ABSTRACT Background Effective treatment options remain limited for patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), including patients who have progressed after platinum‐based chemotherapy and systemic‐therapy‐naïve patients. This Phase Ib trial evaluates the efficacy and safety of finotonlimab, a PD‐1 antibody, combined with SCT200, an EGFR antibody. Methods This prospective, multicenter, open‐label study enrolled patients into two cohorts: Cohort A (previously treated with platinum‐based chemotherapy and immune checkpoint inhibitors) and Cohort B (systemic therapy‐naïve). Patients received finotonlimab (200 mg every 3 weeks) and SCT200 (6 mg/kg weekly for 12 weeks, then 8 mg/kg every 2 weeks). The primary endpoint was objective response rate (ORR). Results Among 41 patients, Cohort A (n = 11) showed an ORR of 27.3%, median progression‐free survival (PFS) of 5.8 months, and median overall survival (OS) of 10.6 months. Cohort B (n = 30) had an ORR of 56.7%, median PFS of 9.6 months, and an estimated median OS of 13.6 months. Common treatment‐related adverse events included hypomagnesemia (63.4%), rash (41.5%), and acneiform dermatitis (36.6%), which were manageable. Conclusions The combination of finotonlimab and SCT200 demonstrates promising efficacy, particularly in systemic therapy‐naïve patients, warranting further investigation. Trial Registration ClinicalTrials.gov identifier: NCT05552807; Chinadrugtrials.org.cn identifier: CTR20220917

T-cell immune responses are key components of the adaptive immune system. The Interferon-γ Release Assay (IGRA), a standardized method for evaluating T-cell function, is widely used for tuberculosis (TB) diagnosis. However, conventional IGRA requires venous blood (approximately 5 mL), involves lengthy processing (around 24 h), and relies on burdensome workflows, limiting its applicability in decentralized or resource-limited settings. Here, we present TOI-IGRA, a fingertip blood-based T-cell functional assay built on our in-house Tip Optofluidic Immunoassay (TOI) platform. Requiring only 15-25 μL of capillary blood, TOI-IGRA offers a minimally invasive, rapid, and efficient renovation to the standard IGRA. We demonstrate that fingertip blood yields comparable T-cell functional results with venous blood, and clinical validation in TB patients confirmed diagnostic performance equivalent to that of the standard IGRA. Furthermore, the TOI-IGRA concept can be extended to assess T-cell responses against other pathogens, including SARS-CoV-2. The platform also enables concurrent quantitative analysis of pathogen-specific T-cell responses and binding antibodies from the same fingertip blood sample. With its minimal blood requirement, operational simplicity, and versatility, TOI-IGRA represents a powerful tool for decentralized diagnostics, large-scale immune surveillance, and personalized vaccine monitoring across diverse healthcare settings.

SCT510 is a proposed biosimilar of bevacizumab (Avastin®), a monoclonal antibody that targets vascular endothelial growth factor. This analysis aimed to characterize the population pharmacokinetics of SCT510, a bevacizumab biosimilar, and its reference product (Avastin®) in healthy subjects and patients with advanced non-squamous non-small cell lung cancer. Secondary objectives were to evaluate the pharmacokinetic similarity between the two drugs and to investigate the effects of factors, including alanine transaminase, creatinine clearance, and age, on their pharmacokinetic profiles. The population pharmacokinetic model was developed by pooling intensive pharmacokinetic data from a phase I trial in healthy male subjects with sparse pharmacokinetic data from a phase III trial in patients with non-squamous non-small cell lung cancer, utilizing a non-linear mixed-effects modeling (NONMEM) approach. A total of 2647 serum concentration data from 399 subjects were included in the population pharmacokinetic analysis. A two-compartment model with linear elimination adequately described the pharmacokinetic data for both SCT510 and Avastin®. The final model identified albumin, body weight, creatinine clearance, sex, study drug (SCT510 vs Avastin®), and subject type (healthy vs patient) as statistically significant covariates. Furthermore, the analysis confirmed the pharmacokinetic similarity of SCT510 and Avastin®, as no substantial differences in exposure were observed after single or multiple doses in either healthy subjects or patients. Finally, covariates such as alanine transaminase, creatinine clearance, and age were found to have no clinically relevant impact on the pharmacokinetics of either drug. SCT510 and Avastin® demonstrated comparable population pharmacokinetic profiles, supporting the biosimilarity of SCT510 to its reference product. The analysis also indicated that no clinically relevant differences in exposure were observed for either agent across a wide range of hepatic or renal function, or age. These findings collectively support that no dose adjustment is necessary for these factors. NCT05113511, NCT03792074.

