Repros Therapeutics Inc (NASDAQ:RPRX) just put out data from its phase II in moderate to severe endometriosis, and the company has gained close to 17% on the data. The drug could be a real game changer for the company if it can pick up approval from the agency, and this potential is what’s driving the gains seen during today’s session. The next step is an FDA meeting and – if all goes to plan – an advancing of the drug into a pivotal trial with an eye to commercialization.
Ahead of the FDA meeting, then, let’s take a look at the drug in question, discuss how it works and what the data says about efficacy, and finally, what an approval might mean for Repros going forward.
So, first up, the drug. As mentioned, it’s called Proellex, and it’s a selective blocker of the what’s called the progesterone receptor. To understand the MOA, it’s first important to understand the indication. Endometriosis is a condition in which the tissue that normally lines a woman’s uterus grows outside of the uterus. It’s not a hugely serious condition, and the main symptoms are pain and menstrual irregularities, but it can be very uncomfortable for sufferers, and this seeks nearly 200,000 new patients annually in the US to seek treatment, combining to a total of more than 6 million sufferers at any one time in North America alone.
Current treatments (SOC) involve hormone therapy, pain management drugs, that sort of thing. These can be effective, but they aren’t addressing any where near the underlying cause, and they have some pretty undesirable side effects. They also aren’t long term – this sort of pain is often chronic and gets more severe during menstruation. There are no treatments available to physicians as prescriptions for long term care in endometriosis patients, at least none that are labelled as such.
So where does Proellex come into the equation?
The drug is a is designed to block progesterone activity, wild allowing tonic hormone secretions. In doing so, it is designed to induce amenorrhea in patients. Amenorrhea is just another word for the absence of normal menstruation cycles. What does this have to do with endometriosis? As mentioned, the vast majority of endometriosis sufferers only experience pain as a symptom of their condition during menstruation. By stopping the menstrual cycle from taking place, Repros Therapeutics Inc (NASDAQ:RPRX) can use Proellex to stop women having to experience this pain.
This is what the trial set out to demonstrate.
The company tested the drug on 60 patients with a mean age group of 30, comprising 13 patients from Argentina and 47 from the U.S. More than 70% of the patients on the trial reported a reduction in menstrual pain, when compared to placebo, and the same number reported a resulting reduction in the use of pain killers to combat menstrual pain.
So what’s the potential impact of this one on Repros’ balance sheet?
The company is targeting an FDA approval first, and as mentioned, will do so on the back of data collected from a pivotal that should kick off late 2016 or early 2017. Safety and tolerability don’t look to be an issue on this one (based on data collected to date) so it’s all going to come down to effective replication. If the company can expand its trial base and carry the numbers recorded in the phase II through to a pivotal trial, there’s every chance of an FDA nod. Once the company gets the green light for commercialization, it will start marketing initially to the single digit millions of sufferers in the US, and then in Europe, based on a projected EMA approval.
In its latest investor presentation, Repros Therapeutics Inc (NASDAQ:RPRX) estimated that the peak sales potential for the drug in the US and Europe is in excess of $1 billion. Of course, this would require the succesfull execution of a marketing and commercialization strategy, but given the scope of the potential market, and the current state of the space (i.e. no currently available long term treatments) then Repros shouldn’t have too difficult a time achieving a decent penetration rate relatively quickly.
One to watch, with the FDA meeting the next major milestone and the phase III initiation beyond that.
Note: This article is written by Mark Collins and originally published at Market Exclusive.