Infection risk and antimicrobial prophylaxis in bendamustine-treated patients with indolent non-Hodgkin lymphoma: An Australasian Lymphoma Alliance study.

Infection and lymphopenia are established bendamustine-related complications. The relationship between lymphopenia severity and infection risk, and the role of antimicrobial prophylaxis, is not well described. This multicentre retrospective study analysed infection characteristics and antimicrobial prophylaxis in 302 bendamustine-treated indolent non-Hodgkin lymphoma patients. Lymphopenia (<1 × 109/L) was near universal and time to lymphocyte recovery correlated with cumulative bendamustine dose. No association between lymphopenia severity and duration with infection was observed. Infections occurred in 44% of patients (50% bacterial) with 27% hospitalised; 32% of infections occurred ≥3 months post bendamustine completion. Infection was associated with obinutuzumab and/or maintenance anti-CD20 therapy, prior therapy and advanced stage. Twenty-four opportunistic infections occurred in 21 patients: ten varicella zoster virus (VZV), seven herpes simplex virus (HSV), one cytomegalovirus, one progressive multifocal leucoencephalopathy, one nocardiosis, one Pneumocystis jiroveci pneumonia (PJP) and three other fungal infections. VZV/HSV and PJP prophylaxis were prescribed to 42% and 54% respectively. Fewer VZV/HSV infections occurred in patients receiving prophylaxis (HR 0.14, p = 0.061) while PJP prophylaxis was associated with reduced risk of bacterial infection (HR 0.48, p = 0.004). Our study demonstrates a significant infection risk regardless of lymphopenia severity and supports prophylaxis to mitigate the risk of early and delayed infections.

Impact and utility of follicular lymphoma GELF criteria in routine care: an Australasian Lymphoma Alliance study.

Follicular Lymphoma (FL) treatment initiation is largely determined by tumor burden and symptoms. In the pre-rituximab era, the Group d'Etude des Lymphomes Folliculaires (GELF) developed widely adopted criteria to identify high tumor burden FL patients to harmonize clinical trial populations. The utilization of GELF criteria (GELFc) in routine therapeutic decision-making is poorly described. This multicenter retrospective study evaluated patterns of GELFc at presentation and GELFc utilization in therapeutic decision-making in newly diagnosed, advanced stage rituximab-era FL. Associations between GELFc, treatment given, and patient survival were analyzed in 300 eligible cases identified between 2002-2019. 163 (54%) had ≥1 GELFc at diagnosis. The presence or cumulative number of GELFc did not predict PFS in patients undergoing watch-and-wait (WW) or those receiving systemic treatment. Of interest, in patients with ≥1 GELFc, 16/163 (10%) underwent initial watch-and-wait (comprising 22% of the watchand- wait cohort). In those receiving systemic therapy +/- radiotherapy, 74/215 (34%) met no GELFc. Our data suggest clinicians are using adjunctive measures to make decisions regarding treatment initiation in a significant proportion of patients. By restricting FL clinical trial eligibility only to those meeting GELFc, reported outcomes may not be applicable to a significant proportion of patients treated in routine care settings.

Australians with chronic lymphocytic leukaemia continue to have high rates of second primary malignancies in the modern era.

Population-based studies have demonstrated a high risk of second cancers, especially of the skin, among patients with chronic lymphocytic leukaemia (CLL). We describe age-standardised incidence ratios (SIRs) of second primary malignancies (SPM) in Australian patients with relapsed/refractory CLL treated with at least two lines of therapy, including ibrutinib. From December 2014 to November 2017, 156 patients were identified from 13 sites enrolled in the Australasian Lymphoma and Related Diseases Registry, and 111 had follow-up data on rates of SPM. At 38.4 months from ibrutinib therapy commencement, 25% experienced any SPM. SIR for melanoma and all cancers (excluding nonmelanomatous skin cancers) were 15.8 (95% confidence interval (CI): 7.0-35.3) and 4.6 (95% CI: 3.1-6.9) respectively. These data highlight the importance of primary preventive interventions and surveillance, particularly as survival from CLL continues to improve.

