Status: Approved in U.S. and EU in early 2009

Organizations involved:

Valneva SA – Manuf.; R&D; Tech.

Intercell AG – Former

Novartis Vaccines and Diagnostics Ltd. – U.S. mark.; Europe mark.; Asia mark.

Novartis AG – Parent

CSL Ltd. – Australia mark.

Vetter Pharma-Fertigung GmbH – Manuf. other

Biological E. Ltd. – India mark.

Walter Reed Army Institute of Research (WRAIR), U.S. Army – R&D

Description: Ixiaro (IC51) vaccine is an aqueous formulation of purified formaldehyde-inactivated attenutated Japanese encephalitis virus SA14-14-2 virus strain cultured in Vero cells, an African green monkey kidney cell line, complexed with aluminum hydroxide adjuvant. Vaccine production is based on the neuro-attenuated JE virus strain SA14-14-2 propagated in Vero cells. Virus harvests are purified, formalin inactivated and adsorbed to aluminium hydroxide Unlike JE-VAX, the only vaccine currently approved in the U.S. and European Union, IC51 requires two inoculations, and a single-dose schedule is being studied.

Ixiaro is a suspension for injection supplied in 0.5 mL single dose syringes. Each 0.5 mL dose contains 6 µg of purified, inactivated JEV proteins and 250 µg of aluminum hydroxide (adjuvant). Each dose of 0.5 ml (extractable volume set to ≥ 0.57 ml) contains JEV target total protein concentration of 6 μg that corresponds to a potency of ≤ 460 ng ED50, adsorbed to 0.1% aluminium hydroxide. Ixiaro contains protamine sulfate, a compound known to cause hypersensitivity reactions in some individuals. Ixiaro is stored refrigerated at 2°-8° C (35°-46° F).

Impurities include substrate, virus and production process-related impurities. Impurities derived from the manufacturing process, i.e. from the virus (JEV WVSB), cell substrate (host cell DNA, host cell protein, the cell culture media components, bovine serum) and residual from the production process (i.e. protamine sulphate, sucrose, formaldehyde, sodium metabisulphite) were examined by the sponsor. Process-related impurities also consist of potential contaminants (viral, mycoplasma, other microbial contaminants and TSE agents).

Note, a similar vaccine using live attenuated (not inactivated) SA14-14-2 virus strain cultured in primary hamster kidney cells, is manufactured by the Chengdu Institute of Biological Products in China.

Intercell/Novartis is focusing initially on making the vaccine available to adults from developed countries traveling to endemic areas (targeting expatriates, military personnel, and tourists).

Nomenclature: Japanese Encephalitis Vaccine/Intercell [BIO]; Ixiaro [TR]; IC51 [SY]; NDC 42515-001-01 [NDC]; Jeev [TR India]

Companies.: The vaccine was developed and is manufactured by InterCell AG. Manufacturing of the virus and final formulation with aluminum hydroxide is performed according to cGMP at Intercell’s state-of-the-art vaccine production facility in Livingston, Scotland. The vaccine is manufactured by Intercell AG's wholly-owned subsidiary Intercell Biomedical Ltd. at its cGMP facility in Livingston, Scotland.

The vaccine was developed for over 10 years under a Collaborative Research and Development Agreement (CRADA) with the Walter Reed Army Institute of Research (WRAIR), U.S. Army.

In the U.S., Intercell distributes Ixiaro to Department of Defense (DOD) customers and Novartis distributes the vaccine to the civilian markets.

In Sept. 2005, Intercell granted CSL Ltd. exclusive marketing rights in Australia, New Zealand, Papua New Guinea and the Pacific Islands. Biological E markets the vaccine as Jeev in India.

In March 2005, Intercell AG (Vienna, Austria) formed a collaboration with Biological E. Ltd. (Hyderabad, India) to develop and market IC51 in India and Asian markets. Intercell is also working with Biological E and PATH to coordinate future development and ultimately provide the vaccine for adults and children in endemic areas.

In June 2006, Novartis AG licensed exclusive marketing rights for the U.S., European and some other markets, including Asia and Latin America, with the exception of countries where Intercell has already entered into marketing agreements. Novartis made an equity investment of €30 million in Intercell. Novartis also received first negotiation rights to certain products from Intercell. Novartis will make milestone payments, potentially worth $46.8 million, including for IC51’s final Phase III trial and U,S. and European Union approvals.

