Minimal Residual Disease Status Predicts Outcome in Patients With Previously Untreated Follicular Lymphoma: A Prospective Analysis of the Phase III GALLIUM Study

PURPOSE

We report an analysis of minimal residual/detectable disease (MRD) as a predictor of outcome in previously untreated patients with follicular lymphoma (FL) from the randomized, multicenter GALLIUM (ClinicalTrials.gov identifier: NCT01332968) trial.

PATIENTS AND METHODS

Patients received induction with obinutuzumab (G) or rituximab (R) plus bendamustine, or cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) or cyclophosphamide, vincristine, prednisone (CVP) chemotherapy, followed by maintenance with the same antibody in responders. MRD status was assessed at predefined time points (mid-induction [MI], end of induction [EOI], and at 4-6 monthly intervals during maintenance and follow-up). Patients with evaluable biomarker data at diagnosis were included in the survival analysis.

RESULTS

MRD positivity was associated with inferior progression-free survival (PFS) at MI (hazard ratio [HR], 3.03 [95% CI, 2.07 to 4.45]; P < .0001) and EOI (HR, 2.25 [95% CI, 1.53 to 3.32]; P < .0001). MRD response was higher after G- versus R-chemotherapy at MI (94.2% v 88.9%; P = .013) and at EOI (93.1% v 86.7%; P = .0077). Late responders (MI-positive/EOI-negative) had a significantly poorer PFS than early responders (MI-negative/EOI-negative; HR, 3.11 [95% CI, 1.75 to 5.52]; P = .00011). The smallest proportion of MRD positivity was observed in patients receiving bendamustine at MI (4.8% v 16.0% in those receiving CHOP; P < .0001). G appeared to compensate for less effective chemotherapy regimens, with similar MRD response rates observed across the G-chemo groups. During the maintenance period, more patients treated with R than with G were MRD-positive (R-CHOP, 20.7% v G-CHOP, 7.0%; R-CVP, 21.7% v G-CVP, 9.4%). Throughout maintenance, MRD positivity was associated with clinical relapse.

CONCLUSION

MRD status can determine outcome after induction and during maintenance, and MRD negativity is a prerequisite for long-term disease control in FL. The higher MRD responses after G- versus R-based treatment confirm more effective tumor cell clearance.

Obinutuzumab Versus Rituximab Immunochemotherapy in Previously Untreated iNHL: Final Results From the GALLIUM Study

The phase III GALLIUM trial assessed the safety and efficacy of obinutuzumab-based versus rituximab-based immunochemotherapy in patients with previously untreated follicular lymphoma (FL) or marginal zone lymphoma (MZL). At the primary analysis, the trial met its primary end point, demonstrating improvement in investigator-assessed progression-free survival (PFS) with obinutuzumab-based versus rituximab-based immunochemotherapy in patients with FL. We report the results of the final analysis in the FL population, with an additional exploratory analysis in the MZL subgroup. Overall, 1202 patients with FL were randomized 1:1 to obinutuzumab- or rituximab-based immunochemotherapy followed by maintenance with the same antibody for up to 2 years. After a median 7.9 (range, 0.0-9.8) years of follow-up, PFS remained improved with obinutuzumab- versus rituximab-based immunochemotherapy, with 7-year PFS rates of 63.4% versus 55.7% (P = 0.006). Time-to-next antilymphoma treatment was also improved (74.1% versus 65.4% of patients had not started their next antilymphoma treatment at 7 y; P = 0.001). Overall survival was similar between the arms (88.5% versus 87.2%; P = 0.36). Irrespective of the treatment received, PFS and OS were higher in patients with a complete molecular response (CMR) versus those with no CMR (P < 0.001). Serious adverse events were reported in 48.9% and 43.4% of patients in the obinutuzumab and rituximab arms, respectively; there was no difference in the rate of fatal adverse events (4.4% and 4.5%, respectively). No new safety signals were reported. These data demonstrate the long-term benefit of obinutuzumab-based immunochemotherapy and confirm its role as a standard-of-care for the first-line treatment of advanced-stage FL, taking into account patient characteristics and safety considerations.

Factors Affecting the Clinical Course of Follicular Lymphoma: A Multistate Survival Analysis Using Individual Patient Data from Eight Multicenter Randomized Clinical Trials

INTRODUCTION/BACKGROUND

Leveraging the Follicular Lymphoma Analysis of Surrogacy Hypothesis database of individual patient data from first-line clinical trials, we studied the clinical course of follicular lymphoma (FL) and investigated clinical factors associated with FL outcomes.

