Immunogenicity of NVX-CoV2373 in PREVENT-19: A Phase 3, Randomized, Placebo-Controlled Trial in Adults in the United States and Mexico.

Background: NVX-CoV2373, an adjuvanted, recombinant SARS-CoV-2 spike (rS) protein vaccine, consistently demonstrated protective efficacy against COVID-19 in clinical trials and has received regulatory authorizations or approvals worldwide. Methods: PREVENT-19 (NCT04611802) is a phase 3, randomized, observer-blinded, placebo-controlled trial evaluating safety, immunogenicity, and efficacy of NVX-CoV2373 in ≈30 000 participants ≥18 years in the United States and Mexico. Vaccine humoral immune response (ie, serum immunoglobulin [IgG] antibodies, hACE2 receptor binding inhibition antibodies, and neutralizing antibodies to SARS-CoV-2) (ancestral strain) was assessed in 1200 participants randomly selected and equally divided between participants 18-64 and ≥65 years. Results: In the per protocol analysis, NVX-CoV2373 induced vigorous serum antibody responses among the 1063 analyzed participants who were SARS-CoV-2 seronegative at baseline, received both doses of study treatment, and had serology results available 2 weeks after dose 2. Geometric mean (GM) responses in both younger and older adults were higher among recipients of vaccine versus placebo for IgG (64 259 vs 121 and 37 750 vs 133 ELISA units, respectively), hACE2 receptor binding inhibition GM titers (GMTs) (222 vs 5 and 136 vs 5, respectively), and neutralizing antibody GMTs (1303 vs 11 and 900 vs 11, respectively). Humoral responses were 30-40% lower in participants ≥65 years or HIV-positive; however, seroconversion rates were high and comparable between the age cohorts, regardless of HIV serostatus. Conclusions: NVX-CoV2373 elicited robust humoral immune responses against ancestral SARS-CoV-2 virus 2 weeks following the second vaccination in adult PREVENT-19 participants, consistent with previously reported high vaccine efficacy.

Perceived effects on patients' health of participation in the atrial fibrillation follow-up investigation of rhythm management study.

BACKGROUND: Patients' views about participation in clinical trials have been explored using end-of-study questionnaires for various disease entities. However, little is known about why individuals with atrial fibrillation (AF) choose to participate in clinical trials or how they view their research experience. Understanding these perceptions should provide valuable information for future studies in developing methods to enhance enrollment, optimize adherence to therapies, and maximize patient retention. METHODS: The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Study was a randomized trial of rate-control versus rhythm-control for the management of AF. This descriptive ancillary study used a 7-item questionnaire comprising closed and open-ended items that explored: (1) perceptions of benefits from participation, (2) motivation for enrolling, and (3) satisfaction with research staff and operations. RESULTS: A total of 741/1,032 participants (72%) at 34 of 213 participating AFFIRM sites responded, representing 18% of the 4,060 patients enrolled. The mean follow-up of these respondents was 3.8 +/- 1.1 years. Most respondents (91%) felt that they received enough information about AFFIRM before enrolling and that the results would benefit themselves (88%) and others (91%). Most respondents felt study participation improved awareness about AF (90%) and facilitated coordination of their healthcare (89%). Virtually all were satisfied with information received from AFFIRM personnel (96%), and most (98%) reported that they had received "good care." Responses were similar between randomization groups (rate-control or rhythm-control) and between those younger than 65 years and those 65 years or older. Participants in sinus rhythm at last follow-up were more likely to believe that their medical care in AFFIRM was better than what they would otherwise have received, and were more likely to perceive their treatment course as entailing fewer emergency room visits, hospitalizations, and doctor visits. Regularly scheduled appointments and ongoing availability of staff to answer questions appeared to increase participants' confidence and reduce anxiety. CONCLUSIONS: Patients enrolled in a long-term clinical trial for management of AF were overwhelmingly satisfied with participation.

Clinical factors that influence response to treatment strategies in atrial fibrillation: the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study.

BACKGROUND: The AFFIRM Study was a randomized multicenter comparison of 2 treatment strategies, rate-control versus rhythm-control, in high-risk patients with atrial fibrillation (AF). The primary outcome of the trial showed no overall difference in survival between strategies. However, there may be important patient subgroups for which there are identifiable differences in outcome with 1 of the 2 strategies. METHODS AND RESULTS: Subgroups that were prespecified for analysis from the main AFFIRM Study were age, sex, coronary artery disease (CAD), hypertension, congestive heart failure (CHF), left ventricular ejection fraction (LVEF), rhythm at randomization, first episode of AF, and duration of the qualifying episode of AF. Baseline characteristics were analyzed for each subgroup. Adjusted hazard ratios for each subgroup and for each stratum were generated using Cox models, and these models were used to determine whether treatment strategy affected overall survival differentially by subgroup. Adjusted survival was worse for patients > or =65 years and for patients with a history of CHF, CAD, or an abnormal LVEF. In the adjusted analyses, the effect of treatment strategy was similar within all of the prespecified subgroups. When each subgroup stratum was analyzed separately, patients > or =65 years and patients without a history of CHF had significantly better outcome with rate-control therapy (each P < .01). CONCLUSIONS: Overall, treatment effect for rate control versus rhythm control was the same within each subgroup. However, certain selected patient categories may have better survival with one particular strategy for management of AF.

Relationships between sinus rhythm, treatment, and survival in the Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) Study.

BACKGROUND: The AFFIRM Study showed that treatment of patients with atrial fibrillation and a high risk for stroke or death with a rhythm-control strategy offered no survival advantage over a rate-control strategy in an intention-to-treat analysis. This article reports an "on-treatment" analysis of the relationship of survival to cardiac rhythm and treatment as they changed over time. METHODS AND RESULTS: Modeling techniques were used to determine the relationships among survival, baseline clinical variables, and time-dependent variables. The following baseline variables were significantly associated with an increased risk of death: increasing age, coronary artery disease, congestive heart failure, diabetes, stroke or transient ischemic attack, smoking, left ventricular dysfunction, and mitral regurgitation. Among the time-dependent variables, the presence of sinus rhythm (SR) was associated with a lower risk of death, as was warfarin use. Antiarrhythmic drugs (AADs) were associated with increased mortality only after adjustment for the presence of SR. Consistent with the original intention-to-treat analysis, AADs were no longer associated with mortality when SR was removed from the model. CONCLUSIONS: Warfarin use improves survival. SR is either an important determinant of survival or a marker for other factors associated with survival that were not recorded, determined, or included in the survival model. Currently available AADs are not associated with improved survival, which suggests that any beneficial antiarrhythmic effects of AADs are offset by their adverse effects. If an effective method for maintaining SR with fewer adverse effects were available, it might be beneficial.