Autologous transplantation as consolidation for high risk aggressive T-cell non-Hodgkin lymphoma: a SWOG 9704 intergroup trial subgroup analysis

Phase II data suggest a benefit to autotransplantation for aggressive T-cell non-Hodgkin lymphoma (T-NHL) in first remission; randomized trials have yet to validate this. We performed a retrospective analysis of aggressive T-NHL patients in the intergroup randomized consolidative autotransplant trial (SWOG 9704). Of the 370 enrolled, 40 had T-NHL: 12 were not randomized due to ineligibility (n = 1), choice (n = 2), or progression (n = 9), leaving 13 randomized to control and 15 to autologous stem cell transplantation (ASCT). Two ASCT patients refused transplant and one failed mobilization. The 5-year landmark PFS/OS estimates for ASCT vs. control groups were 40% vs. 38% (p = .56), and 40% vs. 45% (p = .98), respectively. No difference was seen based on IPI, or histologic subtype. Only 1/7 receiving BCNU-based therapy survived vs. 4/5 receiving TBI. Aggressive T-NHL autotransplanted in first remission did not appear to benefit from consolidative ASCT. This and the 30% who dropped out pre-randomization mostly to progression, suggests that improved induction regimens be developed.

Genomic alterations important for the prognosis in patients with follicular lymphoma treated in SWOG study S0016

Although recent advances in molecular genetics have enabled improved risk classification of follicular lymphoma (FL) using, for example, the m7-FLIPI score, the impact on treatment has been limited. We aimed to assess the prognostic significance of copy-number aberrations (CNAs) and copy-neutral loss of heterozygosity (cnLOH) identified by chromosome genomic-array testing (CGAT) at FL diagnosis using prospectively collected clinical trial specimens from 255 patients enrolled in the SWOG study S0016. The impact of genomic aberrations was assessed for early progression (progressed or died within 2 years after registration), progression-free survival (PFS), and overall survival (OS). We showed that increased genomic complexity (ie, the total number of aberration calls) was associated with poor outcome in FL. Certain chromosome arms were critical for clinical outcome. Prognostic CNAs/cnLOH were identified: whereas early progression was correlated with 2p gain (P = .007; odds ratio [OR] = 2.55 [1.29, 5.03]) and 2p cnLOH (P = .005; OR = 10.9 [2.08, 57.2]), 2p gain specifically encompassing VRK2 and FANCL predicted PFS (P = .01; hazard ratio = 1.80 [1.14, 2.68]) as well as OS (P = .005; 2.40 [1.30, 4.40]); CDKN2A/B (9p) deletion correlated with worse PFS (P = .004, 3.50 [1.51, 8.28]); whereas CREBBP (16p) (P < .001; 6.70 [2.52, 17.58]) and TP53 (17p) (P < .001; 3.90 [1.85, 8.31]) deletion predicted worse OS. An independent cohort from the m7-FLIPI study was explored, and the prognostic significance of aberration count, and TP53 and CDKN2A/B deletion were further validated. In conclusion, assessing genomic aberrations at FL diagnosis with CGAT improves risk stratification independent of known clinical parameters, and provides a framework for development of future rational targeted therapies.

Barriers and facilitators to attendance at Type 2 diabetes structured education programmes: a qualitative study of educators and attendees

AIMS

Attendance at structured diabetes education has been recommended internationally for all people with Type 2 diabetes. However, attendance rates are consistently low. This qualitative study aimed to explore experiences of attending and delivering Type 2 diabetes structured education programmes in Ireland and barriers and facilitators to attendance.

METHODS

People with Type 2 diabetes who had attended one of the three programmes delivered in Ireland and educators from the three programmes took part in semi-structured telephone interviews. Interviews were audio-taped, transcribed and analysed using inductive thematic analysis.