PATIENTS AND METHODS

We examined 2428 patients from 8 randomized trials using multistate survival models with 4 states: induction treatment, progression, death from FL, and death from other causes. We utilized Aalen-Johansen estimator and Cox models to assess the likelihood of FL outcomes and quantify predictors' effects.

RESULTS

Two-year progression, FL-related death, and death from other causes estimates were 26.5%, 3.4% and 1.4%, respectively. FL-associated deaths were the primary cause of mortality within 10 years of follow-up. Male sex (hazard ratio: 1.25; 95% confidence interval: 1.05-1.47), > 4 involved nodal areas (1.51; 1.23-1.86), elevated LDH (1.20; 1.01-1.43), low hemoglobin (1.44; 1.15-1.81), and elevated β-2 levels (1.23; 1.02-1.47) increased risk of progression. CD20-targeting agents reduced risks for progression (0.29; 0.22-0.39), death from FL (0.05; 0.01-0.20), and death from other causes without progression (0.13; 0.05-0.33) and following progression (0.52; 0.30-0.92). Estimated 2-year progression rates were 22.3% and 43.5% with or without CD20-targeting agents, respectively. Two-year FL-associated mortality rate was 8.3% among patients without CD20-targeting agents, 5.4% with B-symptoms, 4.9% with elevated LDH, and 9.1% with low hemoglobin.

CONCLUSION

This study identified independent contributions of baseline clinical factors to distinct outcomes for patients with FL following first-line therapy on a clinical trial. Similar analytical approaches are needed to increase understanding of factors that influence FL outcomes in other settings.

End of induction positron emission tomography complete response (PET-CR) as a surrogate for progression-free survival in previously untreated follicular lymphoma

Progression-free survival (PFS) has been the regulatory primary end-point for recent phase III trials in first-line follicular lymphoma (FL), but requires prolonged follow-up. Complete response (CR) at 30 months after initiation of induction treatment was validated as surrogate end-point for PFS. Our objective was to further evaluate surrogacy of CR measured by [¹⁸ F] fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging at the end of induction (EoI). Individual patient data were analysed from 1505 patients from five randomized trials. Trial-level surrogacy examining the association between treatment effects on EoI-PET-CR and PFS was evaluated using linear regression ( R WLS 2 $$ {R}_{\mathrm{WLS}}^2 $$ ) and bivariate Copula ( R Copula 2 $$ {R}_{\mathrm{Copula}}^2 $$ ) models. Although EoI-PET-CR strongly predicted PFS at a prognostic level, the trial-level assessment did not show strong correlation ( R WLS 2 = 0.56 $$ {R}_{\mathrm{WLS}}^2=0.56 $$ , confidence interval [CI]: 0.20-0.88; R Copula 2 = 0.35 $$ {R}_{\mathrm{Copula}}^2=0.35 $$ , CI: 0.0-0.82). The high uncertainty in estimation was possibly due to the small number of trials and the population of patients with available PET data. Maintenance therapy affecting PFS beyond induction treatment, but not EoI-PET-CR end-point, may have distorted the association between treatment effects. However, there will probably be a number of additional trials approaching completion with available PET response data. Refined evaluation of PET-CR based surrogate end-points is still warranted.

The MAGNOLIA Trial: Zanubrutinib, a Next-Generation Bruton Tyrosine Kinase Inhibitor, Demonstrates Safety and Efficacy in Relapsed/Refractory Marginal Zone Lymphoma

PURPOSE

Marginal zone lymphoma (MZL) is an uncommon non-Hodgkin lymphoma with malignant cells that exhibit a consistent dependency on B-cell receptor signaling. We evaluated the efficacy and safety of zanubrutinib, a next-generation selective Bruton tyrosine kinase inhibitor, in patients with relapsed/refractory (R/R) MZL.

PATIENTS AND METHODS

Patients with R/R MZL were enrolled in the phase II MAGNOLIA (BGB-3111-214) study. The primary endpoint was overall response rate (ORR) as determined by an independent review committee (IRC) based on the Lugano 2014 classification.