In June 2006, Novartis paid $30 million to acquire a 6.1% stake in Intercell, full rights to market IC51 in the U.S., Europe and several South American and Asian markets and certain rights/options to market other vaccines in development.

Intercell has been working to increase its JEV production capacity from 1 million to 2-3 million doses a year.

With Intercell having acquired Iomai and its skin patch vaccine transcutaneous immunization (TCI) adminstration technology, many expect the company to develop and test a skin patch JE vaccine

In later 2008, Intercell reported its intent to bid on a DOD RFP for a contract to supply JE vaccine for use by military personnel. The company expressed confidence that it would be awarded the 5-year supply contract.

In Jan. 2009, Intercell signed an exclusive agreement with Novartis AG for the marketing and distribution of Ixiaro in Japan and Korea.

The following sites are involved in the manufacturing: for IXIARO, Intercell Biomedical Limited, Livingston, UK (formulation), Brenntag Nordic, Frederikssund, Denmark (manufacture of the aluminum hydroxide), Vetter Pharma-Fertigung GmbH & Co. KG, Schützenstrasse, Ravensburg, Germany (aseptic filling), Vetter Pharma-Fertigung GmbH & Co. KG , Holbeinstrasse, Ravensburg, Germany or alternatively Vetter Pharma-Fertigung GmbH & Co. KG , Mooswiesen, Ravensburg, Germany (labelling, packaging and storage).

The Japanese encephalitis (JE) whole virus vaccine was developed and initially manufactured by Walter Reed Army Institute of Research (WRAIR), Forest Glen, MD, USA, (lots for Phase 1 and Phase 2 studies). Intercell sublicensed the rights to manufacture the vaccine from VaccGen International LLC, USA and transferred the process from WRAIR to Intercell’s manufacturing facility in Livingston, Scotland. Phase III clinical materials were prepared in this facility. The manufacture of the commercial active substance is also carried out in this facility, but in new clean rooms. Several important changes have been performed between the WRAIR production process and the Phase III and Commercial Process.

Manufacture: Ixiaro is prepared by propagating JEV strain SA14-14-2 in Vero cells. Multiple viral harvests are performed, which are pooled, clarified and concentrated. The virus suspension is treated with protamine sulfate to remove contaminating DNA and proteins. The resulting partially purified virus is processed through a sucrose density gradient centrifugation step and fractionated. Each fraction is analyzed for the presence of virus, and fractions with the highest virus activity are pooled to give a purified virus suspension. The purified virus is then inactivated by treatment with formaldehyde. Following neutralization of the formaldehyde, the inactivated virus is sterile filtered through two 0.2 μm filters into a Stedim 50-L Flexboy bag. The preparation is adjusted to a specified protein concentration and formulated by addition of aluminum hydroxide adjuvant. Following adsorption of the active substance onto aluminium hydroxide, the final bulk is stored at Intercell Biomedical Limited until shipment to the filling plant Vetter Pharma-Fertigung GmbH & Co. KG, Germany. The final bulk vaccine is mixed continually during the filling process, and the product is dispensed into sterile single dose syringes which are automatically closed with sterile plungers by the filling machine.

The wild-type parental virus, SA-14, was isolated from a pool of Culex pipiens larvae from Xian, China, following 11 passages in mouse brain. The derivation of the strain SA14-14-2 was performed through an empirical process of serial passage performed in Beijing, China, in primary hamster kidney cells (PHK) and was given the strain designation SA14 clone 14-2 (also designated SA14-14-2). No information is available concerning the quality of the animals, cell substrate, reagents or facilities involved in the attenuation of the SA14 strain in China. Following a risk calculation concerning the possibility of TSE contamination during the attenuation process done in China for the SA-14 virus strain, the information provided by the sponsors was considered sufficient (by EMA) to justify the use of these materials.

From the manufacturing process, Ixiaro also contains: formaldehyde (not more than 200 ppm), bovine serum albumin (not more than 100 ng/mL), host cell DNA (not more than 200 pg/mL), sodium metabisulphite (not more than 200 ppm), host cell proteins (not more than 300 ng/mL), and protamine sulfate (not more than 1g/mL). No preservatives, stabilizers, or antibiotics are added to the formulation.

