Structure-Based Optimization of ML300-Derived, Noncovalent Inhibitors Targeting the Severe Acute Respiratory Syndrome Coronavirus 3CL Protease (SARS-CoV-2 3CLpro).

Starting from the MLPCN probe compound ML300, a structure-based optimization campaign was initiated against the recent severe acute respiratory syndrome coronavirus (SARS-CoV-2) main protease (3CLpro). X-ray structures of SARS-CoV-1 and SARS-CoV-2 3CLpro enzymes in complex with multiple ML300-based inhibitors, including the original probe ML300, were obtained and proved instrumental in guiding chemistry toward probe compound 41 (CCF0058981). The disclosed inhibitors utilize a noncovalent mode of action and complex in a noncanonical binding mode not observed by peptidic 3CLpro inhibitors. In vitro DMPK profiling highlights key areas where further optimization in the series is required to obtain useful in vivo probes. Antiviral activity was established using a SARS-CoV-2-infected Vero E6 cell viability assay and a plaque formation assay. Compound 41 demonstrates nanomolar activity in these respective assays, comparable in potency to remdesivir. These findings have implications for antiviral development to combat current and future SARS-like zoonotic coronavirus outbreaks.

Impact of COVID-19 on infliximab prescribing practices in inflammatory bowel disease

PMO-21 Table 1 Oct 19 Nov 19 Dec 19 Jan 20 Feb 20 Mar 20 Apr 20 May 20 Jun 20 Jul 20 No. of tests with complete prescribing data 66 67 70 66 72 71 45 55 71 56 No. on CI % of tests 30 38 36 35 33 33 20 31 35 16 45.5% 56.7% 51.4% 53.0% 45.8% 46.5% 44.4% 56.4% 49.3% 28.6% Thiopurine specifically % of tests 24 24 26 24 22 25 17 22 27 14 36.4% 35.8% 37.1% 36.4% 30.6% 35.2% 37.8% 40.0% 38.0% 25.0% Non standard dosing % of tests 33 30 37 37 34 39 19 32 43 28 50.0% 44.8% 52.9% 56.1% 47.2% 54.9% 42.2% 58.2% 60.6% 50.0% Proactive TDM 42 50 39 42 43 48 31 34 40 31 ConclusionsOur data suggests prescribing practices remain largely static. However July 2020’s drop in CI prescribing may be an early indicator of decreased use. The small rise in non-standard dosing may be due to COVID-19 strategies employed to reduce hospital attendances and requires further review. While the nature of our data will not convey the complete COVID-19 impact, it highlights the need for stringent review of post-COVID-19 clinical practices, patient outcomes, and updated clinical guidance as our understanding of the COVID-19 impact on IBD develops.ReferencesShields S, et al. Frontline Gastroenterology Published Online First: 30 September 2020. doi: 10.1136/flgastro-2020-101563Ungaro RC, et al. Gut Published Online First: 20 October 2020. doi: 10.1136/gutjnl-2020-322539

Adalimumab and Infliximab Impair SARS-CoV-2 Antibody Responses: Results from a Therapeutic Drug Monitoring Study in 11 422 Biologic-Treated Patients.

