Background: Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a validated therapeutic target in haematologic malignancies, including chronic lymphocytic leukaemia (CLL) and mantle cell lymphoma (MCL), where it is selectively expressed on tumour cells but absent from most normal adult tissues. Over 200 patients have been treated with ROR1-directed therapies—including monoclonal antibodies, CAR-T cells, and ADCs—without evidence of on-target, off-tumour toxicity. Importantly, ROR1 is also expressed at low levels on quiescent cancer-initiating stem cells (CISCs), which evade conventional therapies and contribute to disease persistence and relapse. Targeting this compartment may offer a path to deeper and more durable remission. NVG-111 is a novel, humanised, first-in-class bispecific T-cell engager (TCE) that binds ROR1 and CD3. Similar in size to blinatumomab, NVG-111 is designed to redirect cytotoxic T cells to eliminate ROR1-expressing tumour cells, including CISCs. Here we report final safety and efficacy data, with all eligible participants completing 2-year follow-up after time-limited exposure to NVG-111 and data lock in February 2025. Methods: This open-label, dose-escalation study (NCT04763083) evaluated the safety, pharmacokinetics, and efficacy of NVG-111, administered as continuous intravenous infusion across 6 dose levels (0.3–45 µg/day). Fourteen ROR1-positive participants (CLL, n=11; MCL, n=3) received NVG-111 either as monotherapy (n=5) or with ibrutinib (n=9). Median age was 60 years (range 52–83); median prior lines of therapy: 2 (range 2–6), including chemoimmunotherapy and BTKi. Step-up dosing was used in later cohorts. Primary endpoints were safety and tolerability; secondary endpoints included ORR, CR, DoR, and PFS per iwCLL or Lugano criteria. Results: Between May 2021 and April 2023, 14 patients were enrolled (11 CLL, 3 MCL). Per protocol, 13 were evaluable for safety and 12 for efficacy. Among the 11 CLL patients, 9 (82%) had high-risk molecular features, including TP53 aberrations (22%), ATM mutations (44%), and NOTCH1 mutations (11%). All received time-limited NVG-111 therapy, with a median of 3 treatment cycles (range 1–6), per protocol. Treatment-emergent adverse events (TEAEs) occurred in all safety-evaluable participants, mostly during the first week and all fully reversible. Common TEAEs were Grade 1–2 nausea, headache, and fatigue. Cytokine release syndrome (CRS) was observed in 57% (all Grade 1–2) and ICANS in 14% (Grade 2–3). Three DLTs occurred, all reversible. Haematotoxicity was limited to one case of Grade 4 neutropenia, resolved within 48 hours with G-CSF. Mild, transient neutrophilia was seen in all others. Pharmacodynamic analyses showed robust CD8+ T cell activation on-treatment without signs of exhaustion across dose levels. Normal mature B cells were preserved, reducing risk of immunoparesis. Among efficacy-evaluable patients, 67% (8/12) had objective responses, including 33% (4/12) complete responses. Deeper responses were seen with additional cycles. Responders entered a 2-year follow-up without further NVG-111 exposure. With all participants completing follow-up, median PFS was 26.9 months. More than half remained in ongoing response, with restricted mean DoR estimated at 18.3 months. Conclusion: NVG-111, a first-generation ROR1-targeting bispecific TCE, shows encouraging and durable anti-tumour activity in relapsed/refractory CLL and MCL, with a safety profile consistent with its mechanism. Despite limited treatment, outcomes compare favourably with those of continuously administered next-generation BTK inhibitors in R/R CLL. These long-term follow-up data support clinical proof of concept for selective ROR1 targeting via bispecific TCEs. This differentiated approach warrants further evaluation in B-cell malignancies and other ROR1-expressing tumours.

Abstract Background Respiratory viral infections are major drivers of chronic obstructive pulmonary disease (COPD) exacerbations. Interferon-β is naturally produced in response to viral infection, limiting replication. This exploratory study aimed to demonstrate proof-of-mechanism, and evaluate the efficacy and safety of inhaled recombinant interferon-β1a (SNG001) in COPD. Part 1 assessed the effects of SNG001 on induced sputum antiviral interferon-stimulated gene expression, sputum differential cell count, and respiratory function. Part 2 compared SNG001 and placebo on clinical efficacy, sputum and serum biomarkers, and viral clearance. Methods In Part 1, patients (N = 13) with stable COPD were randomised 4:1 to SNG001 or placebo once-daily for three days. In Part 2, patients (N = 109) with worsening symptoms and a positive respiratory viral test were randomised 1:1 to SNG001 or placebo once-daily for 14 days in two Groups: A (no moderate exacerbation); B (moderate COPD exacerbation [i.e., acute worsening of respiratory symptoms treated with antibiotics and/or oral corticosteroids]). Results In Part 1, SNG001 upregulated sputum interferon gene expression. In Part 2, there were minimal SNG001–placebo differences in the efficacy endpoints; however, whereas gene expression was initially upregulated by viral infection, then declined on placebo, levels were maintained with SNG001. Furthermore, the proportion of patients with detectable rhinovirus (the most common virus) on Day 7 was lower with SNG001. In Group B, serum C-reactive protein and the proportion of patients with purulent sputum increased with placebo (suggesting bacterial infection), but not with SNG001. The overall adverse event incidence was similar with both treatments. Conclusions Overall, SNG001 was well-tolerated in patients with COPD, and upregulated lung antiviral defences to accelerate viral clearance. These findings warrant further investigation in a larger study. Trial registration EU clinical trials register (2017-003679-75), 6 October 2017.

