Serum AZD7442 (tixagevimab-cilgavimab) concentrations and in vitroIC50 values predict SARS-CoV-2 neutralising antibody titres.

Objectives: The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) necessitates rapid methods for assessing monoclonal antibody (mAb) potency against emerging variants. Authentic virus neutralisation assays are considered the gold standard for measuring virus-neutralising antibody (nAb) titres in serum. However, authentic virus-based assays pose inherent practical challenges for measuring nAb titres against emerging SARS-CoV-2 variants (e.g. storing infectious viruses and testing at biosafety level-3 facilities). Here, we demonstrate the utility of pseudovirus neutralisation assay data in conjunction with serum mAb concentrations to robustly predict nAb titres in serum. Methods: SARS-CoV-2 nAb titres were determined via authentic- and lentiviral pseudovirus-based neutralisation assays using serological data from three AZD7442 (tixagevimab-cilgavimab) studies: PROVENT (NCT04625725), TACKLE (NCT04723394) and a phase 1 dose-ranging study (NCT04507256). AZD7442 serum concentrations were assessed using immunocapture. Serum-based half-maximal inhibitory concentration (IC50) values were derived from pseudovirus nAb titres and serum mAb concentrations, and compared with in vitro IC50 measurements. Results: nAb titres measured via authentic- and lentiviral pseudovirus-based neutralisation assays were strongly correlated for the ancestral SARS-CoV-2 virus and SARS-CoV-2 Alpha. Serum AZD7442 concentrations and pseudovirus nAb titres were strongly correlated for multiple SARS-CoV-2 variants with all Spearman correlation coefficients ≥ 0.78. Serum-based IC50 values were similar to in vitro IC50 values for AZD7442, for ancestral SARS-CoV-2 and Alpha, Delta, Omicron BA.2 and Omicron BA.4/5 variants. Conclusions: These data highlight that serum mAb concentrations and pseudovirus in vitro IC50 values can be used to rapidly predict nAb titres in serum for emerging and historical SARS-CoV-2 variants.

New variants of COVID-19 (XBB.1.5 and XBB.1.16, the "Arcturus"): A review of highly questioned concerns, a brief comparison between different peaks in the COVID-19 pandemic, with a focused systematic review on expert recommendations for prevention, vaccination, and treatment measures in the general population and at-risk groups.

INTRODUCTION: The COVID-19 pandemic has taken many forms and continues to evolve, now around the Omicron wave, raising concerns over the globe. With COVID-19 being declared no longer a "public health emergency of international concern (PHEIC)," the COVID pandemic is still far from over, as new Omicron subvariants of interest and concern have risen since January of 2023. Mainly with the XBB.1.5 and XBB.1.16 subvariants, the pandemic is still very much "alive" and "breathing." METHODS: This review consists of five highly concerning questions about the current state of the COVID Omicron peak. We searched four main online databases to answer the first four questions. For the last one, we performed a systematic review of the literature, with keywords "Omicron," "Guidelines," and "Recommendations." RESULTS: A total of 31 articles were included. The main symptoms of the current Omicron wave include a characteristically high fever, coughing, conjunctivitis (with itching eyes), sore throat, runny nose, congestion, fatigue, body ache, and headache. The median incubation period of the symptoms is shorter than the previous peaks. Vaccination against COVID can still be considered effective for the new subvariants. CONCLUSION: Guidelines recommend continuation of personal protective measures, third and fourth dose boosters, along with administration of bivalent messenger RNA vaccine boosters. The consensus antiviral treatment is combination therapy using Nirmatrelvir and Ritonavir, and the consensus for pre-exposure prophylaxis is Tixagevimab and Cilgavimab combination. We hope the present paper raises awareness for the continuing presence of COVID and ways to lower the risks, especially for at-risk groups.

Tixagevimab/cilgavimab prophylaxis against COVID-19 in solid organ transplant recipients: a systematic review and meta-analysis.

