JNJ-73763989 and bersacapavir treatment in nucleos(t)ide analog suppressed patients with chronic hepatitis B: REEF-2.

BACKGROUND & AIMS: Functional cure (FC) for chronic hepatitis B (CHB) requires finite treatment. Two agents under investigation aimed at achieving FC are small interfering RNA JNJ-73763989 (JNJ-3989) and capsid assembly modulator JNJ-56136379 (JNJ-6379; bersacapavir). METHODS: REEF-2, a phase 2b, double-blind, placebo-controlled, randomized study (ClinicalTrials.gov Identifier: NCT04129554), enrolled 130 nucleos(t)ide analog (NA)-suppressed hepatitis B e-antigen (HBeAg)-negative CHB patients who received JNJ-3989 (200 mg subcutaneously every 4 weeks)+JNJ-6379 (250 mg oral daily)+NA (oral daily; active arm) or placebos for JNJ-3989 and JNJ-6379 + active NA (control arm) for 48 weeks followed by 48 weeks off-treatment follow-up. RESULTS: At Follow-up Week 24, no patients achieved the primary endpoint of FC (off-treatment hepatitis B surface antigen [HBsAg] seroclearance). No patients achieved FC at Follow-up Week 48. There was pronounced on-treatment reduction in mean HBsAg from baseline at Week 48 in the active arm versus no decline in the control arm (1.89 vs 0.06 log10 IU/mL; P = 0.001). At Follow-up Week 48, reductions from baseline were >1 log10 IU/mL in 81.5% versus 12.5% of patients in the active and control arms, respectively, and 38/81 (46.9%) patients in the active arm achieved HBsAg <100 IU/mL versus 6/40 (15.0%) patients in the control arm. Off-treatment HBV DNA relapse and alanine aminotransferase (ALT) increases were less frequent in the active arm with 7/77 (9.1%) and 11/41 (26.8%) patients in the active and control arms, respectively, restarting NA during follow-up. CONCLUSIONS: Finite 48-week treatment with JNJ-3989+JNJ-6379+NA resulted in fewer and less severe posttreatment HBV DNA increases and ALT flares, and a higher proportion of patients with off-treatment HBV DNA suppression, with or without HBsAg suppression, but did not result in FC. GOV IDENTIFIER: NCT04129554.

Efficacy and safety of the siRNA JNJ-73763989 and the capsid assembly modulator JNJ-56136379 (bersacapavir) with nucleos(t)ide analogues for the treatment of chronic hepatitis B virus infection (REEF-1): a multicentre, double-blind, active-controlled, randomised, phase 2b trial.