RESULTS

Twelve attendees and 14 educators were interviewed. Two themes were identified in relation to experiences of programme attendance and delivery: 'Structured education: addressing an unmet need' and 'The problem of non-attendance'. The third theme 'Barriers to attendance: can't go, won't go, don't know and poor system flow' outlined how practicalities of attending, lack of knowledge of the existence and benefits, and limited resources and support for education within the diabetes care pathway impacts on attendance. The final theme 'Supporting attendance: healthcare professionals and the diabetes care pathway' describes facilitators to participants' attendance and the strategies educators perceived to be important in increasing attendance.

CONCLUSIONS

Healthcare professionals have an important role in improving attendance at structured diabetes education programmes. Improving attendance may require promotion by healthcare professionals and for education to be better embedded and supported within the diabetes care pathway.

Five-year follow-up of lenalidomide plus rituximab as initial treatment of mantle cell lymphoma

We report 5-year follow-up of a multicenter phase 2 study of lenalidomide plus rituximab (LR) as initial treatment of mantle cell lymphoma (MCL). The regimen includes induction and maintenance with the LR doublet. Treatment was continuous until progression, with optional discontinuation after 3 years. The median age of the 38 participants was 65 years, with MCL international prognostic index scores balanced among low, intermediate, and high risk (34%, 34%, and 32%, respectively). Twenty-seven (75%) of the 36 evaluable patients completed ≥3 years of study treatment. At a median follow-up of 64 months (range, 21-78), the 3-year progression-free survival (PFS) and overall survival (OS) were 80% and 90%, respectively, with 5-year estimated PFS and OS of 64% and 77%, respectively. During maintenance, hematologic adverse events (AEs) included asymptomatic grade 3 or 4 cytopenias (42% neutropenia, 5% thrombocytopenia, 3% anemia) and mostly grade 1 or 2 infections managed in the outpatient setting (45% upper respiratory infection, 21% urinary tract infection, 13% sinusitis, 11% cellulitis, 8% pneumonia). Nonhematologic AEs, such as constitutional and inflammatory symptoms, occurred at reduced frequency and intensity compared with induction. A peripheral blood minimal residual disease (MRD) assay (clonoSEQ) showed MRD-negative complete remission in 8 of 10 subjects who had completed ≥3 years of treatment and with available samples for analysis. With longer follow-up, LR continues to demonstrate durable responses and manageable safety as initial induction and maintenance therapy for MCL (ClinicalTrials.gov NCT01472562).

CD47 Blockade by Hu5F9-G4 and Rituximab in Non-Hodgkin's Lymphoma

BACKGROUND

The Hu5F9-G4 (hereafter, 5F9) antibody is a macrophage immune checkpoint inhibitor blocking CD47 that induces tumor-cell phagocytosis. 5F9 synergizes with rituximab to eliminate B-cell non-Hodgkin's lymphoma cells by enhancing macrophage-mediated antibody-dependent cellular phagocytosis. This combination was evaluated clinically.

METHODS

We conducted a phase 1b study involving patients with relapsed or refractory non-Hodgkin's lymphoma. Patients may have had diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma. 5F9 (at a priming dose of 1 mg per kilogram of body weight, administered intravenously, with weekly maintenance doses of 10 to 30 mg per kilogram) was given with rituximab to determine safety and efficacy and to suggest a phase 2 dose.

RESULTS

A total of 22 patients (15 with DLBCL and 7 with follicular lymphoma) were enrolled. Patients had received a median of 4 (range, 2 to 10) previous therapies, and 95% of the patients had disease that was refractory to rituximab. Adverse events were predominantly of grade 1 or 2. The most common adverse events were anemia and infusion-related reactions. Anemia (an expected on-target effect) was mitigated by the strategy of 5F9 prime and maintenance dosing. Dose-limiting side effects were rare. A selected phase 2 dose of 30 mg of 5F9 per kilogram led to an approximate 100% CD47-receptor occupancy on circulating white and red cells. A total of 50% of the patients had an objective (i.e., complete or partial) response, with 36% having a complete response. The rates of objective response and complete response were 40% and 33%, respectively, among patients with DLBCL and 71% and 43%, respectively, among those with follicular lymphoma. At a median follow-up of 6.2 months among patients with DLBCL and 8.1 months among those with follicular lymphoma, 91% of the responses were ongoing.

