Closed form of $\sum \frac {1}{p_1.p_2.….p_r}$ where $p_r$ is the $r^{th}$ prime

Question

Following is an infinite series quite analogous to the exponential series, but composed of prime numbers only. $$\frac {1}{2} + \frac {1}{2.3} +\frac {1}{2.3.5} + \frac {1}{2.3.5.7} + \frac {1}{2.3.5.7.11} + …… ≈ 0.70523$$ How can we express it in closed form i.e. how can it be expressed as a combination of known constants (like $π, e,$ etc.) and/or special functions? The only pattern I can conceive is that the denominators form a part of Euclid's proof for infinite primes.