Wall Street leaders and U.S. officials discussing an intervention at First Republic Bank are exploring the possibility of government backing to encourage a deal that would shore up the lender, people with knowledge of the situation said. The shares dropped Wednesday morning. The group has floated a variety of measures to make the company more attractive to potential investors or a buyer, part of an effort to ensure there isn’t another US bank failure, the people said, asking not to be named describing confidential talks. Among options, the government could play a role in lifting assets out of First Republic that have eroded its balance sheet.