Australia and New Zealand consensus position statement: use of COVID-19 therapeutics in patients with haematological malignancies.

Despite widespread vaccination rates, we are living with high transmission rates of SARS-CoV-2. Although overall hospitalisation rates are falling, the risk of serious infection remains high for patients who are immunocompromised because of haematological malignancies. In light of the ongoing pandemic and the development of multiple agents for treatment, representatives from the Haematology Society of Australia and New Zealand and infectious diseases specialists have collaborated on this consensus position statement regarding COVID-19 management in patients with haematological disorders. It is our recommendation that both patients with haematological malignancies and treating specialists be educated regarding the preventive and treatment options available and that patients continue to receive adequate vaccinations, keeping in mind the suboptimal vaccine responses that occur in haematology patients, in particular, those with B-cell malignancies and on B-cell-targeting or depleting therapy. Patients with haematological malignancies should receive treatment for COVID-19 in accordance with the severity of their symptoms, but even mild infections should prompt early treatment with antiviral agents. The issue of de-isolation following COVID-19 infection and optimal time to treatment for haematological malignancies is discussed but remains an area with evolving data. This position statement is to be used in conjunction with advice from infectious disease, respiratory and intensive care specialists, and current guidelines from the National COVID-19 Clinical Evidence Taskforce and the New Zealand Ministry of Health and Cancer Agency Te Aho o Te Kahu COVID-19 Guidelines.

Outcomes of human immunodeficiency virus-associated Burkitt lymphoma and diffuse large B-cell lymphoma treated in Australia: A report from the Australasian Lymphoma Alliance.

Antiretroviral therapy (ART) has improved outcomes for human immunodeficiency virus-associated non-Hodgkin lymphoma (HIV-NHL). This is an analysis of 44 patients with HIV with Burkitt lymphoma (HIV-BL) and diffuse large B-cell lymphoma (HIV-DLBCL) treated in Australia over a 10-year period (2009-2019) during the ART and rituximab era. At HIV-NHL diagnosis, the majority of presenting patients had adequate CD4 counts and undetectable HIV viral load <50 copies/mL. More than 80% of patients received chemotherapy with curative intent, rituximab, and concurrent ART with chemotherapy (immunotherapy). R-CODOX-M/IVAC or R-Hyper-CVAD (55%) were most commonly used in HIV-BL. CHOP (58%) was the most commonly used chemotherapy backbone for HIV-DLBCL, although 45% of patients received more intense chemotherapy regimens. Overall, 93% of patients who received curative therapy completed their intended course. The 2-year progression-free survival (PFS) and overall survival (OS) for the HIV-BL cohort was 67% and 67% respectively. The 2-year PFS and OS for the HIV-DLBCL cohort was 77% and 81% respectively. Treatment related mortality was 5%. In all, 83% of patients achieved a CD4 count of >0.2 ×109 /L 6 months after the end of treatment. Current Australian practice favours the treatment of HIV-BL and HIV-DLBCL similarly to the HIV-negative population with the use of concurrent ART, achieving outcomes comparable to the HIV-negative population.

Clinical characteristics of Australian treatment-naïve patients with classical Hodgkin lymphoma from the lymphoma and related diseases registry.

Comprehensive clinical characteristics of Australian patients with classical Hodgkin Lymphoma (cHL) have not previously been systematically collected and described. We report real-world data of 498 eligible patients from the first 5 years of the Lymphoma and Related Diseases Registry (LaRDR), including baseline characteristics, histologic subtype, and treatment patterns in first-line therapy. Patient demographics and distribution of histopathological subtypes of cHL are similar to reported international cohorts. Doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) was the most common therapy for both early and advanced-stage disease, and 48% of patients with the early-stage disease received radiotherapy. Treatment patterns are consistent with international guidelines. In comorbid patients ≥60 years of age with advanced-stage disease, there is greater variation in treatment. In patients with a recorded response, the objective response rate (ORR) was 96% in early-stage disease, and 88% in advanced-stage disease. Early progression-free survival data suggest Australian patients with cHL have good outcomes, similar to other international studies.

