Biomarkers in COVID-19: Association with disease severity and outcomes

Background: In coronavirus disease 2019 (COVID-19) the need for intervention increases with disease severity and a risk prediction model that incorporates biomarkers would be beneficial for identifying patients for treatment escalation. Aim(s): To investigate biomarkers changes associated with disease severity and outcomes (mortality, thrombosis). Method(s): COVID-19 patients were sampled between April 15 and May 31 2020. Disease severity was assessed by World Health Organization (WHO) ordinal scale. 132 systemic biomarkers were investigated by routine and multiplex assays and statistical analysis performed to characterise the biomarker profile of COVID-19 patients associated with disease severity, duration, survival and thrombosis. Result(s): The study enrolled 150 COVID-19 positive adults and 16 healthy volunteers. The average age was 64 years, 59% were male, 85% had co-morbidities, 33% had a thrombotic event, and 13% died. A cross comparative analysis of biomarkers identified 13 biomarkers common to severity, mortality and thrombosis with significant correlation;including endothelial dysfunction (VWF, tPA, TFPI), hypercatabolism (low albumin, Hb, FXIII) and inflammatory response (IL-8, Osteopontin). Similarly, 14 biomarkers associated with severity and mortality included pro-inflammatory cytokines and their receptors (sTNFRII, STNFRI, sIL2a, IL6, MIP1a), neutrophils (elevated WBC, Neutrophils, TIMP1) and tissue remodelling (SCGF, EG3A). Nine biomarkers common across severity and thrombosis were angiogenesis (VEGF, LYVE1, Follistatin), acute phase response (SAP, AGP) and clot formation (Fibrinogen and PAPs). Conclusion(s): The biomarker profile associated with poorer outcomes indicates an inflammatory response, endothelial cell disruption, hypercoagulability and hypercatabolism. This study has identified several biomarkers that may be useful indicators of disease severity and progression. Further work is needed to determine how these may be used to direct clinical management. (Figure Presented).

HALT - Targeted Therapy with or without Dose-Intensified Radiotherapy in Oligo-Progressive Disease in Oncogene Addicted Lung Tumours

Introduction: Following initial response to TKI, advanced NSCLC patients with actionable mutations ultimately develop treatment resistance. In a proportion of patients (15-40%), initial, limited progression (≤5 lesions) is observed, termed oligoprogressive disease (OPD). SBRT offers hypofractionated, targeted radiotherapy treatment hypothesised to prolong clinical benefit from TKI prior to widespread disease development. With limited evidence to date, and poor clinical/biological selection criteria, the potential benefit offered by SBRT to ablate OPD sites prior to change in systemic therapy is an important question to address. Methods: HALT is a randomised, multi-centre, phase II/III international trial with seamless transition to phase III incorporated. Eligible patients (stage IV NSCLC, actionable mutation, TKI response prior to OPD) are randomised 2:1 to SBRT/continued TKI or continued TKI alone. Eligibility is confirmed by a virtual MDT (vMDT) comprising trial clinicians and radiologists (confirmation of OPD, SBRT suitability). Follow-up assessments are aligned with routine care at 3-monthly intervals until change in systemic therapy is clinically indicated, with imaging and toxicity assessment at each visit. Results: Recruitment commenced November 2017 with 25 centres (17 UK;8 non-UK) open to date. Following the COVID-19 pandemic, recruitment is recovering with 129 registered and 74 randomised patients. Over the last 4 years, little evidence has emerged to confirm any potential benefit of SBRT in this patient group and the impact on patient toxicity remains unknown. Therefore, with persisting questions around clinical equipoise, HALT remains highly relevant. With an 18-month extension and a recent amendment to the HALT inclusion criteria (≤5 OPD lesions, ≤7cm and OPD assessments by PET-avidity), the target of 110 randomised patients remains achievable. Conclusions: As the first randomised trial assessing SBRT benefit in this mutation-positive NSCLC patient population, HALT will provide valuable treatment efficacy and safety information, informing subsequent trial design and contribute to the development of international guidelines for the identification and clinical management of oligoprogression in mutation positive lung cancer. Keywords: Stereotactic body radiotherapy, NSCLC, Phase II

The effect of anti-cancer therapy on immunological response to COVID-19 vaccination