Background: Interferon beta (IFN-β), a key host antiviral mediator, can be suppressed by virus or host factors locally at the site of infection. Inhaled SNG001 (IFN-β-1a nebuliser solution) aims to restore lung IFN-β levels. In a Phase 2 trial hospitalised COVID-19 patients receiving SNG001 were more than twice as likely to recover, supporting progression to the Phase 3 SPRINTER trial in hospitalised patients and inclusion of SNG001 in the ACTIV-2 Phase 2/3 trial in non-hospitalised volunteers (Figure 1). The SPRINTER study did not meet its primary efficacy endpoints, hospital discharge and recovery, likely due to improved standard of care reducing the window to show a treatment effect. An encouraging signal for the key secondary endpoint, prevention of progression to severe disease or death (26% RRR;OR 0.71(0.44,1.15);p=0.161), was observed and supported by post hoc analyses of at risk groups. Results: In ACTIV-2 there were no statistically significant differences between SNG001 and placebo for the primary outcomes of safety (SNG001 was well-tolerated), symptom resolution, or virology. However, fewer participants required hospitalisation following SNG001 treatment (N=1/110, [1%]) compared to placebo (N=7/110, [6%]), 86% RRR (P=0.07). IDSMB recommended progression to Phase 3. Conclusions: SNG001 was well tolerated across trials and should continue to be investigated for COVID-19 in the home and hospital settings.

Background: Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an oncofetal protein that is absent or expressed at low levels in normal adult tissues but overexpressed in a range of malignancies including CLL and MCL. NVG-111 is a humanized first in class, tandem scFv, ROR1xCD3 bispecific T cell engager. NVG-111 mediates potent killing of ROR1 + tumors by engaging a unique epitope on the Frizzled domain of ROR1 and redirecting T cell activity via the CD3 binder engineered for attenuated cytokine release. Methods: In this phase 1, first-in-human, dose-escalation study (ClinicalTrials.gov identifier: NCT04763083), NVG-111 was evaluated in relapsed/refractory CLL and MCL subjects with an ECOG PS of 0-2 who received ≥2 prior lines of treatment including a Bruton tyrosine kinase inhibitor (BTKi). Bayesian continual reassessment method with overdose control was implemented to guide escalation over a dose range of 0.3-45ug/day. Each subject received at least one dose of NVG-111, administered as a continuous intravenous infusion (cIV) over 21 days followed by 7 days off drug (=1 cycle). NVG-111 was administered in combination (N=8) with ibrutinib to subjects who had achieved a partial response to >1 year of ibrutinib therapy, or as monotherapy in subjects that progressed after covalent BTKi/B-cell lymphoma 2 inhibitor (BCL2i) (N=4). Primary objective was safety, with the secondary objectives being efficacy (overall response rates [ORR], minimal residual disease (MRD) measured by ERIC-compliant flow cytometry and duration of response [DoR]). Serum cytokine levels were determined using a human high sensitivity cytokine premixed magnetic Luminex assay and T cell function was longitudinally evaluated using cytometry by time of flight (CyTOF) analysis. Results: Between May 2021 and July 2023 12 subjects (10 males and 2 females, median age 60 years) completed a maximum of 6 cycles of treatment with NVG-111 (median=3 cycles [range 1-6 cycles]). Pharmacokinetic and pharmacodynamic data demonstrated systemic NVG-111 exposure and exposure-dependent NVG-111 targeting of ROR1 on circulating tumor cells. Adverse events (AEs) related to NVG-111 occurred in 10 subjects (83%), with the most common being nausea (58%), headaches (67%), and fatigue (33%), majority of which were grade 1 or 2. Grade 1(71%) or 2(29%) cytokine release syndrome (CRS) occurred in 58% of subjects during week 1 of cycle 1 except in one subject who had a second grade 1 CRS in cycle 2. Grade 3 dose limiting toxicities (DLTs) occurred in three subjects (25%) consisting of transient elevation of liver enzymes (ALT and AST) in one subject dosed at 3ug/day, immune effector cell-associated neurotoxicity syndrome-like symptoms (ICANS) in one subject dosed at 30ug/day and headache in one subject dosed at 45ug/day. All AEs were fully reversible with no late emergent grade 3 or greater toxicities. Evidence of T cell activation was observed in all 12 subjects with peak cytokine levels at the 30µg/day dose levels (mean±SEM): TNFα, 43±17pg/ml; IL6, 566±541pg/ml; IFNɣ, 18±12pg/ml; and IL10, 103±56pg/ml. Furthermore, T cell profiling showed an increase in cytotoxic CD8 + T cell activation marker expression during each NVG-111 treatment cycle without evidence of T cell exhaustion. Efficacy was evaluable in 11 subjects with objective clinical responses observed in 55% (6/11), including two subjects with clear evidence of single agent activity. Amongst these, three CLL subjects were rendered MRD negative in peripheral blood and one MCL subject achieved complete metabolic response by the Lugano criteria. Two subjects had stable disease but in one of these subjects there was a >50% reduction in peripheral blood lymphocytosis and a 40% reduction in lymphadenopathy. Despite time limited exposure to NVG-111, the restricted mean survival time for DoR is currently 13.6 months (SEM 3.07), the median is not yet calculable with response ongoing in four subjects. The median progression-free survival currently is 18.7 months (95% CI 2.6 - not calculable). Conclusion: These data provide clinical proof of concept for selective targeting of ROR1 with a TCE leading to objective evidence of antitumor activity with encouraging response durability even in CLL patients known to have defective T cell function. The safety profile was consistent with the mechanism of action. Further evaluation of this promising molecule is ongoing.

