While it indicates no partnership or other deal is at the finish line, a great indication. IMO many small insider buys as practiced these days are fluff and even a negative for their transparent effort to signal to shareholders. It's the $10,000 signaling buy from wealthy executives that is a disaster - an empty charade treated as a cost of doing (promotional) business. In contrast, a guy like Luly laying down this cash is significant.
Keep in mind per his ownership what his personal net worth in ENTA was a few years ago vs today. Having seen a pretty reasonable fortune slashed he's putting in real money to own more.
At the risk of taking it a bridge too far, the lack of a conf call combined with the purchase shows that the buy is all about the opportunity at this price rather than a desire to be noticed.