Mosunetuzumab monotherapy is active and tolerable in patients with relapsed/refractory diffuse large B-cell lymphoma.

As part of a phase 1 or 2 study, this single-arm expansion cohort established the efficacy and safety of mosunetuzumab monotherapy in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) (received ≥2 previous lines of therapy). Intravenous mosunetuzumab was administered with cycle (C) 1 step-up dosing for cytokine release syndrome (CRS) mitigation: C1 day (D) 1: 1 mg; C1D8 2 mg; C1D15 and C2D1: 60 mg; C3 + D1: 30 mg. Hospitalization was not mandatory. Patients with complete response (CR) completed treatment after C8; those with partial response or stable disease continued treatment for a total of 17 cycles. The primary end point was CR rate (best response), assessed against a historical control CR rate (20%) by independent review facility. Eighty-eight patients (73.9% de novo DLBCL; 26.1% transformed follicular lymphoma) were enrolled; all had received previous anthracycline and anti-CD20 therapy. Overall response and CR rates were 42.0% (95% confidence interval [CI], 31.6-53.1) and 23.9% (95% CI, 15.4-34.1), respectively; CR rate did not reach statistical significance vs the historical control (P = .36). Median time to first response was 1.4 months. Median progression-free survival was 3.2 months (95% CI, 2.2-5.3). The CR rate in 26 patients who received previous chimeric antigen receptor T-cell (CAR-T) therapy was 12%. CRS was one of the most common adverse events (26.1% of patients); predominantly grade 1 to 2 and primarily in C1. Four patients (4.5%) discontinued mosunetuzumab owing to adverse events. Mosunetuzumab demonstrated notable efficacy and a manageable safety profile in patients with R/R DLBCL, including those previously treated with CAR-Ts. This trial was registered at www.clinicaltrials.gov as #NCT02500407.

Long-term outcomes of corticosteroid graft versus host disease prophylaxis in peripheral blood allogeneic haemopoietic stem cell transplant: a comparative cohort analysis.

BACKGROUND: Corticosteroids (CSs) have previously been incorporated into graft versus host disease (GVHD) prophylaxis regimens for bone marrow (BM) and haemopoietic stem cell transplant (HSCT). AIMS: To assess the impact of prophylactic CS in HSCT using peripheral blood (PB) stem cells. METHODS: Patients were identified from three HSCT centres receiving a first PB-HSCT between January 2011 and December 2015 from a fully human leukocyte antigen (HLA)-matched sibling or unrelated donor for acute myeloid leukaemia or acute lymphoblastic leukaemia. To enable meaningful comparison, patients were divided into two cohorts. RESULTS: Cohort 1 included only myeloablative-matched sibling HSCT, where the only variation in GVHD prophylaxis was the addition of CS. In these 48 patients, there were no differences in GVHD, relapse, non-relapse mortality, overall survival or GVHD-relapse-free-survival (GRFS) at 4 years after transplant. Cohort 2 included the remaining HSCT recipients, where one group received CS-prophylaxis and the non-CS group received an antimetabolite, ciclosporin and anti-T-lymphocyte globulin. In these 147 patients, those receiving CS-prophylaxis experienced higher rates of chronic GVHD (71% vs 18.1%, P < 0.001) and lower rates of relapse (14.9% vs 33.9%, P = 0.02). Those receiving CS-prophylaxis had a lower 4-year GRFS (15.7% vs 40.3%, P = 0.002). CONCLUSIONS: There does not appear to be a role for adding CS to standard GVHD prophylaxis regimens in PB-HSCT.

Efficacy of bortezomib, cyclophosphamide and dexamethasone in cardiac AL amyloidosis.

Cardiac light chain (AL) amyloidosis is a condition with a very poor prognosis. We report a retrospective analysis comparing the traditional melphalan and dexamethasone protocol with cyclophosphamide, bortezomib and dexamethasone in late-stage cardiac AL amyloidosis. The primary end points were overall survival and haematological response. Both regimens provided meaningful responses in this difficult to treat patient group.

Safety and efficacy of mosunetuzumab, a bispecific antibody, in patients with relapsed or refractory follicular lymphoma: a single-arm, multicentre, phase 2 study.

