Vaccine Stockpiling Will Not Encourage Development, Wyeth Exec Says

Vaccine manufacturers look for market growth potential when selecting projects, Wyeth Exec VP George Siber, MD, said.

Firms are hesitant to develop vaccines that have strong but static markets, as is the case with products stockpiled in the event of a bioterrorism attack, Siber explained at the National Institutes of Health Oct. 27.

"Bioterrorism vaccines are not an attractive proposition for a large pharmaceutical company even if the stockpile will be for 200 or 300 mil. doses," he said.

Investors "want to see growth in the companies [they] invest in and a bioterrorism vaccine released to stockpile followed by a rotation of the stockpile is not a growth proposition."

"I don't believe we will see large industrial firms flocking to make bioterrorism vaccines," he added.

HHS awarded the first Project BioShield contract on Nov. 4. VaxGen will receive $877.5 mil. for 75 mil. doses of its recombinant protective antigen anthrax vaccine. The "BioShield II" bill being developed would provide firms patent extensions on larger products in exchange for developing antiterrorism products (¹ , p. 32).

Siber suggested that manufacturers develop vaccines along pathways previously demonstrated to be successful rather than using novel techniques.

Companies should "exploit proven technologies with strong records of safety whenever possible," he said. "That means when possible do subunits, do polysaccharides, do glycoconjugates, and if you have to use an adjuvant use an aluminum adjuvant."

MedImmune's live, intranasal flu vaccine Flumist , which Wyeth codeveloped, employs a novel delivery system. The product has been a commercial failure to this point due in part to concerns over safety with live vaccines (² (Also see "MedImmune Gets Back FluMist: Physicians Will Be Focus Post-Wyeth" - Pink Sheet, 3 May, 2004.), p. 8).

"I would never consider for our company to develop a novel approach unless it was absolutely necessary because the more conventional ones weren't going to work," Siber said.

Wyeth's pneumococcal conjugate vaccine Prevnar is one example of a vaccine that has demonstrated growth potential, the exec stated.

Prevnar "sales are limited only by our ability to supply the product," Siber said. Prevnar sales have been relatively flat since its launch in 2000, largely due to manufacturing problems.

Prevnar manufacturing problems have been overcome, Siber stated; CDC reinstated the full four-dose schedule for the vaccine Sept. 16 (³ 'The Pink Sheet' Sept. 20, 2004, In Brief).

"We didn't do things perfectly" developing and manufacturing Prevnar, Siber acknowledged.

"A highly complex vaccine requires extensive process and analytical development, more than we had actually done with Prevnar," he said.

Wyeth is restructuring its vaccine development and manufacturing strategy in order to expedite approval, ensure supply and decrease cost. "We have spent the last eight months totally revising our strategy for the next 10 years," Siber said.

The company has reinvented "the development process" in hopes of "reducing the time taken and the amount of resources taken" to develop vaccines.

"Our goal was to reduce it by half. That may not be totally achievable," he said.

Wyeth's restructuring will facilitate greater interaction between research & development and manufacturing personnel early in the development process.

A so-called "escort team" of researchers and manufacturers will begin meeting early in product development. The escort team "stays with the manufacturing process and monitors what's going on," to ensure the vaccine is successfully manufactured.

Siber said that Wyeth's experience with Prevnar teaches that companies should build extra manufacturing capacity to ensure supply in the face of high demand.

"What you would like to do is to build some upside capacity into your manufacturing plants so that you can accommodate unanticipated upside demand."