RESULTS

Sixty-eight patients were enrolled. After a median follow-up of 15.7 months (range, 1.6 to 21.9 months), the IRC-assessed ORR was 68.2% and complete response (CR) was 25.8%. The ORR by investigator assessment was 74.2%, and the CR rate was 25.8%. The median duration of response (DOR) and median progression-free survival (PFS) by independent review was not reached. The IRC-assessed DOR rate at 12 months was 93.0%, and IRC-assessed PFS rate was 82.5% at both 12 and 15 months. Treatment was well tolerated with the majority of adverse events (AE) being grade 1 or 2. The most common AEs were diarrhea (22.1%), contusion (20.6%), and constipation (14.7%). Atrial fibrillation/flutter was reported in 2 patients; 1 patient had grade 3 hypertension. No patient experienced major hemorrhage. In total, 4 patients discontinued treatment due to AEs, none of which were considered treatment-related by the investigators.

CONCLUSIONS

Zanubrutinib demonstrated high ORR and CR rate with durable disease control and a favorable safety profile in patients with R/R MZL.

Acceptability, safety, and patterns of use of oral tenofovir disoproxil fumarate and emtricitabine for HIV pre-exposure prophylaxis in South African adolescents: an open-label single-arm phase 2 trial

BACKGROUND

HIV incidence among adolescents in southern Africa remains unacceptably high. Pre-exposure prophylaxis (PrEP) is an effective HIV prevention intervention but there are few data on its implementation among adolescents. We aimed to investigate the safety, feasibility, and acceptability of PrEP with oral tenofovir disoproxil fumarate and emtricitabine as part of a comprehensive HIV prevention package in an adolescent population in South Africa.

METHODS

This open-label single-arm phase 2 study (PlusPills) was done in two research clinics in Cape Town and Johannesburg, South Africa. Adolescents aged 15-19 years were recruited into the study through recruitment events and outreach in the community. Potential participants were eligible for enrolment if they reported being sexually active. Exclusion criteria were a positive test for HIV or pregnancy at enrolment, breastfeeding, or any relevant co-morbidities. Participants were given oral tenofovir disoproxil fumarate and emtricitabine for PrEP to take daily for the first 12 weeks and were then given the choice to opt in or out of PrEP use at three monthly intervals during scheduled clinic visits. Participants were invited to monthly visits for adherence counselling and HIV testing during the study period. The primary outcomes were acceptability, use, and safety of PrEP. Acceptability was measured by the proportion of participants who reported willingness to take up PrEP and remain on PrEP at each study timepoint. Use was defined as the number of participants who continued to use PrEP after the initial 12-week period until the end of the study (week 48). Safety was measured by grade 2, 3, and 4 laboratory and clinical adverse events using the Division of AIDS table for grading the severity of adult and paediatric adverse events, version 1.0. Dried blood spot samples were collected at each study time-point to measure tenofovir diphosphate concentrations. This trial is registered with ClinicalTrials.gov, NCT02213328.

FINDINGS

Between April 28, 2015, and Nov 11, 2016, 244 participants were screened, and 148 participants were enrolled (median age was 18 years; 99 participants [67%] were female) and initiated PrEP. PrEP was stopped by 26 of the 148 (18%) participants at 12 weeks. Cumulative PrEP opt-out, from the total cohort, was 41% (60 of 148 participants) at week 24 and 43% (63 of 148 participants) at week 36. PrEP was well tolerated with only minor adverse events (grade 2) thought to be related to study drug, which included headache (n=4, 3%), gastrointestinal upset (n=8, 5%), and skin rash (n=2, 1%). Two participants (1%) experienced grade 3 weight loss, which was deemed related to the study drug and resolved fully when PrEP was discontinued. Tenofovir diphosphate concentrations were detectable (>16 fmol/punch) in dried blood spot samples in 108 (92%) of 118 participants who reported PrEP use at week 12, in 74 (74%) of 100 participants at week 24, and in 22 (59%) of 37 participants by the study end at week 48.

INTERPRETATION

In this cohort of self-selected South African adolescents at risk of HIV acquisition, PrEP appears safe and tolerable in those who continued use. PrEP use decreased throughout the course of the study as the number of planned study visits declined. Adolescents in southern Africa needs access to PrEP with tailored adherence support and possibly the option for more frequent and flexible visit schedules.

FUNDING

National Institute of Allergy and Infectious Diseases of the US National Institutes of Health.