CONCLUSIONS

The macrophage checkpoint inhibitor 5F9 combined with rituximab showed promising activity in patients with aggressive and indolent lymphoma. No clinically significant safety events were observed in this initial study. (Funded by Forty Seven and the Leukemia and Lymphoma Society; ClinicalTrials.gov number, NCT02953509 .).

Double hit and double expressors in lymphoma: Definition and treatment

Emerging biologic subsets and new prognostic markers are significantly and adversely affecting curability after standard chemoimmunotherapy for aggressive B-cell lymphomas. The identification of concurrent MYC and B-cell CLL/lymphoma 2 (BCL2) deregulation, whether at a genomic or protein level, has opened a new era of investigation within the most common subtype of aggressive B-cell lymphomas. Double-hit lymphoma (DHL), defined as a dual rearrangement of MYC and BCL2 and/or B-cell CLL/lymphoma 6 (BCL6) genes, is an uncommon subset accounting for 5% to 7% of all diffuse large B-cell lymphomas (DLBCLs), and long-term survivors are rare. Double-expressor lymphoma (DEL), defined as overexpression of MYC and BCL2 proteins not related to underlying chromosomal rearrangements, is not a distinct entity in the current World Health Organization classification but accounts for 20% to 30% of DLBCL cases and also has poor outcomes. There are many practical considerations related to identifying, determining the prognosis of, and managing DHL and DEL.

Multicenter Phase II Study of Sequential Brentuximab Vedotin and Doxorubicin, Vinblastine, and Dacarbazine Chemotherapy for Older Patients With Untreated Classical Hodgkin Lymphoma

PURPOSE

To improve the curability of older patients with newly diagnosed Hodgkin lymphoma.

PATIENTS AND METHODS

We conducted a multicenter phase II study that administered brentuximab vedotin (Bv) sequentially before and after standard doxorubicin, vinblastine, and dacarbazine (AVD) for untreated patients with Hodgkin lymphoma age 60 years or older. After two lead-in doses of single-agent Bv (1.8 mg/kg once every 3 weeks), patients received six cycles of AVD chemotherapy followed by four consolidative doses of Bv in responding patients.

RESULTS

Patient characteristics included median age of 69 years (range, 60 to 88 years), 63% male, median Eastern Cooperative Oncology Group performance status 1, 81% stage III to IV disease, 60% International Prognostic Score 3 to 7, median Cumulative Illness Rating Scale-Geriatric comorbidity score of 7 (52% grade 3 to 4); and 12% had loss of instrumental activities of daily living at diagnosis. Thirty-seven (77%) of 48 patients completed six cycles of AVD, and 35 patients (73%) received at least one Bv consolidation. Overall response and complete remission rates after initial Bv lead-in dose were 18 (82%) of 22 and 8 (36%) of 22, respectively, and 40 (95%) of 42 and 34 (90%) of 42, respectively, after six cycles of AVD among 42 response-evaluable patients. Twenty (42%) of 48 patients experienced a grade 3 to 4 adverse event, most commonly neutropenia (44%), febrile neutropenia and pneumonia (8%), or diarrhea (6%); 33% had grade 2 peripheral neuropathy, which was reversible in a majority of patients. By intent-to-treat, the 2-year event-free survival, progression-free survival, and overall survival rates were 80%, 84%, and 93%, respectively. Furthermore, 2-year progression-free survival rates for patients with a Cumulative Illness Rating Scale-Geriatric comorbidity score of ≥ 10 versus < 10 were 45% versus 100%, respectively (P < .001), and with baseline loss versus no loss of instrumental activities of daily living were 25% versus 94% (P < .001), respectively, the latter persisting on multivariable analyses.