BACKGROUND: JNJ-73763989 (JNJ-3989), a small interfering RNA, targets all hepatitis B virus (HBV) RNAs, reducing all HBV proteins. JNJ-56136379 (JNJ-6379; also known as bersacapavir), a capsid assembly modulator, inhibits HBV replication. We aimed to evaluate the efficacy (ie, antiviral activity) and safety of these therapeutics in combination with nucleos(t)ide analogues in patients with chronic hepatitis B. METHODS: The REEF-1 multicentre, double-blind, active-controlled, randomised, phase 2b study was done at 108 hospitals or outpatient centres across 19 countries in Asia, Europe, and North and South America. We included patients aged 18-65 years with chronic hepatitis B (defined as HBsAg positivity at screening and at least 6 months before screening or alternative markers of chronicity [eg, HBV DNA]), including those not currently treated, virologically suppressed, HBeAg positive, and HBeAg negative. Patients were randomly assigned (1:1:2:2:2:2) via permuted block randomisation according to a computer-generated schedule to receive oral nucleos(t)ide analogues once per day plus placebo (control group); oral JNJ-6379 250 mg daily plus nucleos(t)ide analogues (JNJ-6379 dual group); nucleos(t)ide analogues plus subcutaneously injected JNJ-3989 at doses of 40 mg (JNJ-3989 dual 40 mg group), 100 mg (JNJ-3989 dual 100 mg group), or 200 mg (JNJ-3989 dual 200 mg group) every 4 weeks; or JNJ-6379 250 mg plus JNJ-3989 100 mg every 4 weeks plus nucleos(t)ide analogues (triple group) for 48 weeks followed by a follow-up phase. An interactive web response system provided concealed treatment allocation, and investigators remained masked to the intervention groups until the primary analysis at week 48. The primary endpoint was the proportion of patients meeting predefined nucleos(t)ide analogue-stopping criteria (alanine aminotransferase <3 × upper limit of normal, HBV DNA below the lower limit of quantitation, HBeAg negative, and HBsAg <10 IU/mL) at week 48. All patients who received at least one dose of study drug were included in the analysis population used for primary efficacy assessment, excluding those who withdrew because of COVID-19-related reasons, withdrew before week 44, or had no efficacy data (ie, the modified intention-to-treat population). Safety was assessed in all participants who received at least one dose of study drugs. This trial is registered with ClinicalTrials.gov, NCT03982186. The study has been completed. FINDINGS: Between Aug 1, 2019, and April 26, 2022, 470 patients (310 [66%] male and 244 [52%] White) were randomly assigned: 45 to the control group, 48 to the JNJ-6379 dual group, 93 to the JNJ-3989 dual 40 mg group, 93 to the JNJ-3989 dual 100 mg group, 96 to the JNJ-3989 dual 200 mg group, and 95 to the triple group. At week 48, five (5%; 90% CI 2-11) of 91 patients in the JNJ-3989 dual 40 mg group, 15 (16%; 10-24) of 92 in the JNJ-3989 dual 100 mg group, 18 (19%; 13-27) of 94 in the JNJ-3989 dual 200 mg group, eight (9%; 4-15) of 94 in the triple group, and one (2%; 0-10) of 45 in the control group met nucleos(t)ide analogue stopping criteria. No patients in the JNJ-6379 dual group met stopping criteria. 38 (81%) patients who met nucleos(t)ide analogue-stopping criteria at week 48 were virologically suppressed and HBeAg negative at baseline. Ten (2%) of 470 patients had serious adverse events during the treatment phase, and two patients (one each from the JNJ-3989 dual 200 mg group [exercise-related rhabdomyolysis] and the triple group [increase in ALT or AST]) had serious adverse events related to study treatment. During follow-up, 12 (3%) of 460 patients had a serious adverse event; one (<1%), a gastric ulcer, was considered to be related to nucleos(t)ide analogues and occurred in a patient from the JNJ-3989 dual 200 mg group. 29 (6%) of 460 patients in the treatment phase and in ten (2%) of 460 patients in the follow-up phase had grade 3 or 4 adverse events. Five (1%) of 470 patients discontinued treatment due to adverse events, and there were no deaths. INTERPRETATION: Although treatment with JNJ-3989 led to a dose-dependent response for meeting nucleos(t)ide analogue-stopping criteria, it rarely led to HBsAg seroclearance. However, most patients treated with JNJ-3989 had clinically meaningful reductions in HBsAg that might contribute to a liver environment conducive to better immune control and, in turn, might improve the response to immune-modulating therapies. FUNDING: Janssen Research and Development.

Population Pharmacokinetic Analysis of Darunavir and Tenofovir Alafenamide in HIV-1-Infected Patients on the Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide Single-Tablet Regimen (AMBER and EMERALD Studies).