Follicular Lymphoma Evaluation Index (FLEX): A new clinical prognostic model that is superior to existing risk scores for predicting progression-free survival and early treatment failure after frontline immunochemotherapy

Patients with advanced‐stage follicular lymphoma (FL) who progress early after receiving first‐line therapy have poor overall survival (OS). Currently applied clinical prognostic models such as FL International Prognostic Index [FLIPI], FLIPI‐2 and PRIMA‐Prognostic Index [PRIMA‐PI] have suboptimal sensitivity and specificity to predict this poor prognosis subgroup. The primary objective was to develop a novel prognostic model, the FL Evaluation Index (FLEX) score, to identify high‐risk patients and compare its performance with FLIPI, FLIPI‐2 and PRIMA‐PI. Progression‐free survival (PFS) after first‐line immunochemotherapy was the key endpoint, while OS and progression of disease within 24 months (POD24) were also assessed. The model, which includes nine clinical variables, was developed using a cohort of patients with previously untreated advanced‐stage FL from the phase 3 GALLIUM trial (NCT01332968). The performance of the model was validated using data from the SABRINA trial (NCT01200758). In GALLIUM (n = 1004; 127 with and 877 without POD24), FLEX increased the intergroup (low‐risk/high‐risk) difference in 2‐year and 3‐year PFS rates and demonstrated superior intergroup differences in 2‐year and 3‐year OS rates compared with FLIPI, FLIPI‐2 and PRIMA‐PI. Sensitivity for a high‐risk score to predict POD24 was 60% using FLEX compared with 53% for FLIPI and FLIPI‐2, and 69% for PRIMA‐PI, while specificity was 68% for FLEX compared with 58% for FLIPI, 59% for FLIPI‐2 and 48% for PRIMA‐PI. The prognostic value of FLEX in SABRINA was similar to FLIPI. Therefore, FLEX appears to perform better than existing prognostic models in previously untreated FL, in particular for the newer treatment regimens.

The architecture of neoplastic follicles in follicular lymphoma; analysis of the relationship between the tumor and follicular helper T cells

CD4+ T-follicular helper cells are essential for the survival, proliferation, and differentiation of germinal center B cells and have been implicated in the pathogenesis of follicular lymphoma (FL). To further define the role of these cells in FL, we used multiparameter confocal microscopy to compare the architecture of normal and neoplastic follicles and next generation sequencing to analyze the T-cell receptor repertoire in FL lymph nodes (LN). Multiparameter analysis of LN showed that the proportion of T-follic-ular helper cells (TFH) in normal and neoplastic follicles is the same and that the previously reported increase in TFH numbers in FL is thus due to an increase in the number and not content of follicles. As in normal germinal centers, TFH were shown to have a close spatial correlation with proliferating B cells in neoplastic follicles, where features of immunological synapse formation were observed. The number of TFH in FL correlate with the rate of B-cell proliferation and TFH co-localized to activation induced cytidine deaminase expressing proliferating B cells. T-cell receptor repertoire analysis of FL LN revealed that follicular areas are significantly more clonal when compared to the rest of the LN. These novel findings show that neoplastic follicles and germinal centers share important structural features and provide further evidence that TFH may play a role in driving B-cell proliferation and genomic evolution in TFH Our results also suggest that targeting this interaction would be an attractive therapeutic option.

Comparison of efficacy and safety with obinutuzumab plus chemotherapy versus rituximab plus chemotherapy in patients with previously untreated follicular lymphoma: Updated results from the phase III Gallium Study

