Faculty Bibliography

Clinical trials of novel salvage therapies have encouraging outcomes for relapsed/refractory transplant-eligible classic Hodgkin lymphoma (R/R cHL) but comparison with conventional chemotherapy is lacking. Herein, we report the final analysis of a multicenter retrospective cohort of R/R cHL assessing outcomes by type of salvage therapy before autologous stem cell transplant (ASCT). R/R cHL patients who underwent ASCT at 14 institutions across the United States were included. Outcomes were compared among patients receiving conventional chemotherapy, brentuximab vedotin (BV) + chemotherapy, BV alone, and a checkpoint inhibitor (CPI)-based regimens before ASCT. Study endpoints included event-free survival (EFS), progression-free survival (PFS), and overall survival (OS). All endpoints are defined from relapse. Of 936 patients, 728 received conventional chemotherapy, 73 received BV + chemotherapy, 70 received BV alone, and 65 received CPI-based regimens prior to ASCT. When adjusted for time to relapse, pre-ASCT response and use of BV maintenance, patients receiving CPI-based regimens had superior 2-year EFS compared to conventional chemotherapy, BV + chemotherapy, and BV alone (79.7, 49.6, 62.3, and 36.9%, respectively, p < .0001). Among 649 patients transplanted after 1 line of salvage therapy, CPI-based regimens were associated with superior 2-year PFS compared to conventional chemotherapy (98% vs. 68.8%, hazard ratio: 0.1, 95% confidence interval: 0.03-0.5, p < .0001). OS did not differ by pre-ASCT salvage regimen. In this large multicenter retrospective study, CPI-based regimens improved EFS and PFS compared to other salvage regimens independent of pre-ASCT response. These data support earlier sequencing of CPI-based regimens in R/R cHL in the pre-ASCT setting.

Obinutuzumab (G) chemoimmunotherapy demonstrated improved progression-free survival (PFS) vs rituximab-based chemoimmunotherapy in patients with previously untreated follicular lymphoma (FL) in the GALLIUM trial. Atezolizumab (atezo) is a programmed death-ligand 1 inhibitor with a complementary mechanism of action to G by restoring cytotoxic T-cell function. We evaluated the safety and efficacy of atezo-G-bendamustine in patients with previously untreated FL in a phase Ib/II trial (#NCT02596971). A safety run-in phase was followed by an expansion phase with atezo-G-bendamustine induction and atezo-G maintenance for ≤24 months. Forty patients with previously untreated FL were enrolled and treated with atezo-G-bendamustine. The primary endpoint, complete response (CR) rate, assessed by an independent review committee (IRC; modified Lugano 2014 criteria) was 75.0% (95% confidence interval [CI], 61.3% to 85.8%). Three-year investigator-assessed PFS and overall survival rates were 80.9% (95% CI, 63.9% to 90.5%) and 89.3% (95% CI, 73.9% to 95.9%), respectively. At baseline, 21/40 patients had circulating lymphoma-specific clonotypes and underwent repeat testing at end of induction; all were minimal residual disease negative (10-5 sensitivity), with 16 (76.2%) CRs, 3 (14.3%) partial responses, and 2 (9.5%) with stable disease (IRC assessed). Grade 5 (fatal) adverse events (AEs) were reported in 5 patients. The efficacy of atezo-G-bendamustine in previously untreated FL did not appear superior to G-bendamustine efficacy as seen in the GALLIUM trial, and the addition of atezo to G-bendamustine was associated with an increased risk of AEs. Particularly due to the unfavorable safety profile, this regimen cannot be recommended in patients with previously untreated FL. This trial was registered at www.clinicaltrials.gov as #NCT02596971.

