NEW Chairman Blog,
Timing and Pace of Our Clinical Trial
Greetings,
As you are undoubtedly aware, last July we initiated the first-ever clinical trials using a cell therapy derived from human embryonic stem cells (hESCs) to treat various forms of macular degeneration. The end goal for our clinical trials is to test whether or not the retinal pigment epithelial (RPE) cells we make from hESCs are capable of homing to sites of injury in the retina, replacing the native RPE cells that are lost to disease, and ultimately reestablishing the function of this layer of cells in protecting photoreceptors from cell death, i.e. slowing or halting progressive vision loss. One of our ongoing trials is for Stargardt’s Macular Dystrophy (SMD, aka Stargardt’s Disease) and the other is for Dry Age-Related Macular Degeneration (Dry AMD). Last month we also initiated a European clinical trial for Stargardt’s Disease. That same week, we also published some exciting – albeit very preliminary data – relating to the patients treated last July, in The Lancet.
To date, we have treated one patient with Dry AMD (at UCLA), and a total of four patients with SMD (three at UCLA, and one at Moorfields Eye Hospital in London). The recent treatment of the two SMD patients at UCLA represents the entire first cohort of patients for this initial dose of cells in the SMD trial.
We are pleased to have both trials underway and delighted with the results we have reported so far. Clearly, though, the question arises: why does the Stargardt’s Disease trial appear to be moving alongat a faster pace than the Dry AMD trial? This has no doubt been of particular interest to our investors, upon whom the vast size of the potential market for Dry AMD is not lost; a projected market upwards of $25-30 Billion in the US and Europe alone. I intend to briefly address this issue here.
No Two Trials Alike
No two clinical trials are exactly alike or proceed at exactly the same pace. There are a few reasons why patient treatment in our Dry AMD trial has lagged behind our SMD trial a bit. It can be summed up pretty much as follows: luck, age and regulatory factors.
Any large-scale, complex project with a number of moving parts and other variables, no matter how well planned and thought through, is on some level affected by a random interplay of factors beyond the control of its planners. Clinical trials are no exception to this, and simple luck always comes into play on some level.
In the case of the dry AMD trial, four of the initial patients that principal investigator Dr. Steven Schwartz of UCLA had identified as good candidates from which to select patientstwo and threewound up being screened out of eligibility in the final battery of tests. The patients all passed initial health screenings, complete reviews of their medical records and extensive optical analyses. Sadly, on the eve of the surgeries, the longer lead time screenings for cancer and viral infections yielded previously unidentified positive results. Thesepatients hadsurelybeen excited to participate in the trial, and my heart goes out to each of them. They have suffered already with blindness from macular degeneration, and now have another tough set of circumstances to deal with in their lives.
This is, unfortunately, not an overly uncommon occurrence in clinical trials, but clearly it is more likely to happen in a trial with a patient population that tends to be elderly, by definition. Dry AMD is, after all, age-related, and an older patient population will invariably have more complicating health factorsthat could affect final eligibility to participate in a clinical trial.
The Food and Drug Administration’s (FDA) protocol for our surgeries, as you are also likely aware, involves a course of immune suppression before and for a period of time after the transplant, and a patient’s ability to tolerate this without other adverse effects is a critical factor in inclusion in the study. The extremely poor visual acuity requirements in the FDA protocol result in a decidedly elderly patient population (with patients typically being 77 years old or so at the youngest). When that factor is combined with the requirementofan intact Bruch’s Membrane, and the general health-related restrictions mentioned above, it makes for a more challenging patient screening process in the dry AMD trial relative to that for the SMD trial.
That being said, I am pleased to inform you that we are currently in the advanced stages of screening several more clinical trial candidates and are very confident that we will soon be able to treat two additional Dry AMD patients, rounding out the first cohort in the AMD trial.
Thank you, as always, for your interest and support.
Gary Rabin
Chairman and CEO
Advanced Cell Technology, Inc.
