many salvage therapies that are currently available and how to best incorporate novel agents in the current treatment paradigms. In this article, we will summarize the most recent advances in the management of patients with recurrent HL and will mainly focus on the role of new agents approved and under investigation. Aside from brentuximab vedotin and checkpoint inhibitors, other novel agents and therapies are showing promising early results. However, at least with some of the newest targeted strategies, it is important to recognize that we are facing new challenges in terms of toxicities, which require very close monitoring and education of both the patient and treating physician.

Determining the sequence of novel therapies in the treatment of relapsed Hodgkin's lymphoma

INTRODUCTION

Hodgkin's lymphoma (HL) accounts for about 10% of all lymphomas in the U.S.A. Exceptional progress has been made in the treatment of HL with complete response (CR) rates up to 94% in limited stage and 88% in advanced stage disease with regimens such as adriamycin, bleomycin, vinblastine, and dacarbazine in the frontline setting. Nevertheless, up to 10% of patients with limited stage disease and 20-30% of those with advanced stage HL relapse. In the last decade, newer agents such as brentuximab vedotin (BV) and checkpoint inhibitors have been approved by the FDA for treatment of patients with relapsed or refractory HL. As these newer agents are increasingly incorporated in both the frontline and relapsed settings, their optimal sequence becomes challenging for clinicians. Areas covered: This review will discuss the evidence behind the approval of BV and checkpoint inhibitors in HL and the appropriate sequence for using them in relapsed HL. Expert commentary: The appropriate sequence of BV and/or checkpoint inhibitors in the relapsed setting depends on the regimen used in the frontline setting.

A Novel Combination of the mTORC1 Inhibitor Everolimus and the Immunomodulatory Drug Lenalidomide Produces Durable Responses in Patients With Heavily Pretreated Relapsed Lymphoma

BACKGROUND

Treatment outcomes have improved in lymphoid malignancies but relapse remains inevitable for most patients. Everolimus and lenalidomide have shown clinical activity as single agents in patients with relapsed and refractory Hodgkin and non-Hodgkin lymphomas.

PATIENTS AND METHODS

The present phase I/II trial for patients with relapsed and refractory lymphoid malignancy opened at Mayo Clinic from January 2011 to May 2013. The trial used a standard cohort 3 + 3 design to determine the maximum tolerated dose for the combination. Stem cell transplantation had failed in 27 of the patients (49%), 63% had stage IV disease, and ≥ 3 previous therapies had failed in 78%.

RESULTS

Of the 58 patients, enrolled, 55 were evaluable for analysis. The maximum tolerated dose was 5 mg/d for everolimus plus 10 mg/d for 21 days for lenalidomide. The most common grade ≥ 3 toxicities were hematologic and included neutropenia (56%), leukopenia (38%), and thrombocytopenia (33%). Seven patients discontinued the study because of adverse events. One patient died of disease progression. The overall response rate was 27% (15 of 55), with 38% (21 of 55) having stable disease.

CONCLUSION

The present phase I/II trial of everolimus and lenalidomide for R/R lymphoma has shown the combination to be tolerable, with neutropenia as the main dose-limiting toxicity. Encouraging responses were seen in this heavily pretreated group, and the patients with a response had meaningful duration of response.

New Treatment Algorithms in Hodgkin Lymphoma: Too Much or Too Little?

Hodgkin lymphoma treatment continues to evolve as new means of assessing response to treatment, new appreciation of important risk factors, and more effective therapeutic agents become available. Treatment algorithms integrating functional imaging now provide the opportunity to modify therapy during its delivery, allowing adjustment of duration and intensity of chemotherapy and rationale identification of patients who may benefit from the addition of therapeutic irradiation. Novel agents, including the antibody drug conjugate brentuximab vedotin and checkpoint inhibitors such as nivolumab and pembrolizumab can improve the effectiveness of treatment while keeping toxicity within acceptable limits. Carefully designed clinical trials permit the identification of superior approaches in which efficacy is enhanced and toxicity minimized. Clinicians treating patients with Hodgkin lymphoma now have access to novel treatment approaches, which will require detailed assessment of each patient and careful discussion of the goals and risks of treatment at the time of planning primary treatment, again during delivery of that treatment as data indicating ongoing effectiveness become available, at the conclusion of initial intervention, and, when the need arises, at the time of recurrence of disease.

Management of relapsed/refractory classical Hodgkin lymphoma in transplant-ineligible patients

Addition of brentuximab vedotin, a CD30-targeted antibody-drug conjugate, and the programmed death 1 (PD-1) inhibitors nivolumab and pembrolizumab to the armamentarium for transplant-ineligible relapsed/refractory classical Hodgkin lymphoma has resulted in improved outcomes, including the potential for cure in a small minority of patients. For patients who have failed prior transplant or are unsuitable for dose-intense approaches based on age or comorbidities, an individualized approach with sequential use of single agents such as brentuximab vedotin, PD-1 inhibitors, everolimus, lenalidomide, or conventional agents such as gemcitabine or vinorelbine may result in prolonged survival with a minimal or modest effect on quality of life. Participation in clinical trials evaluating new approaches such as combination immune checkpoint inhibition, novel antibody-drug conjugates, or cellular therapies such as Epstein-Barr virus-directed cytotoxic T lymphocytes and chimeric antigen receptor T cells offer additional options for eligible patients.

