option to buy the company outright or to license PRT-201 following a “successful” Phase 2 trial. The deal included an upfront payment (Noyes wouldn’t specify how much), and a host of other potential payments that all added up to more than half a billion dollars. This wasn’t just early validation for Proteon; it also meant potential shareholder returns were within sight, and that the company wouldn’t have to think about how to pay for a Phase 3 trial.
Proteon then got to work in the clinic. It completed a 66-patient, early-stage study in mid-2010, and then kicked off a larger Phase 2 trial a year later. In that study, Proteon enrolled 151 patients and broke them up into three evenly-sized groups. Each group was given either a low (10 microgram) or high (30 microgram) dose of PRT-201, or a placebo injection, right after AVF surgery.
The study had two main goals. One was to show that PRT-201 speeds up the time between surgery and when the AVF can actually be used in dialysis (called a “maturation rate,” typically a 12-week process, according to Noyes). The other goal was to show that PRT-201 could increase the time between an AVF surgery and any necessary corrective procedures.
While Noyes says the study was successful, Proteon didn’t come up all aces. On one hand, Proteon didn’t see any safety or tolerability red flags, and PRT-201 helped speed up the time between patients’ AVF surgeries and dialysis in a statistically significant way, he says. But on the other hand, the company missed its second goal. Noyes says this was because of the small size of the study and a “relatively minor baseline imbalance,” referring to the fact that a few more people in the group receiving PRT-201 than in the placebo group had previously had a procedure that boosted the chance of AVF failure.
“We will increase the size of the Phase 3 trial to probably 300 patients. Had the [Phase 2] trial been that size, with or without the imbalance, we would’ve reached statistical significance,” he says.
Still, is that what caused Novartis to balk? Though a Novartis spokesman wouldn’t comment, Noyes says that ultimately the conflict between the two companies was about the terms of the deal, and not the data. Proteon released the data in January 2013, and designed a Phase 3 program with Novartis following discussions with the FDA, according to Noyes. The two companies “were very well aligned” on the data and potential market opportunity and talked extensively about a deal, but couldn’t come to an agreement, Noyes says.
“I think the difference ended up being a buyer versus a seller,” he says. “And that’s unfortunate, they were a great partner, but we felt that…our team was very well suited to take this program all the way through to approval and launch. And our investors were happy to keep funding the company, so we didn’t feel like we needed to settle for a deal that we didn’t think gave our shareholders proper value for these Phase 2 data and the value of what we believe we’re going to show over the next few years.”
So now, Proteon will have to prove that it made the right call, and get PRT-201 to market. First, Proteon will have to show the Phase 2 study’s failure to reach one of its goals really was due to sample size and baseline differences between groups, and not a worrisome sign. It’ll have to get the cash together to pull off a larger, late-stage study and run it effectively on its own. Noyes says there’s been plenty of interest in financing the company, and expects to get a round together within the next few months to do so.
Then, there’s the potential competition. Shire, through its buyout of Cambridge, MA-based Pervasis Therapeutics, has a competitor in Phase 2 trials called Vascugel, a cell therapy for the same problem Proteon is trying to treat.
Still, Noyes insists that the Proteon and Shire treatments could be used in tandem, rather than competing against one another for market share (assuming they both make it that far).
“This is one of those diseases where it’s multi-factorial, it’s a very bad problem, and I don’t think anyone—neither us nor Shire—is going to completely solve this problem with a single approach,” he says.