8023

Background: Immunochemotherapy is standard of care for patients (pts) with previously untreated advanced stage follicular lymphoma (FL). Four-year data from the Phase III GALLIUM study (NCT01332968) have previously demonstrated an improvement in the primary endpoint of investigator-assessed progression-free survival (PFS) for obinutuzumab (GA101, G) plus chemotherapy (G-chemo) versus rituximab plus chemotherapy (R-chemo) (Townsend et al. ASH 2018). Here, we report efficacy and safety results from an updated analysis. Methods: Eligibility criteria: ≥18 years; advanced stage, previously untreated grade 1–3a FL; requiring treatment according to Groupe d’Etude des Lymphomes Folliculaires criteria. Pts were randomized 1:1 to receive G 1000mg IV (day [D] 1, 8 and 15 of Cycle 1; D1 of each subsequent cycle) or R 375mg/m2 IV (D1 of each cycle) with CHOP, CVP, or bendamustine for 6 or 8 cycles. Responders received maintenance therapy with the same monoclonal antibody every 2 months for 2 years. Results: 1202 pts (median age 59 years) were enrolled (n = 601 per treatment arm). Median duration of follow-up was 76.5 months. Pts receiving G- vs R-chemo demonstrated improved PFS (5-year PFS: hazard ratio [HR] 0.76; 95% CI: 0.62–0.92; p = 0.0043; 70.5% [95% CI: 66.4–74.1] vs 63.2% [95% CI: 59.0–67.1]). There was no notable difference in 5-year overall survival (OS), with few events in either arm (HR 0.87; 95% CI: 0.62–1.22; p = 0.41; G-chemo: 90.2% [95% CI: 87.5–92.4]; R-chemo: 89.4% [95% CI: 86.6–91.6]). Time-to-next-treatment (TTNT) was greater in the G- vs R-chemo arm (5-year TTNT rate: HR 0.72; 95% CI: 0.57–0.90; p = 0.0039; 79.7% [95% CI: 76.1–82.7] vs 72.9% [95% CI: 69.1–76.4]). Incidence of grade 3–5 adverse events was 79.3% in the G-chemo arm and 71.2% in the R-chemo arm, and consistent with those reported in the primary analysis (Marcus et al. N Engl J Med 2017). Conclusions: These data further demonstrate the clinically meaningful and durable benefit of treatment with G-chemo relative to R-chemo in previously untreated FL pts. Acknowledgement: GALLIUM was sponsored by F. Hoffmann-La Roche Ltd. Third-party medical writing assistance, under the direction of William Townsend, was provided by Louise Profit and Stephanie Lacey of Gardiner-Caldwell Communications, and was funded by F. Hoffmann-La Roche Ltd. Clinical trial information: NCT01332968 .

First-line immunochemotherapy for follicular lymphoma in the GALLIUM study: Prognostic value of PET-CT status after long-term follow-up

8025

Background: The prognostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) response assessment following first-line immunochemotherapy for advanced-stage symptomatic follicular lymphoma (FL) was previously demonstrated for patients (pts) enrolled in the Phase III GALLIUM study (NCT01332968; Trotman et al. ICML 2017). Here, we evaluated the association between PET complete metabolic response (CMR) and survival after longer follow-up in this patient population. Methods: In the GALLIUM study, 1202 pts with previously untreated FL were randomized 1:1 to induction therapy of 1000mg obinutuzumab (G; Days 1, 8, 15 of Cycle 1 then Day 1 of subsequent cycles) or 375mg/m2 rituximab (R; Day 1 of each cycle), in combination with chemotherapy (CHOP, CVP, or bendamustine) (Marcus et al. New Engl J Med 2017). PET-CT scans were mandatory, where available, at baseline and end-of-induction (EOI) for the first 170 pts enrolled, and optional thereafter. For this response analysis, the Lugano 2014 criteria were applied by an independent review committee (IRC) (Cheson et al. J Clin Oncol 2014). Associations between EOI PET complete metabolic response (PET-CMR) status and progression-free survival (PFS) and overall survival (OS) were evaluated, with hazard ratios (HR) stratified according to chemotherapy regimen and FL International Prognostic Index. Results: Of the 609 pts with a baseline PET scan, 595 (98%) had detectable lesions. Of these, 519 pts had an EOI PET evaluable by Lugano 2014 criteria. At EOI, per IRC assessment, 450/595 (76%) pts had achieved CMR. Pts with non-available scans were considered as non-responders and were excluded from the landmark (LM) analyses. Pts who died or progressed (CT-based progression assessment) before or at EOI were excluded from the PFS LM analysis; pts who died before EOI were excluded from the OS LM analysis. After a median follow-up of 76.5 months, EOI PET status was highly prognostic for both longer investigator-assessed PFS (non-CMR vs CMR: HR 3.40; 95% CI: 2.33–4.97; p < 0.0001) and longer OS (HR 3.34; 95% CI: 1.81–6.17; p < 0.0001). Six-year investigator-assessed PFS from EOI was 62.6% (95% CI: 57.0–67.6) for CMR pts compared with 23.4% (95% CI: 12.2–36.7) for non-CMR pts; the corresponding OS was 91.3% (95% CI: 88.1–93.6) vs 79.6% (95% CI: 68.0–87.4). Conclusions: With more than 6 years of follow-up, this analysis confirms that after first-line chemoimmunotherapy for FL, achieving CMR on PET-CT is an early and strong predictor of increased PFS and OS. Clinical trial information: NCT01332968 .