Background Despite the availability of vaccines and therapies, patients are being hospitalised with coronavirus disease 2019 (COVID-19). Interferon (IFN)-β is a naturally occurring protein that stimulates host immune responses against most viruses, including severe acute respiratory syndrome coronavirus 2. SNG001 is a recombinant IFN-β1a formulation delivered to the lungs via nebuliser. SPRINTER assessed the efficacy and safety of SNG001 in adults hospitalised due to COVID-19 who required oxygen via nasal prongs or mask. Methods Patients were randomised double-blind to SNG001 (n=309) or placebo (n=314) once daily for 14 days plus standard of care (SoC). The primary objective was to evaluate recovery after administration of SNG001 versus placebo, in terms of times to hospital discharge and recovery to no limitation of activity. Key secondary end-points were progression to severe disease or death, progression to intubation or death and death. Results Median time to hospital discharge was 7.0 and 8.0 days with SNG001 and placebo, respectively (hazard ratio (HR) 1.06 (95% CI 0.89–1.27); p=0.51); time to recovery was 25.0 days in both groups (HR 1.02 (95% CI 0.81–1.28); p=0.89). There were no significant SNG001–placebo differences for the key secondary end-points, with a 25.7% relative risk reduction in progression to severe disease or death (10.7% and 14.4%, respectively; OR 0.71 (95% CI 0.44–1.15); p=0.161). Serious adverse events were reported by 12.6% and 18.2% patients with SNG001 and placebo, respectively. Conclusions Although the primary objective of the study was not met, SNG001 had a favourable safety profile, and the key secondary end-points analysis suggested that SNG001 may have prevented progression to severe disease.

BACKGROUND:Effective therapeutics given early to high-risk ambulatory patients with coronavirus disease 2019 (COVID-19) could improve outcomes and reduce overall healthcare burden. However, conducting site visits in non-hospitalised patients, who should remain isolated, is problematic.AIM:To evaluate the feasibility of a purely remote (virtual) study in non-hospitalised patients with COVID-19; and the efficacy and safety of nebulised recombinant interferon-β1a (SNG001) in this setting.DESIGN & SETTING:Randomised, double-blind, parallel-group study, which was conducted remotely.METHOD:Eligible patients aged ≥65 years (or ≥50 years with risk factors) with COVID-19 and not requiring hospital admission were recruited remotely. They were randomised to SNG001 or placebo once-daily via nebuliser for 14 days. The main outcomes were assessments of feasibility and safety, which were all conducted remotely.RESULTS:Of 114 patients treated, 111 (97.4%) completed 28 days of follow-up. Overall compliance to study medication was high, with ≥13 doses taken by 89.7% and 92.9% of treated patients in the placebo and SNG001 groups, respectively. Over the course of the study, only two patients were hospitalised, both in the placebo group; otherwise there were no notable differences between treatments for the efficacy parameters. No patients withdrew owing to an adverse event, and a similar proportion of patients experienced on-treatment adverse events in the two treatment groups (64.3% and 67.2% with SNG001 and placebo, respectively); most were mild or moderate and not treatment-related.CONCLUSION:This study demonstrated that it is feasible to conduct a purely virtual study in community-based patients with COVID-19, when the study included detailed daily assessments and with medication administered via nebuliser.