Background: The efficacy of SARS-COV-2 vaccination has been demonstrated in healthy individuals. Immune responses are less well characterised in cancer patient groups, especially those receiving anticancer therapy (e.g. immune therapy, chemotherapy and targeted therapies. We aim to assess the immune response to the SARS-COV-2 vaccination in patients with solid organ cancer on different systemic anti-cancer therapies. Methods: All patients received 2 doses of COVID-19 mRNA vaccination as part of the UK National vaccination programme;with the second booster dose administered within 12 weeks of the first dose. All patients received either BNT162b2 (Pfizer/BioNTech) or ChAdOx1 S (AstraZeneca) vaccines. Sequential serum samples were collected pre-booster dose vaccination (baseline/within -30 days) and after second dose SARS-COV-2 vaccination, at 14-35 days and 36-63 days. Presence and titres of serum Anti-SARS-CoV-2 Spike protein (S) antibody titres were measured. Seroconversion is defined as a response >0.8 U/ml, and maximum response to Anti-S is defined as >250 U/ml. Responses were measured in 3 patient groups according to the type of anti-cancer therapy: chemotherapy (CHT group), immune therapy (IO group) and targeted therapies, mainly VEGF TKI (TT group). Results: Overall, 61 patients were recruited: 45.9%(28/61) in CHT group, 32.8% (20/61) in IO group and 21.3% (13/61) in the TT group. Baseline characteristics were comparable between patient groups. In response to the booster dose vaccination at 14-35 days, the number of patients who seroconverted was 79.3% (23/29), 94.7% (18/19) and 84.6% (11/13) in the CHT, IO and TT groups, respectively. At this same time point, 51.7% (15/29) in the CHT group achieved maximum anti-S titre levels (>250 U/ml), compared with 78.9% (15/19) of patients in IO group and 69.2% (9/13) of patients in TT group. All 3 groups demonstrated a significant increase in Anti-S antibodies at 14-35 days after second dose vaccine when compared to pre-booster serum levels, with the largest increase seen in the IO group with a mean Anti-S increase of 149.1 U/ml (SD±105.0, p < 0.0001) followed by the TT group mean increase 120.2 U/ml (SD ±110.8, p < 0.01) and the CHT group, mean increase 83.0 U/ml (SD ±108.4, p < 0.001). Anti-S antibody levels were sustained at 36-63 days post-booster across all groups. However only IO patients had a sustained immune response to vaccination, with median Anti-S titres level of >250 U/ml and a significant drop was seen in the CHT group (median Anti-S level 138, p < 0.05). Conclusions: Anti-S titres increase following vaccination in all 3 groups but remain most sustained in the IO group at 36-63 days post-vaccination. Chemotherapy and other targeted therapy treated patients may benefit from early COVID-19 vaccine boosters, compared to patients receiving immune therapy.

171 HALT: targeted therapy with or without dose-intensified radiotherapy in oligo-progressive disease in oncogene addicted lung tumours

Background: Following initial response to TKI, advanced NSCLC patients with actionable mutations ultimately develop treatment resistance. In a proportion of patients (15-40%), initial, limited progression (<3 lesions) is observed, termed oligoprogressive disease (OPD). SBRT offers hypofractionated, targeted radiotherapy treatment hypothesised to prolong clinical benefit from TKI prior to widespread disease development. The potential benefit offered by SBRT to ablate OPD sites prior to change in systemic therapy is an important question to address, particularly during the current pandemic, where reducing clinic visits is particularly advantageous. Method: HALT is a randomised, multi-centre, phase II/III international trial with seamless transition to phase III incorporated. Eligible patients (stage IV NSCLC, actionable mutation, TKI response prior to OPD) are randomised 2:1 to SBRT/continued TKI or continued TKI alone. Eligibility is confirmed by a virtual MDT comprising trial clinicians and radiologists (OPD, SBRT suitability). Follow-up assessments aligned with routine care at 3-monthly intervals until change in systemic therapy is clinically indicated, imaging and toxicity assessment at each visit. Current status: Recruitment commenced November 2017;27 centres (16 UK;11 non-UK) open to date (09/03/2021), 94 patients registered and 50 randomised. Because of the COVID-19 pandemic, recruitment was temporarily paused on 20/03/2020 and restarted in accordance with national guidelines on 16/06/2020. Of 94 patients registered, vMDT review performed for 74 patients (18 screen fails prior to vMDT);50 randomised, 22 confirmed ineligible via vMDT (inc. >3 lesions, lesion >5cm, intracranial disease identified). Conclusion: The vMDT remains an important, novel aspect of the trial, ensuring robust patient selection ahead of randomisation. As the first randomised trial assessing SBRT benefit in this patient population, HALT will provide valuable treatment efficacy and safety information, informing subsequent trial design and contribute to the development of international guidelines for the identification and clinical management of oligoprogression in mutation positive lung cancer. Disclosure: No significant relationships.

