WASHINGTON, October 27 /PRNewswire/ --

- Data presented at the joint annual meeting of ICAAC and IDSA

- Results suggest candidate vaccine may be as effective as Prevnar for the seven shared serotypes, and provide expanded coverage for six additional serotypes

- Wyeth on track to complete U.S. filing for pediatric use in the first quarter of 2009, with other pediatric global filings expected at the same time, or possibly earlier

Data from a pivotal trial and three other Phase 3 studies presented today indicate that Wyeth's (NYSE: WYE) investigational 13-valent pneumococcal conjugate vaccine (PCV13) may offer broader protection against pneumococcal disease (PD) in infants and young children compared to Prevnar(R), Pneumococcal 7-valent Conjugate Vaccine (Diphtheria CRM197 Protein).

Specifically, the data indicate that PCV13 may be as effective as Prevnar (also referred to as PCV7) in helping to prevent invasive pneumococcal disease (IPD) due to the seven serotypes shared by the vaccines, and may provide expanded coverage for six additional serotypes found worldwide. The data were presented at the joint annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) and the Infectious Diseases Society of America (IDSA) in Washington, D.C.

The candidate vaccine includes the 13 most common pneumococcal serotypes associated with serious PD. Seven of these (4, 6B, 9V, 14, 18C, 19F and 23F) are included in Prevnar -- the current global standard in PD prevention in infants and young children. The six additional serotypes (1, 3, 5, 6A, 7F and 19A) are associated with the greatest burden of residual, or remaining, invasive disease. Both vaccines contain CRM197 -- an immunological carrier protein with a 20-year history of use in pediatric vaccines.

These new data suggest that the 13-valent pneumococcal vaccine has the potential to address a critical unmet need, says Emilio A. Emini, Ph.D., Executive Vice President, Vaccine Research and Development, Wyeth Pharmaceuticals. Based on the known prevalence of pneumococcal serotypes, it is estimated that the candidate vaccine has the potential to cover up to 92 percent of invasive pneumococcal disease in infants and young children worldwide. Given the global burden of serious pneumococcal disease, this candidate vaccine is designed to provide more comprehensive protection.

The Company expects to complete its U.S. filing for pediatric use of the vaccine in the first quarter of 2009, with other pediatric global filings expected at the same time, or possibly earlier. The 13-valent candidate vaccine is also being studied in global Phase 3 clinical trials in adults, with regulatory filings expected in 2010.

Pneumococcal disease affects both children and adults, and is a leading cause of illness and death worldwide. Pneumococcal disease describes a group of illnesses, all caused by the bacterium Streptococcus pneumoniae, that include invasive infections such as bacteremia/sepsis and meningitis, as well as pneumonia and otitis media. Most recently, the pneumococcal serotype 19A, which is included in the candidate vaccine, has been increasing in prevalence in many regions of the world and is frequently resistant to antibiotics.

Phase 3 Data Results

The data presented today represent four of 13 core Phase 3 studies in the pediatric clinical trial program intended to support regulatory filings for licensure of the 13-valent vaccine.

European Pivotal Data

The pivotal Phase 3 trial (#G-2117), conducted in Germany with 604 infants, compared the candidate PCV13 to Prevnar. The immunogenicity assessments were conducted at one month after completion of the infant vaccination series (using a vaccination schedule of 2, 3 and 4 months). The immunogenicity objectives of the study were to:

-- Compare the immune responses elicited by PCV13 and Prevnar against each of the seven pneumococcal serotypes common to the two vaccines. -- Evaluate the immune response elicited by the six additional pneumococcal serotypes included in the 13-valent vaccine.

On the basis of a prospectively defined set of immunogenicity criteria, the results of the study indicated that the responses elicited by PCV13 for all 13 serotypes were comparable (scientifically referred to as non-inferior) to those of Prevnar. Additionally, PCV13 elicited functional (biologically active) antibodies for all 13 serotypes. The results of this study also indicated that the safety and tolerability of PCV13 and Prevnar were comparable.

Finally, the study evaluated the immune responses elicited against several components (hepatitis B, Haemophilus influenzae type B and diphtheria) of the concomitantly administered Infanrix(R) hexa (GlaxoSmithKline) pediatric vaccine. Immune responses to these vaccine antigens were comparable when co-administered with either PCV13 or Prevnar.

Overall, the results of this pivotal study suggest that PCV13 may be as effective as Prevnar in helping to prevent pneumococcal disease caused by the serotypes currently in Prevnar, and that PCV13 may provide expanded coverage in helping to prevent PD caused by the six additional serotypes.

Additional Phase 3 Data Presented at ICAAC/IDSA

Data from three additional Phase 3 European trials (France, Poland and the U.K.) presented at the conference support the pivotal study conclusion that PCV13 is well tolerated, immunogenic and has the potential to provide direct protection against the 13 serotypes included in the vaccine.

-- In the study conducted in France (n=613, #G-2119), three doses of investigational PCV13 administered to infants elicited a significant immune response to all 13 vaccine serotypes. In addition, immune responses to antigens contained in the concomitantly administered pediatric vaccine, Pentavac(TM) (Sanofi-Pasteur), were generally comparable, whether given with PCV13 or Prevnar. Safety and tolerability between the two vaccine groups were also comparable. -- In the U.K. study (n=278, #G-2118), two doses of the candidate vaccine given at 2 and 4 months were immunogenic for all serotypes. Tolerability was comparable to Prevnar, and antibody responses were comparable to concomitantly administered vaccines (Pediacel(R) [Sanofi-Pasteur], NeisVac-C(R) [Baxster] and Menitorix(TM) [GlaxoSmithKline]). -- In the Poland study (n=269, #G-2116), the results indicated that the immunogenicity and tolerability of PCV13 produced at manufacturing scale were similar to that of the candidate vaccine produced at the pilot scale, which was the type used in most of the Phase 3 clinical trials.

