Chinese patients are beginning to benefit from a powerful "biological missile" against their cancer and other serious diseases, although the new product has still a long way to go before its use becomes widespread.

The "biological missile" refers to monoclonal antibodies, which is derived from people's natural defense against diseases.

When bacteria, viruses and other alien agents called antigens invade or appear in human bodies, they will be resisted and in most cases, defeated by the human antibodies.

"But human antibodies are not omnipotent. Sometimes they are not strong enough to resist the invaders, sometimes they are cheated by disguised forms of the antigens such as tumor cells and in most cases, natural human antibodies are not capable of consistent attacks," said Sun Qihong, a scientist at the Chinese Academy of Military Medical Sciences.

Monoclonal antibody technology is an attempt to overcome the natural weakness of human antibodies.

Scientists have found that the invasion of an antigen often ignites human bodies to produce many kinds of antibodies, but among these only one targets the most dangerous form of the invaders and is the most powerful.

Extracting this most powerful antibody, increasing its quantities through man-made skills, and then injecting it into human bodies can help people fight their diseases more effectively, Sun said.

Using monoclonal technology, the US scientists developed the first monoclonal antibody in the mid-1990s, which is often described as a "biological missile".

Since its debut, the antibody has been developed rapidly and in 2004, 22 products embodying the antibody were approved worldwide, with global sales reaching $10.5 billion.

But until last year, nearly all monoclonal antibodies drugs sold in the Chinese market were developed by international pharmaceutical firms such as the US-based Genentech and Johnson&Jonhson.

This was attributed to the difficulty of purifying certain antibodies and of producing them. Unlike a chemical drug, antibodies cannot be made by machines. The most effective method is by using genetically modified human cells, said Sun.

In early 2005, after detailed research, Beijing-based BioTech Pharmaceuticals, Sichuan-based Chengdu Hoist Pharmaceutical Group and Shanghai CP Guojian Pharmaceutical won the license for producing monoclonal antibodies to treat cancers and rheumatoid arthritis.

Among the three, Shanghai CP Guojian successfully passed the production evaluation and its monoclonal antibody against rheumatoid arthritis has been sold on the market.

Industry insiders said that after improving their production techniques, BioTech and Hoist could soon introduce their products in the domestic market.

Even though, the road to success is far from smooth. Internationally, production of monoclonal antibodies would need an investment of US$600-800 million, said Zhang Xin, president of the Beijing-based biotech investment bank Sinocro Partners.

Ma Jian, assistant general manager of Shanghai CP Guojian, said its company's 1 billion yuan (US$125 million) investment was already the largest in China. But even so, its production scale was just on the scale of pilot-experiment by the world's leading players.

"In terms of monoclonal antibody production, the major investment is in equipment, and China's cheap labor and land cannot help much in terms of savings," Ma said.

Ren Ken, general manager of biotech consultant Accelovance, said domestic companies were unlikely to invest heavily in monoclonal antibody production, as the drug is extremely expensive, and most new biotech drugs are not covered by medical insurance in China.

(Source: China Daily January 24, 2007)