With a yes from the FDA last Friday Corcept Therapeutics (CORT) can claim the title of having brought the first endogenus Cushing’s syndrome treatment to the market in the US, a big positive in a field where patients have little options (Event- Corcept not anticipating Cushing defeat at PDUFA hearing, January 24, 2012). While the group will almost certainly be enjoying the moment the next steps will be sorting out a commercialisation strategy, as well as getting approval for and finding a partner for the drug outside of the US.
In terms of selling the drug Corcept is planning on going it alone. The company estimates that the Cushing’s population in the US is roughly 20,000 and should be manageable with a sales force of 10-20 people and funded from the $46m the company has on its balance sheet. A launch of Korlym is now expected within the next two to three months.
Ahead of the curve
Getting approval ahead of Novartis’s SOM230, now called Signifor, is an important win for tiny Corcept. The group now has valuable first mover advantage, which should allow it to pick up a lot of the market. Novartis (NVS) withdrew its US filing for the drug in October following manufacturing and chemistry issues the drug is now expected to be refilled in this half of the year (Therapeutic Focus - Thin Cushing pipeline loses lead candidate, October 27, 2011).
However, Korlym is not without side effects of its own. The drug, which was approved on the back of a small single arm phase III trial involving 50 patients, saw six people drop out due to what is believed to be the drug’s action of inhibiting cortisol, that could have caused adrenal insufficiency and orthostatic hypotension.
While this might affect take up, for those who remained on the trial the drug was highly effective, meeting its primary endpoint of improving blood pressure in Cushing's patients with high blood pressure and lowering glucose levels in diabetic patients. The general condition of patients was also improved and over 50% of them lost considerable amounts of weight.
Weight gain, skin dysfunction and abnormal hair growth are some of the physical symptoms of Cushing's Syndrome, which is caused by either the use of corticosteroids, or malfunctioning endocrine glands. Korlym is approved in endogenous Cushing’s syndrome, the disorder of the endocrine glands.
The next steps
Analysts at Leerink Swann are estimating that the annual cost of the drug, which has orphan status, could be $175,000 and might even be higher because it has to be given in a doctor’s office. Consensus sales forecasts for Korlym are currently running at $409m by 2016.
Additional money in the form of royalties will come from finding an ex-US partner to commercialise the drug. By choosing the right partner and securing decent terms and an upfront payment Corcept could see its shares, which have risen by 5% today to $3.03, rise even further. This would be welcome as they have not recovered the losses they suffered last week amid fears that Korlym would not make it past the regulators.
With little else in the pipeline Corcept is also trying to extend the use of Korlym, a repurposed version of the pregnancy termination drug mifepristone, and so far the results have not been particularly successful. The drug failed in an earlier psychotic depression trial and results from a second are due at the end of this year, but little is expected in this indication.
For now, however, Corcept will almost certainly be reveling in the achievement of getting its first drug to market, an important milestone in the development of any small biotech and the start of very welcome revenues.