Safety and tolerability of PCV13 and Prevnar were comparable in all four studies and the most frequently reported adverse events included injection site reactions, (redness [erythema], swelling [induration], and tenderness), fever (greater than or equal to 38 degrees C/100.4 degrees F), irritability, drowsiness, restless sleep, decreased appetite, vomiting, diarrhea and rash.

Wyeth's 13-valent pneumococcal conjugate vaccine represents an important scientific achievement, and demonstrates Wyeth's continuing commitment to advance health care through pioneering science, adds Dr. Emini. The candidate vaccine builds on the scientific foundation of Prevnar and has the potential to provide direct protection against pneumococcal disease caused by the 13 most prevalent pneumococcal serotypes worldwide.

Pneumococcal Disease

According to the World Health Organization (WHO), pneumococcal disease is the number one vaccine-preventable cause of death in children younger than five years of age. Due to the significant burden of pneumococcal disease and demonstrated vaccine efficacy, WHO recommends the priority inclusion of PCV7 in national childhood immunization programs worldwide. WHO notes that if other pneumococcal vaccines that offer expanded protection become available, countries should assess whether it would be helpful to switch to these vaccines.

Indication

Prevnar is indicated for active immunization of infants and toddlers against invasive disease caused by Streptococcus pneumoniae, including bacteremia (bloodstream infection) and meningitis (infection of the membranes surrounding the brain and spinal cord) caused by the seven serotypes in the vaccine. The seven serotypes (strains) of S. pneumoniae included in the vaccine (4, 6B, 9V, 14, 18C, 19F, and 23F) are the strains that most commonly cause these serious diseases in children. The routine schedule is 2, 4, 6, and 12 to 15 months of age.

Prevnar is also indicated for immunization of infants and toddlers against otitis media (ear infections) caused by the seven serotypes included in the vaccine. Protection against ear infections is expected to be less than that for invasive disease.

As with any vaccine, Prevnar may not protect all individuals receiving the vaccine from serious invasive disease cause by S. pneumoniae. This vaccine should not be used for treatment of active infection.

Important Safety Information for Prevnar

In clinical trials, the most frequently reported adverse events included injection site reactions, fever (greater than or equal to 38 degrees C/100.4 degrees F), irritability, drowsiness, restless sleep, decreased appetite, vomiting, diarrhea, and rash.

Risks are associated with all vaccines, including Prevnar. Hypersensitivity to any vaccine component, including diphtheria toxoid, is a contraindication to its use. Prevnar does not protect 100% of children vaccinated. Immunization with Prevnar does not substitute routine diphtheria immunization.

Wyeth Pharmaceuticals

Wyeth Pharmaceuticals, a division of Wyeth, has leading products in the areas of women's health care, infectious disease, gastrointestinal health, central nervous system, inflammation, transplantation, hemophilia, oncology, vaccines and nutritional products.

Wyeth is one of the world's largest research-driven pharmaceutical and health care products companies. It is a leader in the discovery, development, manufacturing and marketing of pharmaceuticals, vaccines, biotechnology products, nutritionals and non-prescription medicines that improve the quality of life for people worldwide. The Company's major divisions include Wyeth Pharmaceuticals, Wyeth Consumer Healthcare and Fort Dodge Animal Health.

The statements in this press release that are not historical facts are forward-looking statements that are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. In particular, clinical trial data are subject to differing interpretations, and the views of regulatory agencies, medical and scientific experts and others may differ from ours. As noted above, the clinical trial data presented at the meeting reflect only four of 13 core Phase 3 studies of PCV13 in the pediatric population and, accordingly, do not represent the totality of data and other information that may affect regulatory review and commercialization of PCV13. There can be no assurance that PCV13 will ever receive regulatory approval or be successfully developed and commercialized. Other risks and uncertainties that could cause actual results to differ materially from those expressed or implied by forward-looking statements include, without limitation, the inherent uncertainty of the timing and success of, and expense associated with, research, development, regulatory approval and commercialization of our products and pipeline products; government cost-containment initiatives; restrictions on third-party payments for our products; substantial competition in our industry, including from branded and generic products; emerging data on our products and pipeline products; the importance of strong performance from our principal products and our anticipated new product introductions; the highly regulated nature of our business; product liability, intellectual property and other litigation risks and environmental liabilities; uncertainty regarding our intellectual property rights and those of others; difficulties associated with, and regulatory compliance with respect to, manufacturing of our products; risks associated with our strategic relationships; economic conditions including interest and currency exchange rate fluctuations; changes in generally accepted accounting principles; trade buying patterns; the impact of legislation and regulatory compliance; risks and uncertainties associated with global operations and sales; and other risks and uncertainties, including those detailed from time to time in our periodic reports filed with the Securities and Exchange Commission, including our current reports on Form 8-K, quarterly reports on Form 10-Q and annual report on Form 10-K, particularly the discussion under the caption Item 1A, RISK FACTORS in our Annual Report on Form 10-K for the year ended December 31, 2007, which was filed with the Securities and Exchange Commission on February 29, 2008. The forward-looking statements in this press release are qualified by these risk factors. We assume no obligation to publicly update any forward-looking statements, whether as a result of new information, future developments or otherwise.

Media, Lili Gordon of Wyeth Pharmaceuticals, +1-484-865-6671, or Douglas Petkus of Wyeth, +1-973-660-5218; or Investors, Justin Victoria of Wyeth, +1-973-660-5340