Lossos, Izidore S.

Abstract Background: Diffuse large B-cell lymphoma (DLBCL) is frequently curable after frontline therapy, however, relapses can occur after achievement of a PET-negative complete remission (CR). Early detection of relapse may be associated with improved outcomes, particularly given the development of more active therapies for relapsed, refractory DLBCL. Controversy exists regarding the utility of post-therapy surveillance imaging which is associated with patient (pt) anxiety, radiation exposure, false-positive results, and cost, without clear overall survival benefit in retrospective studies (Thompson JCO 2014). A retrospective study found that serial minimal residual disease (MRD) monitoring during DLBCL surveillance could identify pts at risk of relapse before clinical evidence of disease (Roschewski Lancet Oncol 2015). In this multicenter prospective study, we assessed whether a next-generation immunosequencing (IS) MRD assay could be used for early detection of molecular relapse in DLBCL. Methods: Eligible pts with DLBCL or high-grade B-cell lymphoma (HGBCL) who received anthracycline-containing chemotherapy were enrolled across five cancer centers. In pts who achieved a PET-negative CR, serial peripheral blood samples were obtained every 3 months (mos) and CT scans every 6 mos for 2 years (yrs) post-treatment. The IS MRD assay (Adaptive Biotechnologies, Seattle, WA) that leverages multiplex PCR followed by NGS to identify and track rearrangements of IgH, V-J, D-J and IgK/L loci and translocations in Bcl1/2-IgH was used. MRD positive was defined as any detectable rearrangement and MRD undetectable as no evidence of rearrangement. Results: 500 pts were enrolled and 400 were evaluable (pre-treatment tumor pathology available, completed frontline treatment, and achieved PET-negative CR at end-of-treatment). Baseline characteristics were median age of 62 yrs (range 19-95), male sex 58%, advanced stage 61%, and poor-risk by R-IPI 42%. Histologies included DLBCL, NOS (88%), primary mediastinal B-cell lymphoma (6%), HGBCL (5%), T-cell rich B-cell lymphoma (3%), and other (1%). Pts received regimens including RCHOP x 6 cycles (37%), REPOCH x 6 cycles (20%), clinical trial (15%), combined modality therapy (RCHOP+RT) (9%), and other RCHOP variations (19%). Among the 400 evaluable pts, 44 relapses have occurred as of July 1, 2021. In 45% of pts (20/44), clinical relapse was detected using surveillance imaging alone (typically CT CAP with IV contrast) in an otherwise asymptomatic pt with a normal physical exam and laboratory evaluation . In 10% of pts (4/44), relapse was detected by patient-reported clinical symptoms alone. In 45% of pts (20/44), relapse was detected by imaging, clinical symptoms, and/or evaluation by an oncologist. With a median follow-up of 34 months, the 2-year PFS was 88.9% (85.8, 92.1). Advanced age, advanced stage, and poor-risk R-IPI were associated with inferior PFS. Of the 44 relapses, tumor-specific clonotypes were identified in 39 pts (4 failed quality control (QC), 1 failed calibration) and 38 pts had ≥1 sample available within 90 days of relapse. Of 356 patients in ongoing CR, tumor-specific clonotypes were identified in 279 patients (29 failed QC, 33 failed calibration, and 15 are pending sequencing). The patient-level prospective MRD results are shown in Figure 1. The overall sensitivity, specificity, positive predictive value, and negative predictive value of the IS MRD assay was 63% (24/38), 78% (218/279), 28% (24/85), and 94% (218/232), respectively. Plasma MRD detection had improved sensitivity and specificity compared with circulating cells. Among the 24 relapsed patients with a positive MRD result at or before relapse, the median anticipation of the test was 3 months (range 0 to 24 months). Conclusion: Overall outcomes are excellent for DLBCL and HGBCL pts who achieve PET-negative CR. In this multicenter prospective analysis with standardized follow up, a substantial proportion (45%) of clinical relapses are detected radiographically in asymptomatic pts, supporting the value of CT surveillance imaging in DLBCL, particularly for pts with advanced stage or high-risk disease. MRD assessment using the IS MRD assay had suboptimal sensitivity and specificity in the post-treatment surveillance setting in DLBCL. Further study of the clinical context and its correlation with test performance is ongoing. Figure 1 Figure 1. Disclosures Kumar: Kite Pharmaceuticals: Other: advisory board , Research Funding; Abbvie Pharmaceuticals: Research Funding; Celgene: Honoraria, Other: advisory board, Research Funding; Adaptive Biotechnologies, Celgene, Abbvie Pharmaceticals, Pharmacyclics, Seattle