Swinnen, Lode J.

Abstract Background: Positive interim PET scans have been associated with inferior outcomes in DLBCL treated with chemotherapy, alone or with rituximab. In the ECOG 3404 study for bulky and advanced DLBCL, PET scans at baseline and after 3 R-CHOP are centrally reviewed by a single reader; those with positive scans cross-over to R-ICE after 4 R-CHOP, whereas those with negative scans continue on R-CHOP. The primary endpoint of E3404 is progression-free survival. To determine the reproducibility of interim PET scan interpretation, we convened an expert panel. Methods: Three external nuclear medicine physicians visually scored baseline and interim PET scans independently and blinded to other clinical information or outcome. ECOG study criteria were binary (0,1) based on residual disease in initially involved sites with uptake greater than the liver. London criteria were on a scale of 0–5, where 4–5 was positive, based on increased uptake relative to the liver. Overall scores and agreement among experts were evaluated for both criteria, with application of the kappa statistic to correct for chance. Results: Using the ECOG criteria, external reviewers were in complete agreement in 68% of 38 interim scans and completely agreed with the central review in the same 68% cases. Agreement among the experts was 71% employing the London criteria in these cases. The range of PET+ interim scans by reviewer was 16.8% to 34.2% (p=NS) by both ECOG and London criteria. The kappa statistic for overall pairwise correlation between readers was 0.445 (0.396–0.533) using ECOG and 0.502 (0.396–0.630) using London criteria – indicating moderate consistency. Areas of disagreement often, but not exclusively, related to bone disease, the shape and focality of residual uptake, splenic disease, and rare scans without CT-fusion. Conclusions: These data show that visual criteria, either ECOG or London in this series, for interim PET results are moderately reproducible among individual nuclear medicine experts. Our finding of variability among experts indicates the need for caution in interpreting interim PET results in studies and in practice. Review of all E3404 cases is planned after accrual is completed (projected 12/08). Other ongoing studies evaluating interim PET after 1–3 cycles of therapy, the application of quantitative criteria, and consensus panels may provide further valuable information.

Introduction Limited stage disease accounts for 30-40% of Diffuse Large B-cell Lymphoma (DLBCL), with better overall survival than advanced stage disease, but with increased late relapses regardless of treatment strategy (Stephens 2016). Preferred treatment for these patients (pts) per NCCN guidelines is abbreviated R-CHOP followed by radiotherapy. Based on promising results of radioimmunotherapy consolidation in SWOG S0313 (Persky 2015), and of PET-directed experience by the BC Cancer Agency (Sehn 2011), we designed a National Clinical Trials Network (NCTN) PET-directed study to tailor therapy after 3 cycles of R-CHOP, to improve outcomes and decrease toxicities. Methods Pts had non-bulky (< 10 cm) stage I/II untreated DLBCL. Mediastinal, HIV-associated, testicular, central nervous system, and indolent lymphoma were excluded. Pts received standard R-CHOP therapy and had an interim PET scan on day 15-18 of cycle 3, which was centrally reviewed in real time. Pts with negative PET scan (Deauville 1-3, iPET-neg) proceeded with 1 additional cycle of R-CHOP. Pts with positive PET scan (Deauville 4-5, iPET-pos) initiated 36 Gy of involved field radiation therapy (IFRT), plus additional boost to FDG-avid area up to 9 Gy, within 5 weeks of 3rd cycle of R-CHOP. This was followed by ibritumomab tiuxetan (IFRT-Zevalin) 3-6 weeks after completing IFRT. Final PET scan was performed 12 weeks after treatment completion. Results The study completed accrual in June 2016. Safety, response, interim PET, and immunohistochemistry-based cell of origin (COO) and MYC/BCL2 analyses were presented previously (Persky 2017, Stephens 2017). Of 159 pts enrolled, 1 was upstaged by PET, and 26 pts were ineligible - due to incorrect histology (mostly concurrent indolent or follicular lymphoma grade 3B) (21), lack