Kythera’s chin up following double phase III success

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Being a one-product company is no bad thing if that one product succeeds. Wins in two phase III trials means that Kythera Biopharmaceuticals’ ATX-101 has triumphed where many aesthetic treatments have failed, and is on course to enter the hugely lucrative space alongside Botox and Latisse, with some analysts pegging peak sales at more than $500m.

But the primary endpoints of the trials were subjective, and it is perhaps worth considering whether the success of ATX-101 was more a result of its superior efficacy and tolerability or of canny trial design on Kythera’s part.

The primary measures of the two identical studies, named Refine-1 and Refine-2, were ratings, by doctors and patients, of improvement in submental fat – double chin. Their secondary endpoints concerned the reduction in fat volume as measured by MRI (Upcoming events: phase III hopes for Kythera’s fat buster and the ESC meeting, August 22, 2013).

Both trials met both endpoints. Kythera might now be regretting putting the more meaningful measure second.

In all the studies ATX-101 demonstrated a statistically significant improvement compared with placebo on clinician and patient-reported rating scales of submental fat. More importantly, MRI data showed that 46.6% of Refine-1 and 40.0% of Refine-2 patients achieved a predefined reduction in the volume of their submental region, compared with 5.4% and 5.1% for placebo respectively (both p<0.001).

Demand

Bernstein analysts wrote that the project’s chances of approval were high, and that was before the Refine-1 and -2 data were in. Analysts from Leerink Swann responded to the trial results with untempered enthusiasm, saying that it beat even their high expectations for efficacy, and calling the 4% dropout rate “impressive”.

While double chin is perhaps not the world’s most pressing unmet medical need, there will undoubtedly be huge demand for ATX-101 in a world where Botox does over $800m of business per year for aesthetic purposes. And as the citizens of developing countries find themselves with more disposable cash the market will expand: Botox’s sales for facial wrinkles alone are forecast to hit the $1bn mark in 2018, according to EvaluatePharma'ssales by indication.

An NDA filing and a European marketing submission by Bayer, which has rights to ATX-101 outside the US and Canada, are expected in the first quarter of next year. EvaluatePharma’s consensus shows forecast sales of $248m in 2018.

As for the future of the company, it is not too much of a leap to see it being bought by its partner or fitting, perhaps even more snugly, into Allergan’s embrace.

Kythera’s share price is up 24% to $41.50 so far today and has now more than doubled since it floated less than a year ago. Leerink has raised its price target from $34 per share to $50 citing the company’s strategic value in speciality dermatology. Any companies interested in buying might be well advised to act fast.

Study Trial ID
Refine-1 NCT01542034
Refine-2 NCT01546142

To contact the writer of this story email Elizabeth Cairns in London at elizabethc@epvantage.com or follow @LizEPVantage on Twitter

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