Study of a Tetravalent Dengue Vaccine Administered Concomitantly or Sequentially With Adacel® in Healthy Subjects

Dengue Fever Clinical Trial

Official title: Immunogenicity and Safety of a Tetravalent Dengue Vaccine Administered Concomitantly or Sequentially With Adacel® in Healthy Subjects Aged 9 to 60 Years in the Philippines

Status Terminated

Clinical Trial Summary

The aim of the study was to investigate the immunogenicity and safety of CYD dengue vaccine and Tetanus Toxoid (T), Reduced Diphtheria Toxoid (D) and Acellular Pertussis Vaccine Adsorbed (ap) (Tdap) vaccine when both vaccines were administered concomitantly or sequentially.

Primary Objectives:

• To demonstrate the non-inferiority of the humoral immune response to the Tdap booster dose concomitantly administered with the first dose of CYD dengue vaccine as compared to sequential administration, measured 28 days after Tdap booster dose.

• To demonstrate the non-inferiority of the humoral immune response to the first dose of CYD dengue vaccine concomitantly administered with Tdap as compared to sequential administration, measured 28 days after the first dose of CYD dengue vaccine.

Secondary Objectives:

• To demonstrate the non-inferiority of the humoral immune response of 3 doses of CYD dengue vaccine with the first dose concomitantly administered with Tdap as compared to sequential administration, measured 28 days after the third dose of CYD dengue vaccine.

• To describe the humoral immune response at baseline and 28 days after the first and third doses of CYD dengue vaccine, in each and any group.

• To describe the humoral immune response of Tdap vaccine at baseline and 28 days after concomitant administration with the first dose of CYD dengue vaccine as compared to the sequential administration, in each and any group.

• To describe the safety of the CYD dengue vaccine and of the Tdap booster dose after each and any injection in each group.

Clinical Trial Description

Participants were to receive CYD dengue vaccine according to a 3-dose schedule administered 6 months apart, with the first dose of CYD dengue vaccine administered either concomitantly or sequentially with a booster dose of the Tdap vaccine, Adacel®.

During the conduct of the study, a safety signal was identified which led to the Independent Data Monitoring Committee (IDMC) recommendation not to vaccinate participants who had never been infected by dengue prior to the first injection, i.e., dengue non-immune participants. The protocol was amended accordingly but never implemented due to absence of response of Health Authorities (HA) from The Philippines.

After having waited for more than 1.5 years, and as the participants became out of window to complete their immunization schedule and the last safety follow-up call (6 months after the last dose), the Sponsor decided to stop the trial. Participants only attended a last safety follow-up visit to terminate the study and were informed about the end of the study. As a consequence, the study was prematurely terminated before injection of the last dose (3rd dose) of the CYD dengue vaccine.

As a consequence of the IDMC recommendations, the main immunogenicity analyses were done in dengue immune participants which is not what was planned in the protocol (and this is why the primary endpoints are not exactly the same as those defined in the protocol as they were finally assessed only in dengue immune participants whereas initially it was planned to be assessed regardless of baseline status).

All participants were assessed for immunogenicity and safety. Safety assessments included solicited reactions within 7 or 14 days after each injection, unsolicited adverse events within 28 days after each injection, and serious adverse events during the study period. ;

Related Conditions & MeSH terms

• Dengue
• Dengue Fever
• Dengue Hemorrhagic Fever
• Fever
• Hyperthermia
• Severe Dengue

• NCT number: NCT02992418
• Study type: Interventional
• Source: Sanofi
• Status: Terminated
• Phase: Phase 3
• Start date: December 19, 2016
• Completion date: December 10, 2019