Background: Tixagevimab/cilgavimab (Tix/Cil) shows promise as a prophylactic treatment against coronavirus disease 2019 (COVID-19) in solid organ transplant recipients (SOTRs). This study was performed to assess the effectiveness of Tix/Cil for preexposure prophylaxis against COVID-19 in this population. Methods: We systematically searched the Cochrane Library, Web of Science, PubMed, and Embase databases to identify articles relevant to our study up to December 15, 2023. Comprehensive Meta-Analysis (ver. 3.0) was used for data analysis. Results: The meta-analysis included seven eligible retrospective studies, encompassing a total of 4,026 SOTRs. The analysis revealed significant differences in SOTRs who received Tix/Cil preexposure prophylaxis relative to those who did not. Specifically, these differences were observed in the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (odds ratio [OR], 0.30; 95% confidence interval [CI], 0.15-0.60), hospitalization (OR, 0.24; 95% CI, 0.08-0.70), and intensive care unit admission (OR, 0.07; 95% CI, 0.02-0.22). However, mortality rate did not differ significantly between the two groups (P=0.06). Conclusions: The evidence supporting the effectiveness of Tix/Cil as preexposure prophylaxis against SARS-CoV-2 in SOTRs is of a low to moderate level. Further high-quality research is necessary to understand its effects on this population.

Risk of SARS-CoV-2 infection and severe COVID-19 in hematological patients who received or not pre-exposure prophylaxis with tixagevimab/cilgavimab: a target trial emulation.

We emulated a hypothetical target trial in which hematological subjects cared at the University Hospital of Pisa (Italy) received or not SARS-CoV-2 prophylaxis with tixagevimab/cilgavimab. Subjects who received prophylaxis (cases) were compared to those who did not (controls). The main outcome was SARS-CoV-2 infection in the subsequent 6 months. Inverse probability weighting (IPW) was used to adjust for confounders. A multivariable analysis was performed to identify variables associated with SARS-CoV-2 infection. We recruited 462 patients: 228 received prophylaxis, 234 were controls. COVID-19 was lower in cases compared to controls (16.7% vs 24.8%, p = 0.03, after IPW 14.3% vs 24.6%, p = 0.01). On multivariable analysis, B-cell depleting therapies (HR 2.09, 95%CI 1.05-4.18, p = 0.037) were associated with increased risk of COVID-19, while tixagevimab/cilgavimab prophylaxis (HR 0.45, 95%CI 0.27-0.73, p = 0.001) and previous SARS-CoV-2 infection (HR 0.27, 95%CI 0.14-0.51, p < 0.001) were protective. In conclusion, prophylaxis with monoclonal antibodies may reduce the risk of COVID-19 in hematological patients.

Effectiveness of tixagevimab/cilgavimab in reducing SARS-CoV-2 infections, hospitalizations and mortality in inmunocompromised patients. / Efectividad de tixagevimab/cilgavimab en la reducción de la infección, ingresos hospitalarios y mortalidad por SARS-CoV-2 en pacientes inmunodeprimidos.

INTRODUCTION: Inmunocompromised people have higher SARS-CoV-2 morbi-mortality and they are subsidiary to receive pre-exposure prophylaxis. The objective of this study is to evaluate the effectiveness of tixagevimab/cilgavimab (Evusheld) in preventing SARS-CoV-2 infections, hospitalizations and mortality in immunocompromised patients. MATERIALS AND METHODS: 119 immunocompromised people>18 years old eligible of receiving Evusheld were followed for 6 months. People with previous SARS-CoV-2 infection or incomplete vaccination regimen were exluded. A total of 19 people who received Evusheld were matched by propensity score, using a 1:1 ratio, with another 19 people who did not receive Evusheld. Sociodemographic, related to SARS-CoV-2 risk factors and related to immunosuppression variables were included. The dependent variables were infection, hospitalization, and mortality related to SARS-CoV-2. Statistical analyzes were performed using SPSS Statistics 19.0, STATA 11.0, and the R statistical package. RESULTS: In total, 4 people in the Evusheld group and 11 in the control group had SARS-CoV-2 infection, showing an incidence rate of 3.87 and 13.62 per 100 person-months, respectively. The HR (Hazard Ratio) was 0.29 (95% CI=0.09-0.90) for SARS-CoV-2 infection, 0.37 (0.07-1.92) for SARS-CoV-2 hospitalization and, 0.23 (0.03-2.09) for SARS-CoV-2 mortality in the Evusheld group compared to control group. CONCLUSIONS: This study demonstrates that Evusheld reduces the SARS-CoV-2 infections.

Molnupiravir increases SARS-CoV-2 genome diversity and complexity: A case-control cohort study.