BACKGROUND: Mosunetuzumab is a CD20 × CD3 T-cell-engaging bispecific monoclonal antibody that redirects T cells to eliminate malignant B cells. In a phase 1 study, mosunetuzumab was well tolerated and active in patients with relapsed or refractory B-cell lymphoma. We, therefore, aimed to evaluate the safety and anti-tumour activity of fixed-duration mosunetuzumab in patients with relapsed or refractory follicular lymphoma who had received two or more previous therapies. METHODS: We conducted a single-arm, multicentre, phase 2 study at 49 centres in seven countries (Australia, Canada, Germany, South Korea, Spain, UK, and USA). All patients were aged 18 years or older with histologically confirmed follicular lymphoma (grade 1-3a) and an Eastern Cooperative Oncology Group performance status of 0-1. Patients had disease that was relapsed or refractory to two or more previous lines of treatment, including an anti-CD20 therapy and an alkylating agent. Intravenous mosunetuzumab was administered in 21-day cycles with cycle 1 step-up dosing: 1 mg on cycle 1 day 1, 2 mg on cycle 1 day 8, 60 mg on cycle 1 day 15 and cycle 2 day 1, and 30 mg on day 1 of cycle 3 and onwards. Patients with a complete response by investigator assessment using the International Harmonisation Project criteria completed treatment after cycle 8, whereas patients with a partial response or stable disease continued treatment for up to 17 cycles. The primary endpoint was independent review committee-assessed complete response rate (as best response) in all enrolled patients; the primary efficacy analysis compared the observed IRC-assessed complete response rate with a 14% historical control complete response rate in a similar patient population receiving the pan class I PI3K inhibitor copanlisib. Safety was assessed in all enrolled patients. This study is registered with ClinicalTrials.gov, number NCT02500407, and is ongoing. FINDINGS: Between May 2, 2019, and Sept 25, 2020, we enrolled 90 patients. As of the data cutoff date (Aug 27, 2021), the median follow-up was 18·3 months (IQR 13·8-23·3). According to independent review committee assessment, a complete response was recorded in 54 patients (60·0% [95% CI 49·1-70·2]). The observed complete response rate was significantly higher than the historical control complete response rate with copanlisib of 14% (p<0·0001), thereby meeting the primary study endpoint. Cytokine release syndrome was the most common adverse event (40 [44%] of 90 patients) and was predominantly grade 1 (23 [26%] of 90) and grade 2 (15 [17%]), and primarily confined to cycle 1. The most common grade 3-4 adverse events were neutropenia or neutrophil count decreased (24 [27%] of 90 patients), hypophosphataemia (15 [17%]), hyperglycaemia (seven [8%]), and anaemia (seven [8%]). Serious adverse events occurred in 42 (47%) of 90 patients. No treatment-related grade 5 (ie, fatal) adverse event occurred. INTERPRETATION: Fixed-duration mosunetuzumab has a favourable safety profile and induces high rates of complete remissions, allowing potential administration as an outpatient regimen, in patients with relapsed or refractory follicular lymphoma and two or more previous therapies. FUNDING: F Hoffmann-La Roche and Genentech.

Second primary malignancies in chronic lymphocytic leukaemia: Skin, solid organ, haematological and Richter's syndrome.

Chronic lymphocytic leukaemia (CLL) is invariably accompanied by some degree of immune failure, and CLL patients have a high rate of second primary malignancy (SPM) compared to the general population. We comprehensively documented the incidence of all forms of SPM including skin cancer (SC), solid organ malignancy (SOM), second haematological malignancy (SHM) and separately Richter's syndrome (RS) across all therapy eras. Among the 517 CLL/small lymphocytic lymphoma (SLL) patients, the overall incidence of SPMs with competing risks was SC 31.07%, SOM 25.99%, SHM 5.19% and RS 7.55%. Of the 216 treated patients, 106 (49.1%) had at least one form of SPM, and 63 of 106 (29.2% of treated patients) developed an SPM 1.5 years (median) after treatment for their CLL. Melanoma accounted for 30.3% of SC. Squamous cell carcinoma (SCC), including eight metastatic SCCs, was 1.8 times more than basal cell carcinoma (BCC), a reversal of the typical BCC:SCC ratio. The most common SOMs were prostate (6.4%) and breast (4.5%). SHM included seven acute myeloid leukaemia (AML) and five myelodysplasia (MDS) of which eight (four AML, four MDS) were therapy-related. Any SPM occurred in 32.1% of 53 Monoclonal B-lymphocytosis (MBL) patients. Age-adjusted standardised rates of SPM (per 100,000) for CLL, MBL and the general Australian population were 2648, 1855 and 486.9, respectively. SPMs are a major health burden with 44.9% of CLL patients with having at least one SPM, and apart from SC, associated with significantly reduced overall survival. Dramatic improvements in CLL treatment and survival have occurred with immunochemotherapy and targeted therapies, but mitigating SPM burden will be important to sustain further progress.