Australia and New Zealand Transplant and Cellular Therapies (ANZTCT) position statement: COVID-19 management in patients with haemopoietic stem cell transplant and chimeric antigen receptor T cell.

Patients with post-haemopoietic stem cell transplant or chimeric antigen receptor T -cell (CAR-T) therapy face a significant risk of morbidity and mortality from coronavirus disease 2019 because of their immunosuppressed state. As case numbers in Australia and New Zealand continue to rise, guidance on management in this high-risk population is needed. Whilst we have learned much from international colleagues who faced high infection rates early in the pandemic, guidance relevant to local health system structures, medication availability and emerging therapies is essential to equip physicians to manage our patients optimally.

Chronic lymphocytic leukaemia Australasian consensus practice statement.

Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in Australia and New Zealand (ANZ). Considerable changes to diagnostic and management algorithms have occurred within the last decade. The availability of next-generation sequencing and measurable residual disease assessment by flow cytometry allow for advanced prognostication and response assessments. Novel therapies, including inhibitors of Bruton's tyrosine kinase (BTKi) and B-cell lymphoma 2 (BCL2) inhibitors, have transformed the treatment landscape for both treatment-naïve and relapsed/refractory disease, particularly for patients with high-risk genetic aberrations. Recommendations regarding appropriate supportive management continue to evolve, and special considerations are required for patients with CLL with respect to the global SARS-CoV-2 pandemic. The unique funding and treatment environments in Australasia highlight the need for specific local guidance with respect to the investigation and management of CLL. This consensus practice statement was developed by a broadly representative group of ANZ experts in CLL with endorsement by peak haematology bodies, with a view to providing this standardised guidance.

First Report of Candidatus Mycoplasma haemohominis Infection in Australia Causing Persistent Fever in an Animal Carer.

BACKGROUND: Hemotropic mycoplasmas (hemoplasmas) infect animals and humans and can lead to clinical syndromes mainly characterized by hemolytic anemia. A novel pathogen, Candidatus Mycoplasma haemohominis, was recently associated with a case of human hemoplasmosis in Europe. Here we report the first detection of this pathogen in an Australian patient exhibiting persistent fever, hemolytic anemia, and pancytopenia over a 10-month period. METHODS: After exhaustive negative testing for human infectious diseases, whole genome sequencing (WGS) was performed on the patient's bone marrow aspirate, using an Illumina NextSeq500 platform. Conventional polymerase chain reaction (PCR), followed by Sanger sequencing, was then performed on blood samples using novel Mycoplasma-specific primers targeting the 16S ribosomal RNA gene. In addition, a Mycoplasma-specific fluorescence in situ hybridization (FISH) assay was developed to differentiate Mycoplasma cells from other erythrocyte inclusions (eg, Pappenheimer and Howell-Jolly bodies) which are morphologically similar to bacterial cocci by light microscopy. RESULTS: WGS analysis revealed that approximately 0.04% of the total number of unmapped reads to human genome corresponded to Mycoplasma species. A 1-kb Mycoplasma 16S fragment was successfully amplified by conventional PCR, and sequence analyses revealed 100% identity with Candidatus Mycoplasma haemohominis. FISH confirmed that several (approximately 2%) epierythrocytic inclusions initially observed by light microscopy corresponded to Mycoplasma cells. CONCLUSIONS: This represents the second report of hemolytic anemia associated with hemoplasma infection in a human, and the first report of human hemoplasmosis in Australia. This study highlights the importance of new and emerging diagnostic approaches and need for further investigations on the epidemiology of Candidatus Mycoplasma haemohominis in Australia.

Assessment and management of newly diagnosed classical Hodgkin lymphoma: a consensus practice statement from the Australasian Lymphoma Alliance.