CONCLUSION

Altogether, sequential Bv-AVD was well tolerated and was associated with robust outcomes. Furthermore, geriatric-based measures were strongly associated with patient survival.

A phase I/II trial of vorinostat (SAHA) in combination with rituximab-CHOP in patients with newly diagnosed advanced stage diffuse large B-cell lymphoma (DLBCL): SWOG S0806

Loss of major histocompatibility Class II expression (MHCII) in diffuse large B-cell lymphoma (DLBCL) correlates with decreased survival. MHCII transcription is in part regulated by histone acetylation. We tested the hypothesis that combination of histone deacetylase inhibitor (HDACI) with standard chemotherapy would improve outcomes in DLBCL in part through increased MHCII expression. S0806 was a single arm phase I/II trial of vorinostat given at 400 mg po daily on days 1-9 (subsequently amended to days 1-5 due to toxicity), combined with R-CHOP given on day 3 of a 21-day cycle for 8 cycles, with primary phase II endpoint of 2-year progression free survival (PFS). With 72 evaluable patients, at median follow up of 3 years, 2-year PFS estimate was 73%, and OS estimate was 86%. Considering that the regimen fell short of predefined efficacy improvement and was associated with high rates of febrile neutropenia (38%) and sepsis (19%), it cannot be recommended for general use. Consistent with our hypothesis, patients with low MCHII expression on S0806 had numerically superior outcomes compared to those from trial S0433 which did not use an HDACI, but the difference was not statistically significant. Current studies are focused on finding biomarkers of response to HDACI.

An update in treating transformed lymphoma

Indolent lymphomas typically have a prolonged course and favorable prognosis. Recent data support survival times that can reach several decades, even if periodic treatment is needed to manage symptoms or stabilize disease. However, all indolent lymphomas have the potential to undergo transformation to an aggressive phenotype, clinically characterized by a rapid progression of adenopathy, new-onset constitutional symptoms, or laboratory abnormalities, and the immediate need for therapeutic intervention. The most common scenario is transformation of follicular lymphoma to either diffuse large B-cell lymphoma or high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 translocations; however, other indolent subtypes such as marginal zone lymphoma, lymphoplasmacytic lymphoma, small lymphocytic lymphoma/chronic lymphocytic leukemia, or even nodular lymphocyte predominant Hodgkin lymphoma, can undergo similar histologic transformation. The prognosis of transformed lymphomas has historically been quite poor, but there is ample evidence this is changing in the rituximab era. This article will provide a review of transformed lymphomas with an emphasis on treatment and the nuances of diagnosis and clinical management. Unless otherwise specified, all discussion in this review pertains to transformed follicular lymphoma which is the more common scenario and the subtype with the most robust data. In many cases, this information can be extrapolated and applied to other indolent histologies (i.e. transformed marginal zone lymphoma); however, several other clinical scenarios, such as Richter's transformation and "double hit" transformations, warrant a distinct discussion and will be reviewed separately.

Supporting prescribing in Irish primary care: protocol for a non-randomised pilot study of a general practice pharmacist (GPP) intervention to optimise prescribing in primary care

Background

Prescribing for patients taking multiple medicines (i.e. polypharmacy) is challenging for general practitioners (GPs). Limited evidence suggests that the integration of pharmacists into the general practice team could improve the management of these patients. The aim of this study is to develop and test an intervention involving pharmacists, working within GP practices, to optimise prescribing in Ireland, which has a mixed public and private primary healthcare system.