Genetics: Research Funding; Pharmacyclics: Research Funding; Astra Zeneca: Honoraria, Other: Advisory Board, Research Funding; Seattle Genetics: Research Funding. Westin: Novartis: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Curis: Research Funding; Morphosys: Research Funding; ADC Therapeutics: Consultancy, Research Funding; Iksuda Therapeutics: Consultancy; Umoja: Consultancy; MorphoSys: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; 47 Inc: Research Funding. Schuster: TG Theraputics: Research Funding; Incyte: Research Funding; Adaptive Biotechnologies: Research Funding; Pharmacyclics: Research Funding; Merck: Research Funding; Genentech/Roche: Consultancy, Research Funding; Tessa Theraputics: Consultancy; Loxo Oncology: Consultancy; Juno Theraputics: Consultancy, Research Funding; BeiGene: Consultancy; Alimera Sciences: Consultancy; Acerta Pharma/AstraZeneca: Consultancy; Novartis: Consultancy, Honoraria, Patents & Royalties, Research Funding; Abbvie: Consultancy, Research Funding; Nordic Nanovector: Consultancy; Celgene: Consultancy, Honoraria, Research Funding. Nowakowski: Celgene, NanoString Technologies, MorphoSys: Research Funding; Celgene, MorphoSys, Genentech, Selvita, Debiopharm Group, Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees. Lossos: Lymphoma Research Foundation: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy; Janssen: Consultancy, Honoraria; NCI: Research Funding; University of Miami: Current Employment; NIH grants: Research Funding; Stanford University: Patents & Royalties; Verastem: Consultancy, Honoraria. Jacob: Adaptive Biotechnologies: Current Employment. Mullins: Adaptive Biotechnologies: Current Employment. Zelenetz: AstraZeneca: Honoraria; Amgen: Honoraria; Beigene: Honoraria, Other, Research Funding; Gilead: Honoraria, Research Funding; SecuraBio: Honoraria; Genentech/Roche: Honoraria, Research Funding; BMS/Celgene/JUNO: Honoraria, Other; Janssen: Honoraria; LFR: Other; MEI Pharma: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Verastem: Honoraria; MethylGene: Research Funding; NCCN: Other; Pharmacyclics: Honoraria; Novartis: Honoraria; Gilead: Honoraria; MorphoSys: Honoraria.

Summary Even in the era of highly active combination antiretroviral therapy (cART), patients with HIV have a disproportionate risk of developing aggressive lymphomas that are frequently Epstein‐Barr virus (EBV)‐related. Here, we investigate HIV‐associated diffuse large B‐cell lymphoma (HIV‐DLBCL) and compare EBV‐positive and EBV‐negative cases. HIV‐DLBCL were identified from two academic medical centres and characterised by immunohistochemistry, EBV status, fluorescence in situ hybridisation, cell of origin determination by gene expression profiling, and targeted deep sequencing using a custom mutation panel of 334 genes. We also applied the Lymphgen tool to determine the genetic subtype of each case. Thirty HIV‐DLBCL were identified, with a median patient age of 46 years and male predominance (5:1). Thirteen cases (48%) were EBV‐positive and 14 (52%) EBV‐negative. Nine of the 16 tested cases (56%) had MYC rearrangement, three (19%) had BCL6 (two of which were double hit MYC / BCL6 ) and none had BCL2 rearrangements. Using the Lymphgen tool, half of the cases (15) were classified as other. All HIV‐DLBCL showed mutational abnormalities, the most frequent being TP53 (37%), MYC (30%), STAT3 (27%), HIST1H1E (23%), EP300 (20%), TET2 (20%), SOCS1 (17%) and SGK1 (17%). EBV‐negative cases were mostly of germinal centre B‐cell (GCB) origin (62%), showed more frequent mutations per case (a median of 13·5/case) and significant enrichment of TP53 (57% vs. 15%; P = 0·046), SGK1 (36% vs. 0%; P = 0·04), EP300 (43% vs. 0%; P = 0·02) and histone‐modifying gene (e.g. HIST1H1E , HIST1H1D , 79% vs. 31%; P = 0·02) mutations. EBV‐positive cases were mostly of non‐GCB origin (70%), with fewer mutations per case (median 8/case; P = 0·007), and these tumours were enriched for STAT3 mutations ( P = 0·10). EBV‐positive cases had a higher frequency of MYC mutations but the difference was not significant (36% vs. 15%; P = 0·38). EBV‐association was more frequent in HIV‐DLBCLs, arising in patients with lower CD4 counts at diagnosis (median 46·5 vs. 101, P = 0·018). In the era of cART, approximately half of HIV‐DLBCL are EBV‐related. HIV‐DLBCL are enriched for MYC rearrangements, MYC mutations and generally lack BCL2 rearrangements, regardless of EBV status. Among HIV‐DLBCL, tumours that are EBV‐negative and EBV‐positive appear to have important differences, the latter arising in context of lower CD4 count, showing frequent non‐GCB origin, lower mutation burden and recurrent STAT3 mutations.

