LEDERLE-PRAXIS' HIBTITER APPROVED FOR INFANTS DOWN TO TWO

LEDERLE-PRAXIS' HIBTITER APPROVED FOR INFANTS DOWN TO TWO MONTHS of age by FDA on Oct. 4. The approval of Lederle-Praxis' conjugate Haemophilus B vaccine for use in a primary immunization series in infants at ages two, four, and six months comes just six weeks after FDA's Vaccine and Related Biological Products Advisory Committee agreed that the vaccine is safe and effective for infants under 15 months of age. The approved regimen also calls for the administration of booster shots at 15 months or more. The approval gives Lederle a victory in the three-way race in the U.S. to become the first producer of a Haemophilus B conjugate vaccine approved for use in small infants. Lederle edged out Merck's PedvaxHIB conjugate vaccine, which was also reviewed at the Aug. 20 advisory committee meeting and, like Lederle's vaccine, was considered by the committee to be safe and effective in infants ("The Pink Sheet" Aug. 27, p.8). However, the advisory committee had some questions about the duration of antibody response to the Merck vaccine. Merck told the advisory committee that the company is in the process of doing a follow-up sampling of antibodies in about half of the subjects who participated in the clinical trial that served as the basis for the PLA. Connaught's ProHIBIT was the first conjugate Haemophilus influenza vaccine to reach the U.S. market, following its approval in December 1987 for use in children 18-60 months old. However, Connaught's effort to expand the availability of its vaccine to small infants received a setback in January when the Vaccine and Related Biologicals Advisory Committee was unable to reach a consensus on whether the firm's data supported use of the vaccine in infants down to four months of age ("The Pink Sheet" Jan. 29, T&G-8). At issue were poor efficacy results from a study conducted in Alaska with the Connaught vaccine. Lederle's PLA for HibTITER was based on administration of the vaccine to 60,000 infants at the Kaiser Permanente Pediatric Vaccine Study Center in Oakland, California. A Kaiser Permanente investigator reported to the advisory committee that 97% of infants had 1 mcg or greater of antibody after the three innoculation series and that 71% of infants sustained that level of antibody a year after the series. After the booster shot, antibody levels above 1 mcg were found in 97% of the infants. An Oct. 4 HHS press release on the expanded use of HibTITER noted that "the vaccine provided high levels of protection until the recommended Booster dose." The Kaiser Permanente Trials also demonstrated that HibTITER can be administered simultaneously with other traditional infant immunizations. FDA reported that side effects resulting from simultaneous immunization with MMR, Oral Polio and DPT vaccine were only "mild and transient, including swelling and warmth at the vaccination site and occasional fever." The HHS press release, quoting Secretary Sullivan, predicts that "the new use of this vaccine will prevent a serious, contagious disease responsible for the majority of cases of meningitis." HHS also noted that HibTITER is "the first approval of a vaccine for routine use in infants in almost 30 years." To promote HibTITER's new indication, Lederle-Praxis is organizing a major educational/publicity campaign. In the next week, the company expects to begin mailing "Dear Doctor" letters to more than 100,000 pediatricians. Lederle also plans to distribute free brochures to parents through physician offices, daycare centers and nursery schools, and has established an "800" number to provide additional information to parents interested in the vaccine.