Methods

This non-randomised pilot study will use a mixed-methods approach. Four general practices will be purposively sampled and recruited. A pharmacist will join the practice team for 6 months. They will participate in the management of repeat prescribing and undertake medication reviews (which will address high-risk prescribing and potentially inappropriate prescribing, deprescribing and cost-effective and generic prescribing) with adult patients. Pharmacists will also provide prescribing advice regarding the use of preferred drugs, undertake clinical audits, join practice team meetings and facilitate practice-based education. Throughout the 6-month intervention period, anonymised practice-level medication (e.g. medication changes) and cost data will be collected. A nested Patient Reported Outcome Measure (PROM) study will be undertaken during months 4 and 5 of the 6-month intervention period to explore the impact of the intervention in older adults (aged ≥ 65 years). For this, a sub-set of 50 patients aged ≥ 65 years with significant polypharmacy (≥ 10 repeat medicines) will be recruited from each practice and invited to a medication review with the pharmacist. PROMs and healthcare utilisation data will be collected using patient questionnaires, and a 6-week follow-up review conducted. Acceptability of the intervention will be explored using pre- and post-intervention semi-structured interviews with key stakeholders. Quantitative and qualitative data analysis will be undertaken and an economic evaluation conducted.

Discussion

This non-randomised pilot study will provide evidence regarding the feasibility and potential effectiveness of general practice-based pharmacists in Ireland and provide data on whether a randomised controlled trial of this intervention is indicated. It will also provide a deeper understanding as to how a pharmacist working as part of the general practice team will affect organisational processes and professional relationships in a mixed public and private primary healthcare system.

Abstract 699: Pd-l1 gene alterations identify a subset of diffuse large B cell lymphoma harboring a T cell inflamed phenotype

Programmed death – ligand 1 (PD-L1) expression on malignant cells is a dominant immune escape mechanism across a variety of human cancers, and classically occurs as an adaptive response to the presence of activated T cells and interferon gamma (IFN-γ) in the tumor environment. Interestingly, a unique genetic mechanism underlying PD-L1 up-regulation has been described in classical Hodgkin lymphoma (cHL) and in uncommon variants of diffuse large B cell lymphoma (DLBCL), in which the chromosomal region (9p24.1) encoding the PD-1 ligands is highly amplified. While chromosome 9p24.1 copy number alterations (CNA) are ubiquitous in cHL, which is exquisitely sensitive to PD-1 blockade therapy, they also occur in DLBCL, albeit with a lower incidence. Here, FISH was utilized to identify DLBCLs harboring pd-l1 CNA, thereby enabling a characterization the immunogenomic landscape of these lymphomas compared to those lacking pd-l1 CNA. Among 76 DLBCLs analyzed, 25% harbored pd-l1 CNA (12 copy gain, 6 amplified, 1 translocation). Pd-l1 CNA were highly enriched among DLBCLs with an activated B cell (ABC) phenotype (75%). PD-L1 cell surface expression was strikingly enhanced in DLBCLs with pd-l1 CNA versus those without, as assessed by PD-L1 H score. Furthermore, pd-l1 CNA were associated with a pronounced infiltration of DLBCLs by T cells with a restricted T cell receptor (TCR) – beta (β) repertoire, suggesting that lymphoma antigen-specific T cells had expanded in these samples. RNA-sequencing of pd-l1 gene-altered versus non-altered DLBCLs revealed differential expression of pd-l1, as well as genes involved in T cell and cytokine signaling in the former, indicating that pd-l1 gene-amplified DLBCLs have been subjected to host immune surveillance. Lastly, whole exome sequencing (WES) of pd-l1 gene altered versus non-altered DLBCLs to identify potential differences in mutational loads and profiles is ongoing. Collectively, our results indicate that pd-l1 CNA identify a unique biological subset of DLBCL that has activated an endogenous anti-lymphoma immune response, and that may be more likely to respond to checkpoint blockade therapy with anti-PD-1 antibodies. We propose that a straightforward FISH analysis for pd-l1 gene amplification may be useful as a predictive biomarker for immunotherapy responsiveness in DLBCL.

Citation Format: Justin Paul Kline, James Godfrey, Sravya Tumuluru, Girish Venkataraman, Riyue Bao, Sonali M. Smith. Pd-l1 gene alterations identify a subset of diffuse large B cell lymphoma harboring a T cell inflamed phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 699.