Background: Diffuse large B-cell lymphoma (DLBCL) is frequently curable after frontline therapy, however, relapses can occur after achievement of a PET-negative complete remission (CR). Early detection of relapse may be associated with improved outcomes with second-line curative intent therapy or novel therapies. Controversy exists regarding the utility of post-therapy surveillance imaging which is associated with patient (pt) anxiety, radiation exposure, false-positive results, and cost. A retrospective study found that serial minimal residual disease (MRD) monitoring during DLBCL surveillance could identify pts at risk of relapse before clinical evidence of disease (Roschewski, Lancet Oncol, 2015). In this multicenter prospective study, we assessed whether a next-generation sequencing (NGS)-based MRD assay could be used for early detection of molecular relapse in DLBCL. Methods: Eligible pts with DLBCL or high-grade B-cell lymphoma (HGBCL) who received anthracycline-containing chemotherapy were enrolled across five cancer centers. In pts who achieved a PET-negative CR, serial peripheral blood samples were obtained every 3 months (mos) and CT scans every 6 mos for 2 years (yrs) post-treatment. The clonoSEQ® next generation sequencing (NGS) MRD assay (Adaptive Biotechnologies, Seattle, WA) that leverages multiplex PCR followed by NGS to identify and track rearrangements of IgH, V-J, D-J and IgK/L loci and translocations in Bcl1/2-IgH was used. MRD positive was defined as any detectable rearrangement and MRD negative as no evidence of rearrangement. We also reported MRD positivity above the limit of detection (LOD) (observations required to have 95% reproducibility). Interim futility analysis was performed after approximately 50% of anticipated relapses occurred to assess the preliminary sensitivity of the assay. Progression-free survival (PFS) was defined as time from treatment start date to relapse or death. Results: 501 pts were enrolled and 401 were evaluable (pre-treatment tumor pathology available, completed frontline treatment, and achieved PET-negative CR at end-of-treatment). Baseline characteristics were median age of 62 yrs (range 19-95), male sex 58%, advanced stage 61%, and poor-risk by R-IPI 40% (Table 1). Histologies included DLBCL, NOS (86%), primary mediastinal B-cell lymphoma (6%), HGBCL (5%), T-cell rich B-cell lymphoma (1%), and other (1%). Pts received regimens including RCHOP x 6 cycles (36%), REPOCH x 6 cycles (20%), clinical trial (15%), combined modality therapy (RCHOP+RT) (10%), and other RCHOP variations (19%). Among the 401 evaluable pts, 44 relapses have occurred as of June 1, 2020. In 47% of pts (18/38), clinical relapse was detected using surveillance imaging alone (typically CT CAP with IV contrast) in an otherwise asymptomatic pt with a normal physical exam and laboratory evaluation. Clinical relapse was detected by clinical symptoms alone in 11% (4/28), by the evaluation of an oncologist alone in 0%, and by imaging and clinical symptoms and/or evaluation by an oncologist in 42% (16/38) (missing data in 6 pts). With a median follow-up of 2.2 yrs, the 2-yr PFS was 88.1% (84.8, 91.4) (Figure 1). Advanced age, advanced stage, and poor-risk R-IPI were associated with inferior PFS. Of the 44 relapses, 43 pts were included in the interim analysis and tumor-specific clonotypes were identified in 39 pts (91%). In 56% (22/39), the MRD assay was positive at or before clinical relapse. In 38% (15/39), the MRD assay was positive above the limit of detection at or prior to clinical relapse, with only 10 relapses detected more than 3 mos prior to relapse, reflecting the poor clinical sensitivity of the assay. The NGS-MRD assay was more sensitive in the acellular (plasma cell-free DNA) than in the cellular (circulating leukocytes) compartment. Results: Overall outcomes are excellent for DLBCL and HGBCL pts who achieve PET-negative complete remission. In interim analysis, surveillance MRD assessment using the clonoSEQ® assay fails to consistently identify pts at risk of recurrence before clinical evidence of relapse in DLBCL. In a prospective analysis, a substantial proportion (47%) of clinical relapses are detected by imaging in asymptomatic pts, supporting the value of CT surveillance imaging in DLBCL, particularly for pts with advanced stage or high-risk disease. Additional analyses are forthcoming for MRD assessment in all pts, including those in remission. Disclosures Kumar: Celgene: Research Funding; Pharmacyclics: Research Funding; Adaptive Biotechnologies,: Research Funding; AbbVie: Research Funding; Seattle Genetics: Research Funding; Celgene: Honoraria, Other: Honoraria