Picture: 123RF/JOZEF POLC
Picture: 123RF/JOZEF POLC

Bengaluru — US immunotherapy company Inovio Pharmaceuticals said on Wednesday that its experimental vaccine to prevent coronavirus infection produced protective antibodies and immune system responses in mice and guinea pigs.

The company’s shares, which have more than quadrupled this year on hopes of its vaccine working, surged another 18% to $15.77 early trading.

“We saw antibody responses that do many of the things we would want to see in an eventual vaccine,” said Dr David Weiner, director of the vaccine and immunotherapy centre at the Wistar Institute, which has collaborated with Inovio. “We are able to target things that would prevent the virus from having a safe harbour in the body.”

There are currently no approved treatments or vaccines for Covid-19, the disease caused by the new coronavirus, with governments, drugmakers and researchers working on about 100 vaccine programmes. Experts still predict that a safe and effective vaccine could take 12 to 18 months to develop.

Inovio began human testing of its vaccine in April. Many other drugmakers, including Moderna, Pfizer, Johnson & Johnson, Sanofi and AstraZeneca, are also in various stages of vaccine development.

On Monday, Moderna said its experimental Covid-19 vaccine produced protective antibodies in a small group of healthy volunteers, according to very early data, putting it at the front in the race.

Inovio said preliminary results from its human trial are expected in June. The 40 healthy participants in the phase one trial are given two shots, four weeks apart, of the vaccine, called INO-4800, then monitored for two weeks.

“We are already seeing safety data and it has been benign,” Dr Katherine Broderick, head of research and development at Inovio, said. “Some people have slight redness of the arm.”

Both Moderna and Inovio are using newer technology that focuses on specific genes on the outer “spike” portion of the virus.

Inovio’s vaccine was designed using its DNA medicine platform, while Moderna’s uses messenger RNA (mRNA) technology. Both companies have no approved drug in the market.

Inovio has been severely criticised by Citron Research, with the short-seller slapping a target price of $2 on the company’s stock.

Once the preliminary data is in, Inovio expects to approach the US Food and Drug Administration for authorisation to move into a phase two/three trial, which could happen in July or August.

Inovio said the latest animal study results, published in the journal Nature Communications, validate its DNA medicines platform. It plans to test the vaccine in larger animals including rabbits and monkeys, and undertake “challenge” studies in mice, ferrets and monkeys, Broderick said.

“Challenge” studies involve intentionally giving the virus to an animal then seeing if the vaccine prevents infection.

Inovio’s vaccine efforts are funded by a global coalition and the company has said it can manufacture 1-million doses by the end of the year for additional trials and emergency use.