BACKGROUND:Recombinant erythropoietin (rEPO) is commonly used in therapy but may be abused in sports to enhance endurance. In doping analysis, rEPO can be detected in human urine or blood samples at picogram (pg) levels based on its slightly higher molecular weight (MW) than that of endogenous EPO using western blotting (WB). However, a type of variant erythropoietin (VAR-EPO) encoded by the EPO c.577del variant has a similar MW to rEPO, and these 2 molecules cannot be distinguished using conventional analytical methods. A fit-for-purpose method needs to be developed immediately. METHODS:In this study, we introduced a reverse-normal immunopurification technique for sample pretreatment to remove VAR-EPO from samples to eliminate its interference with rEPO detection. Firstly, a rabbit monoclonal antibody (mAb) that can specifically recognize trace amounts of VAR-EPO with high affinity was generated. Then, using this antibody to enrich VAR-EPO, we developed reverse-normal immunopurification coupled with WB on the purpose of analyzing rEPO in urine and serum samples. Next, the method was fully validated and evaluated using blank samples, spiked samples and rEPO excreted samples. Finally, the identification criteria of rEPO was established. RESULTS:A specific anti-VAR mAb with high affinity was developed. Using it, we developed the doping analytical method for rEPO. Our method effectively detects and removes VAR-EPO, enabling accurate rEPO detection. CONCLUSION:A method has already been applied for rEPO confirmation in routine doping analyses.

Background/Objective:The neutralizing monoclonal antibody against SARS-CoV-2 is regarded as one of the most effective therapies for COVID-19.: This study was a randomized, double-blinded, placebo-controlled Phase II trial conducted to evaluate the efficacy of neutralizing monoclonal antibody (SCTA01) in high-risk outpatients diagnosed with COVID-19. Methods:The primary endpoint was the proportion of patients who experienced COVID-19-related hospitalization (defined as at least 24 h of acute care) or death (all causes) by Day 29. Results:109 patients were randomly assigned to and received SCTA01 750 mg (n = 25), 1500 mg (n = 29), 3000 mg (n = 30), or placebo (n = 25). Only two experienced COVID-19-related hospitalization by Day 29, one from the 750 mg group and the other from the 3000 mg group. Statistical analysis revealed no significant differences in viral load reduction (p = 0.20) or symptom score reduction (p = 0.37) between the SCTA01 total and placebo groups. Additionally, the incidence of adverse events was comparable between the SCTA01 group (23.8 %) and the placebo group (24.0 %). Notably, no treatment-related serious adverse events (SAEs) were reported. Conclusions:There was no significant difference in clinical outcome between SCTA01 and placebo in the treatment of high-risk outpatients diagnosed with COVID-19, and it was well tolerated. CLINICAL TRIAL:The trial was registered at ClinicalTrial.gov (NCT04709328).