BACKGROUND AND AIMS: Infliximab attenuates serological responses to SARS-CoV-2 infection. Whether this is a class effect, or if anti-tumour necrosis factor [anti-TNF] level influences serological responses, remains unknown. METHODS: Seroprevalence and the magnitude of SARS-CoV-2 nucleocapsid antibody responses were measured in surplus serum from 11 422 (53.3% [6084] male; median age 36.8 years) patients with immune-mediated inflammatory diseases, stored at six therapeutic drug monitoring laboratories between January 29 and September 30, 2020. Data were linked to nationally held SARS-CoV-2 PCR results to July 11, 2021. RESULTS: Rates of PCR-confirmed SARS-CoV-2 infection were similar across treatment groups. Seroprevalence rates were lower in infliximab- and adalimumab- than vedolizumab-treated patients (infliximab: 3.0% [178/5893], adalimumab: 3.0% [152/5074], vedolizumab: 6.7% [25/375], p = 0.003). The magnitude of SARS-CoV-2 reactivity was similar in infliximab- vs adalimumab-treated patients (median 4.30 cut-off index [COI] [1.94-9.96] vs 5.02 [2.18-18.70], p = 0.164), but higher in vedolizumab-treated patients (median 21.60 COI [4.39-68.10, p < 0.004). Compared to patients with detectable infliximab and adalimumab drug levels, patients with undetectable drug levels [<0.8 mg/L] were more likely to be seropositive for SARS-CoV-2 antibodies. One-third of patients who had PCR testing prior to antibody testing failed to seroconvert, all were treated with anti-TNF. Subsequent positive PCR-confirmed SARS-CoV-2 was seen in 7.9% [12/152] of patients after a median time of 183.5 days [129.8-235.3], without differences between drugs. CONCLUSION: Anti-TNF treatment is associated with lower SARS-CoV-2 nucleocapsid seroprevalence and antibody reactivity when compared to vedolizumab-treated patients. Higher seropositivity rates in patients with undetectable anti-TNF levels support a causal relationship, although confounding factors, such as combination therapy with a immunomodulator, may have influenced the results.

Anti-SARS-CoV-2 antibody responses are attenuated in patients with IBD treated with infliximab.

OBJECTIVE: Antitumour necrosis factor (anti-TNF) drugs impair protective immunity following pneumococcal, influenza and viral hepatitis vaccination and increase the risk of serious respiratory infections. We sought to determine whether infliximab-treated patients with IBD have attenuated serological responses to SARS-CoV-2 infections. DESIGN: Antibody responses in participants treated with infliximab were compared with a reference cohort treated with vedolizumab, a gut-selective anti-integrin α4ß7 monoclonal antibody that is not associated with impaired vaccine responses or increased susceptibility to systemic infections. 6935 patients were recruited from 92 UK hospitals between 22 September and 23 December 2020. RESULTS: Rates of symptomatic and proven SARS-CoV-2 infection were similar between groups. Seroprevalence was lower in infliximab-treated than vedolizumab-treated patients (3.4% (161/4685) vs 6.0% (134/2250), p<0.0001). Multivariable logistic regression analyses confirmed that infliximab (vs vedolizumab; OR 0.66 (95% CI 0.51 to 0.87), p=0.0027) and immunomodulator use (OR 0.70 (95% CI 0.53 to 0.92), p=0.012) were independently associated with lower seropositivity. In patients with confirmed SARS-CoV-2 infection, seroconversion was observed in fewer infliximab-treated than vedolizumab-treated patients (48% (39/81) vs 83% (30/36), p=0.00044) and the magnitude of anti-SARS-CoV-2 reactivity was lower (median 0.8 cut-off index (0.2-5.6) vs 37.0 (15.2-76.1), p<0.0001). CONCLUSIONS: Infliximab is associated with attenuated serological responses to SARS-CoV-2 that were further blunted by immunomodulators used as concomitant therapy. Impaired serological responses to SARS-CoV-2 infection might have important implications for global public health policy and individual anti-TNF-treated patients. Serological testing and virus surveillance should be considered to detect suboptimal vaccine responses, persistent infection and viral evolution to inform public health policy. TRIAL REGISTRATION NUMBER: ISRCTN45176516.

Disease monitoring of biologic treatment in IBD: early impact and future implications of COVID-19 pandemic.

COVID-19 has dominated life in 2020 with, at the time of writing, over 4.9M global cases and >320 000 deaths. The impact has been most intensely felt in acute and critical care environments. However, with most UK elective work postponed, laboratory testing of faecal calprotectin halted due to potential risk of viral transmission and non-emergency endoscopies and surgeries cancelled, the secondary impact on chronic illnesses such as inflammatory bowel disease (IBD) is becoming apparent. Data from the Scottish Biologic Therapeutic Drug Monitoring (TDM) service shows a dramatic drop in TDM testing since the pandemic onset. April 2020 saw a 75.6% reduction in adalimumab testing and a 36.2% reduction in infliximab testing when compared with February 2020 data, a reduction coinciding with the widespread cancellation of outpatient and elective activity. It is feared that disruption to normal patterns of care and disease monitoring of biologic patients could increase the risk of disease flare and adverse clinical outcomes. Urgent changes in clinical practice have been instigated to mitigate the effects of the pandemic on routine clinical care. Further transformations are needed to maintain safe, effective, patient-centred IBD care in the future.

