BioWorld International Correspondent

LONDON - Syntaxin raised £16 million (US$33.3 million) in a second private round, providing funding to take its lead product for treating respiratory diseases to Phase IIb over the next three years and advance two other compounds into the clinic.

"We are very pleased. We originally went for £15 million and took £16 million. We had to turn a couple of investors down, and could have taken more," CEO Patrick Doyle told BioWorld International.

The round was co-led by new investors SR One, the venture capital arm of GlaxoSmithKline plc, of London, and Life Science Partners, with Johnson & Johnson Development Corp. and Quest for Growth. Abingworth Management, which invested £3 million in Syntaxin when it was spun out from the UK Health Protection Agency (HPA) in November 2005, followed on.

"Abingworth is such a high-quality investor, it is good to follow up with similar quality investors and then get corporate input," said Doyle.

Syntaxin's technology platform revolves around Clostridium botulinum neurotoxins, which are modified to target specific cell surface receptors.

Modifying the binding capability strips the neurotoxin of its inherent toxicity while retaining the ability to enter into target cells and block vesicle-mediated cell secretion of hormones or other disease-causing molecules.

Botulinum neurotoxins exhibit prolonged activity over weeks or months, making them suited to the treatment of chronic diseases.

The technology was exemplified by the HPA in the inhibition of neurotransmitter release from peripheral nerves. That program was licensed to Allergan Inc. for the development of long-acting analgesics for the relief of chronic pain. Syntaxin inherited the collaboration at its formation, and Doyle, fresh from a visit to the Irvine, Calif.,-based company said, "The relationship is going extremely well."

Allergan has rights to the technology in pain and all nervous disorders.

"This provides a pretty good endorsement, and the program is on track to go into man," Doyle said.

Abingdon, UK-based Syntaxin has used the platform in house to develop a protease that inhibits mucus release from epithelial cells in the airways. That is intended to prevent the hypersecretion that impairs respiratory function in asthma, cystic fibrosis, chronic bronchitis and chronic obstructive pulmonary disorder.

Doyle said the plan is to take the product to Phase IIb in chronic bronchitis and then out-license it. One of the key challenges will be to show that this large protein can be delivered to the lungs in a nebulized format.

In addition, Syntaxin has demonstrated that its engineered toxins are able to block secretion from a wide range of neuroendocrine and endocrine cells that are implicated in a variety of disorders, including endocrine tumors and obesity.

Within the scope of the £16 million funding round, it is intended to prepare two products, in obesity and endocrine disorders for clinical development.

Syntaxin's approach is to work with well-known, validated targets. The technology platform has a wide scope but Doyle said there is no intention at present to license it further.

"We're pretty confident we can apply it in other indications, but are not looking for another partnership. Right now we want to focus on the internal programs and bringing them forward."