Background: Following SARS-CoV-2 infection, the necessity of vaccination after natural infection remains uncertain. However, many asymptomatic individuals who test negative virologically may nevertheless receive vaccination without being aware of their prior infection. Investigating the implications for vaccine safety and efficacy is crucial. Methods: We analyzed the daily fluctuations in anti-SARS-CoV-2 IgG antibody levels during the enrollment period of a phase 3 randomized, double-blinded, placebo-controlled clinical trial of a tetravalent COVID-19 protein vaccine, SCTV01E. Additionally, we investigated the relationship between baseline IgG levels and their protection against COVID-19 in participants who received placebo. Results: The daily enrolled participants with different baseline IgG levels (<338 BAU/mL, 338–1000 BAU/mL, >1000 BAU/mL) showed dynamic changes with the enrollment date. Among participants with baseline IgG levels < 338 BAU/mL, vaccination conferred a relative protective efficacy of 69.15% (95% CI: 51.14–80.52%) against symptomatic SARS-CoV-2 infection compared with the control group. Conversely, in those with higher baseline IgG levels (≥338 BAU/mL), vaccination did not confer additional benefit. In the placebo group, the relative protection in participants with baseline IgG levels ≥ 338 BAU/mL was 93.79% (87.60%, 96.89%) compared to that of those with baseline IgG levels < 338 BAU/mL. The safety profile of SCTV01E in participants with baseline IgG ≥ 338 BAU/mL was comparable to that in participants with <338 BAU/mL, with favorable safety profiles. Conclusions: During the SCTV01E phase 3 clinical trial, an anti-SARS-CoV-2 IgG antibody IgG level of 338 BAU/mL was suitable for screening individuals in the early phase post-infection alongside virological tests. Vaccinating the infected population was safe and did not compromise efficacy. Clinical Trial: NCT05308576.

There are challenges in selecting SARS-CoV-2 vaccine compositions, primarily due to divergent infection or vaccination history and immunological biases toward previous strains. In this study, we evaluated humoral immune responses induced by variant-based monovalent vaccines as booster shots in mice previously vaccinated with an ancestral strain-based vaccine with or without Omicron BA.5 exposure. Our data suggest that immunological biases toward earlier variants attenuated the potency of variant-based vaccines as a booster dose against subsequent variants, whereas a second booster dose mitigated this effect. Furthermore, in the context of vaccine-induced immunity, prior exposure to Omicron sublineages (e.g., BA.5) attenuated the effect of immunological biases toward earlier variants on the neutralizing potency against Omicron subvariants. In addition, the interval between vaccine doses should also be considered, as an immunologic plateau might occur after repeated vaccination. Furthermore, the XBB.1 monovalent vaccine and a tetravalent vaccine (SCTV01E-2) composed of pre-Omicron variant (Beta) and Omicron subvariants (BA.1, BQ.1.1, and XBB.1) showed comparable neutralizing potency against several Omicron sublineages (BA.1, BA.5, BQ.1.1, XBB.1, XBB.1.5, XBB.1.16, and EG.5) under divergent vaccination history, implicating that multivalent platforms could be explored as a flexible strategy if future strains diverge significantly from current variants.IMPORTANCEContinuous evolution of SARS-CoV-2 variants has raised the need to optimize immunization regimens and update vaccine compositions to protect against the newly emerging variants in the context of repeated vaccination. The significance of this research is briefly summarized as follows:1) Immunological biases toward earlier variants attenuated the potency of variant-based vaccines as a booster dose against subsequent variants, which can be mitigated by a second booster dose.2) In the context of vaccine-induced immunity, a previous exposure to Omicron sublineages, such as BA.5, attenuated the influence of immunological biases toward earlier variants on the neutralizing potency against Omicron subvariants.3) The interval between vaccine doses should be taken into account since an immunologic plateau might occur after repeated vaccination.4) Multivalent vaccines, with epitope diversity, may theoretically enhance the magnitude and breadth of cross-neutralization responses, thereby providing a buffer for unpredictable future variants.

Background/Objectives: Finotonlimab (SCTI10A) is a humanized anti-PD-1 antibody tested in Phase III trials for several solid tumor types. Methods: This study characterized the in vitro and in vivo efficacy, Fc-mediated effector function, and non-clinical PK/PD properties of finotonlimab. Results: The results demonstrated that finotonlimab is effective in stimulating human T cell function in vitro and exhibits marked antitumor efficacy in vivo using both PD-1-humanized and PBMC-reconstructed mouse models. Additionally, finotonlimab exhibited minimal impact on the activation of effector cells via Fc receptor-dependent pathways, potentially facilitating PD-1+ T cell killing. In cynomolgus monkeys, finotonlimab exhibited a nonlinear pharmacokinetic (PK) profile in a dose-dependent manner, and a receptor occupancy rate of approximately 90% was observed at 168 h following a single administration of 1 mg/kg. Finotonlimab’s PK profile (especially Cmax) was better than that of marketed antibodies. Following a 13-week successive administration of finotonlimab, a pharmacodynamic analysis revealed that a sustained mean receptor occupancy of PD-1 molecules on circulating T cells remained at or above 93% for up to 8 weeks, even at a dose of 3 mg/kg, and that there were higher antibody accumulations in different dose groups. Conclusions: Taken together, the preclinical findings are promising and provide the groundwork for evaluating the efficacy and pharmacodynamic characteristics of finotonlimab in clinical trials.

