FDA核准新的腦炎疫苗
作者:Yael Waknine
出處:WebMD醫學新聞
February 23, 2010 — 美國食品藥物管理局(FDA)核准一項四價腦膜炎球菌疫苗(商品名Menveo,Novartis Pharmaceuticals製藥公司),用於預防11-55歲者因為一般腦脊髓膜炎雙球菌(Neisseria meningitides)血清型A、C、Y和W-135引起的侵犯性疾病。
腦膜炎球菌疾病是細菌性腦膜炎的首因,即便有早期且適當的治療仍可能迅速惡化,可能在症狀發生的24-48小時內導致死亡,患此病者約七分之一可存活,但是有一些永久性的後遺症,包括截肢、抽搐、癱瘓、聽力喪失、學習失能等等。
該公司在新聞稿中指出,接種疫苗是可能感染的青少年避免發生感染的關鍵因素之一。自2005年以來,免疫實務諮詢委員會建議,對於所有11-18歲的青少年以及高風險的年紀稍長者如居住在宿舍的大學新生,進行例行性的四價腦膜炎疫苗接種。
Novartis藥廠疫苗與診斷小組主任Andrin Oswald醫師表示,FDA核准Menveo是美國青少年免疫計劃的一個重要里程碑,根據疾病管制中心(CDC)估計,約有1,600萬11-18歲的青少年處於風險且依舊對於腦膜炎球菌疾病沒有抵抗力,腦膜炎球菌疾病特別令人苦惱,因為它會迅速致命或使原本健康的青少年變得相當虛弱。
這項核准是根據一個第3期試驗的資料,分成兩個小組:11-18歲者以及19-55歲成人。
結果顯示,接受新疫苗的青少年對這四種血清型的效果都相當於或優於美國其他核准的腦膜炎球菌共價疫苗 (商品名Menactra,Sanofi-Pasteur藥廠;血清型A為75% vs 67%;血清型C兩者皆為84%;血清型Y為88% vs 69%;血清型W-135為96% vs 88%)。接種疫苗的幾何平均效價達到此一趨勢(血清型A為29 vs 18;血清型C為59 vs 47;血清型Y為51 vs 18;血清型W-135為87 vs 44)。
藥廠官方指出,雖然血清型A、Y和W-135的血清反應顯著較高,此一結果的臨床關聯依舊不清楚。
此疫苗的使用禁忌包括,對於接受過之疫苗其中的任何成分、或其他CRM197、白喉類毒素、或腦膜炎球菌為基礎的疫苗等產生過敏的病患,疫苗可能無法對所有人皆產生保護效果,例如那些免疫不佳或者接受免疫抑制治療者。
試驗中最常被報告的副作用包括過敏反應、昏厥、注射部位疼痛、頭痛、肌肉痛、精神不佳與噁心,病患在接種疫苗之後必須留觀15分鐘。
根據新聞稿,該公司計畫尋求後續核准將此疫苗用於其他年齡層,包括用於2-10歲孩童。
FDA Approves New Meningitis Vaccine
By Yael Waknine
Medscape Medical News
February 23, 2010 — The US Food and Drug Administration (FDA) has approved a quadrivalent meningococcal vaccine (Menveo, Novartis Pharmaceuticals, Inc) for the prevention of invasive disease caused by common Neisseria meningitides serogroups A, C, Y, and W-135 in people aged 11 to 55 years.
Meningococcal disease is a leading cause of bacterial meningitis, which can progress rapidly despite early and appropriate treatment, potentially resulting in death within 24 to 48 hours of symptom onset. About 1 in 7 patients who survive the disease experience serious permanent effects, including amputations, seizures, paralysis, hearing loss, and learning disabilities.
Vaccination may be a key factor for avoiding infection in susceptible adolescents, the company noted in a news release. Since 2005, the Advisory Committee on Immunization Practices has recommended routine immunization with a quadrivalent meningococcal conjugate vaccine for all adolescents aged 11 to 18 years, as well as older high-risk groups, such as college freshmen living in dormitories.
"The FDA approval of Menveo is an important milestone for adolescent immunization in the United States. According to CDC estimates, approximately 16 million adolescents between the ages of 11 and 18 are at risk and remain unprotected against meningococcal disease," said Andrin Oswald, MD, division head of Novartis Vaccines and Diagnostics. "Meningococcal disease is particularly distressing because it can rapidly kill or debilitate previously healthy adolescents."
Approval was based on data from a phase 3 trial that was broken in to 2 subsets: adolescents aged 11 to 18 years and adults aged 19 to 55 years.
Results showed that adolescents receiving the new vaccine demonstrated comparable or greater immune responses to each of the 4 serogroups compared with another US-licensed meningococcal conjugate vaccine (Menactra, Sanofi-Pasteur; serogroup A, 75% vs 67%; serogroup C, 84% for both; serogroup Y, 88% vs 69%; serogroup W-135, 96% vs 88%). Geometric mean titres achieved with vaccination followed this trend (serogroup A, 29 vs 18; serogroup C, 59 vs 47; serogroup Y, 51 vs 18; serogroup W-135, 87 vs 44).
Although the seroresponse was statistically higher for serogroups A, Y, and W-135, the clinical relevance of this finding remains unclear, company officials noted.
Use of the vaccine is contraindicated in patients with hypersensitivity to prior doses of the vaccine, any of its components, or other CRM197, diphtheria toxoid, or meningococcal-based vaccine. Vaccination may not protect all individuals, such as those who are immunocompromised or receiving immunosuppressive therapy.
Adverse events most commonly reported in trial experience include anaphylactic reactions, syncope, injection-site pain, headache, myalgia, malaise, and nausea. Patients should be observed for 15 minutes following vaccine administration.
According to the news release, the company plans to seek supplementary licensures for vaccine use in other age groups, including an indication for children aged 2 to 10 years.