Exhibit 99.1 Iovance Biotherapeutics Reports First Quarter 2024 Financial Results and Corporate Updates Strong Momentum for Amtagvi™ (Lifileucel) U.S. Launch Following U.S. Food and Drug Administration (FDA) Approval 100+ Amtagvi Patients Enrolled Across More Than 40 Current Authorized Treatment Centers (ATCs), with ~50 Total ATCs On Track by End of May and 70+ Total ATCs by Year-End 2024 Amtagvi Regulatory Submissions on Track in the European Union (EU), United Kingdom (UK), and Canada in 2024 SAN CARLOS, ...