Autologous transplantation versus allogeneic transplantation in patients with follicular lymphoma experiencing early treatment failure

BACKGROUND

Early treatment failure (ETF) in follicular lymphoma (FL), defined as relapse or progression within 2 years of frontline chemoimmunotherapy, is a newly recognized marker of poor survival and identifies a high-risk group of patients with an expected 5-year overall survival (OS) rate of approximately 50%. Transplantation is an established option for relapsed FL, but its efficacy in this specific ETF FL population has not been previously evaluated.

METHODS

This study compared autologous hematopoietic stem cell transplantation (auto-HCT) with either matched sibling donor (MSD) or matched unrelated donor (MUD) allogeneic hematopoietic cell transplantation (allo-HCT) as the first transplantation approach for patients with ETF FL (age ≥ 18 years) undergoing auto-HCT or allo-HCT between 2002 and 2014. The primary endpoint was OS. The secondary endpoints were progression-free survival, relapse, and nonrelapse mortality (NRM).

RESULTS

Four hundred forty FL patients had ETF (auto-HCT, 240; MSD hematopoietic stem cell transplantation [HCT], 105; and MUD HCT, 95). With a median follow-up of 69 to 73 months, the adjusted probability of 5-year OS was significantly higher after auto-HCT (70%) or MSD HCT (73%) versus MUD HCT (49%; P = .0008). The 5-year adjusted probability of NRM was significantly lower for auto-HCT (5%) versus MSD (17%) or MUD HCT (33%; P < .0001). The 5-year adjusted probability of disease relapse was lower with MSD (31%) or MUD HCT (23%) versus auto-HCT (58%; P < .0001).

CONCLUSIONS

Patients with high-risk FL, as defined by ETF, undergoing auto-HCT for FL have low NRM and a promising 5-year OS rate (70%). MSD HCT has lower relapse rates than auto-HCT but similar OS. Cancer 2018;124:2541-51. © 2018 American Cancer Society.

Autologous Transplantation in Follicular Lymphoma with Early Therapy Failure: A National LymphoCare Study and Center for International Blood and Marrow Transplant Research Analysis

Patients with follicular lymphoma (FL) experiencing early therapy failure (ETF) within 2 years of frontline chemoimmunotherapy have poor overall survival (OS). We analyzed data from the Center for International Blood and Marrow Transplant Research (CIBMTR) and the National LymphoCare Study (NLCS) to determine whether autologous hematopoietic cell transplant (autoHCT) can improve outcomes in this high-risk FL subgroup. ETF was defined as failure to achieve at least partial response after frontline chemoimmunotherapy or lymphoma progression within 2 years of frontline chemoimmunotherapy. We identified 2 groups: the non-autoHCT cohort (patients from the NLCS with ETF not undergoing autoHCT) and the autoHCT cohort (CIBMTR patients with ETF undergoing autoHCT). All patients received rituximab-based chemotherapy as frontline treatment; 174 non-autoHCT patients and 175 autoHCT patients were identified and analyzed. There was no difference in 5-year OS between the 2 groups (60% versus 67%, respectively; P = .16). A planned subgroup analysis showed that patients with ETF receiving autoHCT soon after treatment failure (≤1 year of ETF; n = 123) had higher 5-year OS than those without autoHCT (73% versus 60%, P = .05). On multivariate analysis, early use of autoHCT was associated with significantly reduced mortality (hazard ratio, .63; 95% confidence interval, .42 to .94; P = .02). Patients with FL experiencing ETF after frontline chemoimmunotherapy lack optimal therapy. We demonstrate improved OS when receiving autoHCT within 1 year of treatment failure. Results from this unique collaboration between the NLCS and CIBMTR support consideration of early consolidation with autoHCT in select FL patients experiencing ETF.