A batch is defined (by the EU) by the volume of active substance obtained from the thawing of a specific number of vials of Vero Working Cell Bank, which are then expanded in cell culture and infected with the appropriate amount of Working Virus Seed Bank material. The batch size is specified

The following steps have been identified as critical (as reported by EMA) and have been used for validation studies:
Infection of Vero cells with Working Virus Seed Bank
Reduction of host cell DNA
Inactivation of virus by treatment with Formaldehyde
Sterile filtration

FDA class: Biologic BLA

Approvals: Date = 20090330; BLA (STN 125280/0)

Date = 20091023; BLA supplement; Indication = revisions to the military version of the package insert

Indications: [full text of the "Indications: and Usage" section of the product insert/labeling, 5/7/2009]:

IXIARO is a vaccine indicated for active immunization for the prevention of disease caused by Japanese encephalitis virus (JEV) in persons 17 years of age and older.

Status: Intercell initiated its BLA for FDA approval on Oct. 12, 2006, and the filing was completed on Dec. 20, 2007. The proposed indication was “for active immunization against JE disease for persons 18 years of age and older who are at risk of exposure to JE virus. Vaccine should be used in persons who plan to reside in or travel to areas where JE is endemic or epidemic, especially if travel will occur during the transmission season.” Intercell is the manufacturer and BLA applicant. Pediatric use approval is projected for 2010/2011. Granting of a DOD contract for vaccine purchase was expected soon after FDA approval.

A MAA for European Union (EU) approval was filed on Dec. 7, 2007. The EU granted orphan status to the vaccine in Jan. 2006. Approval was granted in March 2009.

Note, FDA approval allows for use in subjects age 18 and older, while EU approval allows use in those 18 years and older.

Traditional efficacy trials of Ixiaro or any new JE vaccine are not feasible because of ethical issues. FDA approval will be based on immunogenicity criteria (non-inferiority versus licensed vaccine, JE-VAX). The indicator of efficacy (surrogate marker) is serum dilution giving a 50% reduction in a Plaque Reduction Neutralization Test ≥ 1:10 (PRNT50 ≥ 1:10). A WHO Expert Panel has accepted PRNT50 ≥ 1:10 as protective.

In Jan. 2008, Intercell reported that its fully owned manufacturing site in Livingston, Scotland (Intercell Biomedical Ltd.), has been granted a U.K. manufacturer’s Licence for manufacture of Ixiaro following a GMP inspection performed by the Medicines and Healthcare products Regulatory Agency (MHRA).

The original EU filing included orphan designation, but this was withdrawn prior to approval.

In Feb. 2013, the EU granted supplemental approval for pediatric use in children/adolescents aged 2 months to less than 18 years.

Trials: The Walter Reed Army Institute of Research (WRAIR), U.S. Army, performed Phase I and II trials with IC51. In the Phase I study, the vaccine was found to be safe, well tolerated and immunogenic. A head-to-head Phase II comparison study with JE-VAX showed that the Intercell vaccine was less reactogenic, both in frequency and intensity; more potent, with higher antibody levels at all doses studied one month after the immunizations and high seroconversion rates one month after a single dose; more convenient, using two doses versus three doses and liquid versus freeze-dried formulations; and more persistent, with a higher persistence of antibodies two years after primary immunization. Seroconversion rates up to 100% were observed.

A Comparability Protocol was developed to evaluate the comparability of the manufacturing processes conducted at the WRAIR and Intercell facilities and the equivalence of vaccine manufactured for Phase 1 and 2 clinical trials and pivotal Phase 3 studies. Vaccine lots evaluated for the purposes of this protocol included the Phase 2 WRAIR lot (historical data only), small-scale lots manufactured at WRAIR and Intercell during process transfer, and five consecutive large-scale lots manufactured at Intercell, three of which were evaluated in Phase iii studies. The commercial manufacturing process for the Active substance remains largely the same as the process used for manufacture of Phase III clinical trial material. Comparability was demonstrated for many of the parameters used to compare the WRAIR (Phase 2 & 3 material) with the Intercell (Phase 3 material). Possible impurities are adequately controlled by in-process controls or at the level of active substance release testing

The Phase III trial program of Ixiaro involves 3,558 subjects exposed to IXIARO in Phase 3 Trials, with 3,504 subjects exposed to 2 doses. In total, over 7,150 doses of Ixiaro have been administered. Trials are being conducted at sites in Austria, Germany and in the U.S. The studies are designed to demonstrate non-inferiority in terms of immunogenicity of the Intercell vaccine compared to JE-VAX, in a multicenter, multinational, observer blinded, randomized parallel group design. Study IC51-301 is the pivotal immunogenicity study vs JE-VAX in over 860 patients; IC51-302 is the Pivotal Safety vs Placebo, with 2,012 subjects receiving vaccine and 663 receiving placebo; IC51-303 is the long-term safety study with 2,283 vaccine recipients and 975 control, with a subset of each in a immunogenicity follow-up (sub)study; and IC51-308 is a study with 127 subjects concommitantly receiving Ixiaro and Havrix (hepatitis A vaccine; another travelers’ vaccine) and 65 controls.

