Xconomy -- Logical Therapeutics has secured $10 million to pursue its idea for a safer way to relieve chronic arthritis pain. The Waltham, MA-based company has nailed down the $10 million out of a financing round that could be worth as much as $16.9 million over time, according to a regulatory filing today with the Securities and Exchange Commission. The document doesn’t say who invested, and Logical Therapeutics president Carolyn Green said she couldn’t comment at this time.