Dynavax's shingles vaccine shows similar immune response to GSK's shot in study

Aug 21 (Reuters) - Dynavax Technologies DVAX.O said on Thursday its experimental shingles vaccine generated a similar immune response as GSK's GSK.L blockbuster shot Shingrix, while showing a better safety profile, in an early-to-mid-stage study.

Shares of Dynavax rose nearly 6% to $11.02 in morning trading.

Shingles, or herpes zoster, is a viral infection characterized by painful rashes that could lead to serious complications such as long-term nerve pain and vision loss.

The disease is caused by the varicella-zoster virus, which also causes chickenpox, and affects about 1 million Americans each year, according to government data.

The data "more than met expectations" to further develop the vaccine, Evercore ISI analyst Jonathan Miller said, adding that the safety benefit "looks quite meaningful".

Dynavax tested two variants of its candidate, Z-1018, in the trial of 92 people aged 50 through 69 years. All subjects injected with either of the vaccine variants showed a similar immune response to those given Shingrix, one month after the second dose.

All participants who received Z-1018 showed a measurable antibody response, compared with 96.9% of participants who received Shingrix, Dynavax said.

Meanwhile, 12.5% of people injected with the experimental candidate had post-injection reactions such as swelling and redness, lower than the 52.6% people who took GSK's shot. No safety concerns have been identified in the study, the company said.

The safety and tolerability of vaccines can influence preferences among healthy recipients.

GSK did not immediately respond to Reuters' request for comment on the data from the head-to-head trial.

Dynavax said it plans to begin the second part of the trial with one of the doses by the second half of the year in adults 70 years of age and older.

The U.S. Food and Drug Administration had approved a pre-filled syringe version of GSK's Shingrix last month.