Molnupiravir, an oral direct-acting antiviral effective in vitro against SARS-CoV-2, has been largely employed during the COVID-19 pandemic, since December 2021. After marketing and widespread usage, a progressive increase in SARS-CoV-2 lineages characterized by a higher transition/transversion ratio, a characteristic signature of molnupiravir action, appeared in the Global Initiative on Sharing All Influenza Data (GISAID) and International Nucleotide Sequence Database Collaboration (INSDC) databases. Here, we assessed the drug effects by SARS-CoV-2 whole-genome sequencing on 38 molnupiravir-treated persistently positive COVID-19 outpatients tested before and after treatment. Seventeen tixagevimab/cilgavimab-treated outpatients served as controls. Mutational analyses confirmed that SARS-CoV-2 exhibits an increased transition/transversion ratio seven days after initiation of molnupiravir. Moreover we observed an increased G->A ratio compared to controls, which was not related to apolipoprotein B mRNAediting enzyme, catalytic polypeptide-like (APOBEC) activity. In addition, we demonstrated for the first time an increased diversity and complexity of the viral quasispecies.

Tixagevimab/Cilgavimab does not prevent COVID-19 in patients with multiple sclerosis and related disorders on B-cell depleting therapies.

BACKGROUND: Patients with MS and related disorders (pwMSARD) on B-cell depleting treatments have attenuated immune responses to vaccination and were eligible to receive tixagevimab/cilgavimab. OBJECTIVES: Understand incidence and severity of COVID-19 in pwMSARD on B-cell depleting therapies who received tixagevimab/cilgavimab compared to an untreated group. METHODS: We conducted a retrospective medical records review of adult pwMSARD on B-cell depleting treatments who received tixagevimab/cilgavimab between 1/2022-1/2023. PwMSARD on B-cell depleting treatments who did not served as a control group (CG). We compared COVID-19 incidence and severity within 6 months of tixagevimab/cilgavimab or rituximab/ocrelizumab infusion for the CG. RESULTS: 210 patients were identified, 135 in the treatment group (TG) and 75 in the CG. In the TG, 24 (17.8 %) developed COVID-19 compared to 12 (16 %) in the CG. There was no difference in the odds of developing COVID-19 in an unadjusted logistic regression model (OR=1.14; 95 % CI: 0.53, 2.42; p = 0.74) or after adjusting for age and disease duration (OR=1.05; 95 % CI: 0.47, 2.37; p = 0.91). There was also no difference in COVID-19 severity between groups. CONCLUSIONS: There was no difference in COVID-19 infection rates or severity in pwMSARD on B-cell depleting treatments who received tixagevimab/cilgavimab compared to those who remained untreated.

Implementation of AZD7442 (Tixagevimab/Cilgavimab) COVID-19 Pre-exposure Prophylaxis (PrEP) in the Largest Health Maintenance Organization in Israel: Real-world Uptake and Sociodemographic and Clinical Characteristics Across Immunocompromised Patient Groups.

INTRODUCTION: AZD7442 is a combination of two neutralizing antibodies (tixagevimab/cilgavimab) with demonstrated efficacy in reducing the risk of symptomatic coronavirus disease 2019 (COVID-19) among individuals at high risk of severe COVID-19 ≤ 6 months after administration. On February 15, 2022, the Israeli Ministry of Health (IMoH) authorized the administration of 300 mg AZD7442 as pre-exposure prophylaxis (PrEP) against severe acute respiratory syndrome coronavirus 2 infection among immunocompromised individuals aged ≥ 12 years. This study describes the real-world uptake of AZD7442 in Israel. METHODS: This descriptive, observational study analyzed data from Israel's largest health maintenance organization, Clalit Health Services (CHS). Individuals were assessed for AZD7442 eligibility between February 13 and December 11, 2022, and were included if they were aged ≥ 12 years, had ≥ 1 year of continuous CHS membership, had ≥ 1 moderate or severe immunocompromising condition, and were eligible for AZD7442 per IMoH recommendations during this time frame. RESULTS: Overall, 19,161 AZD7442-eligible individuals with immunocompromising conditions were identified during the study period; 2829 (14.8%) received AZD7442. A higher proportion of individuals receiving AZD7442 were older (aged ≥ 65 years), male, not current smokers and residents in large cities; required more physician visits (> 50 visits); and had ≥ 1 COVID-19 hospitalization over 12 months, while uptake was lowest among ultra-orthodox Jewish individuals. AZD7442 uptake was also higher among individuals with multiple comorbidities (Charlson Comorbidity Index ≥ 5), including hypertension, diabetes and chronic kidney disease. In specific immunocompromised types, AZD7442 uptake was highest among individuals with lung transplantation (41%), primary immunodeficiency (32%), bone marrow transplantation (29%) and multiple myeloma (25%) or those receiving anti-CD20 therapy (26%) and was lowest in individuals with lymphoma (8%). CONCLUSION: These results show AZD7442 uptake among the eligible population of Israel in 2022 was relatively low, at 14.8%. Uptake was generally higher among immunocompromised individuals who may be perceived to be frail or at highest risk of COVID-19 infection and complications, although at 25-41%, further improvements in uptake would be more impactful. These results also indicate there is opportunity to expand AZD7442 uptake across immunocompromised groups and ensure more equitable uptake among some other sociodemographic groups. Overall, this study will help inform and reassess future implementation strategies for vulnerable populations.