We aimed to assess the tolerability and efficacy of finotonlimab (an anti-programmed cell death protein-1 antibody) in combination with SCT510, a bevacizumab biosimilar, versus sorafenib in unresectable advanced HCC. This randomized phase 2 and 3 study (ClinicalTrials.gov, NCT04560894; Chinadrugtrials.org.cn, CTR20201976 and CTR20201974) was performed at 67 hospitals in China. HCC patients (n = 398) were included between 11 November 2020 and 28 September 2022. In phase 2, patients received intravenous finotonlimab (200 mg every 3 weeks) combined with SCT510 (15 mg/kg every 3 weeks). In phase 3, 346 patients were randomized (2:1) to either the finotonlimab plus SCT510 (dual-agent) group or the sorafenib group. The median follow-up time for the dual-agent therapy and sorafenib groups was 19.9 and 19.0 months, respectively. Median PFS, assessed by BICR according to RECIST 1.1, was significantly longer in the dual-agent group (7.1 months [95% confidence intervals {CI}: 6.1, 8.4]) than in the sorafenib group (2.9 months [95% CI: 2.8, 4.1]; stratified hazard ratio [HR]: 0.5, 95% CI: 0.38, 0.65, p < 0.0001). Median OS was also significantly longer in patients receiving finotonlimab plus SCT510 (22.1 months [18.6, not available]) than in those receiving sorafenib (14.2 months [95% CI: 10.2, 15.8]; HR: 0.60 [95% CI: 0.44, 0.81], p < 0.0008). Finotonlimab in combination with bevacizumab demonstrated favorable efficacy, in comparison to sorafenib, as a first-line treatment for unresectable HCC, with a manageable safety profile.

BACKGROUND:This trial evaluated the efficacy and safety of anti-programmed cell death 1 antibody (SCT-I10A) and anti-epidermal growth factor receptor (EGFR) antibody (SCT200) in patients with previously treated advanced esophageal squamous cell carcinoma (ESCC) (trial registration number: NCT04229537). METHODS:This multicenter, open-label, phase 1b clinical trial enrolled patients with advanced ESCC refractory or intolerant to standard chemotherapy. Patients who had not received prior treatment with programmed death-(ligand)1 (PD-(L)1) immune checkpoint inhibitors (ICIs) or anti-EGFR antibodies comprised cohort 1A, and those who had previously failed treatment with PD-(L)1 ICIs or anti-EGFR antibodies comprised cohort 1B. Eligible patients were treated with SCT200 and SCT-I10A. RESULTS:Seventy patients were enrolled. The objective response rate was 25.7%, with a median overall survival and progression-free survival of 6.90 months and 3.98 months, respectively. Twenty-nine patients previously underwent ICI treatment with an objective response rate of 17.24%, median overall survival of 6.08 months, and median progression-free survival of 3.98 months. Grade 3 or higher adverse events were observed in 43.3% and 52.5% of patients in cohort 1A and 1B, respectively. CONCLUSIONS:SCT-I10A plus SCT200 demonstrated durable antitumor activity with a manageable safety profile in previously treated patients with advanced ESCC, even in patients who had previously failed anti-PD-(L)1 therapy.