INTRODUCTION/UNASSIGNED:Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive lymphoma histology. Outcomes for patients with relapsed or refractory (R/R) disease remain suboptimal. Polatuzumab vedotin (polatuzumab) is a recently approved antibody drug conjugate that targets CD79b, with a tubulin toxin payload, that has demonstrated significant clinical activity and an acceptable toxicity profile when administered with both anti-CD20 monoclonal antibodies and chemotherapy in clinical trials. AREAS COVERED/UNASSIGNED:In this article, we discuss the early-phase trials supporting the accelerated FDA approval of polatuzumab for patients with R/R DLBCL and review the status of and data from ongoing trials combining polatuzumab with other agents. EXPERT OPINION/UNASSIGNED:Polatuzumab is an important new tool for the management of patients with R/R DLBCL who are ineligible for or who relapse following standard second-line therapies. Combinations of polatuzumab with other agents may represent an opportunity to improve outcomes for this difficult to treat population. The recent publication of the POLARIX trial (NCT03274492) incorporating polatuzumab in the frontline treatment of DLBCL may impact the future role of this agent in the R/R setting.

PURPOSE/OBJECTIVE:Targeting CD79B using antibody-drug conjugates (ADC) is an effective therapeutic strategy in B-cell non-Hodgkin lymphoma (B-NHL). We investigated DCDS0780A, an anti-CD79B ADC with THIOMAB{trade mark, serif} technology (TDC) that consistently conjugates two anti-neoplastic molecules per antibody, in contrast to ADCs with heterogeneous loads. PATIENTS AND METHODS/METHODS:This phase 1 study enrolled 60 patients with histologically confirmed B-NHL that had relapsed/failed to respond following {greater than or equal to}1 prior treatment regimens; 41 (68%) had diffuse large B-cell lymphoma (DLBCL). Fifty-one patients received DCDS0780A monotherapy once every 3 weeks (0.3-4.8 mg/kg); 9 received combination therapy (3.6-4.8 mg/kg) with rituximab. RESULTS:=20). CONCLUSIONS:DCDS0780A as the TDC format for CD79B was tested at higher doses than its ADC counterpart investigated earlier, leading to deep responses. However, dose intensity was limited by ocular toxicities seen at the higher doses indicating that the TDC format was unable, in the current study, to expand the therapeutic index for the CD79B target. The encouraging anti-tumor activity advocates continuation of investigations into novel ADC technologies.

The engineering of patient T-cells for adoptive cell therapies has revolutionized the treatment of several cancer types. However, further improvements are needed to increase durability and response rate. While CRISPR-based loss-of-function screens have shown promise for high-throughput identification of genes that modulate T-cell response, these methods have been limited thus far to negative regulators of T-cell functions, and raise safety concerns due to the permanent nature of genome modification. Here we identify positive T-cell regulators via overexpression of ~12,000 barcoded human open reading frames (ORFs). Using this genome-scale ORF screen, we find modulator genes that may not normally be expressed by T-cells. The top-ranked genes increased primary human T-cell proliferation, activation, and secretion of key cytokines. In addition, we developed a single-cell genomics method for high-throughput quantification of the transcriptome and surface proteome in ORF-engineered T-cells. The top-ranked ORF, lymphotoxin beta receptor (LTBR), is typically expressed by myeloid cells but absent in lymphocytes. When expressed in T-cells, LTBR induced profound transcriptional and epigenomic remodeling, resulting in an increase in T-cell stemness and effector functions, as well as resistance to apoptosis and exhaustion in chronic stimulation settings. Using mutagenesis and epistasis approaches, we demonstrated that LTBR constitutive activates the canonical NFkB pathway via ligand shortcircuiting and tonic signaling. Expression of several top-ranked genes, including LTBR, improved antigen-specific chimeric antigen receptor (CAR) T-cell responses in healthy donors and diffuse large B-cell lymphoma patients. Finally, the top-ranked genes discovered in alphabeta T-cells also improved antigen-specific responses of gammadelta T-cells, highlighting the potential for cancer-agnostic therapies. Our results provide several strategies for improving next generation T-cell therapies via induction of new synthetic cell programs