Peripheral T cell lymphoma, not otherwise specified (PTCL-NOS). A new prognostic model developed by the International T cell Project Network

Different models to investigate the prognosis of peripheral T cell lymphoma not otherwise specified (PTCL‐NOS) have been developed by means of retrospective analyses. Here we report on a new model designed on data from the prospective T Cell Project. Twelve covariates collected by the T Cell Project were analysed and a new model (T cell score), based on four covariates (serum albumin, performance status, stage and absolute neutrophil count) that maintained their prognostic value in multiple Cox proportional hazards regression analysis was proposed. Among patients registered in the T Cell Project, 311 PTCL‐NOS were retained for study. At a median follow‐up of 46 months, the median overall survival (OS) and progression‐free survival (PFS) was 20 and 10 months, respectively. Three groups were identified at low risk (LR, 48 patients, 15%, score 0), intermediate risk (IR, 189 patients, 61%, score 1–2), and high risk (HiR, 74 patients, 24%, score 3–4), having a 3‐year OS of 76% [95% confidence interval 61–88], 43% [35–51], and 11% [4–21], respectively (P < 0·001). Comparing the performance of the T cell score on OS to that of each of the previously developed models, it emerged that the new score had the best discriminant power. The new T cell score, based on clinical variables, identifies a group with very unfavourable outcomes.

R-CHOP, radioimmunotherapy, and maintenance rituximab in untreated follicular lymphoma (SWOG S0801): a single-arm, phase 2, multicentre study

BACKGROUND

Despite an abundance of therapeutic options, advanced-stage follicular lymphoma remains incurable. Furthermore, the ideal sequence and absolute benefit of post-induction therapy is unclear. We designed SWOG S0801 to assess the efficacy and safety of consolidative radioimmunotherapy and sequential maintenance rituximab following chemoimmunotherapy.

METHODS

For this single-arm, phase 2, multicentre study, we enrolled patients aged 18 years and older with a diagnosis of stage III, IV, or bulky stage II follicular lymphoma, grades 1, 2, or 3a, who had not received previous therapy, from from 20 institutions within the United States National Cancer Institute Clinical Trials Network. Patients were assigned to a 5-year treatment plan consisting of R-CHOP (rituximab plus cyclophosphamide [750 mg/m2], doxorubicin [50 mg/m2], vincristine [1·4 mg/m2], and prednisone or prednisolone [100 mg]) every 21 days for up to six cycles, with rituximab 375 mg/m2 given on day 1 of cycles 1-4, followed by 131iodine tositumomab radioimmunotherapy and subsequent maintenance rituximab 375 mg/m2 within 12 weeks after the sixth cycle of R-CHOP, every 3 months for up to 4 years. The primary endpoint was 3-year progression-free survival in the intention-to-treat population. Efficacy and safety analyses were done in the intention-to-treat population and the per-protocol population. This trial was registered with ClinicalTrials.gov, number NCT00770224.

FINDINGS

Between April 1, 2009, and Dec 15, 2010, we enrolled 84 evaluable patients, of whom 73 completed R-CHOP and radioimmunotherapy. Of 69 patients who registered to maintenance therapy, only 41 completed the 4-year rituximab maintenance treatment. Progression-free survival at 3 years was 90% (95% CI 82-95). The most common grade 3 or worse adverse events included neutropenia in 48 (57%) patients, leucopenia in 34 (40%) patients, thrombocytopenia in 17 (20%) patients, and febrile neutropenia in 14 (17%) patients. Nine patients had possible treatment-related deaths during the study from secondary or unknown causes (n=3), cirrhosis (n=1), cardiac arrest (n=1), and secondary malignancies (n=4). Secondary malignancies occurred in seven patients, including two sarcomas, two colorectal carcinomas, two acute myelogenous leukaemias, and one case of renal-cell carcinoma.

INTERPRETATION

SWOG S0801 showed near universal responses following chemoimmunotherapy and radioimmunotherapy. However, most discontinuations occurred during maintenance therapy, suggesting that rituximab over a 4-year span is not feasible for many patients. Nonetheless, this sequential therapeutic strategy resulted in good overall outcomes for patients, including a low incidence of early disease progression.

FUNDING

The National Cancer Institute and GlaxoSmithKline.