SCTV01E, a novel SARS-CoV-2 tetravalent protein vaccine containing recombinant spike proteins of Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2) and Omicron BA.1 (B.1.1.529.1) variants and SCTVA02B adjuvant, has received Emergency Use Authorization (EUA) in China and the United Arab Emirates (UAE) as a next-generation COVID-19 vaccine. A comprehensive reproductive and developmental toxicity evaluation was conducted in Sprague-Dawley (SD) rats under Good Laboratory Practice (GLP) conditions. Maternal animals were intramuscularly injected with 1 × or 3 × the highest human dose every other week prior to mating, followed by booster immunizations during gestation and lactation periods. The main findings showed that SCTV01E vaccination elicited robust binding IgG and neutralizing antibody responses against all four target variants. While no vaccine-related adverse reproductive effects were observed in parental male or female rats, transient injection site reactions and slight, reversible reductions in body weight gain and food consumption were noted. Key developmental parameters were not affected, and postnatal evaluation revealed no evidence of embryo-fetal malformations, developmental delays, or functional impairments in offspring. These results suggest a favorable safety profile for SCTV01E and its possible suitability for clinical trials in humans of reproductive potential. Furthermore, the efficient transplacental and lactational transfer of maternal antibodies observed in animal models suggests a potential protection: direct immunization of mothers may confer passive immunity to both fetuses in utero and neonates during breastfeeding.

BACKGROUND:The development of bivalent or multivalent vaccines offers a promising strategy for combating SARS-CoV-2 mutations. RESEARCH DESIGN AND METHODS:In this phase 2 trial, conducted from 1 December 2021, to 25 July 2023, 392 unvaccinated adults aged ≥18 years were randomized to receive a primary series of two doses and a booster dose of SCTV01C, a bivalent protein SARS-CoV-2 vaccine. RESULTS:Geometric mean titers (GMTs) of neutralizing antibodies (nAb) against live Alpha, Beta, Delta, and Omicron showed 85.4-, 100.0-, 32.1-, and 9.8-fold increase from baseline on 28 days, and 49.4-, 55.3-, 5.7-fold increase against live Alpha, Beta, and Omicron on 90 days after primary series. At Day 28 and Day 90 following the booster dose, GMTs of nAb against Beta, BA.2 and BA.5 variants showed 12.1- and 8.8-, 13.8- and 7.1-, 18.7-, and 11.9-fold of increase from baseline, respectively. Reactogenicity was generally mild, with one adverse event of special interest (AESI) and 9 ≥Grade 3 treatment-related adverse events (TRAEs); all recovered within 3 days. CONCLUSIONS:SCTV01C, when administered as both a primary series and a booster vaccination, exhibited encouraging sustained immunogenicity against both antigen-matched and antigen-mismatched variants, with no significant safety concerns. CLINICAL TRIAL REGISTRATION:www.clinicaltrials.gov identifier is NCT05148091.

Background: Hospitalized patients with severe COVID-19 are at high risk of clinical deterioration. Methods: A global, randomized, double-blinded, and placebo-controlled phase II trial that investigated the clinical efficacy of SCTA01, an Fc-modified monoclonal antibody, in patients hospitalized with severe COVID-19 during the Delta variant wave was performed. The primary outcome was time to clinical improvement up to Day 29. Secondary outcomes measured the all-cause mortality rate up to Day 29, time to SARS-CoV-2 RNA negativity up to Day 29, and the number of antibody-dependent enhancements. Results: From 27 March 2021, to 11 February 2022, 102 hospitalized adults with severe COVID-19 received a single intravenous infusion of SCTA01 15 mg/kg or 50 mg/kg or placebo in a 1:1:1 ratio. The median time to clinical improvement in the SCTA01 group was numerically shorter than that in the placebo group; however, the between group difference was statistically non-significant (SCTA01 15 mg/kg vs. placebo, HR 0.99, 95% CI 0.55–1.77, p = 0.742; SCTA01 50 mg/kg vs. placebo, HR 1.07, 95% CI 0.61–1.88, p = 0.095). The median time to achieve a negative SARS-CoV-2 status was shorter in the SCTA01 15 mg/kg group (14.0 days vs. 27.0 days) but not in the SCTA01 50 mg/kg group (28.0 days vs. 27.0 days) compared to the placebo group. Adverse events were comparable across all groups, and no treatment-related serious adverse event or antibody-dependent enhancement was reported. Conclusions: The Fc-modified antibody was safe but lacked significant clinical efficacy in vivo, likely due to the SARS-CoV-2 viral mutation.

