Core Viewpoint - Moderna's shares fell nearly 8% after the company voluntarily withdrew its regulatory filing for mRNA-1083, a combination vaccine for influenza and COVID, following consultation with the FDA [1] Group 1: Regulatory Developments - The withdrawal of the filing was anticipated as the FDA had previously requested additional Phase 3 flu efficacy data [2] - Moderna plans to resubmit the filing later this year after obtaining efficacy data from the ongoing Phase III study of its seasonal influenza vaccine, mRNA-1010, with interim data expected this summer [3] Group 2: FDA Guidance - The FDA recently issued new guidance requiring COVID vaccine manufacturers to conduct randomized, placebo-controlled studies to demonstrate the real-world benefits of yearly COVID vaccine boosters for individuals under 65 [4] Group 3: Clinical Data - The initial FDA filing for mRNA-1083 was based on Phase III study data showing it elicited higher immune responses against influenza and COVID compared to standalone vaccines [5] Group 4: Market Performance - Year-to-date, Moderna's shares have decreased by 38%, contrasting with a 4% decline in the industry [6] Group 5: Competitive Landscape - Other companies, including Novavax, Pfizer, and Sanofi, are also developing COVID-flu combination vaccines [8] - Novavax is conducting a late-stage study comparing its combination vaccine's immunogenicity and safety against separate vaccines, with initial data expected later this year [9] - Pfizer faced setbacks in its combination vaccine program and is currently evaluating adjustments to improve immune responses [10][11] - Sanofi has received fast-track designation from the FDA for two of its experimental combination vaccines, currently in Phase I/II studies [12]