Transplant strategies in relapsed/refractory Hodgkin lymphoma

The majority of patients with Hodgkin lymphoma (HL) are cured with initial therapy. However, high-dose therapy with autologous hematopoietic cell transplant (AHCT) allows for the cure of an additional portion of patients with relapsed or primary refractory disease. Positron emission tomography-negative complete remission before AHCT is critical for long-term disease control. Several salvage options are available with comparable response rates, and the choice can be dependent of comorbidities and logistics. Radiation therapy can also improve the remission rate and is an important therapeutic option for selected patients. Brentuximab vedotin (BV) maintenance after AHCT is beneficial in patients at high risk for relapse, especially those with more than 1 risk factor, but can have the possibility of significant side effects, primarily neuropathy. Newer agents with novel mechanisms of action are under investigation to improve response rates for patients with subsequent relapse, although are not curative alone. BV and the checkpoint inhibitors nivolumab and pembrolizumab are very effective with limited side effects and can bridge patients to curative allogeneic transplants (allo-HCT). Consideration for immune-mediated toxicities, timing of allogeneic hematopoietic cell transplant based on response, and the potential for increased graft-versus-host disease remain important. Overall, prospective investigations continue to improve outcomes and minimize toxicity for relapsed or primary refractory HL patients.

Pembrolizumab and its role in relapsed/refractory classical Hodgkin's lymphoma: evidence to date and clinical utility

Immune evasion is a critical mechanism of malignant cell survival, and relies in part on molecular signaling through the programmed cell death 1 (PD-1)/PD-1 ligand (PD-L1) axis that contributes to T cell exhaustion. Immune modulatory therapy with monoclonal antibodies against PD-1 designed to enhance antitumor immune response have shown promise in the treatment of advanced solid tumors and hematologic malignancies. Classical Hodgkin's lymphoma (cHL), a unique B cell malignancy characterized by an extensive but ineffective immune cell infiltrate surrounding a small number of tumor cells, has shown significant response to anti-PD-1 directed therapy. The anti-PD-1 monoclonal antibodies nivolumab and pembrolizumab have shown similarly remarkable activity in relapsed/refractory cHL and have been approved by the Food and Drug Administration for treatment of this disease. In this article we review the rationale of targeting the PD-1/PD-L1 axis in cHL and the pharmacology of pembrolizumab, and summarize the data on activity and safety profile of this agent in the treatment of relapsed/refractory cHL. We also discuss the potential benefits and pitfalls of using PD-1 blockade in the setting of allogeneic stem-cell transplantation, and summarize ongoing prospective trials of single-agent pembrolizumab and combination strategies as well as future directions.

Immune Checkpoint Inhibition in Hodgkin Lymphoma

Intricate systems of checkpoints such as the programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) axis regulate adaptive immune responses to protect against tissue damage. However, diverse cancers can exploit these pathways to evade or suppress antitumor immunity, leading to tumor progression. Correspondingly, immune checkpoint inhibitors that block PD-1/PD-L1 signaling have shown marked therapeutic efficacy in certain cancers, such as Hodgkin lymphoma. Reed-Sternberg cells, the hallmark cells of Hodgkin lymphoma, commonly overexpress PD-1 ligands, and recent clinical trials have demonstrated impressive response rates with the PD-1 inhibitors nivolumab and pembrolizumab in relapsed or refractory Hodgkin lymphoma, leading to their FDA approval in this setting. Current efforts are underway to improve clinical responses by incorporating PD-1 inhibitors into earlier treatment regimens and identifying therapeutic agents that synergize with PD-1 inhibitors. This review summarizes our understanding of the PD-1/PD-L1 axis in Hodgkin lymphoma, recent clinical studies of anti-PD-1 monotherapy and promising combination immunotherapy in the pipeline.

Program death inhibitors in classical Hodgkin's lymphoma: a comprehensive review

Cancer cells are able to induce immune system tolerance through different mechanisms. Recent achievements in the understanding of tumor microenvironment, invasion, and metastasizing have contributed to accelerated drug developments and approvals. Hodgkin lymphoma (HL) cells are the minority in a lymphocyte-rich microenvironment of HL tissue. The program death-1 (PD-1)/PD-ligand-1 checkpoint is one of the known effective pathways in classical HL to escape the immune system cells. The approval of PD-1 inhibitors in different cancer types with exciting response rates is truly revolutionizing our treatment armamentarium against cancer in general and classical HL in specific. Although the disease is one of the most curable tumors, we still need better outcome with more gentle treatment, especially for relapsed and refractory (r/r) patients. In this article, we review the current literature on immune checkpoint inhibitors and currently ongoing studies with nivolumab and pembrolizumab in r/r classical HL.