of diagnostic tissue submission for central pathology review (3), and bulky disease (2). In 132 eligible pts, median age was 62 years, 62% had stage I, 17% had B symptoms, 14% had elevated LDH, 43% had extranodal involvement, and 66% had exclusive involvement of the head and neck region. Stage modified IPI (smIPI, Miller 1998) was 0 in 27%, 1 in 42%, 2 in 28%, and 3 in 4% of the pts. COO by Lymph2Cx was assessable in 87 pts - 68% were GCB, 23% were ABC, and 9% were unclassifiable. Double protein expressers (MYC and BCL2, DPE) were 16%, while 4 (3%) pts had "double hit" lymphoma (DHL) - 2 with MYC/BCL2 and 2 with MYC/BCL6 rearrangements - none of which were DPE. Of 132 eligible pts, 128 had an interim PET scan centrally reviewed, of which 110 were iPET-neg. Only 18 were iPET-pos, 4 of them due to infection (Deauville X) which were treated as iPET-neg. Of 14 truly iPET-pos pts (11%), 2 refused radiation, and 12 pts received IFRT-Zevalin. Eight pts (67%) converted from PR to CR after IFRT-Zevalin and 4 (33%) had PR, for an overall CR of 92% and PR of 4% (with 4% unevaluable). With median follow up of 4.5 yrs (range 1.1 - 7.5 yrs), only 5 pts progressed and 2 died from lymphoma. Of 5 progressors, 3 received R-CHOP x 4, 1 was iPET-pos but declined radiation, and 1 went off treatment after 1 cycle of R-CHOP. Eleven pts died from non-lymphoma causes, including 1 pt from secondary AML (iPET-neg arm), and 1 of lung adenocarcinoma diagnosed upon iPET. S1001 5-yr PFS estimate is 87% and OS estimate is 90% (figure 1), with iPET-pos and iPET-neg pts having similar outcomes - PFS 86% vs. 88%, OS 93% vs. 91%, respectively. Five-yr PFS by smIPI was 97% for smIPI of 0, 86% for 1-2, and 30% for 3. GCB had 5-yr PFS of 95%, vs. 70% for ABC and 47% for unclassifiable. DPE pts had 5-yr PFS of 70, vs. 89% for non-DPE pts. All 4 DHL pts maintain remission. Conclusions S1001 is the largest US study of limited stage DLBCL in the rituximab era, with best NCTN results in this disease subset. Only 5 patients progressed and 2 died from lymphoma. Our study confirms the distinct biology of limited stage DLBCL, with predominance of GCB origin (68%), and head and neck location (66%). Due to small number of lymphoma events, no strong conclusions about prognostic ability of smIPI, COO, DPE, or DHL, could be made. S1001 demonstrated that 89% of pts maintained excellent outcomes after R-CHOP x 4 with PET-directed therapy. Only 11% of pts were iPET-pos and required radiation, but they also had excellent outcomes. Together with the FLYER trial in younger pts (Poeschel 2018), this NCTN trial establishes R-CHOP x 4 alone as the new standard approach to limited stage disease for majority of the pts. Disclosures Persky: Sandoz: Consultancy; Morphosys: Other: Member, Independent Data Monitoring Committee; Debiopharm: Other: Member, Independent Data Monitoring Committee; Bayer: Consultancy. Stephens:Acerta: Research Funding; Karyopharm: Research Funding; Gilead: Research Funding. Park:BMS: Consultancy, Research Funding; Rafael Pharma: Membership on an entity's Board of Directors or advisory committees; G1 Therapeutics: Consultancy; Teva: Consultancy, Research Funding; Gilead: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau. Bartlett:Seattle Genetics: Research Funding; ADC Therapeutics: Consultancy, Research Funding; Pfizer: Research Funding; Millenium: Research Funding; Bristol-Myers Squibb: Research Funding; Celgene: Research Funding; Genenetech: Research Funding; Immune Design: Research Funding; Gilead: Research Funding; Forty Seven: Research Funding; Janssen: Research Funding; Affimed: Research Funding; Merck: Research Funding; Pharmacyclics: Research Funding. Swinnen:Pharmacyclics: Consultancy; AbbVie: Consultancy. Barr:Celgene: Consultancy; Merck: Consultancy; Seattle Genetics: Consultancy; Genentech: Consultancy; Verastem: Consultancy; Gilead: Consultancy; Astra Zeneca: Consultancy, Research Funding; Janssen: Consultancy; AbbVie: Consultancy; Pharmacyclics LLC, an AbbVie company: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding. Leonard:Nordic Nanovector: Consultancy; Akcea Therapeutics: Consultancy; BeiGene: Consultancy; Gilead: Consultancy; Miltenyi: Consultancy; ADC