Dynamics of Epstein-Barr virus on post-transplant lymphoproliferative disorders after antithymocyte globulin-conditioned allogeneic hematopoietic cell transplant.

BACKGROUND: The use of antithymocyte globulin (ATG) in allogeneic hematopoietic cell transplant (HCT) is associated with an increased risk of Epstein-Barr virus (EBV) reactivation and post-transplant lymphoproliferative disorders (PTLD). The dynamics and outcomes of EBV-DNAemia are not well described in this population. METHODS: We retrospectively assessed the kinetics of EBV-DNAemia after ATG conditioning of HCT recipients. Receiver operating characteristic (ROC) curves were used to assess EBV-DNAemia to predict EBV-PTLD in this group. RESULTS: A total of 174/405 (43%) consecutive HCT recipients from two centers met inclusion criteria of ATG conditioned, non-B-cell lymphoma patients. Of these with EBV-DNA measured using standardized IU/ml, 78.6% (92/117) developed EBV-DNAemia: 62% spontaneously resolved; 19% cleared after preemptive rituximab, and 13% developed EBV-PTLD. ROC curve analysis using maximum pre-EBV-PTLD EBV-DNAemia, demonstrated an AUC of 0.912 with EBV-DNAemia of 9782 IU/ml, associated with 82.6% sensitivity and 94.4% specificity for development of EBV-PTLD. Median time for EBV-DNAemia to increase from initial detection to >1000 IU/ml was 7 days; to >10 000 IU/ml, 12 days; and to >100 000 IU/ml, 18 days. Median EBV-DNAemia level prior to administration of rituximab was significantly lower in patients with successful preemptive treatment, compared with those who developed EBV-PTLD (3.41 log10  IU/ml [3.30-3.67] vs. 4.34 log10  IU/ml [3.85-5.13], p = .002; i.e., 2628 IU/ml vs. 21 965 IU/ml, respectively). CONCLUSIONS: EBV-DNAemia >10 000 IU/ml was the strongest predictor of the development of EBV-PTLD, and progression to this level was rapid in ATG-conditioned HCT recipients. This information may guide EBV-PTLD management strategies in these high-risk patients.

SUBA-Itraconazole for Primary Antifungal Prophylaxis After Allogeneic Hematopoietic Cell Transplantation.

Background: Itraconazole (ITZ) is an effective agent when used as primary invasive fungal disease (IFD) prophylaxis, but is limited by drug tolerability and variability in serum concentrations. A new formulation, SUBA-itraconazole (for "super bioavailability"; S-ITZ), addresses the limitations of conventional ITZ formulations. Methods: We conducted a retrospective cohort study at 2 Australian centers to evaluate the safety, tolerability, and effectiveness of S-ITZ as primary antifungal prophylaxis in hematopoietic cell transplant (HCT) recipients without grade II-IV acute graft-vs-host disease, from day 1 until approximately day 100 (cohort A) or day 1 until neutrophil engraftment (cohort B). A total of 204 patients and 1410 trough plasma ITZ concentrations were assessed. Results: The incidence of breakthrough proven/probable IFD at day 180 was 1.0% (95% confidence interval [CI], .2%-3.2%), with 1.6% in cohort A and 0% in cohort B, and overall fungal-free survival of proven/probable IFD was 82.9% (95% CI, 76.8%-87.4%). Preengraftment early permanent S-ITZ discontinuation was 3.4% overall, with no significant difference between cohorts. No patients required cessation due to gastrointestinal intolerance attributed to S-ITZ. The geometric mean trough plasma ITZ concentration was 1130ng/mL (interquartile range, 566-1801ng/mL; coefficient of variation, 56.57%) and the median time to achieve therapeutic levels was 10 days. Conclusions: S-ITZ is a safe and well-tolerated oral formulation and is a novel alternative for primary IFD prophylaxis after HCT.

Cytomegalovirus (CMV) management in allogeneic hematopoietic cell transplantation: Pre-transplant predictors of survival, reactivation, and spontaneous clearance.

