Pfizer threatened to sue renegade executives prior to activist schism, Starboard's Smith says CNBCFormer Pfizer CEO, finance chief step back from Starboard's activist campaign CNBCPfizer’s stock dips after two former execs say they won’t support Starboard, offer backing for CEO Albert Bourla MarketWatchFormer Pfizer executives not involved in Starboard's campaign against drugmaker Yahoo FinancePfizer CEO Bourla to meet with activist investor Starboard Value on turnaround pitch: FT FiercePharma