Kilcoyne, Adrian

Abstract Background Coronavirus disease 2019 (COVID-19) results from SARS-CoV-2-induced hyperinflammatory immune response, orchestrated by granulocyte-macrophage colony-stimulating factor (GM-CSF). GM-CSF increases interleukin-6 (IL-6) levels, ultimately leading to increased C-reactive protein (CRP). The LIVE-AIR trial demonstrated that lenzilumab, the GM-CSF neutralizing antibody, improved the likelihood of survival without invasive mechanical ventilation (IMV) in hospitalized COVID-19 patients requiring supplemental oxygen but not IMV. This sub-analysis correlated levels of cytokines before and after lenzilumab treatment. Methods LIVE-AIR was a phase 3, randomized, double-blind, placebo-controlled trial (NCT04351152). Patients hospitalized with COVID-19 pneumonia, requiring only supplemental oxygen, were randomized to receive lenzilumab (1800 mg in three equally divided doses of 600 mg, q8h) or placebo IV infusion, in addition to standard of care which included remdesivir and corticosteroids. Blood taken at baseline (BL) and subsequent to treatment through day 10 (D10) were obtained and analyzed by high sensitivity enzyme immunoassay for GM-CSF, IL-6, and CRP. Results Baseline IL-6 levels (Loge-transformed for all cytokines and biomarkers) were linearly correlated with higher baseline GM-CSF levels (slope=0.60, p< 0.001). Baseline CRP levels were linearly correlated with higher baseline IL-6 levels (slope=0.29, p < 0.001). GM-CSF levels decreased with lenzilumab treatment on day 1 (D1) which persisted through D10 (Table). In contrast, GM-CSF increased with placebo treatment. IL-6 levels decreased only with lenzilumab treatment. CRP following lenzilumab or placebo treatment decreased on D1 to similar levels and further decreased on D10 only with lenzilumab treatment. Cytokine Levels Associated with Lenzilumab Treatment Conclusion Lenzilumab decreased GM-CSF as well as downstream cytokines and systemic biomarkers of inflammation during the hyperinflammatory immune response of COVD-19. Disclosures Dale Chappell, MD, MBA, Humanigen, Inc: Employee|Humanigen, Inc: Ownership Interest Adrian Kilcoyne, MD, Humanigen, Inc: Employee Frank Cerasoli, PhD, Humanigen, Inc: Advisor/Consultant John Lukas, PhD, Humanigen, Inc: Advisor/Consultant Cameron Durrant, MD, Humanigen, Inc: Employee|Humanigen, Inc: Ownership Interest Zelalem Temesgen, MD, Gilead: unrestricted educational grant (to the institution)|Humanigen, Inc: Grant/Research Support|Merck: unrestricted educational grant (to the institution)|ViiV: Advisor/Consultant Christopher Polk, MD, Gilead: Advisor/Consultant Jason Baker, MD, Gilead: Grant/Research Support|Humanigen, Inc: Grant/Research Support Vincent Marconi, MD, Gilead: Grant/Research Support.

