Inovio drops Lassa, MERS vaccines as clinical data fall short, gutting infectious disease pipeline

Inovio’s Lassa fever and Middle East respiratory syndrome (MERS) vaccine candidates have fallen short of the bar set by the biotech’s partner, prompting the collaborators to pull the plug on the programs after getting a look at clinical data.

The Coalition for Epidemic Preparedness Innovations (CEPI) partnered with Inovio in 2018, committing up to $56 million to support development of DNA vaccine candidates against Lassa and MERS through to phase 2. Inovio began a phase 2 clinical trial of the MERS candidate, INO-4700, and a phase 1b study of the Lassa prospect, INO-4500, last year. CEPI footed the bill for the studies. 

Inovio provided an update on the programs after the market closed Thursday, revealing the data didn’t meet CEPI’s selection criteria for further development. In response, the partners stopped work on the two vaccine candidates.

In a statement, Inovio CEO Jacqueline Shea said the two vaccines “were well-tolerated” and “generated immune responses.” A clearer picture of the factors that led the partners to decide against continuing the development of the candidates should emerge when Inovio shares data from the trials.

The discontinuation of INO-4700 and INO-4500 development blows a hole in Inovio’s infectious disease pipeline but leaves other key opportunities intact. The candidates accounted for half of the biotech’s clinical infectious disease prospects, with the other assets being its phase 3 COVID-19 vaccine and early-phase Ebola shot. All of the infectious disease candidates are externally funded. 

Inovio is pumping its own cash into VGX-3100 and INO-3107, candidates aimed at conditions related to human papillomavirus. Data from the second phase 3 trial of VGX-3100 are due around the turn of the year. The FDA is recommending that the trial, REVEAL2, is used as an exploratory study to evaluate a biomarker population, leaving Inovio one or two new trials from having the data to support approval. 

Shares in Inovio fell 3% to $2.26 in premarket trading.