for Advisory Board; Astra Zeneca: Honoraria, Other: Honoraria for Advisory Board; Kite Pharmaceuticals: Honoraria, Other: Honoraria for Advisory Board. Westin:Kite: Consultancy, Research Funding; Curis: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Amgen: Consultancy; Astra Zeneca: Consultancy, Research Funding; Morphosys: Consultancy, Research Funding; 47: Research Funding; Janssen: Consultancy, Research Funding; BMS: Consultancy, Research Funding. Nowakowski:Curis: Consultancy; Seattle Genetics: Consultancy; Nanostrings: Research Funding; MorphoSys: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Kite: Consultancy; Denovo: Consultancy; Kymera: Consultancy; Ryvu: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other. Lossos:Verastem: Consultancy, Honoraria; Seattle Genetics: Consultancy, Other; NCI: Research Funding; Stanford University: Patents & Royalties; Janssen Biotech: Honoraria; Janssen Scientific: Consultancy, Other. Batlevi:Life Sci, GLG, Juno/Celgene, Seattle Genetics, Kite: Consultancy; Janssen, Novartis, Epizyme, Xynomics, Bayer, Autolus, Roche/Genentech: Research Funding. Drullinsky:Roche: Research Funding; Novartis: Research Funding. Gerecitano:Janssen: Current Employment. Hamlin:Celgene: Consultancy; Karyopharm: Consultancy; Juno Therapeutics: Consultancy; Portola: Research Funding; Molecular Templates: Research Funding; Incyte: Research Funding; J&J Pharmaceuticals: Research Funding; Portola Pharmaceutics: Consultancy. Horwitz:ASTEX: Consultancy; Affirmed: Consultancy; Vividion Therapeutics: Consultancy; Verastem: Consultancy, Research Funding; Myeloid Therapeutics: Consultancy; Miragen: Consultancy; Kura Oncology: Consultancy; Janssen: Consultancy; GlaxoSmithKline: Consultancy; Daiichi Sankyo: Research Funding; C4 Therapeutics: Consultancy; Beigene: Consultancy; Portola: Consultancy, Research Funding; Mundipharma: Consultancy; Innate Pharma: Consultancy; Corvus: Consultancy; Trillium: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Millenium/Takeda: Consultancy, Research Funding; Kyowa Hakka Kirin: Consultancy, Research Funding; Infinity/Verastem: Research Funding; Forty Seven: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Aileron: Consultancy, Research Funding; ADCT Therapeutics: Consultancy, Research Funding. Jacob:Adaptive Biotechnologies: Current Employment, Current equity holder in publicly-traded company. Joffe:AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Epizyme: Membership on an entity's Board of Directors or advisory committees. von Keudell:Bayer: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding. Lahoud:MorphoSys: Other: Advisory Board. Matasar:Bayer: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Rocket Medical: Consultancy, Research Funding; Teva: Consultancy; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Honoraria, Research Funding; Takeda: Consultancy, Honoraria; Daiichi Sankyo: Consultancy; IGM Biosciences: Research Funding; Janssen: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding; Immunovaccine Technologies: Honoraria, Research Funding; Merck: Consultancy; Juno Therapeutics: Consultancy; Genentech, Inc.: Consultancy, Honoraria, Research Funding. Mullins:Adaptive Biotechnologies: Current Employment, Other: shareholder. Noy:Pharmacyclics: Research Funding; NIH: Research Funding; Rafael Pharma: Research Funding; Janssen: Consultancy; Pharmacyclics: Consultancy; Medscape: Consultancy; Targeted Oncology: Consultancy; Morphosys: Consultancy. Straus:Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees; ASH: Other: Conference in December 2019 on HL to other physicians during ASH; Elsevier: Membership on an entity's Board of Directors or advisory committees, Other: CME writer; OncLive: Speakers Bureau; Takeda Pharmaceuticals: Research Funding, Speakers Bureau; NY Lymphoma Rounds: Consultancy; Targeted Oncology: Consultancy, Speakers Bureau; Imedex, Inc.: Speakers Bureau; Karyopharm Therapeutics: Membership on an entity's Board of Directors or advisory committees. Younes:Takeda: Consultancy; HCM: Consultancy; AstraZeneca: Current Employment; Novartis: Consultancy; Daiichi Sankyo: Consultancy; Janssen: Consultancy; Epizyme: Consultancy; BMS: Consultancy; BioPath: Consultancy; Curis: Consultancy. Zelenetz:MEI Pharma: Research Funding; MorphoSys: Research Funding; Sandoz: Research Funding; Celgene: Research Funding; Roche: Research Funding; Gilead: Research Funding; Genentech/Roche: Consultancy; Gilead: Consultancy; Celgene: Consultancy; Janssen: Consultancy; Amgen: Consultancy; Novartis: Consultancy; Adaptive Biotechnology: Consultancy; BeiGene: Membership on an entity's Board of Directors or advisory committees.

