Safety and Immunogenicity of a Respiratory Syncytial Virus Prefusion F (RSVPreF3) Candidate Vaccine in Older Adults: Phase 1/2 Randomized Clinical Trial.

BACKGROUND: The aim of this study was to investigate safety and immunogenicity of vaccine formulations against respiratory syncytial virus (RSV) containing the stabilized prefusion conformation of RSV fusion protein (RSVPreF3). METHODS: This phase 1/2, randomized controlled, observer-blind study enrolled 48 young adults (YAs; aged 18-40 years) and 1005 older adults (OAs; aged 60-80 years) between January and August 2019. Participants were randomized into equally sized groups to receive 2 doses of unadjuvanted (YAs and OAs) or AS01-adjuvanted (OAs) vaccine or placebo 2 months apart. Vaccine safety and immunogenicity were assessed until 1 month (YAs) or 12 months (OAs) after second vaccination. RESULTS: The RSVPreF3 vaccines boosted humoral (RSVPreF3-specific immunoglobulin G [IgG] and RSV-A neutralizing antibody) responses, which increased in an antigen concentration-dependent manner and were highest after dose 1. Compared to prevaccination, the geometric mean frequencies of polyfunctional CD4+ T cells increased after each dose and were significantly higher in adjuvanted than unadjuvanted vaccinees. Postvaccination immune responses persisted until end of follow-up. Solicited adverse events were mostly mild to moderate and transient. Despite a higher observed reactogenicity of AS01-containing vaccines, no safety concerns were identified for any assessed formulation. CONCLUSIONS: Based on safety and immunogenicity profiles, the AS01E-adjuvanted vaccine containing 120 µg of RSVPreF3 was selected for further clinical development. CLINICAL TRIALS REGISTRATION: NCT03814590.

Rhox8 Ablation in the Sertoli Cells Using a Tissue-Specific RNAi Approach Results in Impaired Male Fertility in Mice.

The reproductive homeobox X-linked, Rhox, genes encode transcription factors that are selectively expressed in reproductive tissues. While there are 33 Rhox genes in mice, only Rhox and Rhox8 are expressed in Sertoli cells, suggesting that they may regulate the expression of somatic-cell gene products crucial for germ cell development. We previously characterized Rhox5-null mice, which are subfertile, exhibiting excessive germ cell apoptosis and compromised sperm motility. To assess the role of Rhox8 in Sertoli cells, we used a tissue-specific RNAi approach to knockdown RHOX8 in vivo, in which the Rhox5 promoter was used to drive Rhox8-siRNA transgene expression in the postnatal Sertoli cells. Western and immunohistochemical analysis confirmed Sertoli-specific knockdown of RHOX8. However, other Sertoli markers, Gata1 and Rhox5, maintained normal expression patterns, suggesting that the knockdown was specific. Interestingly, male RHOX8-knockdown animals showed significantly reduced spermatogenic output, increased germ cell apoptosis, and compromised sperm motility, leading to impaired fertility. Importantly, our results revealed that while some RHOX5-dependent factors were also misregulated in Sertoli cells of RHOX8-knockdown animals, the majority were not, and novel putative RHOX8-regulated genes were identified. This suggests that while reduction in levels of RHOX5 and RHOX8 in Sertoli cells elicits similar phenotypes, these genes are not entirely redundant. Taken together, our study underscores the importance of Rhox genes in male fertility and suggests that Sertoli cell-specific expression of Rhox5 and Rhox8 is critical for complete male fertility.

Regulated expression of Rhox8 in the mouse ovary: evidence for the role of progesterone and RHOX5 in granulosa cells.

The gonadotropin surge is the essential trigger to stimulate ovulation and luteinization of ovarian follicles. While the hormone signals from the brain that initiate ovulation are known, the specific targets which regulate this process are not well known. In this study, we assessed the suitability of the Rhox homeobox gene cluster to serve as the master regulators of folliculogenesis. In superovulated (equine chorionic gonadotropin [eCG]/human chorionic gonadotropin [hCG]) mice, the Rhox genes exhibited four distinct windows of peak expression, suggesting that these genes may regulate specific events during the ovulatory cycle. Like many members of the cluster, Rhox8 mRNA and protein were induced by follicle stimulating hormone [FSH]/eCG in granulosa cells. However, Rhox8 displayed unique peak expression at 8 h post-hCG administration, implying it might be the lone member of the cluster regulated by progesterone. Subsequent promoter analysis in granulosa cells revealed relevant homeobox binding and progesterone response elements within Rhox8's 5'-flanking region. In superovulated mice, progesterone receptor (PGR) is recruited to the Rhox8 promoter, as assessed by chromatin immunoprecipitation. In Rhox5-null mice, Rhox8 mRNA was reduced at 2 h and 4 h post-hCG administration but recovered once the follicles passed the antral stage of development. Conversely, in progesterone receptor knockout mice, Rhox8 exhibited normal stimulation by eCG but failed to reach its peak mRNA level at 8 h post-hCG found in wild-type mice. This suggests a model in which Rhox8 transcription is dependent upon RHOX5 during early folliculogenesis and upon progesterone during the periovulatory window when RHOX5 normally wanes. In support of this model, transfection of RHOX5 and PGR expression plasmids stimulated, whereas dominant negative and mutant constructs inhibited, Rhox8 promoter activity.

Safety and immunogenicity of SARS-CoV-2 recombinant protein vaccine formulations in healthy adults: interim results of a randomised, placebo-controlled, phase 1-2, dose-ranging study.

