One- and Two-Dose Vaccinations With Modified Vaccinia Ankara-Bavarian Nordic Induce Durable B-Cell Memory Responses Comparable to Replicating Smallpox Vaccines.

BACKGROUND: Although modified vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccination is approved for smallpox and monkeypox prevention, immunological persistence and booster effects remain undescribed. METHODS: Participants naive to smallpox vaccination were randomized to 1 dose MVA-BN (1×MVA, n = 181), 2 doses MVA-BN (2×MVA, n = 183), or placebo (n = 181). Participants with previous smallpox vaccination received 1 MVA-BN booster (HSPX, n = 200). Subsets of the formerly naive groups (approximately 75 each) received an MVA-BN booster 2 years later. RESULTS: Neutralizing antibody (nAb) geometric mean titers (GMTs) increased from 1.1 (baseline, both naive groups) to 7.2 and 7.5 (week 4, 1×MVA and 2×MVA, respectively), and further to 45.6 (week 6, 2×MVA after second vaccination). In HSPX, nAb GMT rapidly increased from 21.6 (baseline) to 175.1 (week 2). At 2 years, GMTs for 1×MVA, 2×MVA, and HSPX were 1.1, 1.3, and 10.3, respectively. After boosting in the previously naive groups, nAb GMTs increased rapidly in 2 weeks to 80.7 (1×MVA) and 125.3 (2×MVA), higher than after primary vaccination and comparable to boosted HSPX subjects. Six months after boosting, GMTs were 25.6 (1×MVA) and 49.3 (2×MVA). No safety concerns were identified. CONCLUSIONS: Anamnestic responses to boosting without sustained high nAb titers support presence of durable immunological memory following primary MVA-BN immunization. Clinical Trials Registration. NCT00316524 and NCT00686582.

The changing epidemiology of human monkeypox-A potential threat? A systematic review.

Monkeypox, a zoonotic disease caused by an orthopoxvirus, results in a smallpox-like disease in humans. Since monkeypox in humans was initially diagnosed in 1970 in the Democratic Republic of the Congo (DRC), it has spread to other regions of Africa (primarily West and Central), and cases outside Africa have emerged in recent years. We conducted a systematic review of peer-reviewed and grey literature on how monkeypox epidemiology has evolved, with particular emphasis on the number of confirmed, probable, and/or possible cases, age at presentation, mortality, and geographical spread. The review is registered with PROSPERO (CRD42020208269). We identified 48 peer-reviewed articles and 18 grey literature sources for data extraction. The number of human monkeypox cases has been on the rise since the 1970s, with the most dramatic increases occurring in the DRC. The median age at presentation has increased from 4 (1970s) to 21 years (2010-2019). There was an overall case fatality rate of 8.7%, with a significant difference between clades-Central African 10.6% (95% CI: 8.4%- 13.3%) vs. West African 3.6% (95% CI: 1.7%- 6.8%). Since 2003, import- and travel-related spread outside of Africa has occasionally resulted in outbreaks. Interactions/activities with infected animals or individuals are risk behaviors associated with acquiring monkeypox. Our review shows an escalation of monkeypox cases, especially in the highly endemic DRC, a spread to other countries, and a growing median age from young children to young adults. These findings may be related to the cessation of smallpox vaccination, which provided some cross-protection against monkeypox, leading to increased human-to-human transmission. The appearance of outbreaks beyond Africa highlights the global relevance of the disease. Increased surveillance and detection of monkeypox cases are essential tools for understanding the continuously changing epidemiology of this resurging disease.

Broad Antibody and Cellular Immune Response From a Phase 2 Clinical Trial With a Novel Multivalent Poxvirus-Based Respiratory Syncytial Virus Vaccine.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of severe respiratory disease in young children and the elderly. Protective immunity is not generated after repeated infections, but vaccination may hopefully prove effective. METHODS: This phase 2 clinical study investigated a multivalent RSV vaccine (MVA-BN-RSV) designed to induce broad antibody and cellular immune responses by encoding RSV surface proteins F, G (for both A and B subtypes), and internal antigens (M2, N). This study evaluated the immune response in adults aged ≥55 years to identify the optimal MVA-BN-RSV dose and vaccination schedule. RESULTS: A single dose increased the levels of neutralizing (plaque reduction neutralization test to RSV A and B) and total (IgG and IgA ELISA) antibodies (1.6 to 3.4-fold increase from baseline) and induced a broad Th1-biased cellular immune response (interferon-γ ELISPOT) to all 5 vaccine inserts (5.4 to 9.7-fold increases). Antibody responses remained above baseline for 6 months. A 12-month booster dose elicited a booster effect in antibody and T-cell responses (up to 2.8-fold from preboost levels). No drug-related serious adverse events were reported. CONCLUSIONS: MVA-BN-RSV induces a broad immune response that persists at least 6 months and can be boosted at 12 months, without significant safety findings. CLINICAL TRIALS REGISTRATION: NCT02873286.