Objectives:The rapid emergence of SARS-CoV-2 prompted accelerated vaccine development, with neutralization assays serving as essential tools to evaluate vaccine-induced immune responses. Methods:A post-hoc analysis of a Phase I/II trial evaluated the immunogenicity of a bivalent SARS-CoV-2 protein vaccine. We assessed vaccine immunogenicity using live virus neutralization assays (LVNA) and pseudotyped virus neutralization assays (PVNA) to measure antibody responses against different variants, including Alpha B.1.1.7, Beta B.1.351, and Delta B.1.617.2. Various statistical techniques, including correlation coefficients, regression models, and Bland-Altman plots, were employed to assess the relationship between antibody titers from the two assays. Results:We analyzed 324 samples for Alpha and Beta variants and 505 for Delta. Compared with LVNA, the sensitivity and specificity of PVNA were over 90% across all variants, with accuracy rates of 98.8% for Alpha, 99.1% for Beta, and 94.3% for Delta. The Pearson correlation between PVNA and LVNA was strong for Alpha (CORR = 0.9614), Beta (CORR = 0.9517), and Delta (CORR = 0.9072). Bland-Altman plots and Kernel density plots indicated good agreement between PVNA and LVNA. Conclusions:Our findings demonstrate a strong correlation between PVNA and LVNA results, supporting PVNA as a safe, scalable, and reliable surrogate for LVNA in evaluating vaccine immunogenicity.

Background:Lung cancer is the most common cancer in the world, and non-small cell lung cancer (NSCLC) constitutes about 80-85%. In this phase III trial, we evaluate the efficacy and safety of anti-programmed cell death-1 (PD-1) monoclonal antibody (SCT-I10A) plus docetaxel compared to docetaxel in patients with previously treated advanced squamous cell NSCLC (sqNSCLC). Methods:Patients were randomized 2:1 to finotonlimab plus docetaxel group (finotonlimab plus docetaxel) and docetaxel group (placebo plus docetaxel) for up to 6 cycles, followed by maintenance monotherapy with finotonlimab/placebo. The primary endpoint was overall survival (OS). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), duration of response (DoR), progression-free survival (PFS) as well as assessments of safety and immunogenicity. Results:There were 188 eligible patients enrolled (finotonlimab plus docetaxel group: n=126; docetaxel group: n=62). Median OS (mOS) was 17.1 months [95% confidence interval (CI): 11.2, 20.0] in the finotonlimab plus docetaxel group and 10.4 months (95% CI: 5.9, 14.0) in the control group. Hazard ratio (HR) was 0.66 (95% CI: 0.45, 0.96; P=0.03). Median PFS (mPFS) was 4.2 months (95% CI: 3.3, 6.9) and 2.9 months (95% CI: 1.5, 3.8) respectively in the finotonlimab plus docetaxel group and control group. Patients in the finotonlimab plus docetaxel group achieved an ORR of 27.0% (95% CI: 19.5%, 35.6%), which was significantly higher than the 3.2% (95% CI: 0.4%, 11.2%) in the control group. The DCR was 68.3% (95% CI: 59.4%, 76.3%) in the finotonlimab plus docetaxel group and 56.5% (95% CI: 43.3%, 69.0%) in the control group. Treatment-related adverse events (TRAEs) occurred in 91.3% (115/126) patients of finotonlimab plus docetaxel group and 87.1% (54/62) patients of control group. Conclusions:SCT-I10A combined with docetaxel significantly prolonged OS and improved clinical outcomes in patients with treated advanced sqNSCLC compared to docetaxel, without increasing safety risk. Trial Registration:NCT04171284, ClinicalTrials.gov.

Despite the record speed of developing vaccines and therapeutics against the SARS-CoV-2 virus, it is not a given that such success can be secured in future pandemics. In addition, COVID-19 vaccination and application of therapeutics remain low in developing countries. Rapid and low cost mass production of antiviral IgY antibodies could be an attractive alternative or complementary option for vaccine and therapeutic development. In this article, we rapidly produced SARS-CoV-2 antigens, immunized hens and purified IgY antibodies in 2 months after the SARS-CoV-2 gene sequence became public. We further demonstrated that the IgY antibodies competitively block RBD binding to ACE2, neutralize authentic SARS-CoV-2 virus and effectively protect hamsters from SARS-CoV-2 challenge by preventing weight loss and lung pathology, representing the first comprehensive study with IgY antibodies. The process of mass production can be easily implemented in most developing countries and hence could become a new vital option in our toolbox for combating viral pandemics. This study could stimulate further studies, optimization and potential applications of IgY antibodies as therapeutics and prophylactics for human and animals.