The management of Hodgkin lymphoma (HL) has undergone significant changes in recent years. Due to the predilection of HL to affect younger patients, balancing cure and treatment-related morbidity is a constant source of concern for physicians and patients alike. Positron emission tomography adapted therapy has been developed for both early and advanced stage HL to try and improve the outcome of treatment, while minimising toxicities. The aim of this review is to digest the plethora of studies recently conducted and provide some clear, evidence-based practice statements to simplify the management of HL.

COVID-19 vaccination in haematology patients: an Australian and New Zealand consensus position statement.

Australia and New Zealand have achieved excellent community control of COVID-19 infection. In light of the imminent COVID-19 vaccination roll out in both countries, representatives from the Haematology Society of Australia and New Zealand and infectious diseases specialists have collaborated on this consensus position statement regarding COVID-19 vaccination in patients with haematological disorders. It is our recommendation that patients with haematological malignancies, and some benign haematological disorders, should have expedited access to high-efficacy COVID-19 vaccines, given that these patients are at high risk of morbidity and mortality from COVID-19 infection. Vaccination should not replace other public health measures in these patients, given that the effectiveness of COVID-19 vaccination, specifically in patients with haematological malignancies, is not known. Given the limited available data, prospective collection of safety and efficacy data of COVID-19 vaccination in this patient group is a priority.

Australia and New Zealand Transplant and Cellular Therapies COVID-19 vaccination consensus position statement.

Australia and New Zealand have achieved excellent community control of COVID-19 infection. In light of the imminent COVID-19 vaccination roll out in both countries, representatives of all adult and paediatric allogeneic bone marrow transplant and cellular therapy (TCT) centres as well as representatives from autologous transplant only centres in Australia and New Zealand collaborated with infectious diseases specialists with expertise in TCT on this consensus position statement regarding COVID-19 vaccination in TCT patients in Australia and New Zealand. It is our recommendation that TCT patients, should have expedited access to high-efficacy COVID-19 vaccines given that these patients are at high risk of morbidity and mortality from COVID-19 infection. We also recommend prioritising vaccination of TCT healthcare workers and household members of TCT patients. Vaccination should not replace other public health measures in TCT patients given the effectiveness of COVID-19 vaccination in TCT patients is unknown. Furthermore, given the limited available data, prospective collection of safety and efficacy data of COVID-19 vaccination in this patient group is a priority.

Australian and New Zealand consensus statement on the management of lymphoma, chronic lymphocytic leukaemia and myeloma during the COVID-19 pandemic.

The COVID-19 pandemic poses a unique challenge to the care of patients with haematological malignancies. Viral pneumonia is known to cause disproportionately severe disease in patients with cancer, and patients with lymphoma, myeloma and chronic lymphocytic leukaemia are likely to be at particular risk of severe disease related to COVID-19. This statement has been developed by consensus among authors from Australia and New Zealand. We aim to provide supportive guidance to clinicians making individual patient decisions during the COVID-19 pandemic, in particular during periods that access to healthcare resources may be limited. General recommendations include those to minimise patient exposure to COVID-19, including the use of telehealth, avoidance of non-essential visits and minimisation of time spent by patients in infusion suites and other clinical areas. This statement also provides recommendations where appropriate in assessing indications for therapy, reducing therapy-associated immunosuppression and reducing healthcare utilisation in patients with specific haematological malignancies during the COVID-19 pandemic. Specific decisions regarding therapy of haematological malignancies will need to be individualised, based on disease risk, risks of immunosuppression, rates of community transmission of COVID-19 and available local healthcare resources.

A multicenter retrospective comparison of induction chemoimmunotherapy regimens on outcomes in transplant-eligible patients with previously untreated mantle cell lymphoma.

