It seems that aside from Philo's Contemplative Life there's not much information out there on the 1st C. BCE sect that he calls the Therapeutae. Can anyone recommend other sources that investigate the sect's origins, beliefs and practices?
I'm afraid the only assistance I can offer is negative. I am rather certain that Philo is the only contemporary account. There are much later mentions in authors like Eusebius, but they are, so far as I know, totally derivative from Philo.