Abstract Background Respiratory viral infections (RVIs) are major drivers of chronic obstructive pulmonary disease (COPD) exacerbations. Interferon beta (IFN-β) is key in host defence against viruses but can be suppressed by virus or host factors locally at the site of infection. Inhalation of SNG001 (IFN-β-1a nebuliser solution) aims to restore lung IFN-β levels. SG015 (NCT03570359) was a randomized, placebo-controlled Phase 2 clinical study of inhaled SNG001 conducted in COPD patients. Here we describe lung antiviral biomarker and sputum viral clearance data from Part 2 of the study which was conducted in patients with a confirmed RVI. Methods 109 COPD patients with worsening symptoms and a positive respiratory viral test were randomized 1:1 to SNG001 or placebo once-daily for 14 days in two Groups: A (no moderate exacerbation); B (moderate COPD exacerbation [i.e.,acute worsening of respiratory symptoms treated with antibiotics and/or oral corticosteroids]). Sputum samples were collected on days 1, 4, 7, 10, 13, 17 and 28 for analysis of lung antiviral biomarker responses (interferon-stimulated genes (ISGs): Mx1, OAS1 and CXCL10) and lung viral load by RT-qPCR. Results Mx1 and OAS1 sputum cell gene expression were significantly upregulated on day 7, 10 and 13 (p< 0.05) overall and in Groups A and B with SNG001 treatment compared to placebo. CXCL10 sputum cell gene expression was significantly upregulated in the overall population with SNG001 treatment compared to placebo on days 7 and 10, in Group B on days 7, 10 and 13, and there was no significant difference in Group A. Patients had a broad range of RVIs, the most common being human rhinovirus. A post-hoc analysis was therefore conducted in the subgroup of patients who had detectable rhinovirus viral load in sputum. By Day 4 the proportion of patients receiving SNG001 who had detectable rhinovirus reduced to 40.0% (compared to 94.7% of patients receiving placebo; p=0.052), with a further reduction to 20.0% on Day 7 (versus 89.5% receiving placebo; p=0.014). Conclusion Inhaled SNG001 upregulated lung antiviral defenses as assessed using sputum cell biomarker responses and accelerated viral clearance, supporting the proposed mechanism of action as an antiviral treatment for severe viral lung infections. Disclosures Phillip D. Monk, PhD, Synairgen Research Plc: Employee of Synairgen Research Plc and has options on shares|Synairgen Research Plc: Stocks/Bonds Jody L. Brookes, BSc, Synairgen Research Ltd: Share options Victoria J. Tear, PhD, Synairgen Research Ltd.: Stocks/Bonds Marcin Mankowski, MD MFPM (Dis), Multiple companies: Advisor/Consultant|Synairgen: Advisor/Consultant Michael G. Crooks, MBChB (hons), MD, FRCP, AstraZeneca: Advisor/Consultant|AstraZeneca: Grant/Research Support|AstraZeneca: Honoraria|Chiesi: Advisor/Consultant|Chiesi: Honoraria|Gilead: Honoraria|Synairgen: Advisor/Consultant Dave Singh, MD, AstraZeneca: Advisor/Consultant|Chiesi: Advisor/Consultant|gsk: Advisor/Consultant|Novartis: Advisor/Consultant|Orion: Advisor/Consultant|Pulmatrix: Advisor/Consultant|Sanofi: Advisor/Consultant|Synairgen: Advisor/Consultant|Synairgen: Grant/Research Support|Therevance: Advisor/Consultant Rekha Chaudhuri, MD, AstraZeneca: Grant/Research Support|AstraZeneca: Honoraria|Chiesi: Honoraria|GSK: Honoraria|Novartis: Honoraria|Sanofi: Honoraria|Teva: Honoraria Sarah Dudley, N/A, PhD, Synairgen Plc: Employed by Synairgen Research Ltd which is a subsidiary of Synairgen Plc|Synairgen Plc: Stocks/Bonds Felicity Gabbay, MbChb, Synairgen: Board Member Stephen T. Holgate, FMedSci, MD, Synairgen Research Plc: Board Member|Synairgen Research Plc: Stocks/Bonds Ratko Djukanovic, MD, GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Honoraria|KyMab: Advisor/Consultant|Sanofi: Advisor/Consultant|Synairgen: Advisor/Consultant|Synairgen: Stocks/Bonds Tom Wilkinson, PhD, PhD, Synairgen: Advisor/Consultant|Synairgen: Grant/Research Support|Synairgen: Honoraria

7535 Background: NVG-111 is a first in class, humanized, tandem scFv ROR1xCD3 bispecific T cell engager that mediates potent killing of ROR1+ tumours by engaging an epitope on the Frizzled domain of ROR1 and redirecting T cell activity via the CD3 binder. Methods: This phase I/II study is evaluating NVG-111 in patients with relapsed/refractory (R/R) CLL and MCL who have received ≥2 prior systemic therapies and have achieved a stable, or partial response to the last line of therapy. NVG-111 was delivered as continuous intravenous (cIV) infusion over 21 days per cycle, with each patient typically receiving 3 cycles of treatment. The first 3 single patient cohorts were subjected to accelerated dose titration (ADT) over a range of 0.3-30µg/day. Dose-escalation steps in the subsequent, multi-patient, cohorts were determined using a continuous reassessment method with overdose control. The primary endpoints are safety and determination of MTD/RP2D. Secondary objectives are pharmacokinetics, pharmacodynamics, immunogenicity and anti-tumor activity, assessed by multicolor flow cytometry to quantitate minimal residual disease (MRD4). Results: As of January 2022, six patients (all males, median age 60 years) had been enrolled to the study; three into each of the ADT cohorts and the remaining into a 30 µg/day flat dosing cohort. Five patients had CLL, and one had MCL, with all subjects remaining on ibrutinib whilst receiving NVG-111. The most common adverse events were Grade 1 lethargy, headaches, nausea, vomiting and thrombocytopenia. All 3 patients exposed to a flat dose of NVG-111 at 30µg/day suffered Grade 1 cytokine release syndrome (CRS) during week 1 of cycle 1. This did not require tocilizumab or dose interruption except in one patient who developed transient, grade 3 immune effector cell–associated neurotoxicity syndrome-like symptoms (ICANS). CRS or ICANS was not observed in subsequent cycles of treatment at this dose level. Response was observed in all 5 evaluable patients who had completed efficacy assessment after 3 cycles of NVG-111. Amongst these, 2 patients had undetectable MRD in the blood with one being MRD negative in the bone marrow. Dose escalation is ongoing, including exploration of step-up dosing. Conclusions: Early data with NVG-111 shows promising efficacy with a predictable and manageable safety profile. Clinical trial information: NCT04763083.

