Aimmune Therapeutics Inc (NASDAQ:AIMT) just updated us as to the progress of its ongoing pivotal in peanut allergy, and suggested that enrollment will complete this quarter or next, and we should get top line from the trial somewhere around third quarter next year. The treatment has the potential to totally disrupt the space, and meet what is currently a pretty large unmet need in the allergy sector, making Aimmune an intriguing potential allocation ahead of data day. Here is a look at the the candidate in question, and a discussion regarding what to look out for when the company releases top line from the trial.
So, as mentioned, it’s a peanut allergy indication, and it’s called AR101. There is a pretty interesting history behind this sort of treatment, and it is worth touching on briefly to set up our discussion. Back in 1906, a London-based doctor called Alfred Schofield decided to try and treat a boy with egg allergy by gradually giving him increased amounts of egg on a regular basis, starting with a tiny amount (1/10,000th of an egg), and working upwards. The theory was that by introducing what is essentially a pathogen to the patient on such a small scale and gradually increasing that scale, the patient would develop an immunity to the egg. It’s similar in concept to a first-generation vaccine whereby a physician administers a virus to elicit an immune response. By all accounts, it worked, and the physician published his finding and gave the treatment the name oral desensitization immunotherapy (OIT). Since this initial test, OIT has been used numerous times, and is available in the US in some medical centers, but it is not a commercially approved treatment, and data on its efficacy, and specifically its optimal dosing regimen, is thin to nonexistent. With AR101, Aimmune is trying to bring an FDA approved version of OIT to the peanut allergy space.
The drug is basically just a capsule with little bit of peanut protein in it, available in various sizes starting from 0.5 mg and working up to 300 mg.
Simple, yes, but as illustrated by trials to-date, effective. Data from a phase 2 trial was about as good as it could be. 55 patients entered a double-blind signal controlled trial, and 44 of them completed the six months of dosing, at which point they were taking 300 mg of peanut protein a day. 43 of these 44 tolerated 443 mg of peanut protein in a food challenge, and 35 of these tolerated 1043 mg of peanut protein. The 43 patients that tolerated the 443 mg then went on to a maintenance period, where they took a 300 mg capsule daily for three months. At the end of the three months, 100 percent, 90 percent, and 60 percent of patients tolerated cumulative amounts of peanut protein of 443 mg, 1,043 mg, and 2,043 mg, respectively.
For reference, one peanut shell contains two peanut kernels, and each kernel is around 250mg of protein.
The phase 3 that is ongoing is aiming to replicate these data, but also up the ante. It is seeking to enroll more than 500 patients across a wide age range (4 to 55) and after initial up-dosing, and then a maintenance period, see how many of these can tolerate 1043 mg protein. The endpoint is this tolerance.
In the trials to date, there have been no serious adverse events in any of the patients, and only a few mild adverse events generally related to immune system activation. No patients discontinued the phase 2 voluntary, and extensions on the trial reinforced these statistics. Basically, with the information available to us, we see no reason why this treatment won’t get approval when it goes in front of the FDA. If approved, it opens up a wide market for Aimmune. AR101 isn’t going to replace the need to avoid peanuts or carry an Epipen, but it will be prescribed as an ongoing maintenance therapy and pretty much the whole spectrum of sufferers will be eligible for it. There are more than 5.4 million people in the US and Europe that have peanut allergies. That’s a pretty big target market, and even better (for shareholders, at least) patients need to maintain treatment constantly or the effect wears off. Once patients on this, therefore, there’s very little chance that they will come off it. Big market, recurring revenues. We’ve got Aimmune one on our watch list.