From a single cornea to a hundred or more cell therapy transplant injections: is CorneaGen on course to end our dependence on donor tissue?
Phoebe Harkin | | Interview
It would be an understatement to call CorneaGen well-capitalized. Since it was founded three years ago, the Seattle-based company has raised $10 million in Series A funding, $37 million in Series B funding, and accessed a debt vehicle of $25 million more. Its product? Cornea cell therapy transplantation (CCTT), capable of turning a single donated cornea into 100 or more sight-restoring treatments. How? By culturing human endothelial cells and injecting them into the anterior chamber of a blind patient’s eye, eliminating the need for invasive corneal transplant surgery.
The injected cells have been shown to safely restore sight within a month, and all patients who have taken part in clinical trials to date report clear, healthy corneas – a full year post-procedure. CorneaGen is currently creating a subsidiary in Japan to drive the regulatory approval process and initiate commercialization. CEO Monty Montoya claims the treatment will have the same effect on the cornea sub-specialty that phaco had on cataract surgery. In his own words: “CCTT will change the practice of medicine for the better – for patients as well as surgeons.” Here, we speak to him to find out why.
What makes CCTT so disruptive?
It exponentially increases patient access. Instead of doing tens of thousands of corneal transplants, we should be doing hundreds of thousands of cell injections.
So how does it work?
We take a donor cornea, remove the endothelial cells and put them into a culture media that has the “secret sauce.” The cells are expanded over multiple passes (the period of time in which they are cultured), with the high-quality cells being selected and then run again. With every pass, you multiply the cells available. Each pass takes around 45 to 60 days. In clinical trials, we used P three – third pass of cells – the number required to provide 100-plus procedures from a single donor cornea. When we use P four, P five and P six cells, that number increases. By P seven, we could potentially get as many as 50,000 procedures.
Is there a limit to the number of passes you can do?
In CCTT, there is typically a limit of how far you can go as the cells don’t seem to function as well. We feel confident that we will be able to expand to P four or P five cells in the future, but we will probably go to market, at least initially, with P three cells.
Did you expect the results to be so good?
You don’t always expect 100 percent efficacy, so to have had that level of success through three phases of clinical trials is really positive. We have patients who are four and five years out and still have fantastic vision.
The IP originated out of Kyoto Prefectural University of Medicine with Shigeru Kinoshita, who is the inventor and primary investigator. Because the therapy originated in Japan and is already through phase three clinical trials, it makes sense to finish them there. Hopefully the data that has already been generated from those clinical trials will help reduce the regulatory process we have to go through in the US.
Do you know when that process will take place?
Once we have taken the data from Japan, presented it to the FDA and begun to work out an agreeable pathway for us to go through – hopefully we will have the reulatory pathway with the FDA defined by the end of the first quarter of 2020.
Why CCTT over corneal transplants?
The efficacy of the procedure is much more powerful. Typically with any type of cornea transplant, endothelial cell count goes down over time until the patient ultimately needs another transplant or a re-graft. What we’ve seen in our studies is a stabilization of the endothelial cell count over all phases after the injection. At present, patients in our study are maintaining cells amazingly. Of course, we would expect this from patients who had the injection a few months ago, but patients from phase one and phase two still have great cell counts. The durability of the treatment is increased and we’ve had zero incidences of rejection, which is a big deal.
Another benefit is its practicality. Currently, when a patient has DMEK surgery, the physician puts an air bubble underneath the DMEK graft that holds it against the Descemet’s membrane. For patients to have the best chance of success, they need to lie on their backs for three days – that is a long time to lie on your back. With a corneal cell injection, the patient only needs to lie face down for three hours. In the clinical trials, we would literally roll the patient onto a massage table after the procedure, where they could play with an iPad, text their friends or watch a video.
Another benefit is psychological. We have spoken to a lot of doctors and they tell us that patients typically undergo a significant amount of vision loss before they are willing to go through a transplant. Having a cell injection is a very different thing, and a lot more manageable mentally and emotionally. We expect to find patients prepared to access treatment a lot sooner with CCTT, making it a much earlier intervention rather than a last resort.
What is the ultimate goal for CorneaGen?
We are aiming to eliminate corneal blindness by 2040. If we are successful at CCTT, that will take care of half of it. It will also generate the resources for us to be aggressive and innovative in taking care of the other half, so I think it is definitely doable.
What would you like to work on in the future?
There are a lot of challenging ocular surface disorders – Stevens-Johnson syndrome, for example – but not a lot of fantastic curative treatments. Fortunately, the cornea is novel in that it doesn’t have any blood vessels, which allows us to take advantage of advances like gene and cell therapy a lot earlier. These kind of therapies are going to be really critical for eliminating cornea blindness. We haven’t tapped into that yet, but they are going to be important to us in the future.