Safety and immunogenicity of novel modified vaccinia Ankara-vectored RSV vaccine: A randomized phase I clinical trial.

Respiratory disease caused by RSV infection is recognized as a severe public health issue in infants, young children and elderly with no specific treatment option. Vaccination may be the most effective strategy to combat this highly infectious virus although no vaccine has been approved. The novel vaccine candidate MVA-BN-RSV encodes RSV surface proteins F and G (subtypes A, B) as well as internal proteins N and M2 in the MVA-BN viral vector backbone to provide broad protection against RSV. This was a first in human study to investigate safety, reactogenicity and immunogenicity of MVA-BN-RSV. Sixty-three participants were allocated to 3 groups: adult (18-49 years) low (1 × 107 TCID50) or high (1 × 108 TCID50) dose and older adult (50-65 years) high dose. Participants in each group were randomized in a 6:1 ratio to receive 2 doses of MVA-BN-RSV or placebo 4 weeks apart and were monitored for 30 weeks. All participants completed the study, receiving both doses. No serious AEs or AEs of special interest were reported. The most common AEs were injection site pain (56% in the combined high dose groups, 17% in the low dose group). MVA-BN-RSV induced robust T cell responses covering all 5 inserts with fold increases ranging from 1.8 to 3.8. Higher and broader responses were observed in the high dose groups (83% responders to at least 3 peptide pools in the combined high dose groups compared to 63% in the low dose group). Moderate but consistent humoral responses were observed against A and B RSV subtypes (up to approximately 2-fold increases in the high dose groups). No differences were observed between the adult and the older adult groups in safety, reactogenicity or immunogenicity. The study demonstrated that the well tolerated MVA-BN-RSV vaccine candidate induces broad cellular and humoral immune responses, warranting further development.

Phase III Trial of PROSTVAC in Asymptomatic or Minimally Symptomatic Metastatic Castration-Resistant Prostate Cancer.

PURPOSE: PROSTVAC, a viral vector-based immunotherapy, prolonged median overall survival (OS) by 8.5 months versus placebo in metastatic castration-resistant prostate cancer in a phase II study. This phase III study further investigated those findings. PATIENTS AND METHODS: Patients were randomly assigned to PROSTVAC (Arm V; n = 432), PROSTVAC plus granulocyte-macrophage colony-stimulating factor (Arm VG; n = 432), or placebo (Arm P; n = 433), stratified by prostate-specific antigen (less than 50 ng/mL v 50 ng/mL or more) and lactate dehydrogenase (less than 200 v 200 U/L or more). Primary end point was OS. Secondary end points were patients alive without events (AWE)-namely, radiographic progression, pain progression, chemotherapy initiation, or death-at 6 months and safety. The study design was a superiority trial of PROSTVAC (Arm V or Arm VG) versus Arm P. Three interim analyses were planned. RESULTS: At the third interim analysis, criteria for futility were met and the trial was stopped early. Neither active treatment had an effect on median OS (Arm V, 34.4 months; hazard ratio, 1.01; 95% CI, 0.84 to 1.20; P = .47; Arm VG, 33.2 months; hazard ratio, 1.02; 95% CI, 0.86 to 1.22; P = .59; Arm P, 34.3 months). Likewise, AWE at 6 months was similar (Arm V, 29.4%; odds ratio, 0.96; 95% CI, 0.71 to 1.29; Arm VG, 28.0%; odds ratio, 0.89; 95% CI, 0.66 to 1.20; placebo, 30.3%). Adverse events were similar for the treatment and placebo groups, with the most common being injection site reactions (62% to 72%) and fatigue (21% to 24%). Arrhythmias were the most common cardiac-related events (1.4% to 3.5%). There were no reports of either myocarditis or pericarditis. Serious treatment-related events occurred in less than 1% of all patients. CONCLUSION: Whereas PROSTVAC was safe and well tolerated, it had no effect on OS or AWE in metastatic castration-resistant prostate cancer. Combination therapy is currently being explored in clinical trials.

Sample size determination in shared frailty models for multivariate time-to-event data.

The frailty model is increasingly popular for analyzing multivariate time-to-event data. The most common model is the shared frailty model. Although study design consideration is as important as analysis strategies, sample size determination methodology in studies with multivariate time-to-event data is greatly lacking in the literature. In this article, we develop a sample size determination method for the shared frailty model to investigate the treatment effect on multivariate event times. We analyzed the data using both a parametric model and a piecewise model with unknown baseline hazard, and compare the empirical power with the calculated power. Last, we discuss the formula for testing the treatment effect on recurrent events.