Validation of bioanalytical methods is crucial, especially in the pharmaceutical industry, to determine their suitability for specific purposes and the accuracy of analytical results. The pseudovirion-based neutralization assay (PBNA) is considered the gold standard for detecting and quantifying neutralizing antibodies against human papillomavirus in vaccine development for disease prevention. This paper introduces an improved triple-color PBNA method, capable of simultaneous detection of two or three human papillomavirus (HPV types for use in the development of a 14-valent HPV vaccine candidate. The primary objective was to comprehensively validate the triple-color PBNA method for general vaccine immunogenicity assays. Results show that the method has good specificity, accuracy, precision, linearity, robustness, and applicability. This innovative triple-color PBNA offers an improved approach for large-scale immunogenicity assessment in vaccine development. This study lays a solid foundation that can serve as a guiding paradigm for assessing vaccine responses in preclinical and clinical phases, providing valuable insights to the field.

Summary: Background: Limited therapeutic options are available for metastatic colorectal cancer (mCRC) patients after failure of first- and second-line therapies, representing an unmet medical need for novel therapies. Methods: This is an open-label, single arm, multicenter, phase Ⅱ study aiming to perform the efficacy, safety and genomic analysis of SCT200, a noval fully humanized IgG1 anti-epidermal growth factor receptor (EGFR) monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type mCRC. SCT200 (6 mg/kg) was given weekly for the first six weeks, followed by a higher dose of 8 mg/kg every two weeks until disease progression or unacceptable toxicity. Primary endpoint was independent review committee (IRC)-assessed objective response rate (ORR) and secondary endpoints included ORR in patients with left-sided tumor, disease control rate (DCR), duration of response (DoR), time to response (TTR), progression-free survival (PFS), overall survival (OS) and safety. Findings: From February 12, 2018 to December 1, 2019, a total of 110 patients aged between 26 and 77 years (median: 55; interquartile range [IQR]: 47–63) with fluorouracil, oxaliplatin, and irinotecan refractory RAS and BRAF wild-type mCRC were enrolled from 22 hospitals in China. As the data cut-off date on May 15, 2020, the IRC-assessed ORR and DCR was 31% (34/110, 95% confidence interval [CI] 22–40%) and 75% (82/110, 95% CI 65–82%), respectively. Thirty one percent (34/110) patients achieved confirmed partial response (PR). The median PFS and median OS were 5.1 months (95% CI 3.4–5.2) and 16.2 months (95% CI 11.1-not available [NA]), respectively. The most common ≥ grade 3 treatment-related adverse events (TRAEs) were hypomagnesemia (17%, 19/110) and acneiform dermatitis (11%, 12/110). No deaths occurred. Genomic analysis suggested positive association between MYC amplification and patients’ response (P = 0.0058). RAS/RAF mutation and MET amplification were the most frequently detected resistance mechanisms. Patients with high circulating tumor DNA (ctDNA) at baseline or without ctDNA clearance at the 7th week after the first dose of SCT200 administration before receiving SCT200 had worse PFS and OS. Interpretation: SCT200 exhibited promising clinical efficacy and manageable safety profiles in RAS and BRAF wild-type mCRC patients progressed on fluorouracil, irinotecan and oxaliplatin treatment. The baseline ctDNA and ctDNA clearance status at the 7th week after the first dose of SCT200 administration before receiving SCT200 could be a potential prognostic biomarker for RAS and BRAF wild-type mCRC patients with SCT200 therapy. Funding: This study was sponsored by Sinocelltech Ltd., Beijing, China and partly supported by the National Science and Technology Major Project for Key New Drug Development (2019ZX09732001-006, 2017ZX09304015).