Background: NVG-111 is a first in class, humanized, tandem scFv, ROR1xCD3 bispecific T cell engager that mediates potent killing of ROR1+ tumor by engaging an epitope on the Frizzled domain of ROR1 and redirecting T cell activity via the CD3 binder that has been engineered for lower cytokine release. Methods: This multi-center, open-label, phase I study is evaluating NVG-111 in relapsed/refractory CLL and MCL subjects who have received ≥2 prior systemic therapies. An adaptive trial design was used for dose escalation, starting with accelerated dose titration (ATD) followed by a Bayesian continual reassessment method with overdose control. Each patient received at least one dose of NVG-111, administered as a continuous intravenous infusion (cIV) over 21 days followed by 7 days off drug (=1 cycle). NVG-111 was administered in combination (cohorts 1-4) with ibrutinib to patients who had achieved a stable or partial response to >1 year of ibrutinib therapy, or as monotherapy in patients who had progressed after BTKi / BCL2 (cohort 4b). Measurable residual disease (MRD) was assessed using a flow cytometric method with sensitivity 1e4 (MRD4). Mesoscale discovery electrochemiluminescence assay (MSD-ECLA) was used for pharmacokinetic analysis of NVG-111. Serum cytokine levels were determined using a human high sensitivity cytokine A premixed magnetic Luminex assay. Primary endpoints consisted of safety, tolerability and determination of maximum tolerated dose (MTD)/Recommended Phase 2 Dose (RP2D). Additional end-points included overall response rates as well as duration of response. Results: As of July 2022, 10 subjects (8 males and 2 females, median age 60 years) had been enrolled to the study; three into single subject ATD cohorts, 3 into 30 µg/day flat dosing cohort (cohort 4) and 4 into cohort 4b that entailed a step-up dosing of NVG-111 in cycle 1 only; (first week cycle 1: 3 µg/day, second week, cycle 1: 10 µg/day and week 3, cycle 1: 30 µg/day dose). Eight subjects had CLL and 2 MCL. cIV was well tolerated. Adverse events (AEs) were largely limited to week 1 of cycle 1 and all were reversible. The most common AEs were Grade 1 or 2 nausea (70%), headaches (60%), and fatigue (50%) and thrombocytopenia (30%). Grade 1/2 cytokine release syndrome (CRS) was observed in (40%) of subjects. Grade 3 dose limiting toxicities occurred in two subjects consisting of immune effector cell-associated neurotoxicity syndrome-like symptoms (ICANS) in one (cohort 4) and ALT and AST elevation (cohort 4b) in the other. Both subjects recovered upon stopping NVG-111. Average steady-state serum concentration (Cavg.ss) of NVG-111 in serum of patients who received a 10µg/day and 30µg/day dose were 168-288pg/mL and 425-610pg/mL respectively. This was in line with the predicted drug levels from the single species allometric scaling. Evidence of T cell activation was observed in all evaluable subjects (9/10) with cytokine levels at the 30µg/day dose level being: TNFα, 21±6pg/ml; IL6, 206±178pg/ml; IFNɣ, 7±4pg/ml; and IL10, 47±21pg/ml. Objective clinical responses were observed in 66% of subjects and included 2 MRD4 negative clinical remissions (CR). These two subjects remained in MRD4 negative CRs at 6 months after completion of treatment. Conclusion: Early data shows that NVG-111 is generally well tolerated with a predictable and manageable safety profile. Promising evidence of efficacy was observed which appears to be durable in two subjects with MRD4 negative CR. Dose escalation is ongoing in combination or as monotherapy to determine the MTD/RP2D.