BACKGROUND: Cytomegalovirus (CMV) reactivation is a frequent complication after allogeneic hematopoietic cell transplant (alloHCT). METHOD: We analyzed 159 alloHCT recipients with 4409 quantitative CMV viral loads to determine pre-transplant predictors of CMV reactivation, clinically significant CMV infection (cs-CMVi, defined as CMV viral load >1000 IU/mL), CMV disease, kinetics of spontaneous clearance of CMV, and survival using a standardized pre-emptive therapy approach to identify at-risk groups to target prevention strategies. RESULTS: Cs-CMVi was most common in D-/R+ unrelated donor transplants (URD). Spontaneous CMV clearance occurred in 26% of patients who reached a viral load of 56-137 IU/mL, 6% at 138-250 IU/mL and in one patient >250 IU/mL. Median time between the first CMV reactivation (>56 IU/mL) and a viral load >250 IU/mL was 13 days, whereas the time from the first viral load >250 IU/mL to reach a vial load >1000 IU/mL was 4 days. Cs-CMVi was associated with a significant increase in non-relapse mortality (NRM) on multivariate analysis. CONCLUSIONS: Overall, this study indicates that D-/R+ URD recipients are at high-risk for cs-CMVi- and CMV-related mortality, and are potential candidates for targeted CMV prophylaxis. Spontaneous clearance of CMV beyond a viral load of 250 IU/mL is uncommon, suggesting that this could be used as an appropriate threshold to initiate pre-emptive therapy.

Phase 2 study of parsaclisib (INCB050465), a highly selective, next-generation PI3Kδ inhibitor, in relapsed or refractory diffuse large B-cell lymphoma (CITADEL-202).

Parsaclisib, a potent, highly selective, next-generation PI3Kδ inhibitor, was evaluated as monotherapy in CITADEL-202 (NCT02998476), an open-label, multicenter, phase 2 study in patients with relapsed or refractory diffuse large B-cell lymphoma. Patients enrolled into 2 groups (A, Bruton tyrosine kinase [BTK] inhibitor naïve, n = 55; B, BTK inhibitor experienced, n = 5) received oral parsaclisib 20 mg once daily for 8 weeks, then 20 mg once weekly while deriving benefit. The futility boundary was crossed at the interim analysis of Group A, resulting in a negative study. Parsaclisib monotherapy demonstrated an objective response rate (ORR) of 25.5% (8 complete metabolic responses/6 partial metabolic responses) and a median duration of response of 6.2 months. ORR in Group B was 20.0% (1 complete metabolic response). Parsaclisib monotherapy demonstrated manageable toxicities with no new safety signals reported. Further evaluation of parsaclisib in combination with standard therapies and active investigational agents is underway.

Unrelated Donor Transplant Recipients Given Thymoglobuline Have Superior GRFS When Compared to Matched Related Donor Recipients Undergoing Transplantation without ATG.

Recipients of allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated donors (URDs) and mismatched related donors (MMRDs) typically have a higher incidence of acute and chronic graft-versus-host disease (GVHD) compared with matched related donors (MRDs). Anti-T-cell globulins (ATGs) are often used to reduce GVHD in these recipients. We report the outcomes of 211 adult peripheral blood stem cell transplant recipients with myeloid malignancies who received a standardized transplant protocol, in which ATG (Thymoglobuline 4.5 mg/kg) was administered to recipients of URD and MMRD (n = 147) but not MRD (n = 64) transplant. For all patients, incidence of acute GVHD grades 2 to 4 was 21.4%, and chronic GVHD was 35.0%. Two-year overall survival was 63.2% (95% confidence interval, 55.8% to 71.5%), relapse-free survival was 55.3% (47.4% to 64.6%), and GVHD-free, relapse-free survival (GRFS) was 30.7% (23.2% to 40.8%). There were no differences between recipients of MRDs and other donors in relapse, nonrelapse mortality, and overall and relapse-free survival. However, compared with MRD, recipients from URDs and MMRDs had reduced moderate to severe chronic GVHD (10.4% versus 30.1%, P= .002), less chronic GVHD requiring systemic therapy (19.4% versus 38.9%, P = .006), and superior 2-year GRFS (35.5% versus 20.0%, P = .003). In this retrospective review of nonrandomized transplant groups, outcomes of HSCT performed using an URD with ATG during conditioning were superior to transplant from an MRD without ATG. The addition of Thymoglobuline to conditioning in HSCT from MRD should be further examined in prospective trials.

Prolonged administration of low-dose cytarabine and thioguanine in elderly patients with acute myeloid leukaemia (AML) achieves high complete remission rates and prolonged survival.