The engineering of autologous patient T cells for adoptive cell therapies has revolutionized the treatment of several types of cancer¹. However, further improvements are needed to increase response and cure rates. CRISPR-based loss-of-function screens have been limited to negative regulators of T cell functions^2-4 and raise safety concerns owing to the permanent modification of the genome. Here we identify positive regulators of T cell functions through overexpression of around 12,000 barcoded human open reading frames (ORFs). The top-ranked genes increased the proliferation and activation of primary human CD4⁺ and CD8⁺ T cells and their secretion of key cytokines such as interleukin-2 and interferon-γ. In addition, we developed the single-cell genomics method OverCITE-seq for high-throughput quantification of the transcriptome and surface antigens in ORF-engineered T cells. The top-ranked ORF-lymphotoxin-β receptor (LTBR)-is typically expressed in myeloid cells but absent in lymphocytes. When overexpressed in T cells, LTBR induced profound transcriptional and epigenomic remodelling, leading to increased T cell effector functions and resistance to exhaustion in chronic stimulation settings through constitutive activation of the canonical NF-κB pathway. LTBR and other highly ranked genes improved the antigen-specific responses of chimeric antigen receptor T cells and γδ T cells, highlighting their potential for future cancer-agnostic therapies⁵. Our results provide several strategies for improving next-generation T cell therapies by the induction of synthetic cell programmes.

PURPOSE/OBJECTIVE:Mosunetuzumab is a bispecific antibody targeting CD20 and CD3 that redirects T cells to engage and eliminate malignant B cells and is being developed for relapsed or refractory (R/R) B-cell non-Hodgkin lymphomas (B-NHLs). METHODS:This first-in-human trial (ClinicalTrials.gov identifier: NCT02500407) evaluated the safety and tolerability and efficacy of mosunetuzumab in patients with R/R B-NHL and established the recommended phase II dose. Data from dose escalation are presented. Single-agent mosunetuzumab was administered intravenously in 3-week cycles, at full dose in cycle 1 day 1 (group A) or with ascending (step-up) doses during cycle 1 on days 1, 8, and 15 (group B), for eight or 17 cycles on the basis of tumor response. RESULTS:Two hundred thirty patients were enrolled. Doses up to 2.8 mg and 60 mg were assessed in groups A and B, respectively; maximum tolerated dose was not exceeded. In group B (n = 197), common adverse events (≥ 20% of patients) were neutropenia (28.4%), cytokine release syndrome (27.4%), hypophosphatemia (23.4%), fatigue (22.8%), and diarrhea (21.8%). Cytokine release syndrome was mostly low-grade (grade ≥ 3: 1.0%) and mainly confined to cycle 1. Across the doses investigated (group B), best overall response rates were 34.9% and 66.2% in patients with aggressive and indolent B-NHL, respectively, and complete response rates were 19.4% and 48.5%. Among patients with a complete response, the median duration of response was 22.8 months (95% CI, 7.6 to not estimable) and 20.4 (95% CI, 16 to not estimable) in patients with aggressive and indolent B-NHL, respectively. CONCLUSION/CONCLUSIONS:Mosunetuzumab, administered with step-up dosing, has a manageable safety profile and induces durable complete responses in R/R B-NHL. The expansion stage of the study is ongoing at the dose level of 1/2/60/60/30 mg selected for further study.