Background: Plasmablastic lymphoma (PBL) is a rare subtype of Non-Hodgkin Lymphoma with a well-known association with HIV infection. The outcomes of PBL patients are typically described with high relapse rates and poor prognosis. (Loghavi S, J Hematol Oncol. 2015; Morscio J, Am J of Pathol. 2014; Castillo JJ, Clin Lymphoma Myeloma Leuk. 2011; Castillo JJ, Am J Hematol. 2008) There has been a paucity of data suggesting that limited stage disease (Ann Arbor stage I-II) may have a more favorable prognosis. However, due to the rarity of this disease there have been no large-scale reviews to confirm this. Thus, many patients with limited stage disease are subject to the aggressive therapy recommendations based on the poor outcomes of PBL patients as a whole. (Loghavi S, J Hematol Oncol. 2015; NCCN Guidelines, version 2.2020; Al-Malki MM, BBMT. 2014) We attempted to determine the treatment patterns and outcomes of patients with limited stage PBL. Methods: We conducted a multi-center (13 US academic centers) retrospective study of patients with limited stage (Ann Arbor stage I-II) Plasmablastic lymphoma. Determination of limited stage and diagnosis of PBL was determined by the investigators at each individual center. Patients diagnosed between 1/1/1990 and 6/1/2018 were included. Baseline demographic, clinical, laboratory, pathology, and outcomes data were extracted by retrospective chart review. Kaplan Meier was utilized for time to event analysis. Results: Baseline characteristics are included in table 1. A total of 80 patients were identified with limited stage disease. With a median follow up of 34 months the 3-yr Progression free survival (PFS) and overall survival (OS) was 71.9% and 78.7% respectively (Figure 1A and 1B). Patients that received frontline chemotherapy with (n=29) and without RT (n=36) had a 3-yr PFS and OS of 84.6% and 96.2% as compared to 64.5% and 70.8%, respectively (Figure 2A and 2B; Figure 3A and 3B). The Hazard ratio (HR) for PFS and OS for chemo (reference) vs chemo-RT was 0.47 (95% CI 0.18-1.3; P=0.131) and 0.18 (95% CI 0.04-0.84; p=0.029) respectively. The HR for PFS and OS for CHOP (n=14, reference) vs EPOCH (n=33) based regimens was 0.37 (95% CI 0.11-1.2; p=0.106) and 0.36 (95% CI 0.079-1.6; p=0.182) respectively. Patients with stage I/IE disease (n=56) had a 3-yr PFS and OS of 73.1% and 81.2% respectively. Patients with stage II/IIE disease (n=24) had a 3-yr PFS and OS of 69.3% and 73.4% respectively. Patients that received aggressive treatment (n=17) with Hyper-CVAD based regimens and/or Auto-SCT as consolidation had a 3-yr PFS and OS of 63.6% and 72.7% respectively. Patients with concomitant HIV (n=16) had a 3-yr PFS and OS of 80.8% and 77.4% respectively. Seven patients received RT alone and 6 patients had surgical resection alone as frontline therapy; 1 patient received no therapy; 1 patient received HAART therapy only and remains in CR without any other treatment for PBL 29 months after diagnosis. There were 8 deaths (10%) related to PBL, 3 deaths (4%) related to treatment of PBL (2 during frontline chemo and 1 upon relapse with salvage chemo), and 9 deaths (11%) related to other causes. The 3-yr lymphoma free survival (LFS) of the entire cohort, pts receiving chemo alone, and pts receiving chemo-RT (without including treatment related mortality (TRM) as an event) was 89.1%, 85.2%, and 100% respectively. The 3-yr LFS survival of the entire cohort, pts receiving chemo alone, and pts receiving chemo-RT (including TRM as an event) was 85.1%, 80.0%, and 96.2% respectively. Discussion: Here we report the largest review to our knowledge of limited stage PBL. Outcomes appear to be excellent with 3-yr PFS and OS of 71.9% and 78.7% respectively and a 3-yr LFS of 89.1% (85.1% when attributing TRM as an event). There was no obvious benefit to receiving aggressive therapy with H-CVAD based regimens and/or Auto-SCT. Although this is a small, uncontrolled sample size the HR for OS was improved in patients receiving frontline chemo-RT vs chemo alone 0.18 (95% CI 0.04-0.84; p=0.029). However, this did not take into account TRM with or progression while receiving frontline chemotherapy. Patients who were HIV+ had similar PFS and OS outcomes compared to the entire cohort. This retrospective study clearly demonstrates the favorable outcomes in this patient population, especially in those able to receive definitive therapy for their disease. Disclosures Hess: ADC Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS, AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Patel:Takeda: Consultancy, Research Funding; Precision Biosciences: Research Funding; Nektar: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Poseida: Research Funding; Cellectis: Research Funding; Oncopeptides: Consultancy; Janssen: Consultancy, Research Funding. Nowakowski:Nanostrings: Research Funding; Seattle Genetics: Consultancy; Curis: Consultancy; Ryvu: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other; Kymera: Consultancy; Denovo: Consultancy; Kite: Consultancy; Celgene/BMS: Consultancy, Research Funding; Roche: Consultancy, Research Funding; MorphoSys: Consultancy, Research Funding. Chavez:Bayer: Consultancy; AbbVie: Consultancy; BeiGene: Speakers Bureau; Morphosys: Consultancy, Speakers Bureau; Merck: Research Funding; AstraZeneca: Speakers Bureau; Celgene: Consultancy; Genentech: Speakers Bureau; Epizyme: Speakers Bureau; Gilead: Consultancy; Novartis: Consultancy; Kite, a Gilead Company: Consultancy, Speakers Bureau; Karyopharm: Consultancy; Verastem: Consultancy; Pfizer: Consultancy. Hill:Beigene: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Takeda: Research Funding; AstraZenica: Consultancy, Honoraria, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding. Maddocks:Pharmacyclics: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Karyopharm: Consultancy; ADC Therapeutics, AstraZeneca: Consultancy; BMS: Consultancy, Research Funding. Wagner-Johnston:ADC Therapeutics, Regeneron, CALIB-R, Verastem: Membership on an entity's Board of Directors or advisory committees. Kahl:AstraZeneca Pharmaceuticals LP: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy; Pharmacyclics LLC: Consultancy; Genentech: Consultancy; Acerta: Consultancy, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Consultancy; ADC Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BeiGene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche Laboratories Inc: Consultancy. Alderuccio:ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Forma Therapeutics: Other: Family member; Agios Pharmaceuticals: Other: Family member; Oncinfo: Honoraria; Inovio Pharmaceuticals: Other: Family member; Foundation Medicine: Other: Family member; Puma Biotechnology: Other: Family member; OncLive: Honoraria. Lossos:Janssen Biotech: Honoraria; Verastem: Consultancy, Honoraria; Janssen Scientific: Consultancy, Other; Seattle Genetics: Consultancy, Other; Stanford University: Patents & Royalties; NCI: Research Funding. Portell:Bayer: Consultancy; BeiGene: Consultancy, Research Funding; Kite: Consultancy, Research Funding; Acerta/AstraZeneca: Research Funding; Amgen: Consultancy; Janssen: Consultancy; Pharmacyclics: Consultancy; AbbVie: Research Funding; TG Therapeutics: Research Funding; Infinity: Research Funding; Roche/Genentech: Consultancy, Research Funding; Xencor: Research Funding. Landsburg:Celgene: Membership on an entity's Board of Directors or advisory committees; Triphase: Research Funding; Takeda: Research Funding; Curis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Morphosys: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Speakers Bureau. Castillo:TG Therapeutics: Research Funding; Beigene: Consultancy, Research Funding; Kymera: Consultancy; Janssen: Consultancy, Research Funding; Abbvie: Research Funding; Pharmacyclics: Consultancy, Research Funding.