Efficacy, Safety, and Pharmacokinetics of AZD7442 (Tixagevimab/Cilgavimab) for Prevention of Symptomatic COVID-19: 15-Month Final Analysis of the PROVENT and STORM CHASER Trials.

INTRODUCTION: The phase 3 PROVENT and STORM CHASER studies evaluated AZD7442 (tixagevimab/cilgavimab) for pre-exposure and post-exposure prophylaxis of symptomatic coronavirus disease 2019 (COVID-19). We report the final 15-month results of both studies. METHODS: In PROVENT, participants were randomized 2:1 to receive 300 mg AZD7442 (n = 3460) or placebo (n = 1737). In STORM CHASER, participants were enrolled within 8 days of exposure to a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individual and randomized 2:1 to receive 300 mg AZD7442 (n = 749) or placebo (n = 372). RESULTS: In PROVENT, the relative risk reduction (RRR) in symptomatic COVID-19 for AZD7442 versus placebo was 76.7% at primary analysis [95% confidence interval (CI) 46.1, 90.0; p < 0.001], 83.0% at day 183 (95% CI 67.3, 91.2; nominal p < 0.001), and 46.3% at day 366 (95% CI 23.1, 62.4; nominal p < 0.001). Severe/critical COVID-19 was reduced by 91.4% with AZD7442 versus placebo by day 366 (95% CI 61.3, 98.1; nominal p < 0.0001). Adverse events (AEs) occurred in 58.2% and 58.0% of participants administered AZD7442 or placebo, respectively; serious AEs (SAEs) occurred in 6.2% and 5.6%, respectively. In STORM CHASER, the RRR in symptomatic COVID-19 for AZD7442 versus placebo was 33.3% at primary analysis (95% CI - 25.9, 64.7; p = 0.212), 43.3% at day 183 (95% CI 1.4, 67.4; nominal p = 0.044) and 3.4% at day 366 (95% CI - 35.6, 31.2; nominal p = 0.842). Severe/critical COVID-19 did not occur in participants receiving AZD7442 versus 0.5% of participants receiving placebo by day 366. AEs occurred in 46.5% and 51.9% of participants administered AZD7442 or placebo, respectively; SAEs occurred in 2.7% and 4.3%, respectively. In both studies, serum concentration-time profiles over 457 days were similar for tixagevimab and cilgavimab and consistent with the extended half-life reported for AZD7442 (approximately 90 days). CONCLUSION: This analysis provides proof of concept supporting long-term safety of intramuscularly administered AZD7442 for prevention of symptomatic/severe COVID-19. A graphical abstract is available with this article. GOV IDENTIFIERS: PROVENT (NCT04625725) and STORM CHASER (NCT04625972).

Antibodies are proteins produced by the body's immune system to specifically target foreign substances, such as viruses. AZD7442 is made up of an antibody pair (tixagevimab and cilgavimab) that specifically bind and neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus causing coronavirus disease 2019 (COVID-19). AZD7442 was designed to give several months of protection against the virus. These antibodies were tested in two clinical trials to see if they could either protect people from getting COVID-19 (PROVENT trial) or prevent people already exposed to SARS-CoV-2 from getting COVID-19 (STORM CHASER trial). In the two trials, approximately 6000 adults received AZD7442 or placebo (injections that look exactly like AZD7442 but contain no medicine). Protection against COVID-19 was monitored for up to 1 year, and safety for up to 15 months. The percentage of trial participants who reported side effects was similar in the AZD7442 and placebo groups, in both trials. The PROVENT trial showed that AZD7442 reduced the risk of getting COVID-19 up to 6 months and protected against severe COVID-19 for up to 1 year. In STORM CHASER, participants were treated after SARS-CoV-2 exposure but before a positive COVID-19 test. Some participants were already infected with SARS-CoV-2 at the start of the trial, others were not. STORM CHASER showed that AZD7442 protected people against COVID-19 for up to 6 months if they were not already infected at the start. The results of these trials provide proof of concept to support the long-term safety of AZD7442 for the prevention of COVID-19.

