MannKind's stock plummeted 11.13% in pre-market trading on Thursday, as investors reacted negatively to the company's first-quarter financial results.

The biopharmaceutical company reported revenue of $90.17 million for the quarter, representing a 15% year-over-year increase but falling short of analyst consensus estimates. More critically, MannKind swung to a net loss of $16.62 million, or $0.05 per share, compared to net income in the same period last year. This result missed Wall Street expectations for breakeven or small profit performance.

The disappointing earnings were driven by a substantial increase in operating expenses, with selling, general and administrative costs more than doubling and research and development expenses rising significantly. These increased costs were attributed to the promotion and support of recently acquired Furoscix, expanded field-based teams, and advancing development programs.