e19505 Background: Receptor tyrosine kinase-like Orphan Receptor-1 (ROR1) is widely expressed on hematological and solid tumors. NVG-111, a first in class humanized tandem scFv ROR1xCD3 bispecific antibody elicits potent killing of ROR1+ tumor cells in vitro and in vivo. This bispecific T-cell engager (TCE) is being evaluated in a first in human, Phase I trial in patients with relapsed/refractory chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). The predicted therapeutic dose and steady state serum concentrations of NVG-111 were estimated by allometric scaling using relevant doses from a murine PK study. To assess free drug levels in patients following 21 days of continuous infusion of NVG-111, a bespoke, sensitive pharmacokinetics (PK) assay with high levels of specificity and sensitivity was developed. Methods: Anti-idiotype (anti-ID) antibodies directed to anti-ROR1 (αROR1-ID) and anti-CD3 (αCD3-ID) were generated by mouse immunization or by phage display from customized libraries. A proof-of-concept sandwich ELISA assay was developed using αCD3-ID to capture NVG-111 and detection by biotinylated hROR1-streptavidin-HRP. Gyrolab and Quanterix Simoa high sensitivity ELISA platforms were used to detect NVG-111 by αCD3-ID capture and αROR1-ID detection. The mesoscale discovery electrochemiluminescence assay (MSD-ECLA) was developed using a reversed format; NVG-111 capture with αROR1-ID and detection with αCD3-ID. Results: Allometric scaling predicted a theoretically relevant therapeutic dose and steady state serum concentration of 1ng/mL NVG-111 in humans, which was just at the level of sensitivity of a conventional ELISA under non-matrix conditions. Transferring the format to Quanterix Simoa had limited success due to high background levels in all configurations evaluated. The Gyrolab platform increased sensitivity to 75pg/mL, but suboptimal individual human sera matrix selectivity limited assay validity. Assessment of MSD-ECLA provided the best signal/noise, enhanced human disease and healthy sera selectivity, and a dynamic sensitivity range of 250pg/mL to 32ng/mL, which enabled the development of a GCLP qualified PK assay. The MSD-ECLA assay was employed to measure NVG-111 concentrations in CLL or MCL subjects dosed with 0.3-30µg/day NVG-111. MSD-ECLA detected drug in patients receiving NVG-111, with a range of steady-state serum concentrations (Cavg.ss) of 168-610pg/mL. This was in-line with the predicted drug levels from the single species allometric scaling, albeit with observed levels being marginally lower than expected. Conclusions: Development, custom optimization and validation of a highly sensitive MSD-ECLA PK assay has enabled GCLP-compliant measurement of circulating NVG-111 in CLL or MCL patients treated with at least 10µg/day cIV NVG-111.

People with post-COVID conditions can have a wide range of symptoms lasting months and it can affect as many as one in five infected people. Interferon beta (IFN-β) is key in host defence against viruses but can be suppressed by virus or host factors locally at the site of infection. Inhalation of SNG001 (IFN-β-1a nebuliser solution) aims to restore lung IFN-β levels. SPRINTER (NCT04732949) was a RCT of inhaled interferon beta in hospitalised COVID-19. There was no effect of SNG001 on the primary endpoints of time to discharge or recovery most likely due to improvements in the standard of care. However, there was an encouraging signal for the key secondary endpoint of prevention of progression to severe disease or death (ITT 26% relative risk reduction [RRR]; Odds Ratio [95% CI]: 0.71 [0.44, 1.15]; Per Protocol 36% RRR; OR 0.63 [0.35, 1.13]). Post hoc analyses showed enhanced effects favouring SNG001 in subgroups at higher risk of progression. We report on the impact of SNG001 on long COVID symptoms in SPRINTER. Patients requiring low-flow oxygen were randomized to receive SNG001 (314) or placebo (309) once daily for 14 days, plus standard-of-care. Long COVID symptoms were assessed as a secondary endpoint at follow-up visits via telephone/video call on Day 60 and Day 90. The following patient reported outcome (PRO) measures were also assessed: General Anxiety Disorder 7 Questionnaire (GAD-7), Patient Health Questionnaire-9 (PHQ-9), Functional Assessment of Chronic Illness Therapy (FACIT) - Fatigue Scale and Brief Pain Inventory (Short Form). When compared to placebo, SNG001 reduced the relative risk of common symptoms of long COVID (fatigue/malaise [RRR=35.4%]; dyspnoea [RRR=28.3%]; loss of smell and/or taste [RRR=61.4%]). Analysis of the PROs is ongoing. Assessment of COVID symptoms at Day 60 and 90 follow up visits Effect of SNG001 treatment on long COVID symptoms Long COVID can leave patients with lingering cognitive, respiratory, and functional symptoms months after a SARS-CoV-2 infection. Given the shift from pandemic to endemic status for COVID-19 and the need for new treatments then these findings, suggesting SNG001 may be impacting common long COVID symptoms, provide additional support for the further investigation of SNG001. Phillip D. Monk, PhD, Synairgen Plc (Employed by Synairgen Research Ltd which is a subsidiary of Synairgen Plc, Stocks/Bonds): Board Member|Synairgen Plc (Employed by Synairgen Research Ltd which is a subsidiary of Synairgen Plc, Stocks/Bonds): Stocks/Bonds Victoria J. Tear, PhD, Synairgen Plc (Employed by Synairgen Research Ltd which is a subsidiary of Synairgen Plc, Stocks/Bonds): Stocks/Bonds Jody L. Brookes, BSc, Synairgen Plc (Employed by Synairgen Research Ltd which is a subsidiary of Synairgen Plc, Stocks/Bonds): Stocks/Bonds Marcin Mankowski, MD, MFPM (Dis), CytoDyn: Advisor/Consultant|Entasis: Advisor/Consultant|ImmuPharma: Advisor/Consultant|Menarini: Advisor/Consultant|Pfizer: Advisor/Consultant|Synairgen: Advisor/Consultant|Venatorx: Advisor/Consultant Ratko Djukanovic, MD, Synairgen: Advisor/Consultant|Synairgen: Honoraria|Synairgen: Stocks/Bonds Stephen T. Holgate, FMedSci, MD, Synairgen: Board Member|Synairgen: Non executive board director, patent on inhaled interferon beta|Synairgen: Stocks/Bonds chris brightling, FMedSci, Synairgen: Advisor/Consultant|Synairgen: Grant/Research Support Tom Wilkinson, PhD, PhD, AZ: Grant/Research Support|AZ: Honoraria|My mhealth: Board Member|My mhealth: Ownership Interest|My mhealth: Stocks/Bonds|Synairgen: Grant/Research Support|Synairgen: Honoraria.

