CITIUS ONCOLOGY, INC.

Public companies file this within four business days when something important happens that investors should know about before the next quarterly report.

CITIUS ONCOLOGY, INC. filed this to release information to investors under Regulation FD — usually a press release, conference presentation, or other event the company considers important. htm PRESS RELEASE, DATED JUNE 1, 2026 Exhibit 99. 1 Citius Oncology Highlights Phase 1 Data in an Investigator-Initiated Study of LYMPHIR ® (denileukin diftitox-cxdl) in Combination with Pembrolizumab in Recurrent or Refractory Gynecologic Malignancies Investigator-initiated study data presented May 30, 2026, at the American Society of Clinical Oncology…