The single-tablet regimen darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg has undergone phase III studies AMBER (NCT02431247) and EMERALD (NCT02269917) in HIV-infected patients. An existing population pharmacokinetic (PopPK) model for cobicistat-boosted darunavir (DRV) was updated to describe DRV PK in AMBER and EMERALD. For TAF, a PopPK model was developed using richly sampled phase I/II data and updated with sparsely sampled AMBER data. Individual exposure metrics for DRV and TAF in patients receiving D/C/F/TAF were derived (AMBER, n=356; EMERALD, n=750). The DRV PopPK model is a two-compartment model with sequential zero-order, first-order input. TAF PK is described by a one-compartment model with dual parallel input for absorption (slow and fast pathway). DRV covariates were α1-acid-glycoprotein and body weight. TAF covariates were lean body weight and α1-acid-glycoprotein. DRV and TAF PK were unaffected by age, race, or gender. Estimated DRV mean (SD) C0h and AUC24h, respectively, were 1899 (759) ng/mL and 87,909 (20,232) ng*h/mL in AMBER; 1813 (859) ng/mL and 85,972 (22,413) ng*h/mL in EMERALD. Estimated TAF mean (SD) AUC24h was 132 (41) ng*h/mL. These PK parameters were in line with historical data. No apparent relationships of DRV or TAF exposure with efficacy (virologic response) or safety (metabolic, cardiac, liver, gastrointestinal, skin, bone, renal, pancreas, lipid events) parameters were seen. Additionally, our findings demonstrate that in patients with low plasma concentrations, there is no risk of decreased virologic response or virologic rebound. This supports the use of a once-daily, single-tablet regimen of D/C/F/TAF 800/150/200/10 mg for the treatment of HIV-1-infected subjects.

Week 96 resistance analyses of the once-daily, single-tablet regimen (STR) darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) in adults living with HIV-1 from the phase 3 randomized AMBER and EMERALD trials.

In AMBER and EMERALD, darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg demonstrated high virological response and low virological failure (VF) through week 96. Week 96 resistance analyses are presented. Post-baseline samples for genotyping/phenotyping were analyzed from protocol-defined-VFs with viral load (VL) ≥ 400 copies/ml at failure/later time points. Post-hoc analyses were deep sequencing (AMBER) and HIV-1 proviral DNA sequencing from baseline samples (VL < 50 copies/ml) (EMERALD). Through week 96 across studies, no darunavir, primary protease inhibitor (PI), or tenofovir resistance-associated-mutations (RAMs) occurred in patients continuing (N = 1125) or switching to D/C/F/TAF (N = 715). M184I/V (emtricitabine RAM) was detected in one patient in each arm of AMBER. In EMERALD D/C/F/TAF patients with prior VF and baseline genoarchive data (N = 98), 4% had darunavir RAMs, 36% emtricitabine RAMs, mainly at position 184 (32%), 4% tenofovir RAMs, and 19% ≥3 thymidine-analogue-associated-mutations at screening. The predicted phenotype showed 0% had reduced susceptibility to darunavir, 37% to emtricitabine, and 22% to tenofovir. All achieved VL < 50 copies/ml at week 96/prior discontinuation, with no VF. D/C/F/TAF has a high barrier to resistance; no darunavir, primary PI, or tenofovir RAMs occurred through 96 weeks in AMBER and EMERALD. In EMERALD, baseline archived darunavir, emtricitabine, and tenofovir RAMs in patients with prior VF did not preclude virologic response.

Week 96 subgroup analyses of the phase 3, randomized AMBER and EMERALD trials evaluating the efficacy and safety of the once daily darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) single-tablet regimen in antiretroviral treatment (ART)-naïve and -experienced, virologically-suppressed adults living with HIV-1.