BACKGROUND:Obinutuzumab with polatuzumab vedotin or lenalidomide showed tolerability and activity in phase 1b/2 trials that recruited patients with relapsed or refractory follicular lymphoma. We aimed to examine whether the novel polatuzumab vedotin-obinutuzumab-lenalidomide (Pola-G-Len) combination might enhance antitumour response in patients with relapsed or refractory follicular lymphoma. METHODS:This multicentre, single-arm phase 1b/2 study tested Pola-G-Len in patients with relapsed or refractory follicular lymphoma, and polatuzumab vedotin in combination with rituximab and lenalidomide in patients with relapsed or refractory diffuse large B-cell lymphoma. Here we report the results from the cohort of patients with follicular lymphoma. The trial was done in 18 cancer centres across three countries (Spain, UK, and USA). Patients (≥18 years old) with CD20-positive relapsed or refractory follicular lymphoma (excluding grade 3b) and Eastern Cooperative Oncology Group performance status of 2 or less who had previously received anti-CD20-containing chemotherapy were eligible for inclusion. During the dose-escalation phase, patients received six 28-day cycles of induction treatment with intravenous obinutuzumab 1000 mg (all cohorts), and intravenous polatuzumab vedotin and oral lenalidomide (Celgene, Summit, NJ, USA) in the following doses: 1·4 mg/kg polatuzumab vedotin and 10 mg lenalidomide (cohort 1); 1·8 mg/kg polatuzumab vedotin and 10 mg lenalidomide (cohort 2); 1·4 mg/kg polatuzumab vedotin and 15 mg lenalidomide (cohort 3); 1·8 mg/kg polatuzumab vedotin and 15 mg lenalidomide (cohort 4); 1·4 mg/kg polatuzumab vedotin and 20 mg lenalidomide (cohort 5); and 1·8 mg/kg polatuzumab vedotin and 20 mg lenalidomide (cohort 6). Polatuzumab vedotin was administered on day 1, lenalidomide on days 1-21, and obinutuzumab on days 1, 8, and 15 of cycle one and day 1 of cycles two to six of each 28-day cycle. During phase 2 (dose expansion phase), patients received six cycles of induction with Pola-G-Len at the recommended phase 2 dose established during dose-escalation. Patients who had a response or stable disease at the end of induction were eligible to enter the maintenance phase, in which they received obinutuzumab for 24 months at 1000 mg on day 1 of every other 28-day cycle for a total of 12 doses, and lenalidomide for 12 months at 10 mg on days 1-21 of each 28-day cycle for a maximum of 12 cycles. The primary activity endpoint was complete response at the end of induction. Adverse events were monitored throughout the study. The primary safety objective was to determine the maximum tolerated dose of Pola-G-Len. Analyses were in the safety population, which included all patients that received at least one dose of any of the component drugs (ie, all patients who entered the induction phases in both the escalation and expansion phases), and activity-evaluable population, which included all patients who received at least one dose of any of the component drugs at the recommended phase 2 dose (ie, all patients who received the recommended phase 2 dose in the dose escalation investigation and all patients who entered induction in the dose expansion investigation). This ongoing trial is registered at ClinicalTrials.gov, NCT02600897. FINDINGS/RESULTS:Between March 24, 2016, and August 23, 2018, 56 patients (33 [59%] men and 23 [41%] women; 49 [88%] non-Hispanic or Latino) were enrolled. Two of four patients in cohort 2 reported dose-limiting toxicity events during dose escalation (one patient had grade 4 amylase and lipase elevation and one patient had grade 4 neutropenia and grade 3 thrombocytopenia), and there were no dose-limiting toxicities observed in cohorts 3 or 5; therefore, the recommended phase 2 dose for the dose-expansion was 1·4 mg/kg polatuzumab vedotin plus 20 mg lenalidomide. 46 (82%) patients were included in the activity-evaluable population. After a median follow up of 26·7 months (IQR 22·2-31·3) the objective response rate was 76% (90% CI 64-86) and complete response rate was 63% (90 CI 50-75). After a median follow-up of 27·0 months (IQR 18·7-34·0), the most common grade 3-4 adverse events were neutropenia (31 [55%] of 56 patients) and thrombocytopenia (14 [25%] patients). 61 serious adverse events were reported in 35 (63%) patients; the most common of which were febrile neutropenia (five [9%] patients; a sixth patient had febrile neutropenia, but this was not considered serious by the investigator), pneumonia (four [7%] patients), and pyrexia (four [7%] patients). One fatal adverse event (grade 5 septic shock) occurred in a patient who had discontinued study treatment due to disease progression and had initiated a new anti-lymphoma tyrosine kinase inhibitor treatment. This was not considered related to study treatment by the investigator. INTERPRETATION/CONCLUSIONS:Pola-G-Len showed high complete response rates, although it did not reached the prespecified threshold for activity, in patients who were heavily pretreated with refractory follicular lymphoma. Our findings compare favourably with available therapies and support future investigation of Pola-G-Len in a larger patient population. FUNDING/BACKGROUND:Genentech/F Hoffmann-La Roche.

