CORONAVIRUS/Medigen expects results from Phase 3 vaccine trial in Paraguay in Q4

Taipei, Oct. 20 (CNA) Taiwan's Medigen Vaccine Biologics Corp. is accelerating a Phase 3 clinical trial in Paraguay for its COVID-19 vaccine, with the trial expected to produce key safety and efficacy data during the fourth quarter of this year, the company said Wednesday.

The Medigen COVID-19 vaccine doses were sent to Paraguay in the third quarter for the Phase 3 clinical trial, the company said in a statement.

The company started the clinical trial on Oct. 13 in cooperation with the faculty of the School of Medical Sciences at the National University of Asuncion in the Paraguayan capital.

The trial compares recipients of the Medigen and AstraZeneca (AZ) vaccines via a technique known as immunobridging, which uses the immune responses measured in trial participants to infer a vaccine's overall level of protection, the company said.

Medigen said it began the acceleration of its vaccine trial on Wednesday and that almost 100 out of more than 300 people enrolled to participate in its Phase 3 clinical trial in Paraguay have received their first shot of the vaccine.

Under the company's plan, the administration of the first dose of Medigen vaccine for 330 individuals in Paraguay is expected to be completed this week, it added.

The Phase 3 clinical trial in Paraguay involves 1,000 volunteers for the shot and is expected to produce key safety and comparative immunogenicity data in the fourth quarter before the vaccine will be brought into Central and Southern America, according to the company.

In addition to Medigen, French pharmaceutical company Valneva's Phase 3 clinical trial for its COVID-19 vaccine candidate VLA2001, which was carried out in late April in the United Kingdom and involved 4,000 participants, also used immunobridging, Medigen said.

VLA2001 demonstrated superiority against the AZ vaccine in terms of geometric mean titer for neutralization antibodies (GMT ratio=1.39) as well as non-inferiority in terms of seroconversion rates (SCR above 95 percent in both treatment groups), according to Medigen, citing Valneva's reports.

On July 19, the Medigen vaccine became the only locally developed vaccine to receive emergency use authorization from Taiwan's Food and Drug Administration (FDA).

The FDA decision was criticized by some as Medigen has yet to complete a Phase 3 trial, which is normally required for determining the efficacy of a vaccine.

The administration said at the time that it had granted authorization because the neutralizing antibodies generated in Medigen recipients compared well to those inoculated with the AZ vaccine, a concept known as immunobridging.

Taiwan began its rollout of the Medigen vaccine on Aug. 23.