Investigation of severe acute respiratory syndrome coronavirus 2 infection status in solid organ transplant recipients treated with tixagevimab/cilgavimab.

INTRODUCTION: Tixagevimab and cilgavimab (T/C) are neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that can be used to prevent SARS-CoV-2 infection in solid organ transplant (SOT) recipients. However, their neutralizing activity against recent variants was reduced, raising concerns regarding the emergence of breakthrough coronavirus diseases 2019 (COVID-19). This study aimed to investigate the status of the COVID-19 breakthrough after T/C administration. METHODS: We retrospectively investigated breakthrough COVID-19 in SOT recipients administered T/C at Kyoto University Hospital, Japan, from November 2022 to March 2023. Patients were monitored for 6 months after T/C administration. SARS-CoV-2 infection was diagnosed using polymerase chain reaction or antigen tests. The monthly incidence rates of SARS-CoV-2 infection were calculated using the person-time method. RESULTS: T/C were administered to 67 SOT recipients (liver, 16; lung, 36; and kidney, 15), of whom five were infected with SARS-CoV-2. All five cases were classified as mild, and none of these patients required admission to the intensive care unit (ICU) or died. All infected individuals tested positive for SARS-CoV-2 after March 2023, when T/C-resistant subvariant strains became predominant. The monthly incidence rate of SARS-CoV-2 infection, calculated using the person-time method, suggested an increasing trend. CONCLUSIONS: During the T/C-resistant variant epidemic, SARS-CoV-2 infections were identified even after T/C administration, suggesting that the prophylactic effects of T/C were invalid. Therefore, emerging variants must be carefully monitored and characterized to determine appropriate antiviral strategies, such as the use of suitable neutralizing antibodies.

Comprehensive procedure for injecting Evusheld® for hematological diseases in a single institute.

Tixagevimab and cilgavimab (EVA, Evusheld®), monoclonal antibody combination treatments, consisted of two neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). EVA showed prophylactic and therapeutic effects against coronavirus disease 2019. The Japanese Society of Hematology recommended EVA for such patients with active treatment, but each institution decided on comprehensive administration. We develop a systematic procedure for comprehensive EVA injection prophylactically in patients with hematological malignancies without any over/under-indication. We listed all patients with the required indications from November 2022 to March 2023. We included 178 cases, 84 females and 94 males, with a median age of 70 (range: 19-90) years. Underlying diseases are myeloid neoplasms in 36 (20%), lymphoid neoplasms in 75 (73%), and others. Indications were intensively hematological malignancy treatment, rituximab treatment within 12 months, burton kinase inhibitor treatment, after chimeric antigen receptor T cell immunotherapy, and after stem cell transplantation in 74 (41%), 73 (41%), 3 (2%), 5 (3%), and 23 (13%) cases, respectively. Of the 178 cases, 22 (12.4%) refused EVA injection. Further, 42 and 136 cases were administered outpatient and inpatient, respectively. Over 95% of the listed cases received EVA injection within 3 months. No severe toxicities were observed among them (N = 156), and 8 (5.2%) cases had breakthrough SARS-CoV-2 infection, which was significantly lower (P = 0.02) than those without EVA (4 [18.2%] of 22 cases). Both groups showed no moderate or severe infection cases. This single-center experience showed that comprehensive EVA injection management effectively generated safer completion with preferable clinical impact.

Pre-Exposure Prophylaxis and Treatment with Tixagevimab/Cilgavimab for COVID-19 among Immunocompromised Pediatric Patients.