Mantle cell lymphoma (MCL) is an uncommon and typically aggressive form of lymphoma. Although often initially chemosensitive, relapse is common. Several induction and conditioning regimens are used in transplant-eligible patients, and the optimal approach remains unknown. We performed an international, retrospective study of transplant-eligible patients to assess impact of induction chemoimmunotherapy and conditioning regimens on clinical outcomes. We identified 228 patients meeting inclusion criteria. Baseline characteristics were similar among the induction groups except for some variation in age. The type of induction chemoimmunotherapy received did not influence overall response rates (ORRs) (0.43), progression-free survival (PFS) (P > .67), or overall survival (OS) (P > .35) on multivariate analysis (PFS and OS). Delivery of autologous stem cell transplant (ASCT) was associated with favorable PFS and OS (0.01) on univariate analysis only; this benefit was not seen on multivariate analysis-PFS (0.36) and OS (0.21). Compared with busulfan and melphalan (BuMel), the use of the carmustine, etoposide, cytarabine, melphalan (BEAM)-conditioning regimen was associated with inferior PFS (HR = 2.0 [95% CI 1.1-3.6], 0.02) but not OS (HR = 1.1 [95% CI 0.5-2.3], 0.81) on univariate analysis only. Within the limits of a retrospective study and modest power for some comparisons, type of induction therapy did not influence ORR, PFS, or OS for transplant-eligible patients with MCL. International efforts are required to perform randomized clinical trials evaluating chemoimmunotherapy induction regimens.

Daratumumab plus lenalidomide and dexamethasone versus lenalidomide and dexamethasone in relapsed or refractory multiple myeloma: updated analysis of POLLUX.

In the POLLUX study, daratumumab plus lenalidomide/dexamethasone significantly reduced risk of progression/death versus lenalidomide/dexamethasone alone in relapsed/refractory multiple myeloma. We provide one additional year of follow up and include the effect on minimal residual disease and in clinically relevant subgroups. After 25.4 months of follow up, daratumumab plus lenalidomide/dexamethasone prolonged progression-free survival versus lenalidomide/dexamethasone alone (median not reached vs 17.5 months; hazard ratio, 0.41; 95% confidence interval, 0.31-0.53; P<0.0001). The overall response rate was 92.9% versus 76.4%, and 51.2% versus 21.0% achieved a complete response or better, respectively (both P<0.0001). At the 10-5 sensitivity threshold, 26.2% versus 6.4% were minimal residual disease-negative, respectively (P<0.0001). Post hoc analyses of clinically relevant patient subgroups demonstrated that progression-free survival was significantly prolonged for daratumumab plus lenalidomide/dexamethasone versus lenalidomide/dexamethasone regardless of number of prior lines of therapy. Patients previously treated with lenalidomide or thalidomide and those refractory to bortezomib received similar benefits (all P<0.01). Treatment benefit with daratumumab plus lenalidomide/dexamethasone was maintained in high-risk patients (median progression-free survival 22.6 vs 10.2 months; hazard ratio, 0.53; 95% confidence interval, 0.25-1.13; P=0.0921) and patients with treatment-free intervals of >12 and ≤12 months and >6 and ≤6 months. No new safety signals were observed. In relapsed/refractory multiple myeloma patients, daratumumab plus lenalidomide/dexamethasone continued to improve progression-free survival and deepen responses versus lenalidomide/dexamethasone. Trial Registration: clinicaltrials.gov identifier: 02076009.

Arterial line versus venous line administration of low molecular weight heparin, enoxaparin for prevention of thrombosis in the extracorporeal blood circuit of patients on haemodialysis or haemodiafiltration: A randomized cross-over trial.

