Making a play, IMHO Mr.Kovner wants to take control of SYNTA, He once said that Synta was his Baby.
He's buying all these shares and already has 34.2% of SNTA stock.
If you read the 13D you'll get little hints in there that to me makes it clear his intentions with SNTA.
From SEC Site = Schedule 13D reports the acquisition and other information within ten days after the purchase. The schedule is filed with the SEC and is provided to the company that issued the securities and each exchange where the security is traded. Any material changes in the facts contained in the schedule require a prompt amendment. The schedule is often filed in connection with a TENDER OFFER
Tender offer is a corporate finance term denoting a type of takeover bid. The tender offer is a public, open offer or invitation