Background: Patients treated with hemato-oncological malignancies (HO) or undergoing cellular therapies such as hematopoietic stem cell transplantation (HSCT) or chimeric antigen receptor T cells (CAR-T) were significantly affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite the success of SARS-CoV-2 vaccination, immunocompromised patients remain at increased risk for severe coronavirus disease (COVID-19), rendering this group of population a high priority for additional prevention and treatment options. Tixagevimab and Cilgavimab (TIXA/CILGA, AZD7442, Evusheld®) is a combination of two fully human, long-acting monoclonal antibodies. TIXA/CILGA have been approved as pre-exposure prophylaxis and treatment in patients at risk of severe disease with impaired vaccine response. Our objective was to describe the efficacy and safety among immunocompromised pediatric patients. Methods: This was an observational multicenter cohort study of immunocompromised pediatric patients receiving TIXA/CILGA conducted at nine Polish centers of Pediatric Oncology, Hematology and Bone Marrow Transplantation. We analyzed patients in two groups; those treated with HO and those undergoing cellular therapies: HSCT or CAR-T cells. In addition, two other cohorts were identified: patients given TIXA/CILGA as pre-exposure prophylactic and therapeutic intervention. Results: A total of 78 patients were evaluated during the study period: 69 (88.5%) received TIXA/CILGA as pre-exposure prophylaxis and 9 (11.5%) as a treatment strategy. A total of 52 (66.6%) patients were treated with standard chemotherapy at HO departments; 21 (27%) underwent HSCT, and 5 (6.4%) received CAR-T cell therapy. All children with COVID-19 receiving TIXA/CILGA presented a mild degree of severity. The most common clinical manifestations were fever, cough and coryza. At least one adverse event (AE) was reported in two (3.8%) patients excluding standard injection site reactions. Reported AEs were mild or moderate in intensity. One child reported mild myalgia and one reported moderate bone pain and weakness. Conclusions: In our observational multicenter cohort study, we explored the use of TIXA/CILGA as pre-exposure prophylaxis and treatment for COVID-19 among immunocompromised pediatric patients. While our findings suggest a potential benefit in preventing and managing COVID-19 in this vulnerable population, it is important to note the study's non-comparative design. Our results highlight the need for well-designed clinical trials to confirm these observations and further assess the efficacy and safety of TIXA/CILGA in immunocompromised children.

Tixagevimab/cilgavimab (AZD7442/Evusheld) prevent from COVID19 in patients with hematologic malignancies under active chemotherapy.

Despite the efficacy of COVID-19 vaccines, patients with hematologic malignancy may still be fatal from COVID19. Therefore, we prospectively performed the analysis of administration of tixagevimab/cilgavimab in the real-world. In August 2022, 94 patients under active chemotherapy for lymphoma, multiple myeloma, or acute leukemia received a single dose AZD7442/Evusheld (two consecutive intramuscular injections of tixagevimab and cilgavimab, 300 mg each). Quantitative measurement of anti-SARS-CoV-2 spike protein (anti-S) and viral nucleocapsid (anti-N) titers were conducted before administration of tixagevimab/cilgavimab and at 1, 3, and 6 months after administration. Twenty-five patients (26.6%) had previously confirmed COVID-19 infection. Fifty-eight patients (61.7%) had previously received COVID-19 vaccinations, with a median of two doses (range, 1-5). The median anti-S Ab level increased from baseline (997.05 AU/mL) to 1 month (20,967.25 AU/mL), then decreased at 3 months (13,145.0 AU/mL), and 6 months (7123.0 AU/mL) (p < 0.001). There was no significant safety issue with tixagevimab/cilgavimab. With a median follow-up time of 6 months, thirteen patients (13.8%) had documented SARS-Cov-2 infection. A 20.2% rate of anti-N positivity was observed six months after the administration of tixagevimab/cilgavimab. The results of this study support the potential role of tixagevimab/cilgavimab for the prevention of symptomatic and severe COVID-19.Trial registration: KCT0007617; August 16, 2022.

Risk of SARS-CoV-2 infection in patients with hematologic diseases receiving tixagevimab/cilgavimab as pre-exposure prophylaxis in most recent Omicron sublineages era.

OBJECTIVES: Whether pre-exposure prophylaxis (PrEP) with tixagevimab/cilgavimab 150 mg/150 mg (T/C) in individuals with hematologic disease (HD) may lead to a reduced risk of SARS-CoV-2 breakthrough infection (BTI)/hospitalization, or death in the Omicron era remains to be established. METHODS: An observational study included participants with HD who received PrEP. BTIs were defined as SARS-CoV-2 positivity by reverse transcription-polymerase chain reaction. The incidence of BTIs (95% CI) and of BTIs/hospitalization/death was calculated using the Kaplan-Meier method and as the number of BTIs per 100 person-years of follow-up according to the circulating variant of concern (VoC). A Poisson regression model was used to evaluate the association between the rate of incidence and circulating VoCs after controlling for demographics and clinical factors. RESULTS: We included 550 HD patients: 71% initiated T/C PrEP when BA.5 was the most prevalent, followed by XBB/EG, BA.2, and BA.1 (19%, 7%, and 3%, respectively). Overall, the 1-year incidence estimate of BTIs/hospitalization/death was 24% (18.7-29.4%). A greater risk of incident infections was observed when BA.5 and XBB/EG sub-lineages circulated (aRR 5.05 [2.17, 11.77]; P < .001 and 3.82 [1.50, 9.7]; P = 0.005, compared to BA.1, respectively). CONCLUSIONS: The 1-year incidence of SARS-CoV-2 BTIs/hospitalization/death was 24% which is in line with what was observed in other similar studies. The risk appeared to be higher when more recent Omicron sub-lineages were circulating suggesting a reduction of in vitro neutralization.