In study IC51-301, non-inferiority was demonstrated, with 97.5% of Ixiaro recipients seroconverting (achieving PRNT50 ≥ 1:10) four weeks after their last dose vs. 95.3% with JE-VAX. Geometric Mean Titers (GMT) four weeks after last injection were 243.6 in Ixiaro recipients vs. 102 in JE-VAX recipients.

Overall, in its studies, seroconversion rates, defined as proportion of subjects achieving a titer of PRNT50 ≥ 1:10, were over 95% for the first 6 months and over 83% after one year. Systemic tolerability and adverse events were similar between Ixiaro, placebo and JE-VAX. Ixiaro appeared to have a more favorable local tolerability profile than JE-VAX. The most common (≥ 10%) systemic adverse events were headache and myalgia. The most common (≥ 10%) injection-site reactions were pain and tenderness.

In five clinical studies submitted in the BLA and conducted in North America, Europe, Australia and New Zealand, a total of 3,558 adults aged 18 to 86 years received at least one dose of Ixiaro (92% completed the 2 dose series) and were followed-up for safety for at least 6 months after the first dose.

Medical: Ixiaro is administered as two intramuscular injections into the deltoid muscle of 6 µg antigen/0.5 mL vaccine on days 0 and 28. Immunization series should be completed at least 1 week prior to potential exposure to JEV.

Disease: Japanese encephalitis (JE) virus, a mosquito-borne flavivirus, is an important cause of encephalitis in Asia with a case fatality rate of 20%--30% and neurologic or psychiatric sequelae in 30%--50% of survivors. Travelers to JE-endemic countries and laboratory personnel who work with infectious JE virus are at potential risk for JE virus infection.

In June 2009, CDC's Advisory Committee on Immunization Practices (ACIP) made significant changes to their previous Japanese Encephalitis recommendations, last updated in 1993, noting that many more travelers are now visiting areas where the disease is endemic. In addition to recognizing the recent licensure of IXIARO, the committee’s expanded recommendations urged clinicians to consider vaccinating travelers visiting endemic areas during the transmission season, even those on short-term visits, if they plan to spend a substantial amount of time outdoors. The panel also concluded that IXIARO, which is derived from a well-established cell line and does not contain stabilizers or preservatives, has a lower risk of vaccine-associated adverse events than older Japanese Encephalitis vaccines

ACIP now recommends that if the primary series of JE-VC was administered >1 year previously, a booster dose may be given before potential JE virus exposure. However, data on the response to a booster dose administered >2 years after the primary series of JE-VC are not available. Data on the need for and timing of additional booster doses also are not available. No data exist on the use of JE-VC as a booster dose after a primary series with inactivated mouse brain-derived JE vaccine (JE-Vax). Adults aged ≥17 years who have received JE-MB previously and require further vaccination against JE virus should receive a 2-dose primary series of JE-VC.

Market: The cost for the 2-course vaccination in the U.S. is reported to be about $300, with U.S. military use costing about 25% less.

The Novartis U.S. price has been reported to be $195/dose.

Competition: Comparing the Ixiaro and JE-VAX, Ixiaro uses a an attenutated virus, while JE-VAX uses a wild virus; Ixiaro is cell cultured, while JE-VAX is cultured in mouse brains; Ixiaro contains aluminum-based adjuvat, while JE-VAX has none; Ixiaro contains no preservatives or stabilizers, while JE-VAX contains porcine gelatine as stabilizer and thimersals (mercury derivative as a preservative; and Ixiaro is liquid, while JE-VAX is lyophilized. JE-VAX requires three inoculations, while Ixiaro requires only two, two-weeks apart, making it much more convenient.

Most important for marketing, Ixiaro only involves two doses, while JE-VAX involves three, while Chimerivax-JE involves only one injection.