This biotech innovator in inhaled therapeutics reported a notable insider sale amid ongoing product development and licensing activity.On Dec. 17, 2025, Michael Castagna, Chief Executive Officer of MannKind Corporation (MNKD +0.00%), executed an exercise and immediate sale of 65,804 common shares for a transaction value of approximately $395,482, according to the SEC Form 4 filing.Transaction summaryMetricValueShares sold (direct)65,804Transaction value~$395,482Post-transaction shares (direct ownership)2,50 ...