Despite recent therapeutic advances in the management of non-Hodgkin lymphoma (NHL), up to 50% of patients with diffuse large B-cell lymphoma (DLBCL) relapse after first line therapy, and for DLBCL patients who relapse within 12 months after subsequent stem cell transplant (SCT), the median overall survival (OS) is 6.3 months. Recently, chimeric antigen receptor (CAR) T-cell therapy has shown remarkable activity in relapsed DLBCL with complete response (CR) rate of 40% and 54% for the two of the FDA-approved CAR T-cell products, tisagenlecleucel and axicabtagene ciloleucel, respectively. However, at a median follow-up of 18 months, only 36% of patients treated with tisagenlecleucel remained in CR; with longer follow-up for axicabtagene ciloleucel the median progression free survival (PFS) was 5.9 months. Immune escape and immune evasion are primary mechanisms of CAR-T resistance; clearly improvements are needed to increase response rate and cure. While CRISPR-based loss-of-function screens have shown promise for high-throughput identification of genes that modulate T-cell response, these methods have been limited thus far to negative regulators of T-cell functions, and raise safety concerns due to the permanent nature of genome modification. Here we identify positive T-cell regulators via overexpression of ~12,000 barcoded human open reading frames (ORFs). Using this genome-scale ORF screen, we found modulator genes which increased primary human CD4+ and CD8+ T-cell proliferation, including activation markers like CD25 and CD40L, and secretion of key cytokines like interleukin-2 and interferon-gamma. In addition, we developed a single-cell genomics method (OverCITE-seq) for high-throughput quantification of the transcriptome and surface proteome in ORF-engineered T-cells. The top-ranked ORF, lymphotoxin beta receptor (LTBR), is typically expressed in a subset of myeloid cells but absent in lymphocytes. When expressed in T-cells, LTBR induces a profound transcriptional remodelling, resulting in increased resistance to exhaustion and activation-induced apoptosis, as well as upregulation of a plethora of proinflammatory cytokines, co-stimulatory molecules and antigen presentation machinery. In order to investigate the mechanism of action of LTBR, we developed an epistasis assay which allows for simultaneous gene knockout and LTBR overexpression in primary T cells. Thus, LTBR appears to induce both canonical and non-canonical NFkB pathways - but the phenotype observed in T cells is dependent only on the former. Finally, we co-expressed several top-ranked genes, including LTBR, with FDA approved CD19-targeting CARs utilizing either 4-1BB or CD28 co-stimulatory domains. In line with previous results, co-expression of top-ranked ORFs increased proinflammatory cytokine secretion and cytotoxicity against CD19+ positive cancer cell lines. This functional improvement was also observed when top-ranked ORFs and CARs were delivered to T cells isolated from DLBCL patients as shown in Figure 1. Our results provide several strategies for improving next generation CAR T-cell therapies via induction of new synthetic cell programs which may optimize immune activation and enhance the efficacy of these important therapies, a high priority for patients with relapsed and refractory DLBCL and other lymphomas. [Formula presented] Disclosures: Mimitou: Immunai: Current Employment. Smibert: Immunai: Current Employment. Diefenbach: Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; IMab: Research Funding; Gilead: Current equity holder in publicly-traded company; Celgene: Research Funding; AbbVie: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Merck Sharp & Dohme: Consultancy, Honoraria, Research Funding; IGM Biosciences: Research Funding; Morphosys: Consultancy, Honoraria, Research Funding; MEI: Consultancy, Research Funding; Perlmutter Cancer Center at NYU Langone Health: Current Employment; Incyte: Research Funding; Trillium: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Genentech, Inc./ F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding. Sanjana: Qiagen: Consultancy; Vertex: Consultancy.
Copyright