Abstract Background: Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive sub-type of non-Hodgkin's lymphoma(Liu, et al. Am J Hematol 2019). All three approved CD19-directed CAR-T therapies (axicabtagene ciloleucel, tisagenlecleucel, lisocabtagene maraleucel) are associated with toxicities, including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) that can be severe, resulting in non-relapse mortality, ICU admission, and significant non-drug related health resource utilization which represent barriers to access and adoption (Nabhan, et al. J Clin. Pathway 2017). Studies have shown that early elevation of granulocyte-macrophage colony-stimulating factor (GM-CSF) levels 1-day post CAR-T infusion correlates with severe ICANS (Rossi, et al. EMA Workshop 2016), which is a negative prognostic factor for overall survival (Karschnia, et al. Blood 2019). It has been proposed that upon contact with the tumor, CAR-Ts produce GM-CSF, which serves as a communication conduit between the specific immune response of CAR-T and the off-target inflammatory cascade produced by myeloid lineage cells, causing myeloid cells to expand and promote the production of other downstream proinflammatory chemokines (MCP-1, IL-8, IP-10), cytokines (IL-1, IL-6), and other markers of systemic inflammation (CRP, Ferritin) (Sterner, et al. Blood 2019). Moreover, IL-6 is predominately released by tumor cells in a contact-independent manner (Barrett et al. Blood 2016), which helps explain why the prophylactic administration of tocilizumab is not effective in reducing the overall incidence of CRS or ICANS, as this cytokine is downstream in the inflammatory cascade. Further, the prophylactic use of tocilizumab has been shown to increase the incidence of all-grades and grade >3 ICANS (Locke, et al. Blood 2017). Lenzilumab is a novel Humaneered ® monoclonal antibody that neutralizes GM-CSF and has demonstrated potential to reduce the hyper-immune mediated cytokine storm induced by SARS-CoV-2 infection and significantly improve the likelihood of survival without ventilation in hospitalized COVID-19 patients, as reported in the LIVE-AIR phase 3 study (Temesgen, et al. medRxiv 2021). Methods: Eligible patients are adults (≥ 18 y) with relapsed or refractory DLBCL or are chemorefractory. Prior therapy must have included an anti-CD20 monoclonal antibody and an anthracycline-containing regimen. Patients will undergo leukapheresis and may receive optional corticosteroid bridging therapy. Patients will then receive lymphodepleting chemotherapy on Days ‒3 to ‒5 followed by infusion of lenzilumab on Day 0, 6-hrs prior to CAR-T infusion. Approximately 40 accredited sites across the U.S. certified to administer the three commercially available CAR-Ts have been engaged to participate in this 2-part study. In Part 1, all patients will receive lenzilumab 1800mg via a single 2-hour infusion prior to CAR-T administration. The objective of Part 1 is to evaluate the optimal regimen and assess whether a second dose of lenzilumab post-CAR-T infusion is required. A translational assessment of GM-CSF axis suppression, levels of CAR-T cells in blood, other inflammatory markers and lenzilumab PK/PD will be evaluated, along with the incidence and severity of CRS and ICANS, objective response rates (ORR) and rates of complete response (CR) by Day 28 to select the optimal regimen to carry forward into Part 2. The objective of Part 2 is to confirm whether lenzilumab can improve the toxicity and tolerance of CAR-T while maintaining or improving efficacy and durability of response. Up to 250 patients will be randomized 1:1 to receive lenzilumab or placebo with CAR-T per standard of care. The primary endpoint of the study is incidence of grade >2 CRS and/or ICANS by Day 28, with a key secondary endpoint of CR at 6-months in patients without grade ≥ 2 CRS and/or ICANS at Day 28 (Toxicity-free CR). This design and sample size yields 90% power to detect a 50% reduction in the primary outcome measure. Secondary endpoints include incidence of all grades and grade >3 CRS and/or ICANS, respectively; ORR and CR at 1, 3, 6, 12 months; durability of CR; progression-free survival, overall survival and health related quality of life using validated patient reported outcome measures. In addition, the study will explore the CRS and ICANS grading criteria that have been utilized with each of the approved CAR-Ts. Disclosures Kenderian: Humanigen, Inc.: Consultancy, Honoraria, Research Funding. Durrant: Humanigen, Inc.: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. Chappell: Humanigen Inc.: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. Ahmed: Humanigen Inc.: Current Employment, Current equity holder in publicly-traded company. Kilcoyne: Humanigen, Inc.: Current Employment, Current equity holder in publicly-traded company.

PURPOSE Patients with the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) historically showed inferior survival with standard rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Phase II studies demonstrated that adding the immunomodulatory agent lenalidomide to R-CHOP improved outcomes in ABC-type DLBCL. The goal of the global, phase III ROBUST study was to compare lenalidomide plus R-CHOP (R2-CHOP) with placebo/R-CHOP in previously untreated, ABC-type DLBCL. METHODS Histology and cell-of-origin type were prospectively analyzed by central pathology prior to random assignment and study treatment. Patients with ABC-DLBCL received lenalidomide oral 15 mg/d, days 1-14/21 plus standard R-CHOP21 versus placebo/R-CHOP21 for six cycles. The primary end point was progression-free survival (PFS) per independent central radiology review. RESULTS A total of 570 patients with ABC-DLBCL (n = 285 per arm) were stratified by International Prognostic Index score, age, and bulky disease, and randomly assigned to R2-CHOP or placebo/R-CHOP. Baseline demographics were similar between arms. Most patients completed six cycles of treatment: 74% R2-CHOP and 84% placebo/R-CHOP. The most common grade 3/4 adverse events for R2-CHOP versus placebo/R-CHOP were neutropenia (60% v 48%), anemia (22% v 14%), thrombocytopenia (17% v 11%), and leukopenia (14% v 15%). The primary end point of PFS was not met, with a hazard ratio of 0.85 (95% CI, 0.63 to 1.14) and P = .29; median PFS has not been reached for either arm. PFS trends favoring R2-CHOP over placebo/R-CHOP were seen in patients with higher-risk disease. CONCLUSION ROBUST is the first DLBCL phase III study to integrate biomarker-driven identification of eligible ABC patients. Although the ROBUST trial did not meet the primary end point of PFS in all patients, the safety profile of R2-CHOP was consistent with individual treatments with no new safety signals.