Accelerating therapeutics development during a pandemic: population pharmacokinetics of the long-acting antibody combination AZD7442 (tixagevimab/cilgavimab) in the prophylaxis and treatment of COVID-19.

AZD7442 is a combination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-neutralizing antibodies, tixagevimab and cilgavimab, developed for pre-exposure prophylaxis (PrEP) and treatment of coronavirus disease 2019 (COVID-19). Using data from eight clinical trials, we describe a population pharmacokinetic (popPK) model of AZD7442 and show how modeling of "interim" data accelerated decision-making during the COVID-19 pandemic. The final model was a two-compartmental distribution model with first-order absorption and elimination, including standard allometric exponents for the effect of body weight on clearance and volume. Other covariates included were as follows: sex, age >65 years, body mass index ≥30 kg/m2, and diabetes on absorption rate; diabetes on clearance; Black race on central volume; and intramuscular (IM) injection site on bioavailability. Simulations indicated that IM injection site and body weight had > 20% effects on AZD7442 exposure, but no covariates were considered to have a clinically relevant impact requiring dose adjustment. The pharmacokinetics of AZD7442, cilgavimab, and tixagevimab were comparable and followed linear kinetics with extended half-lives (median 78.6 days for AZD7442), affording prolonged protection against susceptible SARS-CoV-2 variants. Comparison of popPK simulations based on "interim data" with a target concentration based on 80% viral inhibition and assuming 1.81% partitioning into the nasal lining fluid supported a decision to double the PrEP dosage from 300 mg to 600 mg to prolong protection against Omicron variants. Serum AZD7442 concentrations in adolescents weighing 40-95 kg were predicted to be only marginally different from those observed in adults, supporting authorization for use in adolescents before clinical data were available. In these cases, popPK modeling enabled accelerated clinical decision-making.

Longitudinal outcomes of COVID-19 in solid organ transplant recipients from 2020 to 2023.

Data regarding coronavirus disease 2019 (COVID-19) outcomes in solid organ transplant recipients (SOTr) across severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) waves, including the impact of different measures, are lacking. This cohort study, conducted from March 2020 to May 2023 in Toronto, Canada, aimed to analyze COVID-19 outcomes in 1975 SOTr across various SARS-CoV-2 waves and assess the impact of preventive and treatment measures. The primary outcome was severe COVID-19, defined as requiring supplemental oxygen, with secondary outcomes including hospitalization, length of stay, intensive care unit (ICU) admission, and 30-day and 1-year all-cause mortality. SARS-CoV-2 waves were categorized as Wildtype/Alpha/Delta (318 cases, 16.1%), Omicron BA.1 (268, 26.2%), Omicron BA.2 (268, 13.6%), Omicron BA.5 (561, 28.4%), Omicron BQ.1.1 (188, 9.5%), and Omicron XBB.1.5 (123, 6.2%). Severe COVID-19 rate was highest during the Wildtype/Alpha/Delta wave (44.6%), and lower in Omicron waves (5.7%-16.1%). Lung transplantation was associated with severe COVID-19 (OR: 4.62, 95% CI: 2.71-7.89), along with rituximab treatment (OR: 4.24, 95% CI: 1.04-17.3), long-term corticosteroid use (OR: 3.11, 95% CI: 1.46-6.62), older age (OR: 1.51, 95% CI: 1.30-1.76), chronic lung disease (OR: 2.11, 95% CI: 1.36-3.30), chronic kidney disease (OR: 2.18, 95% CI: 1.17-4.07), and diabetes (OR: 1.97, 95% CI: 1.37-2.83). Early treatment and ≥3 vaccine doses were associated with reduced severity (OR: 0.29, 95% CI: 0.19-0.46, and 0.35, 95% CI: 0.21-0.60, respectively). Tixagevimab/cilgavimab and bivalent boosters did not show a significant impact. The study concludes that COVID-19 severity decreased across different variants in SOTr. Lung transplantation was associated with worse outcomes and may benefit more from preventive and early therapeutic interventions.