Rationale: Interferon beta (IFN-β) is key in host defence against viruses but can be suppressed by virus or host factors locally at the site of infection. Inhalation of SNG001 (IFN-β-1a nebuliser solution) aims to restore lung IFN-β levels. Methods: Adults hospitalised due to COVID-19 requiring low flow oxygen were randomized to receive SNG001 (314) or placebo (309) OD for 14 days, plus standard-of-care. Efficacy was assessed by change in clinical condition using the WHO 9-point Ordinal Scale for Clinical Improvement (OSCI). Primary endpoints: time to discharge (OSCI ≤2) and time to recovery (OSCI ≤1). Key secondary endpoints: progression to severe disease or death (OSCI ≥5), progression to intubation or death (OSCI ≥6), and death. Results: Most patients were discharged rapidly from hospital and there was no effect of SNG001 on time to discharge or recovery. However, there was an encouraging signal for prevention of progression to severe disease or death (ITT 26% relative risk reduction (RRR); Odds Ratio (95% CI): 0.71 (0.44, 1.15); Per Protocol 36% RRR; OR 0.63 (0.35, 1.13)). Post hoc analyses supported this observation with enhanced effects favouring SNG001 in subgroups at higher risk of progression (≥65 years; ≥1 comorbidity; oxygen saturation ≤92% and/or respiratory rate ≥21 breaths/min on oxygen). Conclusion: If the encouraging signal in the relative risk of disease progression or death (~30% reduction) observed in this 300 patient/arm trial were confirmed in a larger trial, SNG001 could become a useful treatment option for hospitalised COVID-19 patients.

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection carries a substantial risk of severe and prolonged illness; treatment options are currently limited. We assessed the efficacy and safety of inhaled nebulised interferon beta-1a (SNG001) for the treatment of patients admitted to hospital with COVID-19.MethodsWe did a randomised, double-blind, placebo-controlled, phase 2 pilot trial at nine UK sites. Adults aged 18 years or older and admitted to hospital with COVID-19 symptoms, with a positive RT-PCR or point-of-care test, or both, were randomly assigned (1:1) to receive SNG001 (6 MIU) or placebo by inhalation via a mouthpiece daily for 14 days. The primary outcome was the change in clinical condition on the WHO Ordinal Scale for Clinical Improvement (OSCI) during the dosing period in the intention-to-treat population (all randomised patients who received at least one dose of the study drug). The OSCI is a 9-point scale, where 0 corresponds to no infection and 8 corresponds to death. Multiple analyses were done to identify the most suitable statistical method for future clinical trials. Safety was assessed by monitoring adverse events for 28 days. This trial is registered with Clinicaltrialsregister.eu (2020-001023-14) and ClinicalTrials.gov (NCT04385095); the pilot trial of inpatients with COVID-19 is now completed.FindingsBetween March 30 and May 30, 2020, 101 patients were randomly assigned to SNG001 (n=50) or placebo (n=51). 48 received SNG001 and 50 received placebo and were included in the intention-to-treat population. 66 (67%) patients required oxygen supplementation at baseline: 29 in the placebo group and 37 in the SNG001 group. Patients receiving SNG001 had greater odds of improvement on the OSCI scale (odds ratio 2·32 [95% CI 1·07–5·04]; p=0·033) on day 15 or 16 and were more likely than those receiving placebo to recover to an OSCI score of 1 (no limitation of activities) during treatment (hazard ratio 2·19 [95% CI 1·03–4·69]; p=0·043). SNG001 was well tolerated. The most frequently reported treatment-emergent adverse event was headache (seven [15%] patients in the SNG001 group and five [10%] in the placebo group). There were three deaths in the placebo group and none in the SNG001 group.InterpretationPatients who received SNG001 had greater odds of improvement and recovered more rapidly from SARS-CoV-2 infection than patients who received placebo, providing a strong rationale for further trials.FundingSynairgen Research.