SOHO State of the Art Updates and Next Questions: Hodgkin Lymphoma

Until recently, advances in classic Hodgkin lymphoma (HL) treatment primarily consisted of minor modifications of highly effective decades-old chemotherapy and radiation approaches. In early-stage disease, excellent outcomes have been reported with fewer cycles of chemotherapy, lower doses, smaller radiation fields and in some circumstances, radiation elimination. In advanced-stage disease, maintaining the dose intensity of standard chemotherapy regimens has resulted in modest improvements in outcomes. During the past decade, the use of early interim positron emission tomography (PET) scans to escalate or de-escalate treatment has been the subject of intense investigation with the goal of maximizing efficacy and minimizing toxicity. Important updates from recent PET-directed trials include; elimination of bleomycin in patients with advanced-stage HL and negative interim PET findings, the benefit of therapy escalation in patients with unfavorable early-stage HL and positive interim PET findings, and the minimal benefit of consolidative radiotherapy in patients with unfavorable early-stage HL and negative interim PET findings. A more nuanced approach to consolidative radiotherapy is required for patients with favorable early-stage disease based on age, disease sites, secondary cancer risk, and cardiovascular disease. Brentuximab vedotin and nivolumab/pembrolizumab have provided promising new options with surprisingly high response rates and modest toxicity for patients with relapsed HL whose disease does not respond to standard treatments. Incorporating these agents into earlier therapy is an area of active investigation for all stages of HL. Although the overall prognosis for HL patients has seen incremental improvement, efforts to optimize treatment with more effective and less toxic approaches continue.

Managing Tumor Lysis Syndrome in the Era of Novel Cancer Therapies

Abstract Tumor lysis syndrome (TLS) is a potentially life-threatening emergency that can develop rapidly after the release of intracellular contents from lysed malignant cells. The advent of novel and targeted therapies that have improved tumor-killing efficacy has the potential to increase the risk of TLS when used as part of front-line therapy. A recent review of TLS risk in patients with hematologic malignancies treated with newer targeted agents highlighted the need to revisit TLS risk stratification and to describe the practical challenges of TLS prevention, treatment, and monitoring. Although this era of rapid development of novel cancer therapies provides new hope for patients with hematologic malignancies, it is essential to be prepared for TLS because monitoring and prophylaxis can almost always prevent severe and life-threatening consequences. Heightened awareness of the development of TLS with novel and targeted agents, accompanied by aggressive hydration and rational, risk-appropriate management, are the keys to successful outcomes.

Where Do the New Drugs Fit in for Relapsed/Refractory Hodgkin Lymphoma?

The standard approach for relapsed or refractory (rel/ref) Hodgkin lymphoma (HL) following frontline treatment failure is salvage therapy followed by consolidation with high-dose therapy and autologous stem cell transplant (HDT/ASCT). While this overall treatment paradigm has been in place for several decades, recent studies have aimed to improve the efficacy and tolerability of salvage therapies by incorporating newer drugs, such as brentuximab vedotin (BV) and checkpoint inhibitors. Following HDT/ASCT, survival is improved due to the availability of BV and the checkpoint inhibitors, nivolumab and pembrolizumab; however, for patients responding to checkpoint inhibition, the appropriate length of treatment and the role of allogeneic stem cell transplant are unclear. In this review, we discuss our management of rel/ref HL, with particular focus on how BV, nivolumab, and pembrolizumab are currently incorporated into the treatment paradigms for rel/ref HL.

Post-autologous transplant maintenance therapies in lymphoma: current state and future directions

Disease relapse following high-dose chemotherapy and autologous stem cell transplant (ASCT) remains the principal cause of mortality in patients with relapsed or refractory lymphomas. In an effort to prevent post-ASCT relapse, a number of studies have evaluated the role of maintenance therapy with varying success. In diffuse large B-cell lymphoma, studies evaluating maintenance rituximab (MR) following ASCT failed to demonstrate improved outcomes. In follicular lymphoma, MR was associated with an improvement in PFS; however, no overall survival (OS) benefit was noted. Emerging data evaluating MR in mantle cell lymphoma (MCL) have demonstrated improvements in PFS, although a consistent improvement in OS has yet to be demonstrated. Given the aggressive and incurable nature of MCL, it is prudent for practitioners to weigh the risks and benefits of MR in the post-ASCT setting. Similarly, post-ASCT maintenance therapy with brentuximab vedotin in Hodgkin lymphoma, has led to improved PFS and may be considered in those with a high risk of relapse. Ongoing clinical studies evaluating a multitude of novel maintenance therapies are crucial to the efforts of further defining and optimizing the role of post-transplant maintenance therapy in lymphoma.