Flexible stopping boundaries when changing primary endpoints after unblinded interim analyses.

It has been widely recognized that interim analyses of accumulating data in a clinical trial can inflate type I error. Different methods, from group sequential boundaries to flexible alpha spending functions, have been developed to control the overall type I error at prespecified level. These methods mainly apply to testing the same endpoint in multiple interim analyses. In this article, we consider a group sequential design with preplanned endpoint switching after unblinded interim analyses. We extend the alpha spending function method to group sequential stopping boundaries when the parameters can be different between interim, or between interim and final analyses.

Sample size and power determination in joint modeling of longitudinal and survival data.

Owing to the rapid development of biomarkers in clinical trials, joint modeling of longitudinal and survival data has gained its popularity in the recent years because it reduces bias and provides improvements of efficiency in the assessment of treatment effects and other prognostic factors. Although much effort has been put into inferential methods in joint modeling, such as estimation and hypothesis testing, design aspects have not been formally considered. Statistical design, such as sample size and power calculations, is a crucial first step in clinical trials. In this paper, we derive a closed-form sample size formula for estimating the effect of the longitudinal process in joint modeling, and extend Schoenfeld's sample size formula to the joint modeling setting for estimating the overall treatment effect. The sample size formula we develop is quite general, allowing for p-degree polynomial trajectories. The robustness of our model is demonstrated in simulation studies with linear and quadratic trajectories. We discuss the impact of the within-subject variability on power and data collection strategies, such as spacing and frequency of repeated measurements, in order to maximize the power. When the within-subject variability is large, different data collection strategies can influence the power of the study in a significant way. Optimal frequency of repeated measurements also depends on the nature of the trajectory with higher polynomial trajectories and larger measurement error requiring more frequent measurements.

Suboptimal adherence to darunavir/ritonavir has minimal effect on efficacy compared with lopinavir/ritonavir in treatment-naive, HIV-infected patients: 96 week ARTEMIS data.

OBJECTIVES: To examine how treatment adherence differences in ARTEMIS (96 week analysis) affected clinical outcome, and to assess factors impacting adherence. PATIENTS AND METHODS: ARTEMIS is a Phase III trial, in HIV-1-infected treatment-naive patients, comparing efficacy and safety of once-daily darunavir/ritonavir (800/100 mg) versus lopinavir/ritonavir (800/200 mg total daily dose), each with a fixed-dose background tenofovir and emtricitabine regimen. Self-reported treatment adherence was assessed using the Modified Medication Adherence Self-Report Inventory (M-MASRI). In post-hoc analyses, mean adherence from weeks 4-96 was used to assess overall adherence for each patient, and transformed into a binary variable (>95% , adherent; < or = 95% , suboptimally adherent). RESULTS: Overall adherence was high: 83% of darunavir/ritonavir-treated patients and 78% of lopinavir/ritonavir-treated patients were >95% adherent. The difference in virological response rate for adherent versus suboptimally adherent patients was smaller for darunavir/ritonavir (6% difference: 82% versus 76%, P = 0.3312) than for lopinavir/ritonavir (25% difference: 78% versus 53%, P < 0.0001). In suboptimally adherent patients, a higher virological response rate was seen with darunavir/ritonavir (76%) versus lopinavir/ritonavir (53%) (P < 0.01). Suboptimally adherent patients (both treatment groups) reported more adverse events (AEs), including gastrointestinal AEs, than adherent patients. Darunavir/ritonavir had a lower rate of AEs, including gastrointestinal AEs, than lopinavir/ritonavir, in adherent and suboptimally adherent patients. CONCLUSIONS: Suboptimal adherence had no significant effect on the virological response rate with once-daily darunavir/ritonavir treatment. In contrast, the lopinavir/ritonavir response rate was significantly reduced in suboptimally adherent patients compared with adherent patients. Once-daily darunavir/ritonavir resulted in a higher virological response rate in suboptimally adherent patients compared with lopinavir/ritonavir.

Basic concepts and methods for joint models of longitudinal and survival data.

Joint models for longitudinal and survival data are particularly relevant to many cancer clinical trials and observational studies in which longitudinal biomarkers (eg, circulating tumor cells, immune response to a vaccine, and quality-of-life measurements) may be highly associated with time to event, such as relapse-free survival or overall survival. In this article, we give an introductory overview on joint modeling and present a general discussion of a broad range of issues that arise in the design and analysis of clinical trials using joint models. To demonstrate our points throughout, we present an analysis from the Eastern Cooperative Oncology Group trial E1193, as well as examine some operating characteristics of joint models through simulation studies.

