|出版日||ページ情報||英文 12 Pages
Sanofi社のMenactraは、4価多糖体ジフテリアトキソイド結合ワクチンで、髄膜炎菌 (血清型A、C、Y、W-135) による侵襲性髄膜炎菌感染症 (IMD) の予防を目的としています。
Menactra (Sanofi) is a quadrivalent polysaccharide diphtheria toxoid conjugate vaccine indicated for active immunization to prevent invasive meningococcal disease (IMD) caused by Neisseria meningitidis (N. meningitidis) serogroups A, C, Y, and W-135 in individuals aged nine months through to 55 years in the US. It contains N. meningitidis capsular polysaccharide antigens individually conjugated to diphtheria toxoid protein. The presence of bactericidal anti-capsular meningococcal antibodies has been associated with protection from IMD, and Menactra induces production of these antibodies specifically for the aforementioned serogroups.
Despite a large patient population, broad serotype coverage, and first-to-market status for meningococcal conjugate vaccines, Menactra's dominant position in the US market has been weakened by Menveo (quadrivalent oligosaccharide diphtheria CRM-197 conjugate vaccine; GlaxoSmithKline), a vaccine that covers the same serotypes and is recommended for the same risk groups as Menactra. In addition, Menveo is the only approved quadrivalent meningococcal conjugate vaccine for high-risk children aged below nine months.
The lack of clinical differentiation between the two vaccines means that competition is driven primarily by price, and Menveo possesses a competitive advantage in this regard. Menactra's US price increased slightly from $89.16 per dose in 2016 to $91.81 in 2019 for the pediatric population, whereas Menveo's price decreased from $85.22 to $73.83 per dose in the same period. This competitive pricing seems to have incentivized some prescribers to preferentially procure Menveo over Menactra, as reflected by Menveo's increasing US sales from $157.3m in 2016 to $226.2m in 2018, and Menactra's declining sales from $563.6m in 2016 to $465.2m in 2018. Sanofi is developing a successor vaccine, MenQuadfi (quadrivalent polysaccharide tetanus toxoid conjugate vaccine; Sanofi), which could cannibalize some of Menactra's market share, but it is unlikely to gain significant uptake without a discounted price, due to limited available trial data suggesting only non-inferiority to Menactra. In the long term, both of Sanofi's vaccines face a significant threat from GlaxoSmithKline's MenABCW-135Y (pentavalent meningococcal conjugate vaccine), which is being positioned to replace standalone meningococcal ACWY (MenACWY) and meningococcal B (MenB) vaccinations in persons aged ≥10 years.