Abstract In relapsed/refractory Hodgkin lymphoma (R/R HL), immunotherapies such as the anti-programmed death-1 inhibitor pembrolizumab have demonstrated efficacy as monotherapy and are playing an increasingly prominent role in treatment. The CD30/CD16A-bispecific antibody AFM13 is an innate immune cell engager, a first-in-class, tetravalent antibody, designed to create a bridge between CD30 on HL cells and the CD16A receptor on natural killer cells and macrophages, to induce tumor cell killing. Early studies of AFM13 have demonstrated signs of efficacy as monotherapy for patients with R/R HL and the combination of AFM13 with pembrolizumab represents a rational new treatment modality. Here, we describe a phase 1b, dose-escalation study to assess the safety and preliminary efficacy of AFM13 in combination with pembrolizumab in patients with R/R HL. The primary objective was estimating the maximum tolerated dose; the secondary objectives were to assess safety, tolerability, antitumor efficacy, pharmacokinetics, and pharmacodynamics. In this heavily pretreated patient population, treatment with the combination of AFM13 and pembrolizumab was generally well tolerated, with similar safety profiles compared to the known profiles of each agent alone. The combination of AFM13 with pembrolizumab demonstrated an objective response rate of 88% at the highest treatment dose, with an 83% overall response rate for the overall population. Pharmacokinetic assessment of AFM13 in the combination setting revealed a half-life of up to 20.6 hours. This proof-of-concept study holds promise as a novel immunotherapy combination worthy of further investigation. This phase 1b study was registered at www.clinicaltrials.gov as NCT02665650.

Abstract Background: Patients with diffuse large B-cell lymphoma (DLBCL) not cured by first line R-CHOP chemotherapy or second line high-dose chemotherapy with autologous stem cell rescue have a poor prognosis and represent a clear unmet medical need. Lenalidomide (Revlimid®), an immunomodulatory drug, has activity in hematological malignancies including relapsed/refractory multiple myeloma, chronic lymphocytic leukemia and cutaneous T-cell lymphoma. Aim: To determine the activity and safety of lenalidomide monotherapy in relapsed/refractory DLBCL. Methods: Patients with relapsed/refractory DLBCL with measurable disease after at least 1 prior treatment regimen were eligible. Patients received 25 mg lenalidomide orally once daily on Days 1–21 every 28 days and continued therapy for 52 weeks as tolerated or until disease progression. Response and progression were evaluated using the IWLRC methodology. Univariate analyses using Fisher’s exact test was conducted to investigate and characterize associations of prognostic variables with response. Results: Twenty-six patients with DLBCL lymphoma were enrolled. The median age was 66 (45–86) and 13 were female. Median time from diagnosis to lenalidomide was 2.4 (0.5–12) years and median number of prior treatment regimens was 3 (1–6). Three patients (12%) exhibited an objective complete response (1 complete response (CR) and 2 complete responses unconfirmed (CRu)). Two patients had a partial response (PR) for an overall response rate of 19% and 7 had stable disease (SD). Response to lenalidomide was associated with low disease burden (33% for < 50 cm2v 0% for ≥ 50 cm2, P=0.06) and longer time from rituximab to lenalidomide treatment (33% for ≥ 230 days v 0% for < 230 days, P=0.05). Patients with favorable values for both these prognostic factors (N = 10) had a 50% response rate [RR] (30% CR/CRu RR) compared with a 0% RR for patients with unfavorable values (N = 16; P < 0.004) and a progression free survival (ongoing) of 7.4 months v 1.9 months. Although there were no responses in the poor prognosis group, 4 patients exhibited stable disease with an ongoing median PFS of > 4.2 months (> 3.6 - > 6.2). Eight patients (31%) required at least one dose reduction with a median time to first dose reduction of 1.8 months (0.4–2.9). One patient each (4%) had Grade 4 anemia, cauda equinine syndrome, febrile neutropenia, intermittent rash, lymphopenia, neutropenia, pneumonitis and thrombocytopenia. Most common Grade 3 adverse events were neutropenia (19%), thrombocytopenia (15%) and leukopenia (12%). Conclusion: The prognostic factors of tumor burden and time from last dose of rituximab appear to identify relapsed/refractory DLBCL patients with a high likelihood of response to lenalidomide oral monotherapy.