Therapeutics: Consultancy; Nordic Nanovector: Consultancy; Akcea Therapeutics: Consultancy; Sandoz: Consultancy; ADC Therapeutics: Consultancy; Miltenyi: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy; Karyopharm Therapeutics: Consultancy; Epizyme, Inc: Consultancy; Sutro Biopharma: Consultancy; AstraZeneca: Consultancy; AstraZeneca: Consultancy; Bayer Corporation: Consultancy; Bayer Corporation: Consultancy; Celgene: Consultancy; Epizyme, Inc: Consultancy; Celgene: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy; Merck: Consultancy; MorphoSys: Consultancy; Karyopharm Therapeutics: Consultancy; Gilead: Consultancy; Sutro Biopharma: Consultancy; BeiGene: Consultancy; Merck: Consultancy; MorphoSys: Consultancy; Sandoz: Consultancy. Kahl:TG Therapeutics: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Seattle Genetics: Consultancy; BeiGene: Consultancy. Fisher:Celgene: Consultancy; AstraZeneca: Consultancy; Barclays: Honoraria; prIME: Honoraria. Rimsza:NanoSting: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution]. Smith:Portola Pharmaceuticals: Research Funding. Friedberg:Bayer: Honoraria, Other: Data & Safety Monitoring Committee; Acerta: Other: Data & Safety Monitoring Committee. OffLabel Disclosure: Ibritumomab tiuxetan in diffuse large B-cell lymphoma

Abstract Abstract 1671 Poster Board I-697 Background Bevacizumab (Avastin), a humanized monoclonal antibody directed against vascular endothelial growth factor (VEGF-A), is approved in combination with chemotherapy in lung, colorectal, breast and brain cancers. VEGF-A expression is reported in all lymphoma subtypes, with strongest expression in PTCL. Given the relatively poor prognosis of PTCL with standard therapy, we combined bevacizumab (A) with CHOP in the ECOG 2404 phase II trial. Methods Untreated PTCL pts with a normal baseline cardiac ejection fraction received bevacizumab 15 mg/ kg IV and CHOP chemotherapy on day 1 for 6-8 cycles. Patients (pts) with CR/PR/SD received maintenance therapy with bevacizumab 15 mg/ kg IV q 3 weeks for 4 cycles. Due to the reported 3.7% incidence of cardiac toxicity associated with bevacizumab in metastatic breast cancer pt previously exposed to anthracyclines (Avastin package insert), cardiac function was monitored prospectively with ejection fraction (EF) determination at the completion of A-CHOP prior to the start of bevacizumab maintenance. Results Among 33 pts who came off study, toxicity data are available for all and coded using CTCAE Version 3.0. 22 received at least 4 cycles of A-CHOP (median treatment duration 3.6 months (< 1-10.6 months). One or more designated cardiac toxicities were recorded for 5 of these 22 pts. Congestive heart failure (CHF), defined as grade 2-4 left ventricular dysfunction was recorded in 4 pt (18%, 90% CI 5.2%-40.3%): grade 4 (n=1), grade 3 (n=3). In 3 pts clinical CHF occurred after A-CHOP x 6 and in one during bevacizumab maintenance after A-CHOP x 8. The median time to development of a cardiac adverse event was 5 months (3.5 – 8.8 months). One pt required a ventricular assist device in addition to medical management. In 3 of the 4 pts, ongoing medical management for CHF has been required. Other cardiac toxicities included ventricular arrhthymia (one grade 4, one grade 2), and one grade 2 cardiac troponin elevation. In addition, one patient experienced sudden death of uncertain cause. Three pts developed thromboses or embolic toxcities (two grade 4 and one grade 3). Conclusions We observed four cases of clinical CHF early after cumulative doxorubicin doses of 300-400 mg/m2 in our study, The incidence of CHF among study patients who received 4 or more A-CHOP cycles is concerning and suggests that bevacizumab may potentiate the adverse cardiac effects of anthracyclines, resulting in clinically significant toxicity. Careful monitoring of cardiac function is warranted in ongoing trials combining bevacizumab and doxorubicin in lymphomas and solid tumors to assess long-term safety and better understand underlying mechanisms and risks. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 687 Background: A persistently positive PET scan after just a few cycles of therapy is predictive of a poor clinical outcome in diffuse large B-cell lymphoma (DLBCL). Prior data suggested that about one third of patients remain PET positive after 2–4 cycles, with ≤ 20% 2 year progression-free survival (PFS) for such patients. A response-adapted strategy was studied in E3404 to test the hypothesis that an early treatment change to four cycles of R-ICE might reduce the treatment failure rate of patients whose PET scan remained positive after an initial 3 cycles of R-CHOP. Study Design: Previously untreated patients with DLBCL stage III, IV, or bulky II, with measurable disease, HIV negative, and with adequate organ reserve, were eligible. PET/CT scan was performed before treatment and again after 3 cycles of R-CHOP. A fourth cycle of R-CHOP was given while the scan was centrally reviewed and scored as either positive or negative for FDG-avid tumor by a single reviewer using criteria based on modifications of the Harmonization Criteria. Persistently PET-positive patients received 4 cycles of R-ICE, while PET-negative patients received 2 more cycles of R-CHOP, for a total of 6 cycles. PET/CT was performed again at the end of treatment. A ≥45% 2 year PFS for mid-treatment PET- positive patients was viewed as a promising result, with 88% power if 33 such patients were accrued. Total accrual of 99 patients was therefore planned. Results: Of 100 patients accrued, 78 were eligible; all but 1 ineligibility was based on central pathology review. Fifty-eight were male; median age was 62 years (20–74); 13% IPI 0–1, 31% IPI 2, 37% IPI 3, and 19% IPI 4–5. Seventy-four of 78 (95%) patients completed the first 3 cycles of R-CHOP. Of 72 patients continuing treatment, 67 (93%) completed protocol treatment: 83% of mid-treatment PET-positive and 93% of PET-negative patients. Of 74 patients undergoing mid-treatment PET scan, 12 (16%) were scored as positive, and 62 (84%) as negative. At the end of treatment, 13% were scored as positive, and 87% as negative. Two-year PFS, from the time of study entry, was 72% among all eligible patients. Two year PFS from the time of mid-treatment PET scan was 45% (90% CI, 21–67%) for patients scored as mid-treatment PET-positive, and 77% (90% CI 67–85%) for patients scored as mid-treatment PET-negative. The 80% confidence interval (corresponding to a test with a one-sided type I error of 10%) did not include the null hypothesis of 25%, implying that the results met the pre-specified threshold. Among all 78 eligible patients, 10 have died (13%); 5-year overall survival was 87% (90% CI 78–92%) Three-year overall survival was 67% (90% CI 40–84%) for mid-treatment PET-positive patients, and 93% (90% CI 85–97%) for mid-treatment PET-negative patients. Conclusions: The 2-year PFS for mid-treatment PET-positive patients met the threshold to be considered promising, but the confidence interval was wider than expected due to the small patient number. In addition, the inter-observer variability in the interpretation of mid-treatment PET scans as a binary variable in this study (studied and reported separately in Horning SJ et al. Blood 2010) implies that treatment modification based on early PET scanning should remain confined to clinical trials. Disclosures: Swinnen: Celgene: Consultancy; Genentech: Research Funding. Quon:Genentech: Research Funding. Advani:Pharmacyclics: Research Funding. Kahl:Roche/Genentech: Consultancy; Celgene: Consultancy; Cell Therapeutics: Consultancy; Janssen: Consultancy; GSK: Consultancy; Gilead: Consultancy. Horning:Genentech: Employment; Roche: stock, stock Other.

Diffuse large B-cell lymphomas (DLBCLs) and follicular lymphoma (FL) are the most common subtypes of B-cell non-Hodgkin’s lymphomas in adults. Histologic transformation of FL to DLBCL (TFL) occurs in approximately 15% of patients and is generally associated with a poor clinical outcome. Phosphatidylinositol 3-kinase (PI3K) inhibitors have shown promising results in the treatment of relapsed/refractory FL. CAR T-cell therapy (axicabtagene ciloleucel and tisagenlecleucel) has emerged as a novel treatment option for relapsed/refractory DLBCL and TFL. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines for B-Cell Lymphomas regarding the treatment of TFL and relapsed/refractory FL and DLBCL.