STUDY OBJECTIVE: The objective of the study is to compare the anti-factor Xa (AXa) level in the blood, after arterial and venous line administration of equivalent doses of enoxaparin for prevention of thrombosis in the extracorporeal blood circuit. DESIGN: The design of the study is a dual centre, prospective, open-labelled randomized crossover, 7 weeks trial. SETTING: The setting of the study is on a patient on long-term haemodialysis (HD) or haemodiafiltration (HDF) using high-flux membrane. PARTICIPANT: There were eight patients on HD and eight on HDF. INTERVENTION: Participants were randomly assigned to receive enoxaparin either through the arterial line or venous line of extracorporeal blood circuit for an initial study interval of 2 weeks, followed by 2 weeks of alternate route administration. During the run-in period of 1 week and the follow-up period of 2 weeks, enoxaparin was administered through the arterial line. OUTCOMES: The primary outcome measure was to compare AXa blood level 4 h after enoxaparin administration. The secondary outcome measures were manual compression time to stop bleeding from arteriovenous fistula, extracorporeal circuit clotting and systemic bleeding episodes. RESULTS: The mean AXa blood level, 4 h after venous circuit administration (0.58 ± 0.21 (HD), 0.82 ± 0.29 (HDF)) of enoxaparin, was significantly greater than that after arterial administration of enoxaparin (0.39 ± 0.25 (HD), 0.39 ± 0.14 (HDF) U/mL), (P < 0.001). CONCLUSION: In patients on HD or HDF, venous line administration of enoxaparin achieves greater 4 h blood AXa level compared with arterial line administration of equivalent dose. Based on this, we suggest a 25% or 50% reduction in the dose of venous line enoxaparin, compared with the dose administered through arterial line in patients receiving either HD or HDF, respectively.

Poor outcomes for trial-ineligible patients receiving polatuzumab for relapsed/refractory diffuse large B-cell lymphoma in routine care: An Australian Lymphoma and Related Diseases Registry project.

Polatuzumab vedotin (Pola) is an approved therapy in combination with rituximab and bendamustine for relapsed or refractory diffuse large B-cell lymphoma (RR-DLBCL) based on positive results of the landmark phase II randomised G029365 trial. However, trial results for many approved novel therapies in RR-DLBCL have not been replicated in routine care cohorts, as RR-DLBCL patient populations are heterogeneous and trial eligibility is increasingly restrictive. We evaluated outcomes from pola ± bendamustine and rituximab in patients with RR-DLBCL enrolled in a compassionate access program with no alternative treatment options identified via the Australasian Lymphoma and Related Diseases Registry according to their eligibility for the original phase II published study. Of 58 eligible patients, 74% met the criteria deeming them ineligible for the G029365 original study at the time of pola's commencement. Median progression-free survival and overall survival in our cohort were 2.3 and 3.5 months, respectively. In contrast to the landmark trial cohort, more of our patients ceased therapy prior to completion, the majority due to progressive disease and only 8/58 received any subsequent treatment. Dismal outcomes in this Australian real-world population demonstrate trial eligibility is challenging to meet, and newer treatments can be difficult to deliver in routine care. Clinically applicable results from therapeutic studies require trial cohorts to reflect representative clinical populations wherever possible, and more research is required to address the benefit of novel agents in the increasing majority who are ineligible for modern studies.

Daratumumab, cyclophosphamide, bortezomib, and dexamethasone for transplant-ineligible myeloma: AMaRC 03-16.

ABSTRACT: In newly diagnosed transplant-ineligible patients with myeloma, daratumumab has improved outcomes when added to the standard-of-care regimens. In a randomized trial, we tested whether similar improvements would be observed when daratumumab was added to the bortezomib, cyclophosphamide, and dexamethasone (VCD) regimen. Transplant-ineligible patients with untreated myeloma were randomized to receive VCD or VCD plus daratumumab (VCDD). A total of 121 patients were randomized: 57 in the VCD arm and 64 in the VCDD arm. Baseline characteristics were balanced between the 2 arms. The median progression-free survival (PFS) was 16.8 months (95% confidence interval [CI], 15.3-21.7) and 25.8 months (95% CI, 19.9-33.5) in the VCD and VCDD arms, respectively (hazard ratio, 0.67; log-rank test P = .066). In a preplanned analysis, it was demonstrated that the daratumumab-containing arm showed a significant improvement in PFS from 18 months onward, based on estimates at fixed time points after randomization. The proportions of patients who were progression-free at the following time points were: 18 months, 48% vs 68% (P = .0002); 24 months, 36% vs 52% (P = .0001); and 30 months, 27% vs 41% (P < .0001) in the VCD and VCDD arms, respectively. The best overall response and very good partial response rate were significantly higher in the daratumumab arm compared with the VCD and VCDD arms, respectively (65% vs 86%, P = .007; and 28% vs 52%, P = .009). Seventy-two percent of the VCDD patients completed the 9 cycles of induction therapy with no grade 3 or 4 peripheral neuropathy adverse events. This study supports VCDD as an option for the initial treatment of transplant-ineligible patients with myeloma. This trial was registered at the Australian New Zealand Clinical Trials Registry (ACTRN12617000202369).