The link between inflammation, coagulation and endothelium damage in COVID-19: Evidence from an exploratory crosssectional study

Background: Increasing evidence suggests that endothelial activation and dysfunction contribute to COVID-19 pathogenesis by altering vessel integrity, promoting pro-coagulative and inflammatory state. Aims: 1. Investigate changes in coagulation, inflammation and endothelium associated with the progression and severity of COVID-19, as well as their correlation to survival and/or occurrence of venous thromboembolic events (VTE). 2. Explore potential new biomarkers to predict COVID-19 severity. Methods: Samples were collected from COVID-19 patients after appropriate consent. Disease severity was assessed with WHO ordinal scale on day of sampling. In addition to routine haematology, biochemistry and coagulation analysis, additional analysis spanning coagulation, endothelium, platelet, inflammatory biomarkers by conventional assays and multiplex immuno-assays were undertaken. Results: Participants included 151 COVID-19 patients aged 18 years and greater, 16 healthy volunteers and 9 non-COVID-19 ICUcontrols. COVID-19 patients were categorised in 7 groups based on severity and time from symptom onset and the data also provides mortality and VTE rates (Table 1). The biomarker profile of hospitalised COVID-19 patients demonstrated an increase in plasma levels of cytokines, inflammatory, soluble endothelial cell markers and markers of coagulation activation when compared to the ambulatory group (Figure 1). Significantly higher levels of inflammatory markers (CRP, WBC, fibrinogen, serum amyloid P, alpha 1 acid glycoprotein) were observed in patients with VTE and in the non-survivors group. Interestingly, the same trend was seen for coagulation (FVIII, VWF) and fibrinolysis markers (D-dimer, TFPI, t-PA) with higher levels in the VTE and non-survivors group. In addition, higher plasma levels of endothelial markers (ICAM-1, angiopoietin, TIE-2, LYVE-1, syndecan) were observed in severe COVID-19 when compared to non-COVID-19 ICU-controls. (Figure Presented) Conclusions: Our study provides evidence of a strong, global inflammatory response in COVID-19 patients. The elevation of circulating markers suggests significant endothelial cell activation/dysfunction and a possible cause for the pro-coagulant phenotype observed in these patients.

LATE-BREAKING AND COVID-19 ORAL COMMUNICATION SESSION ABSTRACTS

FLT180a is an investigational gene therapy medicinal product candidate intended for treating HB patients. It includes a novel synthetic capsid, AAVS3, with a higher liver transduction efficiency than wild type AAV, and a codon optimised F9 gene with a gain of function mutation. To assess the safety and efficacy of a single systemic adminis-tration of FLT180a in adult patients with HB. Phase 1/2, multi- centre, ongoing, open- label and long- term follow- up study assessing FLT180a dose levels in an escalating/descending adaptive design, to identify a dose that consistently normalises FIX activity (50- 150%). Participants have severe or moderately severe HB and are negative for neutralis-ing AAVS3 antibodies. Pre- emptive immunosuppression is given to mitigate vector related transaminitis and associated reduction in FIX expression. Ten patients with severe HB have been treated across 4 dose levels, with week 3 FIX activity levels ranging between 24 and 168%. The first two patients, receiving the 4.5e11vg/Kg dose, have stable, therapeutic, FIX activity levels through week 104. No patient has had a bleeding episode requiring FIX concentrates. The most common drug related serious adverse event was transient transaminitis (in four patients) requiring supplemental immunosup-pression. FIX activity levels above 150% have been observed, which were individually assessed for risk of thrombosis, and one patient is being treated with DOACs. Refinement of the immunosuppression regimen for the latest three patients (9.75e11 vg/kg dose) prevented transaminitis during the critical phase (4- 16 weeks). FLT180a achieves clinically meaningful, dura-ble FIX activity levels in patients with HB, associated with in-dependence from FIX replacement therapy and zero treated bleeds. Transient transaminitis was largely averted by prophy-lactic immunosuppression. A dose between 7.5 to 9.75e11vg/Kg can potentially create sustained, normal FIX activity levels in patients with severe HB.