7549 Background: Receptor tyrosine kinase-like Orphan Receptor 1 (ROR1) is a type I transmembrane protein is highly expressed on an array of haematological and solid tumours. NVG-111 is a humanised, tandem scFv ROR1xCD3 bispecific antibody previously shown to elicit potent killing of tumour cells in vitro and in vivo by engaging a membrane-proximal epitope in the Wnt5a-binding Frizzled domain of ROR1 and redirecting T cell activity. The in vitro potency and pharmacodynamic responses to NVG-111 were assessed to support progression to a first-in-human study. Methods: The potency of NVG-111 in vitro was determined by evaluating the concentration response for cytotoxicity, T cell activation, and cytokine release in co-cultured Jeko-1 and unstimulated human T cells. Comparative data were generated for the marketed CD19xCD3 bispecific antibody, blinatumomab. Potency data for NVG-111 were used together with allometric scaling from murine PK studies to inform planned clinical doses. Results: NVG-111 demonstrated T cell-dependent cytotoxicity, T cell activation and levels of cytokine release similar in potency to blinatumomab. Cytotoxic responses of both NVG-111 and blinatumomab were more potent than T cell activation and cytokine release. Dose response curves for NVG-111 showed a decrease in activity beyond the concentration of maximal response (ie “hook effect”). We hypothesise this is due to receptor saturation, inhibiting synapse formation. NVG-111 has progressed to a Phase 1/2 first-in-human study in patients with debulked, relapsed/refractory chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), the drug given as add-on to ≥2nd line therapy with a Bruton’s tyrosine kinase inhibitor, or venetoclax. Phase 1 includes escalating doses of 0.3 to 360 µg/day via continuous infusion over 3 cycles (each 21 days on, 7 days off) to establish safety, PK, pharmacodynamics (PD) and recommended phase 2 dose (RP2D). Predicted exposure at 0.3 µg/day is ̃EC20 for cytotoxicity in vitro and below the lowest EC10 for cytokine release. PD biomarkers in the study include systemic cytokines. Phase 2 will study efficacy and safety of the RP2D in CLL and MCL, with primary endpoint complete response rate; other efficacy endpoints include minimal residual disease and progression free survival. Conclusions: NVG-111 shows potent T-cell mediated lymphoma cell cytotoxicity in vitro at concentrations well below those associated with extensive cytokine release. NVG-111 is in an ongoing Phase 1/2 study and may present a novel option for adoptive immunotherapy in patients with non-Hodgkin lymphoma and potentially other cancers. Clinical trial information: 2020-000820-20. [Table: see text]

Background: Our knowledge of allergen structure and function continues to rise and new scientific data on the homology and cross-reactivity of allergen sources should be considered to extend the work of Lorenz et al., 2009 (Int Arch Allergy Immunol. 148(1): 1-1, 2009) and the concept of homologous groups. In addition to this, sophisticated techniques such as mass spectrometry (MS) are increasingly utilised to better characterise the complex mix and nature of allergen extracts.Methods: Homology models were used of Fag s 1 (Beech) and Cyn d 1 (Bermuda grass) and compared with template crystal structures of Bet v 1 and Phl p 1 from the 'exemplar' species of Birch and Timothy grass, respectively. ELISA experiments were performed to assess cross-reactivity of Beech (tree) and Bermuda (grass) extracts to rabbit sera raised to either "3-Tree" (Birch, Alder and Hazel) extract or "Grass" (12-grass mix extract), respectively. The comparability of biochemical stability of different allergen sources was assessed through statistical methods for a range of tree and grass species.Results: Allergen cross-reactivity and/or structural homology have been described providing justification for inclusion of Beech within the Birch homologous tree group. Data from Bermuda grass (Cyn d 1) provides further justification for the inclusion of this species into the homologous group of the sweet grasses. However, further characterisation of relevant allergens from Bermuda grass and, in particular, comparison of cross-reactive patterns between subjects specifically in areas with high abundance of both Pooideae and Chloridoideae is sought.Conclusion: MS allows the possibility to identify individual proteins or allergens from complex mixes by mass and/or sequence, and this has been extensively applied to the allergen field. New data on the homology, cross-reactivity and biological parameters of allergen sources have been considered to extend the work of Lorenz et al., 2009 in the context of tree and grass species. The concept of homologous groups is certainly dynamic allowing the flexibility and potential in streamlining quality parameters, such as stability profiles, due to extrapolation of exemplar data to a wider range of allergens.

IntroductionBroad-spectrum grass pollen immunotherapies contain large numbers of allergenic proteins from multiple species. The principle of homologous grouping is used as a tool to assist in the standardization of allergen immunotherapy. This study reviews the principle of homologous grouping, questions what an exemplar grass should be, and queries whether a 1-way system of inferring homology is appropriate.MethodsGrass pollens were extracted and analyzed using a variety of techniques, including enzyme-linked immunosorbent assay, Bradford protein assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and quantitative analysis of Western blots.ResultsVariation in protein content, IgG, IgE, and Phl p 5 reactivity is evident among all grasses analyzed. There is significant evidence of similarity but also disparity consistent with variation resulting from evolutionary change. Proprietary software called Gel Electrophoresis Protein Profile Analysis has been developed, which highlights that each grass exhibits a greater than 55% similarity measure; this is considered high similarity.DiscussionNone of the grass species examined display an identical biological profile. However, data indicate that there is a high degree of homology, and Crested Dogstail is similar to each of the other 12 species analyzed; these levels of similarity can only be possible because of molecular profile and extensive sharing of epitopes. These data are considered to be sufficient to include Crested Dogstail within the sweet grasses group of the Pooideae family; however, the subtle differences in grasses also justify the inclusion of multiple species to create a broad-spectrum immunotherapy.