The Risk of Living Longer: What if new senolytic drugs fulfil their potential?

In an effort to avoid a sudden step-change in expectations, Club Vita’s recent Risk of Living Longer webinar series explored potential drivers of significant increases in future lifespan and health span. During this series we heard from a range of industry experts about potential areas of medical and technological research that could contribute to significant increases in longevity. If even half of the possibilities discussed are realised, they could drastically change the outlook for life expectancy currently used in actuarial circles.

In session 4, Dr Peter Joshi (University of Edinburgh, Humanity Inc) gave us an overview of biological clocks, detailing key biological markers that can be used to define a person’s biological age. An individual’s biological age can differ from their chronological age if these markers have degraded at a different rate to the average. Much of longevity science is focused on reducing biological age comparative to chronological age.

In session 2, we explored one such possibility for reducing biological age. Prof Richard Faragher (University of Brighton) discussed exciting developments in a new class of drugs known as senolytics: potential treatments aimed at reducing the impact of aging by clearing out senescent cells in the body (senescent cells are damaged cells that can no longer replicate themselves, they build-up as we age and are believed to trigger various physical signs of aging). If senolytics can replicate in humans the results they have seen in mice, it’s possible that there could be a wide-scale reduction in biological age across the population.

Prof Faragher highlighted that a possible future scenario for the population could be an increase in life expectancy at age 65 of around 10 years by 2044 (also dependent on developments from this area of research being accompanied by additional manufacturing and supply developments).

Impact on reserving requirements

Remaining cohort life expectancy for a medium/high socio-economic man or woman at age 65 in 2024 increases by around 9 years (around 35%) when moving from our current best estimate improvements to our stressed scenario. This means, at a real discount rate of 0% we would expect to see liabilities increase by around 35%. At a higher real discount rate of 4%, we could still expect to see increases in liabilities by around 20%. And even at a real discount rate of 7% we’d still see increases in liabilities of over 10%.

Further considerations

The scenario presented here is one possible trajectory of outcomes following a significant breakthrough in senolytics over the next 20 years. We note that such a breakthrough could take many forms. Some further considerations around such a scenario could be:

• The timing of gains in life expectancy affecting the population (we have assumed a linear increase in life expectancy over the next 20 years, but this might instead materialise as a lagged step-change in life expectancy).
• The specific population that would be most affected by advances in senolytics (would these treatments be equally available to all socio-economic groups, would they have the same impact on groups with different starting longevity rates?)
• Is it possible for senolytics to increase maximum lifespan or would an increase in life expectancy due to senloytics have to come from increases in longevity at younger ages (given senolytics claims to tackle the aging process itself, we have assumed it is capable of increasing maximum lifespan in our scenario).