New Delhi: Offering a glimmer of hope in fight against Alzheimer’s, an experimental drug trial conducted by a US multinational biotechnology company, Biogen Inc showed that anti-amyloid antibody, BAN2401 was successful in slowing down cognitive decline in early-stage patients.

The findings of the phase 2 clinical trial were presented by Biogen Inc and partner Japan-based pharmaceutical company, Eisai Co ltd in the Alzheimer’s Association International Conference held from 20-26 July, in Chicago.

The 18-months trial conducted by Biogen Inc and Eisao Ltd based on traditional statistical methods included 856 patients with early Alzheimer’s disease who had beta-amyloid in their brains indicative of the disease. The highest does of 10 mg/kg bi-weekly was given to 161 patients. Another 253 patients were treated with the second-highest dose of 10 mg/kg monthly, while 247 were in the placebo group.

According to the data presented by the company, patients with early-stage Alzheimer’s who were treated with BAN2401 experienced 30% less cognitive decline than patients who got a placebo. The second-highest dose of the drug also showed some benefit, but did not meet statistical significance, as per data.

“30 per cent is a major reduction, but it varies according to the scale which was used to measure the cognitive ability. The findings are definitely exciting, but there is also some degree of cautious hope and skepticism about its clinical effect, “said Dr Raghu Padinjat from National Centre for Biological Science, Bangalore, “It is a very limited trial. We have to see if it continues to be equally promising in a late-stage trial as well."

The scale devised by Eisai for the trials included a combination of the currently used Alzheimer’s assessment scales.

The findings also give a significant weight to the hypothesis that reducing amyloid plaques in brain could hold the key to combating the disease, however, researchers highlight that it is subject to debate.

“Deposition of amyloid beta deposition is not the primary cause for Alzheimer’s as it was believed to be earlier. Rather it is one of the consequences. The major challenge is that the exact cause of the disease has not yet been identified. There is lot more research required," said Dr Pravat K Mandal from National Brain Research Centre (NBRC), Gurgaon.

Another significant concern is whether the drug would be effective for severely-ill patients, since most drugs are not very helpful in the later stages.

“These are preliminary findings which require further examination in bigger samples and also in multi-centric clinical trials. Though it is promising, since other drugs have not shown this much results, but we have to wait. Also, whether decrease in amyloid deposition will reverse the consequences and reduce cognitive decline, that is also not very clear," said Dr Naren Rao from National Institute of Mental Health and Neurosciences (NIMHANS) who attended the conference in Chicago.

The most common form of Dementia, Alzhemier’s is an irreversible progressive brain disease among older individuals, that slowly destroys thinking and memory skills of patients, and eventually their ability to conduct simplest tasks of daily life.

Over 26 million people are struggling with Dementia all over the world and it is expected to become threefold by 2050. In India, more than 4 million people have some form of Dementia and researchers highlight that at least 3 % of population is at risk of developing mental illness.

Despite the ongoing research, no major drug has been discovered to cure the debilitating disease. Currently available drugs are symptomatic, which reduce the symptoms for some time but do not change the course of disease. Prevention by vaccine has not been successful either.

“Currently, there are no drugs that can reduce the size of the plaque in the brain. This drug does send a positive signal, but it has not yet reached phase-3 which would be a large-scale human trial. Till then there can only be cautious optimism. But it is still important as it shows at least, in principle that the drug can reduce cognitive decline," added Dr Padinjat, who is one of the co-ordinators of one of the first large-scale studies on mental illness including Alzheimer’s being conducted in India by NCBS.