Elias and Alex deAngelis will be replaced by Marco Simoncelli and his fellow Italian Marco Melandri, who returns to the team he raced for from 2005-07.
"We found the number of new infections remained quite stable over the decade, there was no evidence of a decline, " researcher Dr Daniela DeAngelis told the BBC.
Lorenzo cruised to victory more than nine seconds clear of Alex deAngelis, who earned his first podium finish after starting fourth on the grid for San Carlo Honda Gresini.
Rounding out the top-10 on Saturday were DeAngelis, Ducati's former world champion Nicky Hayden of the U.S., Italian Loris Capirossi on a Suzuki and Finland's Mika Kallio -- despite a crash in his stint as a temporary stand-in rider for Ducati.