Efficacy of adjunctive aripiprazole to lithium or valproate in the long-term treatment of mania in subjects with bipolar i disorder (CN138–189)

Objectives

To evaluate the long-term safety and efficacy of adjunctive aripiprazole (ARI) to lithium (LI) or valproate (VAL) in delaying time to relapse in bipolar I disorder.

Methods

Bipolar I disorder subjects with a current manic or mixed episode received LI or VAL for at least 2 weeks; inadequate responders (YMRS score ≥ 16 and ≤35% decrease from baseline at 2 weeks) received adjunctive ARI. Subjects maintaining mood stability (YMRS and MADRS ≤ 12 for 12 consecutive weeks) were randomised 1:1 to double-blind ARI (10 to 30 mg/day) or placebo (PBO) plus LI or VAL. Relapse was monitored up to 52 weeks.

Results

337 subjects were randomised to continuation of mood stabiliser plus adjunctive ARI or PBO; 61.3% and 52.7%, respectively, completed the study. Adjunctive ARI significantly delayed the time to any relapse, hazard ratio = 0.544 (95% CI: 0.33, 0.89, log-rank p = 0.014). Overall relapse rates at 52 weeks were 14.9% and 25.4% in ARI vs PBO subjects. A superior reduction in CGI-BP Mania Severity of Illness from baseline at 52 weeks was also observed (0.3 vs. 0.0, respectively, p = 0.01). Adverse events generally were as expected per known drug and illness profiles with no significant difference in mean change in body weight between adjunctive PBO (0.60 kg) and adjunctive ARI (1.07 kg) (p = 0.49 Week 52, LOCF).

Conclusion

Continuation of aripiprazole treatment increased time to relapse to any mood episode compared with placebo plus LI/VAL over 1 year, indicating a long-term benefit in continuing adjunctive aripiprazole to a mood stabiliser after sustained remission is achieved.

Phase 2 study of zanubrutinib (BGB-3111) in patients with relapsed/refractory marginal zone lymphoma (R/R MZL)

TPS7568

Background: Bruton tyrosine kinase (BTK) plays a critical role in B-cell receptor signaling, mediating B-cell proliferation, migration, adhesion and survival. BTK inhibition has emerged as a strategy for targeting B-cell malignancies, including MZL. In preclinical studies, zanubrutinib was shown to be a potent, irreversible, highly specific BTK inhibitor with excellent oral bio-availability and favorable pharmacokinetic/pharmacodynamic properties. Clinical data to date have shown that complete and sustained 24-hour BTK occupancy is associated with durable responses and suggested that zanubrutinib is generally well tolerated with low rates of serious adverse events. Preliminary results from the MZL cohort enrolled in the open-label, multicenter, phase 1 study demonstrated responses in 7 of 9 patients for an overall response rate (ORR) of 78%. Cumulative safety data also showed that zanubrutinib monotherapy was associated with infrequent incidence of atrial fibrillation and major hemorrhage and infrequent drug discontinuation due to treatment-related adverse events. This study is designed to evaluate the safety and efficacy of zanubrutinib in patients with R/R MZL. Methods: This ongoing global phase 2, single-arm, open-label study is examining zanubrutinib monotherapy in patients with R/R MZL who have received one or more prior lines of systemic therapy. Patients are treated with oral zanubrutinib at 160 mg twice-daily until progressive disease, unacceptable toxicity, or withdrawal of consent. Eligible patients must have histologically confirmed MZL, have received prior anti-CD20 antibody therapy, and have measurable disease. Disease response is assessed per the 2014 Lugano Classification for non-Hodgkin lymphoma. The primary endpoint is ORR determined by independent review committee (IRC). Key secondary endpoints include ORR by investigator assessment, time to and duration of response, time to treatment discontinuation, progression-free survival (all determined by IRC and investigator assessments), and overall survival and safety. Recruitment is ongoing.

Role of obinutuzumab exposure on clinical outcome of follicular lymphoma treated with first-line immunochemotherapy

AIMS

Obinutuzumab (G) is a humanized type II, Fc-glycoengineered anti-CD20 monoclonal antibody used in various indications, including patients with previously untreated front-line follicular lymphoma. We investigated sources of variability in G exposure and association of progression-free survival (PFS) with average concentration over induction (C_meanIND ) in front-line follicular lymphoma patients treated with G plus chemotherapy (bendamustine, CHOP, or CVP) in the GALLIUM trial.

