UNITY Biotechnology and Oisin Biotechnologies are both early stage startups working on commercial development of therapies capable of clearance of senescent cells. Since accumulation of senescent cells is one of the root causes of aging and age-related disease, periodic removal of these cells is a narrowly focused form of rejuvenation. There are a number of other forms of damage and disarray that contribute to degenerative aging, and all will have to be fixed if aging is to be controlled by medicine, but an individual with fewer senescent cells is absolutely better off than one with more senescent cells regardless of the state of other forms of damage. Earlier this year researchers associated with UNITY Biotechnology published the results of the first life span study in normal mice engineered to destroy their own senescent cells, showing a 25% extension of median life span.

While the Oisin Biotechnologies principals have been pretty open on the topic of how their approach to senescent cell clearance works - it is a form of sophisticated gene therapy - the path chosen by UNITY Biotechnology remains less clear. In part this is because the public research based on gene therapy in mice that led to the life span study noted above is not something that could easily be adapted for use in human trials: it could be done, but almost every other option on the table would be both substantially easier to accomplish and more palatable to regulators. There is a trail of patents for other research leading in to the merger of groups that formed the company, but they cover a fairly wide selection of possible methodologies, including the use of immunotherapies and engineered viruses.

Gene therapies, immunotherapies, and more esoteric modern medical technologies are not the only possible approach to senescent cell clearance, however. In the past couple of years research groups have produced classes of drug - now called senolytic compounds - that can selectively drive senescent cells to self-destruct via the process of apoptosis. The combination of dasatinib and quercetin, for example, removes enough senescent cells in enough different tissues to produce meaningful benefits in mice. It isn't unreasonable to think that this type of result can be improved upon to the point at which it is a competitive option. Judging from recent news, it seems that UNITY Biotechnology will take the apoptosis-inducing drug development path, and, interestingly, is also setting up from the outset to deploy therapies outside the US in less heavily regulated regions:

Ascentage Pharma and UNITY Biotechnology Announce Collaboration for the Development of Senolytic Healthspan Therapies