GlaxoSmithKline (GSK) has received a positive opinion for its malaria vaccine candidate from the Committee for Medicinal Products for Human Use (CHMP) of the EMA. The vaccine candidate Mosquirix (RTS,S) is the first QS-21 Stimulon containing product to receive a positive regulatory decision.

The adjuvant QS-21, licensed by GSK from Agenus, is designed to increase immune response to antigens in vaccines. The positive opinion signals that Mosquirix meets the necessary quality, safety and efficacy requirements according to E.U. standards.

“This is a significant milestone for the field of Malaria and our QS-21 Stimulon, which is an integral component of the adjuvant contained in Mosquirix, the first malaria candidate vaccine to generate positive phase III data, now awaiting the World Health Organization’s (WHO) recommendations and approvals by African Health authorities,” said Garo Armen, Ph.D., chairman and chief operating officer of Agenus. “We look forward to seeing Mosquirix achieve the required final clearances so it can begin benefiting children at risk of contracting and dying from Malaria.”

The CHMP scientific opinion is a key step in the regulatory process toward making a vaccine against Malaria available. The positive opinion follows review by the CHMP of the candidate vaccine’s safety, efficacy and quality. Clinical data supporting the filing were mainly from a phase III clinical program involving more than 16,000 infants and young children.

Following the CHMP positive opinion, two of the WHO's independent advisory groups, the Strategic Advisory Group of Experts (SAGE) on Immunization and the Malaria Policy Advisory Committee (MPAC), now will jointly review the evidence base for the vaccine candidate and make a joint policy recommendation for how the vaccine should be used in the event that it ultimately is approved by the national regulatory authorities in the sub-Saharan African countries for which the vaccine is intended. The WHO has indicated that such a policy recommendation may be possible by end of this year.

QS-21 Stimulon is a saponin extracted from the bark of the Quillaja saponaria tree, an evergreen also known as the soap bark tree. The adjuvant is a key component of investigational vaccines to prevent a wide variety of infectious diseases, and therapeutic vaccines for cancer and degenerative disorders. QS-21 Stimulon has been evaluated in approximately 50,000 individuals and patients. Agenus is entitled to receive a modest milestone payment upon approval of the first licensed product with GSK, as well as low single digit royalties on potential commercial sales for 10 years after commercial launch, with some exceptions.