SummaryThe rituximab extended schedule or retreatment trial (RESORT; E4402) was a phase 3 randomized prospective trial comparing maintenance rituximab (MR) versus a retreatment (RR) dosing strategy in asymptomatic, low tumour burden indolent lymphoma. A planned exploratory sub‐study compared the two strategies for small lymphocytic (SLL) and marginal zone lymphomas (MZL). Patients responding to rituximab weekly × 4 were randomized to MR (single dose rituximab every 3 months until treatment failure) or RR (rituximab weekly × 4) at the time of each progression until treatment failure. The primary endpoint was time to treatment failure (TTTF). Patients with SLL (n = 57), MZL (n = 71) and unclassifiable small B‐cell lymphoma (n = 3) received induction rituximab. The overall response rate (ORR) was 40% [95% confidence interval (CI) 31–49%; SLL ORR 22·8%; MZL ORR 52·1%]; all 52 responders were randomized. At a median of 4·3 years from randomization, treatment failure occurred in 18/23 RR and 15/29 MR. The median TTTF was 1·4 years for RR and 4·8 years for MR (P = 0·012); median time to first cytotoxic therapy was 6·3 years for RR and not reached for MR (P = 0·0002). Survival did not differ (P = 0·72). In low tumour burden SLL and MZL patients responding to rituximab induction, MR significantly improved TTTF as compared with RR.

Summary A persistently positive positron emission tomography ( PET ) scan during therapy for diffuse large B‐cell lymphoma ( DLBCL ) is predictive of treatment failure. A response‐adapted strategy consisting of an early treatment change to four cycles of R‐ ICE (rituximab, ifosfamide, carboplatin, etoposide) was studied in the Eastern Cooperative Oncology Group E3404 trial. Previously untreated patients with DLBCL stage III, IV, or bulky II, were eligible. PET scan was performed after three cycles of R‐ CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) and scored as positive or negative by central review during the fourth cycle. PET ‐positive patients received four cycles of R‐ ICE , PET ‐negative patients received two more cycles of R‐ CHOP . A ≥45% 2‐year progression‐free survival ( PFS ) for mid‐treatment PET ‐positive patients was viewed as promising. Of 74 patients, 16% were PET positive, 79% negative. The PET positivity rate was much lower than the 33% expected. Two‐year PFS was 70%; 42% [90% confidence interval (CI), 19–63%] for PET ‐positives and 76% (90% CI 65–84%) for PET ‐negatives. Three‐year overall survival ( OS ) was 69% (90% CI 43–85%) and 93% (90% CI 86–97%) for PET ‐positive and ‐negative cases, respectively. The 2‐year PFS for mid‐treatment PET ‐positive patients intensified to R‐ ICE was 42%, with a wide confidence interval due to the low proportion of positive mid‐treatment PET scans. Treatment modification based on early PET scanning should remain confined to clinical trials.

Abstract In classical Hodgkin lymphoma, circulating clonotypic malignant cells express CD20, which potentially explains the observed activity of rituximab. This multicenter phase 2 study investigated the combination of rituximab-ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) for stage II-IV untreated classical Hodgkin lymphoma. A goal was to assess the behavior of circulating clonotypic B cells clinically. Of 49 evaluable patients, 69% had stage IIB-IV disease; 8% had CD20+ Hodgkin and Reed-Sternberg cells. Rituximab-ABVD was generally well tolerated. Delivered relative dose intensity was 94% for AVD and 79% for bleomycin. After 6 cycles, 81% of patients were in complete remission. Only 8% received radiation therapy. The actuarial 3-year event-free and overall survival rates were 83% and 98%, respectively. EBV copy number in plasma fell dramatically during cycle 1 in patients with EBV+ tumors. Persistence of detectable circulating clonotypic B cells was associated with a greater relapse frequency (P < .05). Rituximab-ABVD and clonotypic B cells warrant additional study in classical Hodgkin lymphoma. This trial was registered at www.clinicaltrials.gov as NCT00369681.

Abstract Positive interim positron emission tomography (PET) scans are thought to be associated with inferior outcomes in diffuse large B-cell lymphoma. In the E3404 diffuse large B-cell lymphoma study, PET scans at baseline and after 3 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone were centrally reviewed by a single reader. To determine the reproducibility of interim PET interpretation, an expert panel of 3 external nuclear medicine physicians visually scored baseline and interim PET scans independently and were blinded to clinical information. The binary Eastern Cooperative Oncology Group (ECOG) study criteria were based on modifications of the Harmonization Criteria; the London criteria were also applied. Of 38 interim scans, agreement was complete in 68% and 71% by ECOG and London criteria, respectively. The range of PET+ interim scans was 16% to 34% (P = not significant) by reviewer. Moderate consistency of reviews was observed: κ statistic = 0.445 using ECOG criteria, and κ statistic = 0.502 using London criteria. These data, showing only moderate reproducibility among nuclear medicine experts, indicate the need to standardize PET interpretation in research and practice. This trial was registered at www.clinicaltrials.gov as #NCT00274924.