BACKGROUND: Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg was investigated in AMBER (treatment-naïve adults; NCT02431247) and EMERALD (treatment-experienced, virologically-suppressed adults; NCT02269917). OBJECTIVE: To describe a Week 96 pre-planned subgroup analysis of D/C/F/TAF arms by demographic characteristics (age ≤/>50 years, gender, black/non-black race), and baseline clinical characteristics (AMBER: viral load [VL], CD4+ count, WHO clinical stage, HIV-1 subtype and antiretroviral resistance; EMERALD: prior virologic failure [VF], antiretroviral experience, screening boosted protease inhibitor [PI], and boosting agent). METHODS: Patients in D/C/F/TAF and control arms could continue on/switch to D/C/F/TAF in a single-arm, open-label extension phase after Week 48 until Week 96. Efficacy endpoints were percentage cumulative confirmed VL ≥50 copies/mL (virologic rebound; EMERALD), and VL <50 (virologic response), or ≥50 copies/mL (VF) (FDA snapshot; both trials). RESULTS: D/C/F/TAF demonstrated high Week 96 virologic responses (AMBER: 85% [308/362]; EMERALD: 91% [692/763]) and low VF rates (AMBER: 6% [20/362]; EMERALD: 1% [9/763]). In EMERALD, D/C/F/TAF showed low virologic rebound cumulative through Week 96 (3% [24/763]). Results were consistent across subgroups, including prior antiretroviral experience in EMERALD. No darunavir, primary PI, or tenofovir resistance-associated mutations were observed post-baseline. Study-drug-related serious adverse events (AEs) and AE-related discontinuations were <1% and 2%, respectively (both D/C/F/TAF arms), and similar across subgroups. eGFRcyst and bone mineral density improved or were stable and lipids increased through Week 96 across demographic subgroups, with small changes in total-cholesterol/HDL-cholesterol ratio. CONCLUSIONS: D/C/F/TAF was effective with a high barrier to resistance and bone/renal safety benefits, regardless of demographic or clinical characteristics for treatment-naïve and treatment-experienced, virologically-suppressed adults.

Week 96 results of a phase 3 trial of darunavir/cobicistat/emtricitabine/tenofovir alafenamide in treatment-naive HIV-1 patients.

BACKGROUND: Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg was investigated through 96 weeks in AMBER (NCT02431247). METHODS: Treatment-naive, HIV-1-positive adults [screening plasma viral load ≥1000 copies/ml; CD4 cell count >50 cells/µl) were randomized (1 : 1) to D/C/F/TAF (N = 362) or D/C plus emtricitabine/tenofovir-disoproxil-fumarate (F/TDF) (N = 363) over at least 48 weeks. After week 48, patients could continue on or switch to D/C/F/TAF in an open-label extension phase until week 96. RESULTS: At week 96, D/C/F/TAF exposure was 626 patient-years (D/C/F/TAF arm) and 109 patient-years (control arm post switch), week 96 virologic suppression (viral load <50 copies/ml; FDA-Snapshot, from baseline) was 85.1% (308/362) (D/C/F/TAF) and 83.7% (304/363) (control). Week 96 virologic failure (viral load ≥50 copies/ml; FDA-Snapshot) was 5.5% (20/362) and 4.4% (16/363), respectively. No darunavir, primary protease inhibitor or tenofovir resistance-associated mutations (RAMs) were observed post baseline. In one patient in each arm, an M184I and/or V RAM was detected. Few adverse event-related discontinuations (3% D/C/F/TAF; <1% control post switch) and no deaths occurred on D/C/F/TAF. Improved renal and bone parameters were maintained in the D/C/F/TAF arm and observed in the control arm post switch. Increases in total-cholesterol/high-density-lipoprotein--cholesterol rtio at week 96 were +0.25 versus baseline (D/C/F/TAF) and +0.24 versus switch (control). CONCLUSION: At week 96, D/C/F/TAF resulted in high virologic response and low virologic failure rates, with no resistance development to darunavir or TAF/TDF. Bone, renal and lipid safety were consistent with known D/C/F/TAF component profiles. Control arm safety post switch was consistent with the D/C/F/TAF arm. AMBER week 96 results confirm the efficacy, high barrier to resistance and bone/renal safety benefits of D/C/F/TAF for treatment-naive patients.

Week 48 Resistance Analyses of the Once-Daily, Single-Tablet Regimen Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide (D/C/F/TAF) in Adults Living with HIV-1 from the Phase III Randomized AMBER and EMERALD Trials.

Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg is being investigated in two Phase III trials, AMBER (NCT02431247; treatment-naive adults) and EMERALD (NCT02269917; treatment-experienced, virologically suppressed adults). Week 48 AMBER and EMERALD resistance analyses are presented. Postbaseline samples for genotyping/phenotyping were analyzed from protocol-defined virologic failures (PDVFs) with viral load (VL) ≥400 copies/mL at failure/later time points. Post hoc analyses were deep sequencing in AMBER, and HIV-1 proviral DNA from baseline samples (VL <50 copies/mL) in EMERALD. Through week 48 across both studies, no darunavir, primary PI, or tenofovir resistance-associated mutations (RAMs) were observed in HIV-1 viruses of 1,125 participants receiving D/C/F/TAF or 629 receiving boosted darunavir plus emtricitabine/tenofovir-disoproxil-fumarate. In AMBER, the nucleos(t)ide analog reverse transcriptase inhibitor (N(t)RTI) RAM M184I/V was identified in HIV-1 of one participant during D/C/F/TAF treatment. M184V was detected pretreatment as a minority variant (9%). In EMERALD, in participants with prior VF and genoarchive data (N = 140; 98 D/C/F/TAF and 42 control), 4% had viruses with darunavir RAMs, 38% with emtricitabine RAMs, mainly at position 184 (41% not fully susceptible to emtricitabine), 4% with tenofovir RAMs, and 21% ≥ 3 thymidine analog-associated mutations (24% not fully susceptible to tenofovir) detected at screening. All achieved VL <50 copies/mL at week 48 or prior discontinuation. D/C/F/TAF has a high genetic barrier to resistance; no darunavir, primary PI, or tenofovir RAMs were observed through 48 weeks in AMBER and EMERALD. Only one postbaseline M184I/V RAM was observed in HIV-1 of an AMBER participant. In EMERALD, baseline archived RAMs to darunavir, emtricitabine, and tenofovir in participants with prior VF did not preclude virologic response.

Darunavir/cobicistat/emtricitabine/tenofovir alafenamide in treatment-naïve patients with HIV-1: subgroup analyses of the phase 3 AMBER study.

Background: The once-daily, single-tablet regimen darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg is approved for the treatment of HIV-1 infection. The 48-week efficacy and safety of D/C/F/TAF versus darunavir/cobicistat + emtricitabine/tenofovir disoproxil fumarate (control) in treatment-naïve adults were demonstrated in the phase 3 AMBER study. Objective: To describe AMBER outcomes across patient subgroups based on demographic and clinical characteristics at baseline. Methods: AMBER patients had viral load (VL) ≥1000 copies/mL, CD4+ cell count >50 cells/µL, and genotypic susceptibility to darunavir, emtricitabine, and tenofovir. Primary endpoint was the proportion of patients with virologic response (VL <50 copies/mL; FDA snapshot). Safety was assessed by adverse events, estimated glomerular filtration rate (cystatin C; eGFRcystC), and bone mineral density. Outcomes were assessed by age (≤/>50 years), gender, race (black/non-black), baseline VL (≤/>100,000 copies/mL), baseline CD4+ cell count (50 years and women, relative to their comparator groups, regardless of treatment arm (notably, sample sizes were small for patients >50 years and women). Improvements in eGFRcystC and stable bone mineral density were observed with D/C/F/TAF overall, and results were generally consistent across subgroups. Conclusions: For treatment-naïve patients in AMBER, initiating therapy with the D/C/F/TAF single-tablet regimen was an effective and well-tolerated option, regardless of demographic or clinical characteristics.

Week 96 efficacy and safety results of the phase 3, randomized EMERALD trial to evaluate switching from boosted-protease inhibitors plus emtricitabine/tenofovir disoproxil fumarate regimens to the once daily, single-tablet regimen of darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) in treatment-experienced, virologically-suppressed adults living with HIV-1.

Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg was investigated through 96 weeks in EMERALD (NCT02269917). Virologically-suppressed, HIV-1-positive treatment-experienced adults (previous non-darunavir virologic failure [VF] allowed) were randomized (2:1) to D/C/F/TAF or boosted protease inhibitor (PI) plus emtricitabine/tenofovir-disoproxil-fumarate (F/TDF) over 48 weeks. At week 52 participants in the boosted PI arm were offered switch to D/C/F/TAF (late-switch, 44 weeks D/C/F/TAF exposure). All participants were followed on D/C/F/TAF until week 96. Efficacy endpoints were percentage cumulative protocol-defined virologic rebound (PDVR; confirmed viral load [VL] ≥50 copies/mL) and VL < 50 copies/mL (virologic suppression) and ≥50 copies/mL (VF) (FDA-snapshot analysis). Of 1141 randomized patients, 1080 continued in the extension phase. Few patients had PDVR (D/C/F/TAF: 3.1%, 24/763 cumulative through week 96; late-switch: 2.3%, 8/352 week 52-96). Week 96 virologic suppression was 90.7% (692/763) (D/C/F/TAF) and 93.8% (330/352) (late-switch). VF was 1.2% and 1.7%, respectively. No darunavir, primary PI, tenofovir or emtricitabine resistance-associated mutations were observed post-baseline. No patients discontinued for efficacy-related reasons. Few discontinued due to adverse events (2% D/C/F/TAF arm). Improved renal and bone parameters were maintained in the D/C/F/TAF arm and observed in the late-switch arm, with small increases in total cholesterol/high-density-lipoprotein-cholesterol ratio. A study limitation was the lack of a control arm in the week 96 analysis. Through 96 weeks, D/C/F/TAF resulted in low PDVR rates, high virologic suppression rates, very few VFs, and no resistance development. Late-switch results were consistent with D/C/F/TAF week 48 results. EMERALD week 96 results confirm the efficacy, high genetic barrier to resistance and safety benefits of D/C/F/TAF.

A week-48 randomized phase-3 trial of darunavir/cobicistat/emtricitabine/tenofovir alafenamide in treatment-naive HIV-1 patients.

OBJECTIVES: To investigate efficacy and safety of a single-tablet regimen of darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg vs. darunavir/cobicistat plus emtricitabine/tenofovir disoproxyl fumarate (TDF) (control) in antiretroviral-treatment-naive, HIV-1-infected adults. DESIGN: Phase-3, randomized, active-controlled, double-blind, international, multicenter, noninferiority study (NCT02431247). METHODS: Seven hundred and twenty-five participants were randomized (1 : 1) to D/C/F/TAF (362) or control (363). The primary objective was to demonstrate noninferiority of D/C/F/TAF vs. control for percentage viral load less than 50 copies/ml (FDA-snapshot analysis) at 48 weeks (10% margin). RESULTS: At week 48, D/C/F/TAF was noninferior to control (91.4 vs. 88.4% achieved viral load <50 copies/ml, respectively; difference 2.7%; 95% CI -1.6 to 7.1; P < 0.0001), with 4.4 vs. 3.3% of patients, respectively, having viral load greater or equal to 50 copies/ml. No treatment-emergent mutations associated with darunavir or TAF/TDF resistance were observed in either group. One patient (D/C/F/TAF) was identified with M184I/V conferring resistance to emtricitabine. Incidences of grades 3 and 4 adverse events (5 vs. 6%), serious adverse events (5 vs. 6%) and adverse event-related discontinuations (2 vs. 4%) were low and similar between groups. Mean decrease in urine protein/creatinine ratio was greater with D/C/F/TAF than control (-22.42 vs. -10.34 mg/g, P = 0.033). Mean percentage change in bone mineral density with D/C/F/TAF vs. control was 0.21 vs. -2.73%, P < 0.0001 (hip), -0.68 vs. -2.38%, P = 0.004 (lumbar spine), and -0.26 vs. -2.97%, P < 0.0001 (femoral neck). Median change from baseline in total cholesterol/HDL-cholesterol ratio was 0.20 vs. 0.08, P = 0.036. CONCLUSION: D/C/F/TAF achieved a high virologic suppression rate (91.4%) and was noninferior to darunavir/cobicistat with F/TDF. D/C/F/TAF also demonstrated the bone and renal safety advantages of TAF in combination with darunavir/cobicistat.

