Vical Completes Target Enrollment in Its Phase 2 Therapeutic HSV-2 Vaccine Trial

SAN DIEGO, April 19, 2017 -- Vical Incorporated (Nasdaq:VICL) announced today that it has completed the target enrollment of 225 subjects in a Phase 2 trial of its therapeutic bivalent vaccine for herpes simplex virus type 2 (HSV-2), the leading cause of recurrent genital herpes.

The randomized, double-blind, placebo-controlled trial is designed to evaluate the efficacy and safety of the vaccine in healthy adults aged 18 to 50 years with symptomatic genital HSV-2 infection and is being conducted at 15 U.S. clinical sites. Subjects are evaluated for lesion recurrences over a 12-month period following a 4-dose vaccination series. The study is powered to show a reduction in annualized lesion recurrence rate, an endpoint which is clinically meaningful in this chronic disease setting because it provides information on the number of recurrences over time.

“A therapeutic vaccine is an important and promising new approach for reducing genital lesion recurrences because of its potential ability to boost immunity against HSV-2,” said Dr. John Kriesel, Associate Professor and infectious disease specialist at the University of Utah School of Medicine and one of the investigators in the Phase 2 trial. “Genital herpes afflicts one in six people in the United States and can be emotionally debilitating. A therapeutic vaccine would give patients a new treatment for this chronic disease.”

“We are pleased with the outstanding support we have received from our investigators and site staff, as the completion of the target enrollment of this Phase 2 trial represents an important milestone for this program,” said Dr. Mammen “Anza” Mammen, Vical’s Vice President, Clinical Vaccines. “We continue to follow these subjects and anticipate release of top-line efficacy results during the second quarter of 2018.”

HSV-2 is a sexually transmitted virus that causes a persistent infection that can result in painful genital lesions, as well as intermittent virus shedding placing sexual partners at risk of infection. Infection with HSV-2 also significantly increases the risk of acquiring the HIV-1 virus from HIV-infected sexual partners. There is no FDA approved vaccine for HSV-2. Vical’s investigational therapeutic bivalent vaccine encodes two full-length, HSV-2 antigens, glycoprotein D and VP11/12 tegument protein (also referred to as UL46) and is formulated with our patented adjuvant Vaxfectin^®.

About Vical
Vical develops biopharmaceutical products for the prevention and treatment of chronic or life-threatening infectious diseases, based on its patented DNA delivery technologies and other therapeutic approaches. Additional information on Vical is available at www.vical.com.

This press release contains forward-looking statements subject to risks and uncertainties that could cause actual results to differ materially from those projected. Forward-looking statements include statements about the potential uses and benefits of Vical's therapeutic HSV-2 vaccine, the parameters of the Phase 2 trial and timing regarding results from the Phase 2 trial. Risks and uncertainties include whether Vical's technology will be successfully applied; whether preclinical results will be predictive of results in human clinical testing; whether the HSV-2 vaccine or any product candidates will be shown to be safe and effective in clinical trials; whether the Phase 2 trial of Vical’s HSV-2 vaccine will proceed on Vical’s expected timing or be completed, and if so, whether results will support further development or commercialization; whether Vical will successfully develop and commercialize its HSV-2 vaccine; whether Vical or its collaborative partners will seek or gain approval to market any product candidates; whether Vical or its collaborative partners will succeed in marketing any product candidates; and additional risks set forth in the company's filings with the Securities and Exchange Commission. These forward-looking statements represent the company's judgment as of the date of this release. The company disclaims, however, any intent or obligation to update these forward-looking statements.

Contact:
Andrew Hopkins
(858) 646-1127
Website: www.vical.com