The prognosis of AML in elderly patients is poor and research into novel therapeutic approaches is urgently needed. This study examined the use of low-dose chemotherapy with cytarabine and thioguanine administered in repetitive cycles in 62 elderly patients with newly diagnosed or relapsed/refractory AML. The overall response rate was 58% in the total cohort. Response rates (CR/CRi) were significantly higher in patients with newly diagnosed AML (74%) compared to patients with relapsed/refractory disease (25%, p = .0004). Kaplan-Meier estimate of overall survival was 289 days (95% CI; 183-395 days) with a relapse rate of 65.7%. The induction mortality rate was 16.1% with treatment successfully undertaken in the outpatient setting. Similar clinical outcomes were observed in a retrospective analysis of a second cohort of 25 AML patients treated at a different site. These results support the use of a sustained low intensity chemotherapy approach as a therapeutic option for elderly patients with AML.

Serum levels, safety and tolerability of new formulation SUBA-itraconazole prophylaxis in patients with haematological malignancy or undergoing allogeneic stem cell transplantation.

OBJECTIVES: To assess therapeutic levels, safety and tolerability of a novel formulation SUBA-itraconazole (where SUBA stands for SUper BioAvailability) when compared with conventional itraconazole liquid when used as antifungal prophylaxis in patients undergoing allogeneic HSCT or in haematological malignancy patients with an intermediate/high risk of invasive fungal infection (IFI). METHODS: This was a single-institution, prospective cohort study using a historical control group as the comparator. RESULTS: A total of 57 patients were assessed: 27 in the SUBA-itraconazole cohort and 30 in the liquid itraconazole cohort. Therapeutic concentrations were achieved significantly more quickly in the SUBA-itraconazole group: median of 6 (95% CI 5-11) days versus 14 (95% CI 12-21) days in the liquid itraconazole group (P < 0.0001). At day 10, therapeutic concentrations were achieved in 69% (95% CI 44%-81%) of the SUBA-itraconazole group versus 21% (95% CI 7%-33%) of the liquid itraconazole group (P < 0.0001). The mean trough serum concentrations at steady-state of SUBA-itraconazole were significantly higher, with less interpatient variability [1577 ng/mL, coefficient of variation (CV) 35%] versus liquid itraconazole (1218 ng/mL, CV 60%) (P < 0.001). There were two (7.4%) treatment failures in the SUBA-itraconazole group, both due to cessation of therapy for mucositis, compared with seven (23.3%) treatment failures in the liquid itraconazole group, due to subtherapeutic levels (five), mucositis (one) and gastrointestinal intolerance (one) (P = 0.096). CONCLUSIONS: The use of the SUBA-itraconazole formulation was associated with more rapid attainment of therapeutic levels with less interpatient variability compared with conventional liquid itraconazole when used as IFI prophylaxis in allogeneic HSCT or intermediate-/high-IFI risk haematological malignancy patients.

Early treatment intensification with R-ICE and 90Y-ibritumomab tiuxetan (Zevalin)-BEAM stem cell transplantation in patients with high-risk diffuse large B-cell lymphoma patients and positive interim PET after 4 cycles of R-CHOP-14.

In the treatment of diffuse large B-cell lymphoma, a persistently positive [18F]fluorodeoxyglucose positron emission tomography (PET) scan typically carries a poor prognosis. In this prospective multi-center phase II study, we sought to establish whether treatment intensification with R-ICE (rituximab, ifosfamide, carboplatin, and etoposide) chemotherapy followed by 90Y-ibritumomab tiuxetan-BEAM (BCNU, etoposide, cytarabine, and melphalan) for high-risk diffuse large B-cell lymphoma patients who are positive on interim PET scan after 4 cycles of R-CHOP-14 (rituximab, cyclophosphamide, doxorubicin, and prednisone) can improve 2-year progression-free survival from a historically unfavorable rate of 40% to a rate of 65%. Patients received 4 cycles of R-CHOP-14, followed by a centrally-reviewed PET performed at day 17-20 of cycle 4 and assessed according to International Harmonisation Project criteria. Median age of the 151 evaluable patients was 57 years, with 79% stages 3-4, 54% bulk, and 54% International Prognostic Index 3-5. Among the 143 patients undergoing interim PET, 101 (71%) were PET-negative (96 of whom completed R-CHOP), 42 (29%) were PET-positive (32 of whom completed R-ICE and 90Y-ibritumomab tiuxetan-BEAM). At a median follow up of 35 months, the 2-year progression-free survival for PET-positive patients was 67%, a rate similar to that for PET-negative patients treated with R-CHOP-14 (74%, P=0.11); overall survival was 78% and 88% (P=0.11), respectively. In an exploratory analysis, progression-free and overall survival were markedly superior for PET-positive Deauville score 4 versus score 5 (P=0.0002 and P=0.001, respectively). Therefore, diffuse large B-cell lymphoma patients who are PET-positive after 4 cycles of R-CHOP-14 and who switched to R-ICE and 90Y-ibritumomab tiuxetan-BEAM achieved favorable survival outcomes similar to those for PET-negative R-CHOP-14-treated patients. Further studies are warranted to confirm these promising results. (Registered at: ACTRN12609001077257).