Infliximab is associated with attenuated immunogenicity to BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines in patients with IBD.

OBJECTIVE: Delayed second dose SARS-CoV-2 vaccination trades maximal effectiveness for a lower level of immunity across more of the population. We investigated whether patients with inflammatory bowel disease treated with infliximab have attenuated serological responses to a single dose of a SARS-CoV-2 vaccine. DESIGN: Antibody responses and seroconversion rates in infliximab-treated patients (n=865) were compared with a cohort treated with vedolizumab (n=428), a gut-selective anti-integrin α4ß7 monoclonal antibody. Our primary outcome was anti-SARS-CoV-2 spike (S) antibody concentrations, measured using the Elecsys anti-SARS-CoV-2 spike (S) antibody assay 3-10 weeks after vaccination, in patients without evidence of prior infection. Secondary outcomes were seroconversion rates (defined by a cut-off of 15 U/mL), and antibody responses following past infection or a second dose of the BNT162b2 vaccine. RESULTS: Geometric mean (SD) anti-SARS-CoV-2 antibody concentrations were lower in patients treated with infliximab than vedolizumab, following BNT162b2 (6.0 U/mL (5.9) vs 28.8 U/mL (5.4) p<0.0001) and ChAdOx1 nCoV-19 (4.7 U/mL (4.9)) vs 13.8 U/mL (5.9) p<0.0001) vaccines. In our multivariable models, antibody concentrations were lower in infliximab-treated compared with vedolizumab-treated patients who received the BNT162b2 (fold change (FC) 0.29 (95% CI 0.21 to 0.40), p<0.0001) and ChAdOx1 nCoV-19 (FC 0.39 (95% CI 0.30 to 0.51), p<0.0001) vaccines. In both models, age ≥60 years, immunomodulator use, Crohn's disease and smoking were associated with lower, while non-white ethnicity was associated with higher, anti-SARS-CoV-2 antibody concentrations. Seroconversion rates after a single dose of either vaccine were higher in patients with prior SARS-CoV-2 infection and after two doses of BNT162b2 vaccine. CONCLUSION: Infliximab is associated with attenuated immunogenicity to a single dose of the BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines. Vaccination after SARS-CoV-2 infection, or a second dose of vaccine, led to seroconversion in most patients. Delayed second dosing should be avoided in patients treated with infliximab. TRIAL REGISTRATION NUMBER: ISRCTN45176516.

SARS-CoV-2 vaccination for patients with inflammatory bowel disease: a British Society of Gastroenterology Inflammatory Bowel Disease section and IBD Clinical Research Group position statement.

SARS-CoV-2 has caused a global health crisis and mass vaccination programmes provide the best opportunity for controlling transmission and protecting populations. Despite the impressive clinical trial results of the BNT162b2 (Pfizer/BioNTech), ChAdOx1 nCoV-19 (Oxford/AstraZeneca), and mRNA-1273 (Moderna) vaccines, important unanswered questions remain, especially in patients with pre-existing conditions. In this position statement endorsed by the British Society of Gastroenterology Inflammatory Bowel Disease (IBD) section and IBD Clinical Research Group, we consider SARS-CoV-2 vaccination strategy in patients with IBD. The risks of SARS-CoV-2 vaccination are anticipated to be very low, and we strongly support SARS-CoV-2 vaccination in patients with IBD. Based on data from previous studies with other vaccines, there are conceptual concerns that protective immune responses to SARS-CoV-2 vaccination may be diminished in some patients with IBD, such as those taking anti-TNF drugs. However, the benefits of vaccination, even in patients treated with anti-TNF drugs, are likely to outweigh these theoretical concerns. Key areas for further research are discussed, including vaccine hesitancy and its effect in the IBD community, the effect of immunosuppression on vaccine efficacy, and the search for predictive biomarkers of vaccine success.