網路城邦
回本城市首頁 打開聯合報 看見紐約時報
市長:AL  副市長:
加入本城市推薦本城市加入我的最愛訂閱最新文章
udn城市文學創作其他【打開聯合報 看見紐約時報】城市/討論區/
討論區Health 字體:
上一個討論主題 回文章列表 下一個討論主題
阿茲海默症 美新藥現曙光?
2015/09/11 09:25 瀏覽991|回應0推薦1

kkhsu
等級:8
留言加入好友
文章推薦人 (1)

AL

New Data on 2 Alzheimer’s Drugs Alters Hope and Expectation
By ANDREW POLLACK

New data released on Wednesday raised hopes somewhat that an experimental Alzheimer’s drug from Eli Lilly & Company might be effective. At the same time, other results were released on Wednesday that could reduce expectations a bit for a similar drug being developed by Biogen.

The drugs aim to prevent or remove so-called amyloid plaques in the brain. The buildup of the plaques has become a leading hypothesis about the cause of Alzheimer’s disease.

But so far in clinical trials, drugs aimed at reducing the plaques have failed to stem the decline in cognition that is a sign of the disease, which afflicts more than five million Americans.

“Now all of a sudden we have a number of pieces of information that all point in the same direction — that there really is something to this amyloid hypothesis,” said Dr. Eric Siemers, a neurologist at Lilly. Data about the drugs was presented at the Alzheimer’s Association International Conference in Washington.

Lilly reported in 2012 that its drug, solanezumab, had not worked in two large 18-month clinical trials involving patients in mild or moderate stages of the disease. But the company said it had an effect in the subset of patients with mild symptoms. As a result, it has started a third big trial restricted to patients with mild disease. Results are expected by early 2017.

The data announced Wednesday is not from the new study, but from an extension of the two older ones, in which all patients in the trial were given the option of receiving solanezumab for another two years.

That meant that those originally in the placebo group would be switching to the drug, but starting on it 18 months later than those who had been receiving the drug all along. Neither the patients nor the doctors knew which group the patients had been in originally.

The idea behind such a “delayed start” study is that if the drug was truly slowing the mental deterioration caused by the disease, the patients who were new to the drug would not be able to catch up in cognitive ability with the patients who had been taking the drug all along.

That was what was seen among patients with mild disease in the study, which was also published in the journal Alzheimer’s & Dementia: Translational Research & Clinical Interventions.

The gap in cognition and ability to carry out daily tasks that existed between the drug and placebo groups at the end of the initial 18-month study persisted for another year. There was also a gap two years out, though it was no longer statistically significant.

Still, the “delayed start” clinical trial design is new and not universally accepted, and some experts not involved in the study were cautious.

“The statistical analysis reported today does not provide any information on efficacy or on the amyloid hypothesis,” said Dr. Lon Schneider, a professor at the University of Southern California.

Vamil K. Divan, an analyst at Credit Suisse, said in a note on Wednesday that it was hard to draw major conclusions from the data, but that “today’s results at least allow investors to maintain hope that this potentially transformative product may make it to the market.”

Biogen generated great interest in March when it released results of an early-stage study showing that its anti-amyloid drug, aducanumab, sharply slowed the decline in cognition compared to a placebo. Still, the most effective dose, the highest one, had a high rate of a side effect, localized swelling in the brain.

The new data presented Wednesday was from 30 patients who got a medium dose. Ideally, it would be nearly as effective as the high dose but with fewer side effects.

That turned out to be only partly the case. The middle dose did not reduce cognitive decline by a statistically significant amount on either of two measures after a year of treatment. On one of those measures, the middle dose was actually worse than a lower dose. And the side-effect rate was relatively high.

However, the middle dose results fell between those of the lower and higher doses on the other measure of cognitive decline and on a measure of plaques in the brain. Such a relationship, where a drug works better with an increasing dose, is often a sign that the drug has a true effect.

Dr. Jeffrey Sevigny, senior director of clinical development for Biogen, said that given the small numbers of patients involved, “One ought not to be surprised about data points that don’t perfectly line up.”

He said the results over all were “fantastic” and that Biogen had started two late-stage trials aimed at winning approval of the drug in several years. The doses being used in those trials have not been disclosed.

Wall Street analysts were divided on whether Biogen’s results were good or disappointing. Biogen’s shares fell about 4 percent Wednesday. Lilly’s shares rose about 1 percent.

阿茲海默症 美新藥現曙光?

阿茲海默症國際研討會(AAIC)廿二日在美國華盛頓舉行,美國兩大生技藥廠「禮來」(Eli Lilly 和「百健」(Biogen)分別提出治療阿茲海默症的實驗新藥研究數據,禮來表示,新藥「solanezumab」對僅有輕微症狀者有效,由於阿茲海默症迄今無藥可醫,此一進展已令人鼓舞。

紐約時報報導,這些藥物的目標是避免腦內「類澱粉斑塊」(amyloid plaques)合成,或移除這些學者假定造成阿茲阿茲海默症的斑塊。但目前臨床試驗結果顯示,這些原本應減少斑塊合成的藥物未能阻止患者認知退化。

禮來表示,2012年的藥品「solanezumab」未能在十八個月的臨床試驗中,針對輕度或中度阿茲海默症患者發揮療效,但對只有輕微症狀的人產生一些效果。禮來已針對只有輕微症狀者開始第三次的大規模臨床試驗,最快後年初才有結果。

禮來在AAIC中公布前兩次試驗數據,這些數據成果亦刊登於「阿滋海默症及失智症」期刊。禮來在2012年對一千三百名患者進行實驗,分成兩組,一組立刻服用「solanezumab」,另一組在前十八個月服用「安慰劑」,之後才開始服用實驗藥物。

這項「延遲開始」的試驗旨在比較先服藥者與後服藥者的認知能力,研究新藥是否真能減緩阿茲海默症造成的退化。但「延遲開始」試驗未獲普遍接受,美國南加州大學教授施奈德說:「禮來公布的數據未提供藥物對類澱粉斑塊效果的任何資訊。」

原文參照:
http://www.nytimes.com/2015/07/23/business/new-data-on-2-alzheimers-drugs-alters-hope-and-expectation.html

2015-07-24.聯合報.A17.國際.編譯陳韻涵


回應 回應給此人 推薦文章 列印 加入我的文摘

引用
引用網址:https://city.udn.com/forum/trackback.jsp?no=50132&aid=5372209