Allogeneic haematopoietic stem cell transplantation for mitochondrial neurogastrointestinal encephalomyopathy.

Haematopoietic stem cell transplantation has been proposed as treatment for mitochondrial neurogastrointestinal encephalomyopathy, a rare fatal autosomal recessive disease due to TYMP mutations that result in thymidine phosphorylase deficiency. We conducted a retrospective analysis of all known patients suffering from mitochondrial neurogastrointestinal encephalomyopathy who underwent allogeneic haematopoietic stem cell transplantation between 2005 and 2011. Twenty-four patients, 11 males and 13 females, median age 25 years (range 10-41 years) treated with haematopoietic stem cell transplantation from related (n = 9) or unrelated donors (n = 15) in 15 institutions worldwide were analysed for outcome and its associated factors. Overall, 9 of 24 patients (37.5%) were alive at last follow-up with a median follow-up of these surviving patients of 1430 days. Deaths were attributed to transplant in nine (including two after a second transplant due to graft failure), and to mitochondrial neurogastrointestinal encephalomyopathy in six patients. Thymidine phosphorylase activity rose from undetectable to normal levels (median 697 nmol/h/mg protein, range 262-1285) in all survivors. Seven patients (29%) who were engrafted and living more than 2 years after transplantation, showed improvement of body mass index, gastrointestinal manifestations, and peripheral neuropathy. Univariate statistical analysis demonstrated that survival was associated with two defined pre-transplant characteristics: human leukocyte antigen match (10/10 versus <10/10) and disease characteristics (liver disease, history of gastrointestinal pseudo-obstruction or both). Allogeneic haematopoietic stem cell transplantation can restore thymidine phosphorylase enzyme function in patients with mitochondrial neurogastrointestinal encephalomyopathy and improve clinical manifestations of mitochondrial neurogastrointestinal encephalomyopathy in the long term. Allogeneic haematopoietic stem cell transplantation should be considered for selected patients with an optimal donor.

Post-transplant lymphoproliferative disease in heart and lung transplantation: Defining risk and prognostic factors.

BACKGROUND: Heart and lung transplant recipients have among of the highest incidence rates of post-transplant lymphoproliferative disease (PTLD). Despite this, there is a paucity of data specific to this group. We collated data on heart, lung and heart-lung transplant recipients with PTLD to identify disease features and prognostic factors unique to this group of patients. METHODS: Seventy cases of PTLD were identified from a single institution (41 heart, 22 lung, 6 heart-lung and 1 heart-kidney transplant) from 1984 to 2013. Demographics, immunosuppression, treatment, response, complications and survival data were analyzed. Uni- and multivariate Cox regression analyses were performed to identify prognostic factors. RESULTS: The incidence of PTLD was 7.59% in heart-lung, 5.37% in heart and 3.1% in lung transplant recipients. Extranodal disease (82%) with diffuse large B-cell lymphoma (72%) was the most common presentation. Bone marrow involvement (13%) and central nervous system disease (3%) were uncommon. Heart transplant recipients had later onset of PTLD (>1 year post-transplant), with less allograft involvement, compared with lung and heart-lung recipients. Poor prognostic markers were bone marrow involvement (HR 6.75, p < 0.001) and serum albumin <30 g/liter (HR 3.18, p = 0.006). Improved survival was seen with a complete response within 3 months of treatment (HR 0.08, p < 0.001). Five-year overall survival was 29%. CONCLUSION: This analysis is the largest to date on PTLD in heart and lung transplant recipients. It provides a detailed analysis of the disease in this group of patients and identifies unique prognostic features to aid risk stratification and guide treatment allocation.