METHODS

Individual exposures (C_meanIND ) were obtained from a previously established population pharmacokinetic model updated with GALLIUM data. Multivariate Cox proportional hazard models and univariate Kaplan-Meier plots investigated relationships of PFS with exposure and other potential prognostic factors.

RESULTS

Overall, G exposure was lower in high body-weight patients and in males, and slightly lower in patients with high baseline tumour burden. Analysis of clinical outcomes showed that variability in G exposure did not impact PFS in G-bendamustine-treated patients; PFS was inferior in males and patients with FCGR2a/2b T232 T low-affinity receptor variant, and superior in patients with FCGR2a/2b I232T variant. In G-CHOP/CVP arms, PFS improved with increasing C_meanIND (hazard ratio = 1.74 and 0.394 at 5^th and 95^th percentile compared to median C_meanIND ) and was inferior in patients with high baseline tumour size and B symptoms.

CONCLUSIONS

It remains unclear whether for G-CHOP/CVP patients lower G exposure is a consequence of adverse disease biology and/or resistance to chemotherapy backbone (higher clearance in nonresponder patients, as demonstrated for rituximab) rather than being the cause of poorer clinical outcome. A study with >1 dose level of G could help resolve this uncertainty.

Prognostic Impact of Natural Killer Cell Count in Follicular Lymphoma and Diffuse Large B-cell Lymphoma Patients Treated with Immunochemotherapy

PURPOSE

Natural killer (NK) cells are key effector cells for anti-CD20 monoclonal antibodies (mAb), such as obinutuzumab and rituximab. We assessed whether low pretreatment NK-cell count (NKCC) in peripheral blood or tumor tissue was associated with worse outcome in patients receiving antibody-based therapy.

PATIENTS AND METHODS

Baseline peripheral blood NKCC was assessed by flow cytometry (CD3^-CD56⁺ and/or CD16⁺ cells) in 1,064 of 1,202 patients with follicular lymphoma treated with obinutuzumab or rituximab plus chemotherapy in the phase III GALLIUM trial (NCT01332968) and 1,287 of 1,418 patients with diffuse large B-cell lymphoma (DLBCL) treated with obinutuzumab or rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (G-CHOP or R-CHOP) in the phase III GOYA trial (NCT01287741). The prognostic value of tumor NK-cell gene expression, as assessed by whole-transcriptome gene expression using TruSeq RNA sequencing, was also analyzed. The association of baseline variables, such as treatment arm, was evaluated using multivariate Cox regression models using a stepwise approach.

RESULTS

In this exploratory analysis, low baseline peripheral blood NKCC was associated with shorter progression-free survival (PFS) in both follicular lymphoma [hazard ratio (HR), 1.48; 95% confidence interval (CI), 1.02-2.14; P = 0.04] and DLBCL (HR, 1.36; 95% CI, 1.01-1.83; P = 0.04), and overall survival in follicular lymphoma (HR, 2.20; 95% CI, 1.26-3.86; P = 0.0058). Low tumor NK-cell gene expression was associated with shorter PFS in G-CHOP-treated patients with DLBCL (HR, 1.95; 95% CI, 1.22-3.15; P < 0.01).

CONCLUSIONS

These findings indicate that the number of NK cells in peripheral blood may affect the outcome of patients with B-cell non-Hodgkin lymphoma receiving anti-CD20-based immunochemotherapy.

Optimum processing conditions for single cell RNA sequencing on frozen human PBMCs

The field of single cell RNA sequencing (sc-SEQ) has exploded in the past few years. From picking up single cells manually under a microscope, to droplet-based encapsulation of cells using microfluidics – this technology has improved in leaps and bounds. Common droplet-based technologies include inDrop, Drop-seq and 10X Genomics Chromium. All three technologies utilize microfluidics for encapsulating single cells & uniquely barcoded beads within an oil droplet. They differ in their bead material/manufacturing, barcode design and the range to which their operation can be customized by the end user. However, the performance of each sc-SEQ each technology is dependent on factors such as ability to obtain pure, viable single-cell suspension, and ability to accurately quantify the number of cells before running them through the machine. Here, we compare and contrast different conditions for cell processing that can affect single-cell sequencing results – including cell counting and purifying methods, as well as cell subtype enrichment kits; followed by single cell encapsulation, library preparation and analysis using 10X Genomics Chromium workflow.