Abstract Background: Mantle cell lymphoma (MCL) is a distinct type of non-Hodgkin’s Lymphoma characterized by being incurable with a low response rate and short progression free survival when treated with conventional chemotherapy agents. Lenalidomide (Revlimid®), an immunomodulatory drug, is approved for the treatment of relapsed/refractory multiple myeloma and myelodysplastic syndromes associated with a del(q5) cytogenetic abnormality. Lenalidomide has also shown activity in chronic lymphocytic leukemia and cutaneous T-cell lymphoma. Aim: To determine the activity and safety of lenalidomide in relapsed/refractory MCL. Methods: Patients with relapsed/refractory MCL and measurable disease ≥ 2 cm after at least 1 prior treatment regimen were eligible. Patients received 25 mg lenalidomide orally once daily on Days 1–21 every 28 days and continued therapy for 52 weeks as tolerated or until disease progression. Response and progression were evaluated using the IWLRC methodology. Results: Fifteen patients with MCL were enrolled. Median age was 67 (45–84) and 7 were female. Median time from diagnosis to lenalidomide was 5.1 (0.7–12.7) years and median number of prior treatment regimens was 4 (2–6). Eight patients (53%) exhibited an objective response (1 complete response (CR), 1 complete response unconfirmed (CRu) and 6 partial responses (PR)), 2 had stable disease (SD) and 5 had progressive disease (PD). All eight responses were in eleven patients having a tumor burden < 50 cm2 and a time since last rituximab therapy of ≥ 230 days. No responses were achieved in four patients having a tumor burden ≥ 50 cm2 or a time since last rituximab therapy of < 230 days. Four of 5 patients (80%) with a prior stem cell transplant responded. Progression free survival [PFS] is 5.7 months and ongoing. Seven patients (47%) required at least one dose reduction with a median time to first dose reduction of 2.3 months (1.2–4.9). Grade 4 adverse events were neutropenia (13%), thrombocytopenia (13%), and thromboembolism (13%). Most common Grade 3 adverse events were neutropenia (33%) and leukopenia (20%). Conclusion: Lenalidomide oral monotherapy produced a 53% response rate in relapsed/refractory MCL with manageable side effects.

Abstract Background: High dose chemotherapy with stem cell transplant is currently employed in relapsed/refractory aggressive Non-Hodgkin’s Lymphoma (NHL). Lenalidomide (Revlimid®), an immunomodulatory drug, has shown activity in hematological malignancies including relapsed/refractory multiple myeloma, chronic lymphocytic leukemia and cutaneous T-cell lymphoma. Aim: To determine the activity and safety of lenalidomide monotherapy in relapsed/refractory aggressive NHL following stem cell transplant (SCT). Methods: Patients with relapsed/refractory aggressive NHL with measurable disease ≥ 2 cm after at least 1 prior treatment regimen were eligible. Patients received 25 mg lenalidomide orally once daily on Days 1–21 every 28 days and continued therapy for 52 weeks as tolerated or until disease progression. Response and progression were evaluated using the IWLRC methodology. Results: Fourteen (29%) of the 49 patients enrolled into the study had a prior SCT. Median age was 61 (23–76) and 5 were female. Histology was diffuse large B-cell lymphoma [DLBCL] (n=5), follicular center lymphoma grade 3 [FL] (n=2), mantle cell lymphoma [MCL] (n=5) and transformed [TSF] (n=2). Median time from diagnosis to lenalidomide was 3.9 (1.1–31.4) years and median time from SCT to study entry was 1.9 (0.5–11.7) years. The median number of prior treatment regimens was 5 (2–8). Seven patients (50%) exhibited an objective response (1 complete response unconfirmed (CRu), and 6 partial responses (PR)), 5 had stable disease (SD) and 2 patients had progressive disease (PD). Six responses were in eight patients having a tumor burden < 50 cm2 and a time since last rituximab therapy of ≥ 230 days. One response was achieved in six patients having a tumor burden ≥ 50 cm2 or a time since last rituximab therapy of < 230 days. Four of 6 (67%) patients who had SCT as their last treatment prior to lenalidomide [median time from SCT to lenalidomide = 0.8 (0.5–4.8) years] responded. Progression free survival [PFS] is 4.5 months and ongoing. Six patients (43%) required at least one dose reduction with a median time to first dose reduction of 1.6 months (0.4–4.9). Two patients each (14%) had Grade 4 adverse events of neutropenia and thrombocytopenia. The most common Grade 3 adverse events were neutropenia (36%), thrombocytopenia (21%), and leukopenia (14%). Conclusion: Lenalidomide produced a 50% response rate with manageable side effects in relapsed/refractory aggressive NHL following stem cell transplant.

