This study is for patients that have been diagnosed with advanced solid tumors. This study is testing an investigational drug called At0365-P1-01. "Investigational" means it has not been approved by the United States Food and Drug Administration (FDA). The primary purpose of this study is to evaluate how safe the drug is, how well participants can handle the drug, how it moves through the body, how it affects the body, and if the drug helps treat the cancer of AT03-65. AT03-65 is administered via intravenous (IV) infusion. Participants can continue to receive this study drug until it no longer gives them benefit. The estimated study duration is approximately 30-35 months for subjects screening, treatment and follow-up.

This study aims to evaluate real-world effectiveness of pacritinib through a site-based retrospective chart review of medical records of adult patients with myelofibrosis treated with pacritinib in routine clinical settings with platelet count ≥50 x 10^9/L at the time of treatment initiation. Treatment effectiveness will be based on spleen size and symptom burden, hematological parameters, progression to leukemia, survival, pacritinib treatment patterns, patient demographic and clinical characteristics, and allogenic-hematopoietic stem cell transplant (allo-HSCT)-related outcomes. Data will be collected from medical charts of patients with pacritinib initiation between 01 June 2022 and 31 December 2025 with an end of study observation on 30 June 2026.