Efficacy and safety of tixagevimab/cilgavimab as passive immunisation against COVID-19 infections in patients with hematological malignancies.

Monoclonal antibodies, as tixagevimab/cilgavimab, have been introduced as prophylaxis against COVID-19 infections in high-risk populations. However, data on efficacy are limited. This study investigates efficacy and tolerability of tixagevimab/cilgavimab in hematological patients under real-life conditions. Tixagevimab/cilgavimab was administered to 155 hematological patients (March-August 2022) at two Austrian centres. S/RBD-antibody assessments were performed before (T0), four weeks (T1), and six months (T2) after application. Side effects, the occurrence of COVID-19 infections, and the course of S/RBD-antibody titres were analysed retrospectively in relation to clinical variables. 155 hematological patients, who refused tixagevimab/cilgavimab, were included as a control group to compare the frequency of COVID-19 infections. Of all immunised patients (52.3% males; 91% triple vaccinated), 25.8% had a COVID-19 breakthrough infection (76% mild) compared to 43.9% in the control group. Patients with chronic lymphocytic leukaemia (CLL)/lymphoma were at highest risk of a COVID-19 infection (OR = 2.21; 95% CI 1.05-4.65; p = 0.037). After immunisation, a steep increase in median antibody levels (1193.4BAU/ml, IQR 0-2318.94) was observed in 67.8%, followed by a rapid decrease between T1 and T2 (465.95BAU/ml, IQR 0-1900.65.3) with the greatest declines in CLL/lymphoma (848.7BAU/ml, IQR 0-1949.6, p = 0.026). Side-effects occurred in 21.2% (CTCAE I/II). These real-world data indicate that S/RBD antibodies respond rapidly after passive immunisation in all hematological patients without safety concerns. Given the rapid decline in S/RBD antibodies, early booster immunisations should be considered for future scenarios in this vulnerable group.

Effectiveness of tixagevimab/cilgavimab (Evusheld) in antiCD20­treated patients with multiple sclerosis and neuromyelitis optica spectrum disorder.

BACKGROUND: AntiCD20 therapy, such as rituximab, ocrelizumab, or ofatumumab, effectively treats patients with multiple sclerosis (pwMS) or neuromyelitis optica spectrum disorder (pwNMOSD) but negatively affects the humoral immune response to COVID-19 vaccination. One strategy to protect these patients is using tixagevimab/cilgavimab (T/C) as pre-exposure prophylaxis. This study aimed to evaluate the effect of T/C on the incidence of COVID-19 in pwMS and pwNMOSD. METHODS: Data in this observational cohort study were collected in two Czech MS centres through ReMuS registry between March 1, 2020 and December 31, 2022. Adult pwMS and pwNMOSD who were (1) treated with antiCD20 therapy at least six months before T/C administration, or at least from February 1, 2022 in the control group; (2) were already on antiCD20 therapy at the time of vaccination or COVID-19 infection; and (3) were on antiCD20 therapy at least 100 days after T/C, or at least 90 days after August 1, 2022 in the control group, were included. Analysis was performed using frequency-based (propensity score matching) and Bayesian statistical methods (informative and non-informative priors). RESULTS: Using propensity score matching 1:1, 47 patients who received T/C (mean age 45.7 years, median disease duration 12.5 years) were matched with those who did not receive T/C (n = 341; mean age 46.6 years, median disease duration 11.4 years) based on age, MS/NMOSD duration, and number of vaccine doses. None of the T/C patients and three in the control matched group, developed COVID-19 between 10 and 100 days after receiving T/C, August 1, 2022, respectively. The frequency of COVID-19 was not significantly different between groups (p = 0.242). Due to the low number of patients, a Bayesian analysis was also added. Using a non-informative Bayesian prior, the median relative risk of COVID-19 after T/C was 7.6 % (95 % CrI 0.02-115.9 %). The posterior probability of risk difference lower than zero was 96.4 %. Using an informative prior (based on the registration study of Evusheld), the median relative risk of COVID-19 after T/C was 20.2 % (95 % CI 8.4-43.8 %). The posterior probability of the risk difference lower than zero was 100 %. CONCLUSION: This work highlights the possible good efficacy of T/C in antiCD20-treated pwMS and pwNMSOD. Based on Bayesian analysis with an informative prior, the T/C group's risk of COVID-19 infection was approximately 20.2 % of the control group's risk. However, given the low frequency of COVID-19, the results of this pilot analysis must be interpreted with caution.