Abstract Background: Lenalidomide (Revlimid®) has been reported to show activity in non-Hodgkin’s Lymphoma (NHL). However, prognostic factors predicting an individual patient’s response were unavailable. Aim: To investigate prognostic factors for lenalidomide response in patients with relapsed/refractory aggressive NHL. Methods: Patients with relapsed/refractory aggressive NHL with measurable disease ≥2 cm after at least 1 prior treatment regimen were eligible. Patients received 25 mg lenalidomide orally once daily on Days 1-21 every 28 days and continued therapy for 52 weeks as tolerated or until disease progression. Response and progression were evaluated using the IWLRC methodology. Univariate analyses using Fisher’s exact test and multivariate analyses using logistic regression were conducted to investigate associations of prognostic variables with response. Results: Forty-nine patients received lenalidomide oral monotherapy. The median age was 65 (23-86) and 24 were female. Histology was diffuse large B-cell lymphoma (n=26), follicular center lymphoma grade 3 (n=5), mantle cell lymphoma (n=15) and transformed (n=3). Median time from diagnosis was 2.7 (0.4-32) years and median number of prior treatment regimens was 4 (1-8). Forty-five (92%) of the patients had received prior rituximab and 63% were rituximab-refractory. Seventeen patients (35%) exhibited an objective response (2 complete responses, 4 complete responses unconfirmed and 11 partial responses). Response to lenalidomide was the same for patients who were refractory to rituximab (30%) and those who were not (31%). Three of 4 patients who were rituximab naive responded. Multivariate analysis including IPI, ECOG PS, stage, LDH, # of extranodal sites, age, sex, # of prior regimens and time from diagnosis identified only time since last rituximab and tumor burden as correlated with response. Response to lenalidomide was associated with low tumor burden (52% for <50 cm2v 0% for ≥50 cm2, P=0.033, odds ratio=10.9) and longer time from rituximab to lenalidomide treatment (52% for ≥ 230 days v 6% for <230 days, P=0.031, odds ratio=6.6). Rituximab depletes normal host B-cells and the kinetics for their loss and recovery are consistent with the timing of lenalidomide activity following rituximab. This may be a basis for this effect. However other tumor/host biological factors may also play a role. Patients with favorable values for both prognostic factors (N=24) had a 67% response rate [RR] compared to a 4% RR for patients with unfavorable values (N=25; P< 0.001) and a progression free survival (ongoing) of 7.5 months v 1.9 months. Although absolute lymphocyte count was not selected as a prognostic indicator of response in the multivariate setting, a trend was evident in the univariate analysis (42% for > 0.6 × 109/L v 9% for ≤0.6 × 109/L, P=0.071). Conclusion: Tumor burden and host immune competence may determine the response of relapsed/refractory aggressive NHL to lenalidomide monotherapy.

17569 Background: Lenalidomide is an immunomodulatory drug of the IMiD class that has activity in multiple myeloma, myelodysplastic syndromes and chronic lymphocytic leukemia. We report preliminary results of two Phase II studies assessing the safety and efficacy of lenalidomide monotherapy in subjects with relapsed/refractory indolent or aggressive non-Hodgkin’s lymphoma (NHL). Methods: Subjects with indolent (study NHL-001) or aggressive (study NHL-002) relapsed/refractory NHL following ≥ 1 prior treatment regimen with measurable disease are eligible. Subjects receive 25 mg lenalidomide orally once daily on Days 1–21 every 28 days and continue therapy for 52 weeks as tolerated until disease progression. Response and progression are evaluated using cross sectional imaging by the NCI criteria. Results: 10 subjects (2 indolent (I), 8 aggressive (A)) of a planned 80 (40 in each study) have enrolled thus far. Median age is 66 (45–80) and 7 subjects are female. Indolent histology is follicular center lymphoma grade 1, 2 (n = 2) and aggressive histology diffuse large cell lymphoma (n = 7) and follicular center lymphoma grade 3 (n = 1). Median time from diagnosis to lenalidomide monotherapy is 2.9 years (1.1–10) and median number of prior treatment regimens per subject is 3 (1–6). Median duration of follow-up is 2 months. Of eight subjects (2 I, 6 A) evaluable for response at two months, three demonstrated a decrease in their tumor burden by 72% (I), 68% (A) and 52% (A), two subjects (2 A) exhibited stable disease and three subjects (1 I, 2 A) had disease progression. Six of the ten subjects (2 I, 4 A) demonstrated no Grade 3 or 4 adverse events. Grade 3 or 4 hematological adverse events (neutropenia, thrombocytopenia) occurred in four subjects including one febrile neutropenia and one of these four subjects also exhibited Grade 3 cellulitis. No tumor flare or tumor lysis has been observed to date. Conclusions: Preliminary data of lenalidomide monotherapy in relapsed and refractory NHL are encouraging. [Table: see text]