Safety Overview of a Recombinant Live-Attenuated Tetravalent Dengue Vaccine: Pooled Analysis of Data from 18 Clinical Trials.

A recombinant live attenuated tetravalent dengue vaccine (CYD-TDV) has been shown to be efficacious in preventing virologically-confirmed dengue disease, severe dengue disease and dengue hospitalization in children aged 2-16 years in Asia and Latin America. We analyzed pooled safety data from 18 phase I, II and III clinical trials in which the dengue vaccine was administered to participants aged 2-60 years, including long-term safety follow-up in three efficacy trials. The participants were analyzed according to their age at enrollment. The percentage of participants aged 2-60 years reporting ≥1 solicited injection-site or systemic reactions was slightly higher in the CYD-TDV group than in the placebo group. The most common solicited injection-site reactions were pain. Headache and malaise were the most common solicited systemic reactions. In both groups 0.3% of participants discontinued for safety reasons. The most common unsolicited adverse events were injection-site reactions, gastrointestinal disorders, and infections. Reactogenicity did not increase with successive doses of CYD-TDV. The frequency and nature of SAEs occurring within 28 days of any dose were similar in the CYD-TDV and placebo groups and were common medical conditions that could be expected as a function of age. Baseline dengue virus serostatus did not appear to influence the safety profile. No vaccine-related anaphylactic reactions, neurotropic events or viscerotropic events were reported. In year 3 after dose 1, an imbalance for dengue hospitalization, including for severe dengue, observed in participants aged <9 years in the CYD-TDV group compared with the placebo group was not observed for participants aged ≥9 years. In Year 4, this imbalance in participants aged <9 years was less marked, giving an overall lower risk of dengue hospitalization or severe dengue from dose 1 to Year 4 in the CYD-TDV group. These results have contributed to the definition of the target population for vaccination (≥9 years old) for which CYD-TDV has a satisfactory safety profile. Long-term safety will continue to be monitored in the ongoing follow-up of efficacy trials. Safety and effectiveness in real-life settings will be assessed through post-licensure studies.

Immunogenicity and Safety of Yellow Fever Vaccine (Stamaril) When Administered Concomitantly With a Tetravalent Dengue Vaccine Candidate in Healthy Toddlers at 12-13 Months of Age in Colombia and Peru: A Randomized Trial.

BACKGROUND: Dengue and yellow fever (YF) viruses are closely related members of the Flaviviridae family. Given the inherent similarities between the YF vaccine and dengue vaccine (CYD-TDV) candidate, it is possible that the latter could interfere with the response to the licensed YF vaccine when coadministered. METHODS: In this randomized, observer-blind, controlled, phase III trial, conducted in Colombia and Peru, 787 toddlers were administered YF vaccine concomitantly with CYD-TDV (group 1) or placebo (group 2), followed by CYD-TDV after 6 and 12 months. YF and dengue neutralizing antibody titers were determined using a 50% plaque reduction neutralization test. Noninferiority was demonstrated if the lower limit of the 2-sided 95% confidence interval of the difference in seroconversion rates [(YF + CYD-TDV) - YF alone] was greater than -10%. The safety of both vaccines was also assessed. RESULTS: Concomitant administration of YF with either CYD-TDV or placebo yielded YF seroconversion rates of 100.0% and 99.7%, respectively. The difference in YF seroconversion rates between the 2 groups was 0.33% (95% confidence interval:0.98; 1.87), demonstrating that the immune response against YF administered concomitantly with CYD-TDV was noninferior to YF administered with placebo. After 2 injections of CYD-TDV, the percentage of participants with dengue titres ≥10 (1/dil) for the 4 dengue serotypes were 91.2%-100% for group 1 and 97.2%-100% in group 2. There were no safety concerns during the study period. CONCLUSIONS: Concomitant administration of YF vaccine with CYD-TDV has no relevant impact on the immunogenicity or safety profile of the YF vaccine.