They are a startup in their funding-press-funding-doing-things-press-funding cycle, so expect a certain amount of positioning. This is all serious work, however. Deep Knowledge Life Sciences recently took a position, so BioViva is within the circle that includes the reputable In Silico Medicine, Biogerontology Research Foundation, and other for- and non-profit groups in life science and aging research and advocacy:
http://www.eurekalert.org/pub_releases/2016-04/brf-dkl041916...
Take a look at the BioViva board of advisors, and note the presence of George Church, who is essentially the center of the network of connections for all gene therapy activities these days, and a luminary in the field.
The nature of the BioViva press here is that they did a thing, and the thing worked as expected based on the only available way to take a short-term measurement. That seems quite a reasonable thing to announce when you are a young company working on traction. It doesn't really imply rejuvenation without more useful data, such as DNA methylation assays of biological age, for example, and the details on that front are complicated, see below.
Telomerase gene therapies to treat aging are heading for human trials one way or another. Look at this position paper for example, from one of the groups to have demonstrated improved health, stem cell function, and longevity in mice using telomerase gene therapies in past years:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4815611/
BioViva's principals are taking the stance that present regulation and talk of moratoriums are ridiculous given the fact that so much good might be done, and that new gene therapy technologies such as CRISPR are now making it cheap and easy to run these sorts of edits in humans. I agree with this.
So telomerase gene therapy in mice extends life modestly: there are years of pretty robust results to demonstrate that. Average telomere length appears to be a reflection of aging, most likely not a significant contributer to aging. It is a poor measure, as the trend downward with age is statistical over populations. Average telomere length is some function of stem cell activity (delivering new cells with long telomeres) and cell division rates (shortening telomeres with each division). Stem cell activity declines with aging. Average telomere length is presently measured in white blood cells, which are going to have a whole lot of influences on cell division and replacement rates that don't exist in other tissues, due to immune system reactions to circumstances. Telomerase is clearly doing a lot of other things beyond telomere lengthening. Look at the work suggesting it is acting as a mitochondrial antioxidant, for example, or other cryptic activities.
The present consensus is that telomerase therapies in mice extend life through increased stem cell and/or immune activity. Mice have very different telomere dynamics, however, and there are concerns regarding cancer risk in humans. Trying it in dogs or primates would be the next safe thing to do - move to a mammalian species with telomere/telomerase dynamics that are closer to ours.
There is an argument that runs along these lines: telomerase gene therapy is just (primarily) another way of triggering old stem cells to get back to work, and therefore vis a vis cancer and risk should fall in the same ballpark as stem cell therapies carried out over the past fifteen years, and therefore full steam ahead because all of that work produced far less cancer that was feared. Prudence would suggest trying it out in something other than mice first, but I suspect the sudden ease of gene therapy means that this will be bypassed by the adventurous.
I'm totally in favor of adventure when it comes to gene therapies for follistatin/myostatin - I think the risk situation there is pretty much as low as it can get prior to hundreds or thousands of enhanced human patients. I'm more cautious on the cancer and telomerase front; I think more data there would be desirable before I stepped up to try it out. Other people can have other viewpoints, and that is the point - it should be the patient's informed decision, not that of a bunch of self-interested bureaucrats.