LONDON ¿ Shares in Peptide Therapeutics Group plc fell by one-third last week when the company announced it was dropping its broad-spectrum allergy vaccine, being developed in partnership with SmithKline Beecham plc.
Apart from the financial impact, it was a psychological blow to Peptide, which was formed around that technology in 1995.
Nick Higgins, commercial director at the Cambridge, U.K.-based company, told BioWorld International that although it was dropping the vaccine, the relationship with SKB would continue, with the two working on a number of other compounds, currently in preclinical development. ¿The company started with this general-purpose allergy vaccine, and we are still working on that concept,¿ he said ¿We are in the process of setting up a new agreement to work on new constructs, in which we will co-fund the preclinical research and SB will carry out trials.
¿Dropping this is a delay, but apart from the share price, financially it will not hit us too badly,¿ Higgins said.
The company will not have to scale back development on its portfolio of seven compounds in clinical trials. Its lead product now is Arilvax, a yellow fever vaccine in Phase III. Peptide acquired that compound earlier in the year when it took over OraVax Inc.
The company had about #30 million in cash, which Higgins said will last for around three years. He expects Arilvax to be approved in the first quarter of 2000, with the first sales in 2001.
The aim of the general-purpose vaccine was to stop all allergic reactions before they started by preventing immunoglobulin E (IgE) antibodies from releasing histamine when they come into contact with an allergen. Histamine causes the inflammatory effects of runny noses and sore eyes in hay fever, the wheezing in asthma and the symptoms of food allergy. Peptide founder Denis Stanworth identified a decapeptide within the IgE molecule, which was believed to be the trigger for releasing histamine.
Before partnering with SKB, Peptide Therapeutics carried out clinical trials in food allergy and hay fever that indicated the vaccine was effective. In the case of food allergies, every one of 15 subjects was protected, while in hay fever all 17 subjects experienced some relief of symptoms.
However, trials conducted by SKB failed to repeat the findings. While it was well tolerated and immunogenic in 36 subjects, there was no statistically significant effect of the vaccine compared to placebo in a trial of 60 sufferers of Cypress tree pollen allergy. In a food allergy trial in 30 subjects, 75 percent of vaccinated patients were able to tolerate higher amounts of allergen, but the placebo group showed the same response. The earlier study did not include a placebo-vaccinated group.
¿Under the circumstances we had two choices ¿ redo the trials in different ways with the same construct or say it hasn¿t worked and move onto the other constructs we have coming through,¿ Higgins said.
The new constructs are based on the same principle than the IgE molecule, but use different peptide sequences. ¿These are showing a stronger response in the lab, and we aim to have a clinical candidates within a year,¿ Higgins said.