Biota Holdings of Australia and partner Daiichi Sankyo have been boosted by the news that their investigational influenza drug laninamivir has shown promising results in a late-stage study in Asia.

The companies unveiled data from a 1,000-adult Phase III trial, conducted by Daiichi Sankyo in Japan, Taiwan, Hong Kong and Korea. The results revealed that in patients with influenza A and B, a single inhaled dose of laninamivir was shown to be as effective as Roche’s Tamiflu (oseltamivir) administered orally twice daily for five days. A parallel Phase II/III trial in paediatric patients of the drug, also known as CS-8958, also met the primary and secondary endpoints compared to Tamiflu.

Tamiflu is famously being used against H1N1 (swine flu) and H5N1 (avian flu) and Biota noted that laninamivir, which like its predecessor Relenza (zanamivir) is a neuraminidase inhibitor, has proved effective against bird flu in preclinical trials, while a recent paper published in the journal Nature indicated that laninamivir is also active against H1N1.

Daiichi Sankyo will submit laninamivir with Japanese regulators by March 2010 and plans to start a clinical study for prophylaxis of influenza by the end of the year. Biota will also receive royalties and fixed sum payments on the achievement of certain sales milestones.

The Melbourne-headquartered group said it would now pursue clinical trials in western markets. Biota chief executive Peter Cook told PharmaTimes World News that to date the US National Institute of Health has put in $5.6 millon for ‘bridging studies’ which have confirmed/supported the earlier Phase I and Phase II studies in Japan.

The last of the Phase II UK studies are currently being concluded, he added and at this stage no Phase III studies in the west have been commissioned. However Biota noted that “there are two or three seriously interested potential partners” to take laninamivir forward in Europe and the USA.

Relenza is currently marketed by GlaxoSmithKline while Biota also has a partnership in place with Boehringer Ingelheim in hepatitis C. Mr Cook added that “while we would be very happy to partner with any of these companies, there is no preferred party at this stage and discussions are continuing”.

Registration may accelerate depending on swine flu
He also told PharmaTimes World News that “if swine flu takes a turn for the worse and becomes more virulent in the northern hemisphere flu season, authorities may accelerate the registration and approval process”. It is then possible that laninamivir could be available in US and European markets in 2010 and he added that the long-acting drug offers “particular advantages for stockpiling applications”.

The laninamivir news has gone down well with analysts and Scott Power at ABN Amro said that the Melbourne-based company “is in a sweet spot currently”, saying that management “seem to be able to deliver milestones on _time”._ He added that Biota will succeed in licensing _out_ laninamivir “in a timely fashion” and a deal could be secured in the next six months.

Biota’s share price has more than doubled since the start of the year and stands close to the A$2.15 per share mark. Its market capitalisation is about A$360 million ($305 million).

RSV drug partnered with AstraZeneca pulled
In less positive news, Biota revealed that development of its respiratory syncytial virus drug BTA9881 had been halted after a Phase Ia trial on safety grounds.

As a result, a collaboration and licensing deal with AstraZeneca has been terminated and all rights to the programme will revert back to Biota. The company will now spend A$3 million in developing promising back-up compounds and will look to re-licence the programme.

This does not represent particularly bad news, said Mr Power, adding that “the RSV programme is a clear example of the business model of licensing_ early with the risk of failure sitting with the larger pharmaceutical_ company”.