ACCELERATE and European Medicine Agency Paediatric Strategy Forum for medicinal product development for mature B-cell malignancies in children

Paediatric Strategy Forums have been created by the multistakeholder organisation, ACCELERATE, and the European Medicines Agency to facilitate dialogue between all relevant stakeholders and suggest strategies in critical areas of paediatric oncology drug development. As there are many medicines being developed for B-cell malignancies in adults but comparatively few in children with these malignancies, a Paediatric Strategy Forum was held to discuss the best approach to develop these products for children. It was concluded that as current frontline therapy is highly successful, despite associated acute toxicity, de-escalation of this or substitution of presently used drugs with new medicines can only be undertaken when there is an effective salvage regimen, which is currently not available. Therefore priority should be given to developing treatment for patients with relapsed and refractory mature B-cell lymphomas. The consensus of the clinicians attending the meeting was that CAR T-cells, T-cell engagers and antibody drug conjugates (excluding those with a vinca alkaloid-like drug) presently have the greatest probability of providing benefit in relapse in view of their mechanism of action. However, as producing autologous CAR T-cells currently takes at least 4 weeks, they are not products which could be quickly employed initially at relapse in rapidly progressing mature B-cell malignancies but only for the consolidation phase of the treatment. Global, industry-supported, academic-sponsored studies testing compounds from different pharmaceutical companies simultaneously should be considered in rare populations, and it was proposed that an international working group be formed to develop an overarching clinical trials strategy for these disease groups. Future Forums are planned for other relevant paediatric oncologic diseases with a high unmet medical need and relevant molecular targets.

Association of early disease progression and very poor survival in the GALLIUM study in follicular lymphoma: benefit of obinutuzumab in reducing the rate of early progression

We evaluated early disease progression and its impact on overall survival (OS) in previously untreated follicular lymphoma patients in GALLIUM (clinicaltrials.gov identifier: 01332968), and investigated the effect on early disease progression of the two randomization arms: obinutuzumab-based versus rituximab-based immunochemotherapy. Cause-specific Cox regression was used to estimate the effect of treatment on the risk of disease progression or death due to disease progression within 24 months of randomization and to analyze OS in patients with or without disease progression after 24 months. Mortality in both groups was analyzed 6, 12, and 18 months post randomization (median follow up, 41 months). Fewer early disease progression events occurred in obinutuzumab (57 out of 601) versus rituximab (98 out of 601) immunochemotherapy patients, with an average risk reduction of 46.0% (95%CI: 25.0-61.1%; cumulative incidence rate 10.1% vs. 17.4%). At a median post-progression follow up of 22.6 months, risk of mortality increased markedly following a progression event [HR of time-varying progression status, 25.5 (95%CI: 16.2-40.3)]. Mortality risk was higher the earlier patients progressed within the first 24 months. Age-adjusted HR for OS after 24 months in surviving patients with disease progression versus those without was 12.2 (95%CI: 5.6-26.5). Post-progression survival was similar by treatment arm. In conclusion, obinutuzumab plus chemotherapy was associated with a marked reduction in the rate of early disease progression events relative to rituximab plus chemotherapy. Early disease progression in patients with follicular lymphoma was associated with poor prognosis, with mortality risk higher after earlier progression. Survival post progression did not seem to be influenced by treatment arm.

New Treatment Options in Advanced Stage Follicular Lymphoma

Follicular lymphoma is one of the most common non-Hodgkin's lymphomas with an expected survival of more than 20 years for the majority of patients. This impressive outcome has been achieved with the introduction of immunochemotherapy, as first line treatment with remissions lasting over 8 years, followed by other treatment options at first or subsequent relapse. However, certain groups of patients still have a poor prognosis. In recent years the efficacy of chemotherapy regimens has been augmented by new compounds selectively targeting the cell surface, intracellular pathways, and/or the microenvironment. Some of these are beginning to change the therapeutic landscape. This review summarizes prognostic factors in follicular lymphoma in order to identify patients with greatest medical need for these new treatment options and reviews recent data from prospective clinical studies testing new agents in first-line and relapsed follicular lymphoma. Finally, we assess the current role of immunochemotherapy and discuss the requirements for future clinical trials.