To Evaluate the Safety, Tolerability, Pharmacokinetics and Antitumor Activity of DAY301 in Participants With Locally Advanced or Metastatic Solid Tumors

Exclusion Criteria9

• Prior use of PTK7 targeting treatment (Phase 1a) or prior use of PTK7 targeting treatments and/or topoisomerase 1 (TOP1) inhibitor-based antibody-drug conjugate (ADC) (Phase 1b).
• Cohort 1: Neuroendocrine tumors or endometrial sarcoma (eg, stromal sarcoma, leiomyosarcoma, or other types of pure sarcomas)
• Cohort 2: Ovarian cancer that progressed >6 months after the last dose of platinum-based chemotherapy (platinum-sensitive disease), or disease that did not respond (partial response \[PR\] or complete response \[CR\]) to or progressed ≤91 days after the last dose of first-line platinum-based chemotherapy (primary platinum-refractory disease)
• Cohort 3: nasopharyngeal primary tumors.
• History of small bowel obstruction requiring hospitalization within 3 months prior to the first dose of study treatment.
• Ascites requiring frequent paracentesis (more often than approximately every 4 weeks) for symptomatic management, or new onset within 4 weeks prior to the first dose of study treatment. Patients with an indwelling catheter may be considered eligible, after consultation with the medical monitor.
• Active or progressing brain metastases or evidence of leptomeningeal disease.
• Persistent toxicities from previous systemic antineoplastic treatments of Grade >1, excluding alopecia and vitiligo.
• Systemic antineoplastic therapy within five half-lives or 4 weeks, whichever is shorter, prior to first dose of study treatment, including investigational agents.