New data suggests that Inovio Pharmaceutical’s Ebola booster vaccine produces a strong immune response, adding a needed boost to the company’s DNA vaccine pipeline.

Inovio presented full data from an investigator-sponsored Phase Ib trial (NCT04906629) testing its DNA vaccine INO-4201 as a booster for Merck’s Ebola vaccine Ervebo (rVSV-ZEBOV) at the 33rd European Congress of Clinical Microbiology and Infectious Diseases (ECCMID).

The results indicate that INO-4201 can elicit strong humoral and cellular responses, restoring antibody titers to protect against Ebola.

Inovio specializes in DNA medications, though the company has a mixed track record in developing DNA vaccines. In October 2022, Inovio discontinued internal funding for its Covid-19 vaccine INO-4800, following a rocky drug development path that included a partial clinical hold. Meanwhile, Inovio’s lead candidate VGX-3100, which targets HPV-associated diseases, is in Phase III development.

Phase Ib data in Ebola

In the Phase Ib trial of INO-4201, 46 healthy volunteers who had previously received Ervebo received a single shot of either INO-4201 or a placebo. Subjects also received electroporation with Inovio’s Cellectra, a smart device that produces immune responses against targeted pathogens.

INO-4201 led to an increase in mean neutralizing antibody titers from 23.4 to 62.8 by week 4, remaining at 50.4 at the end of the 24-week study. All 36 patients who received the vaccine had boosted humoral response, and INO-4201 was reported to be safe and well-tolerated.

Inovio’s INO-4201 encodes for a synthetic antigen designed to account for the genetic variability of Ebola viruses observed in various outbreak strains.

Funding for the Phase Ib study came from the US Defense Advanced Research Projects Agency (DARPA), the Global Urgent and Advanced Research and Development (GuardRX), and Inovio’s internal funds. The University of Geneva, Switzerland, is the study sponsor.

Following the recent outbreak of Ebola in Sudan, there has been a renewed push to contain the virus and develop new effective therapies and vaccines.