Characteristics and outcomes for critically ill patients with prolonged intensive care unit stays.

OBJECTIVE: Prolonged stay in the intensive care unit (ICU) is associated with high mortality, morbidity, and costs. Identifying those patients who are most likely to benefit from an extended ICU stay would be helpful in guiding clinical decisions. We sought to describe the characteristics and outcomes for a heterogeneous group of patients who required a prolonged ICU stay. DESIGN: Observational study. SETTING: Adult ICUs of three teaching and five community hospitals. PATIENTS: The study group comprised 5,881 patients consecutively admitted to the ICUs during a 10-month period. MEASUREMENTS AND MAIN RESULTS: A prolonged stay was defined as one >21 days at teaching hospitals and >10 days at community hospitals. For patients meeting the criteria of prolonged stay, Therapeutic Intervention Scoring System (TISS) score and Multiple Organ Dysfunction Score (MODS) were measured prospectively from days 10 and 21 in community and teaching hospitals, respectively, and retrospectively before this. Prolonged-stay patients represented 5.6% of ICU admissions and 39.7% of ICU bed-days. Compared with short-stay patients, they were significantly older and had higher admission Acute Physiology and Chronic Health Evaluation (APACHE) II scores (p < .01). ICU and hospital mortality for prolonged-stay patients were 24.4% and 35.2%, respectively, compared with 11% and 15.9% for short-stay patients (p < .001). Mean admission TISS and MODS scores for prolonged-stay patients were 30.8 (sd, 11.1) and 4.8 (sd, 3.3) respectively. For prolonged-stay patients the dominant reason for ICU care was multiple organ failure (37.8%), ventilator support (30.7%), or nonventilated single organ failure (31.5%). Hospital mortality was highest in the group with multiple organ failure (53%). CONCLUSIONS: We developed a method to broadly classify a heterogeneous population of prolonged-stay ICU patients on the basis of MODS and the ICU interventions received. Mortality among prolonged-stay patients was highest for those with multiple organ failure. Future research should evaluate whether the proposed classification system can be used to influence the delivery of ICU care.

Assessing communication between oncology professionals and their patients.

BACKGROUND: Effective communication with cancer patients continues to be an elusive goal for health care professionals (HCPs) and cancer educators. METHODS: We posted a survey on the ConversationsInCare.com Web site to collect information from oncology HCPs regarding attitudes, effectiveness, and specific patient communication skills. RESULTS: The 291 respondents agreed that good communication enhances patient satisfaction (76%) and treatment compliance (88%). Only 34% of respondents felt comfortable discussing complementary or alternative therapies, and approximately half of all respondents felt they lack the skills to help patients maintain hope. CONCLUSIONS: Oncology HCPs believe that good communication is important and wish to improve their skills. Implications for cancer educators are discussed.

Attitudes regarding organ donation from non-heart-beating donors.

PURPOSE: To determine the attitudes toward organ donation from non-heart-beating cadaver donors in a sample of the general public and health care workers. MATERIALS AND METHODS: A moderator-administered questionnaire was completed by members of the general public, recruited randomly from a professional consumer research group's database, and health care workers recruited from the same database, family practice clinics, and local hospitals. Two primary scenarios were tested: (1) patient in coma, not going to survive intensive care unit (ICU), and (2) patient lapsing in and out of consciousness, lifetime institutional care. RESULTS: Sixty members of the general public and 68 health care workers completed the questionnaire. The majority of both groups were aware life support could be withdrawn in Scenario 1, however, significantly fewer were aware life support could also be withdrawn in Scenario 2 (83% general public vs 34% general public, P <.001 and 94% health care workers vs 78% health care workers, P =.012). Uncertainty in prognosis was cited as the primary concern. The issue of organ donation was directly linked with withdrawal of life support. The majority of both groups believed that organ donation would be permissible if further life support were deemed to be not in the patient's best interest because of poor short-term prognosis (94% health care workers and 98% general public for Scenario 1 and 87% health care workers and 81% general public for Scenario 2). The greatest difficulty arose in defining futility of care. Expected quality of life, patient's and family's values, opinions, and religious beliefs were felt to be most important in determining decisions regarding futility and withdrawal of life support. Physician beliefs and values were felt to influence decisions more than they should. CONCLUSIONS: Both the general public and health care workers support the use of non-heart-beating cadaver donors once a decision has been made to withdraw life support. However, both groups raised concerns regarding how the decision to withdraw life support is made.