Sinoasis Pharmaceuticals, a young Guangzhou biopharma founded in 2003, is building its business around a proprietary platform technology for discovering fully human therapeutic antibodies. “We have a technology that can functionally select an antibody or domains with thermodynamic stability,” said Shengfeng Li, PhD, in an exclusive ChinaBio® Today interview. Thermodynamic stability “is one of the key properties for therapeutic antibodies as they often require a long half-life,” he explained.

“This proprietary intracellular capturing antigen-binders – or Icab – technology also isolates functional domains. Antibody domains with a molecular weight of 12 kD, versus full antibody molecular weight of 150 kD, have the ability to penetrate tumor tissues well. It is believed they will play an important role in future biotherapeutics and in in vivo imaging diagnosis,” he continued.

Dr. Li, a prototypical sea turtle, was most recently a co-founder and founding Chief Scientific Officer of Abmaxis, Inc., a California biotech that was sold in 2006 to Merck (NYSE: MRK). At Abmaxis, Dr. Li developed antibody engineering methods. Dr. Li also did his graduate work in the US, earning a PhD in Microbiology at the University of Georgia.

Sinoasis believes the Icab technology is a lower cost solution that also speeds up the discovery process. It exploits a yeast genetic system to generate diverse human antibody/domain libraries and to select specific fully human antibody/domains with functionality and stability (see box for potential advantages of Sinosis’ Icab technology).

Thus the Icab technology represents a drug discovery advantage for the drug development company, as new molecules can move from research to clinical trials much more quickly. Sinoasis has secured IP on its Icab technology in both China and the US.

At the ChinaBio® Investor Forum held in Hong Kong this March, Sinoasis was the recipient of the “Most Promising Company” award in the drug development category. Seventeen early to mid-stage companies from Hong Kong and the Pearl River Delta region presented their stories to potential investors at the conference. From these companies, all of which were pre-screened by ChinaBio® prior to presenting, only two were selected as the “Most Promising” by a group of industry insiders from VC firms and global pharmaceutical companies.

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 The Advantages of Icab Technology, According to Sinoasis

1. The unique expression design of Icab captures all family member genes, enabling selection of binders with high specificity and high affinity;
2. Icab links the affinity directly with sequence information, facilitating antibody gene isolation, affinity maturation (if necessary), expression and purification;.
3. Unlike synthetic libraries, antibody chimerization and humanization, Icab technologies generate an antibody with 100% human sequences. Thus, the antibody can be quickly moved to therapeutic use once its efficacy is demonstrated;
4. Antibodies or domains created using Icab are intracellularly functional, and can be used to probe intracellular protein function in vivo. Most importantly, intracellularly functional antibodies are generally much more thermodynamically stable and have a longer half-life when administered via IV (in an extracellular environment) in human or animal models. This means the captured antibody and/or domain drug candidates create fewer development problems than the usual antibody candidate, which often requires a tedious engineering process to make it more thermodynamically stable.

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Drug Development

In the past few years, the company has applied the Icab technology to its own internal drug development. The most advanced drug in Sinoasis’ pipeline is Bat-2094, an antibody domain derivative that is aimed at treating coronary heart disease (CHD), the leading cause of death in both China and developed countries. It will seek approval for use in patients with acute coronary syndrome and other thrombosis related diseases.

In animal models, Bat-2094 has produced a better pharmacological profile than existing drugs. It reportedly showed greater efficacy and a reduced tendency to cause bleeding, giving it a competitive advantage over drugs already in the market. Sinoasis believes that Bat-2094 has the potential to become the best in class.

Dr. Li said the Phase II trial of Bat-2094, which is being conducted in China, is proceeding well, with results expected before the end of the year. He anticipates that, if approved, over 5 million ACS patients in China will benefit from the treatment, especially patients in less developed regions, where percutaneous coronary intervention (PCI) is rarely performed. Hospitals in these less developed areas often don’t have the sophisticated equipment or the trained physicians required for PCI.

While Bat-2094 is seeking recognition as a best-in-class medication, the other two drugs in Sinoasis’ portfolio are first-in-class drugs that target cancer. Both are fully human monoclonal antibodies isolated by the company’s Icab technology; Bat-5051 targets cancer cells while Bat-7354 targets both cancer cell growth and tumor angiogenesis.

Funding

To get this far, Sinoasis has raised over $6 million from private and angel investors. It is now seeking additional capital, which will allow the company to advance its coronary heart drug from Phase II to Phase III trials, and eventually seek market approval. The funding will also underwrite the completion of pre-clinical work on the two anti-cancer molecules and bring at least one of them through an IND filing for a Phase I clinical trial in both China and the US. Sinoasis also intends to expand its proprietary intracellular capturing antigen-binders technology capability, offering it to customers, partners and collaborators.

Conclusion

“Our platform technology is used to discover therapeutic antibodies, the only class of biological therapeutics that is growing fast,” said Dr. Li. Despite his pride in the Icab technology, the process remains a means to an end, not an end in itself for Sinoasis. “Sinoasis is a drug development company, not a company interested only in technology,” he insisted.

Note: Sinoasis Pharmaceuticals will present at the ChinaBio® Partnering Forum in Shanghai, June 23-24, 2009 (www.CBPF2009.com).

Disclosure: none.