BACKGROUND: CoV2 preS dTM is a stabilised pre-fusion spike protein vaccine produced in a baculovirus expression system being developed against SARS-CoV-2. We present interim safety and immunogenicity results of the first-in-human study of the CoV2 preS dTM vaccine with two different adjuvant formulations. METHODS: This phase 1-2, randomised, double-blind study is being done in healthy, SARS-CoV-2-seronegative adults in ten clinical research centres in the USA. Participants were stratified by age (18-49 years and ≥50 years) and randomly assigned using an interactive response technology system with block randomisation (blocks of varying size) to receive one dose (on day 1) or two doses (on days 1 and 22) of placebo or candidate vaccine, containing low-dose (effective dose 1·3 µg) or high-dose (2·6 µg) antigen with adjuvant AF03 (Sanofi Pasteur) or AS03 (GlaxoSmithKline) or unadjuvanted high-dose antigen (18-49 years only). Primary endpoints were safety, assessed up to day 43, and immunogenicity, measured as SARS-C0V-2 neutralising antibodies (geometric mean titres), assessed on days 1, 22, and 36 serum samples. Safety was assessed according to treatment received in the safety analysis set, which included all randomly assigned participants who received at least one dose. Neutralising antibody titres were assessed in the per-protocol analysis set for immunogenicity, which included participants who received at least one dose, met all inclusion and exclusion criteria, had no protocol deviation, had negative results in the neutralisation test at baseline, and had at least one valid post-dose serology sample. This planned interim analysis reports data up to 43 days after the first vaccination; participants in the trial will be followed up for 12 months after the last study injection. This trial is registered with ClinicalTrials.gov, NCT04537208, and is ongoing. FINDINGS: Between Sept 3 and Sept 29, 2020, 441 individuals (299 aged 18-49 years and 142 aged ≥50 years) were randomly assigned to one of the 11 treatment groups. The interim safety analyses included 439 (>99%) of 441 randomly assigned participants (299 aged 18-49 years and 140 aged ≥50 years). Neutralising antibody titres were analysed in 326 (74%) of 441 participants (235 [79%] of 299 aged 18-49 years and 91 [64%] of 142 aged ≥50 years). There were no vaccine-related unsolicited immediate adverse events, serious adverse events, medically attended adverse events classified as severe, or adverse events of special interest. Among all study participants, solicited local and systemic reactions of any grade after two vaccine doses were reported in 81% (95% CI 61-93; 21 of 26) of participants in the low-dose plus AF03 group, 93% (84-97; 74 of 80) in the low-dose plus AS03 group, 89% (70-98; 23 of 26) in the high-dose plus AF03 group, 95% (88-99; 81 of 85) in the high-dose plus AS03 group, 29% (10-56; five of 17) in the unadjuvanted high-dose group, and 21% (8-40; six of 29) in the placebo group. A single vaccine dose did not generate neutralising antibody titres above placebo levels in any group at days 22 or 36. Among participants aged 18-49 years, neutralising antibody titres after two vaccine doses were 13·1 (95% CI 6·40-26·9) in the low-dose plus AF03 group, 20·5 (13·1-32·1) in the low-dose plus AS03 group, 43·2 (20·6-90·4) in the high-dose plus AF03 group, 75·1 (50·5-112·0) in the high-dose plus AS03 group, 5·00 (not calculated) in the unadjuvanted high-dose group, and 5·00 (not calculated) in the placebo group. Among participants aged 50 years or older, neutralising antibody titres after two vaccine doses were 8·62 (1·90-39·0) in the low-dose plus AF03 group, 12·9 (7·09-23·4) in the low-dose plus AS03 group, 12·3 (4·35-35·0) in the high-dose plus AF03 group, 52·3 (25·3-108·0) in the high-dose plus AS03 group, and 5·00 (not calculated) in the placebo group. INTERPRETATION: The lower than expected immune responses, especially in the older age groups, and the high reactogenicity after dose two were probably due to higher than anticipated host-cell protein content and lower than planned antigen doses in the formulations tested, which was discovered during characterisation studies on the final bulk drug substance. Further development of the AS03-adjuvanted candidate vaccine will focus on identifying the optimal antigen formulation and dose. FUNDING: Sanofi Pasteur and Biomedical Advanced Research and Development Authority.

A look at the long-term safety of an extended-regimen OC.

BACKGROUND: Oral contraceptives (OCs) are the most widely used method of reversible contraception. Recent alterations of the standard 28-day regimen have included shortening the traditional hormone-free interval (HFI), supplementing the HFI with low-dose estrogen, or increasing the number of active pills administered, thus extending the time between withdrawal bleeding episodes by a variable number of months. In light of these changes in regimens, clinicians may be seeking evidence that the new regimens are safe and will not result in unexpected adverse events. METHODS: We initiated a long-term extension trial to evaluate the safety of a 91-day extended-regimen OC containing 150 mcg levonorgestrel/30 mcg ethinyl estradiol (EE) for 84 days, followed by 7 days of 10 mcg EE. After participation in a 1-year, open-label, phase 3 contraceptive program, 320 women qualified for enrollment in a multicenter, nonrandomized study of 91-day extended-regimen OCs for up to 3 additional consecutive years; 116 completed the study. We evaluated incidence of reported adverse events (AEs), rates of study discontinuation, and reported bleeding patterns. RESULTS: Total exposure was equivalent to 8292 28-day cycles. Participants reported no thromboembolic events. Thirty-one (9.7%) women discontinued treatment due to AEs. Unscheduled bleeding and spotting diminished during the course of the trial. Overall rates of study discontinuation and incidence of AEs were consistent with those observed in the phase 3 clinical program. CONCLUSION: This study demonstrated that the AE profile of the 91-day extended-regimen OC over 4 years was similar to that seen in the 1-year clinical trials, with no unexpected adverse events.