Epcoritamab monotherapy in patients with relapsed or refractory follicular lymphoma (EPCORE NHL-1): a phase 2 cohort of a single-arm, multicentre study.

BACKGROUND: A standard of care and optimal duration of therapy have not been established for patients with multiply relapsed or refractory follicular lymphoma. The aim of this study was to evaluate epcoritamab, a novel CD3 × CD20 bispecific antibody, in the third-line and later setting of follicular lymphoma. METHODS: EPCORE NHL-1 is a multicohort, single-arm, phase 1-2 trial conducted at 88 sites across 15 countries. Here, we report the primary analysis of patients with relapsed or refractory follicular lymphoma in the phase 2 part of the trial, which included the pivotal (dose expansion) cohort and the cycle 1 optimisation cohort. Eligible patients were aged 18 years or older, had relapsed or refractory CD20+ follicular lymphoma (grade 1-3A), an Eastern Cooperative Oncology Group performance status of up to 2, and had received at least two previous lines of therapy (including an anti-CD20 monoclonal antibody and an alkylating agent or lenalidomide). Patients were treated with subcutaneous epcoritamab 48 mg in 28-day cycles: weekly in cycles 1-3, biweekly in cycles 4-9, and every 4 weeks until disease progression or unacceptable toxicity. To mitigate the risk and severity of cytokine release syndrome, in the pivotal cohort, cycle 1 consisted of a step-up dosing regimen of a 0·16-mg priming dose on day 1 and a 0·80-mg intermediate dose on day 8, followed by subsequent 48-mg full doses and prophylactic prednisolone 100 mg; in the cycle 1 optimisation cohort, a second intermediate dose of 3 mg on day 15, adequate hydration, and prophylactic dexamethasone 15 mg were evaluated during cycle 1 to further reduce risk and severity of cytokine release syndrome. Primary endpoints were independently reviewed overall response rate for the pivotal cohort and the proportion of patients with grade 2 or worse and any-grade cytokine release syndrome for the cycle 1 optimisation cohort. Analyses were done in all enrolled patients who had received at least one dose of epcoritamab. This study is registered with ClinicalTrials.gov, NCT03625037, and is ongoing. FINDINGS: Between June 19, 2020, and April 21, 2023, 128 patients (median age 65 years [IQR 55-72]; 49 [38%] female and 79 [62%] male) were enrolled and treated in the pivotal cohort (median follow-up 17·4 months [IQR 9·1-20·9]). The overall response rate was 82·0% (105 of 128 patients; 95% CI 74·3-88·3), with a complete response rate of 62·5% (80 of 128; 95% CI 53·5-70·9). The most common grade 3-4 treatment-emergent adverse event was neutropenia in 32 (25%) of 128 patients. Grade 1-2 cytokine release syndrome was reported in 83 (65%) of 128 patients; grade 3 cytokine release syndrome was reported in two (2%). Immune effector cell-associated neurotoxicity syndrome was reported in eight (6%) of 128 patients (five [4%] grade 1; three [2%] grade 2). Between Oct 25, 2022, and Jan 8, 2024, 86 patients (median age 64 years [55-71]; 37 [43%] female and 49 [57%] male) were enrolled and treated in the cycle 1 optimisation cohort. The incidence of cytokine release syndrome was 49% (42 of 86 patients; eight [9%] grade 2; none of grade 3 or worse), with no reported immune effector cell-associated neurotoxicity syndrome. INTERPRETATION: Epcoritamab monotherapy showed clinically meaningful activity in patients with multiply relapsed or refractory follicular lymphoma, and had a manageable safety profile. FUNDING: Genmab and AbbVie.