Recruiting
Phase 1

DAY301

Sponsor:

Day One Biopharmaceuticals, Inc.

Code:

NCT06752681

Conditions

Advanced or Metastatic Solid Tumors

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

DAY301

Study Details

Brief summary:

This is a Phase 1a/1b, open-label, dose escalation and expansion study to evaluate the safety and anti-tumor activity of DAY301, a PTK7-directed antibody-drug conjugate (ADC) in participants with advanced or metastatic solid tumors. The study comprises of 2 phases: Phase 1a dose escalation where participants will be administered DAY301 at escalating dose levels to assess safety and tolerability, and to determine the maximum tolerated dose (MTD) and/or the recommended dose (RD); In Phase 1b dose expansion, DAY301 will be evaluated in dose expansion cohorts.

Conditions

Advanced or Metastatic Solid Tumors

Study ID

NCT06752681

Start date

Nov 18, 2024

Status verified date

Jul, 2026

Completion date

Dec, 2028

Anticipated

Primary completion date

Dec, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Histologically or cytologically confirmed diagnosis of advanced or metastatic solid tumors of the following histologies:
  • Ovarian cancer
  • Esophageal squamous cell carcinoma
  • Triple-negative breast cancer
  • Non-small cell lung cancer
  • Small cell lung cancer
  • Head and neck squamous cell carcinoma
  • Cervical squamous cell carcinoma
  • Endometrial cancers

(Participants must have been previously treated with standard of care systemic therapy, have refused standard therapy, or have no standard therapy available).

  • Availability of tumor tissue sample (either an archival specimen or a fresh biopsy) at screening
  • Measurable disease per Response Evaluation Criteria in Solid Tumors, Version 1.1 (RECIST v1.1).
  • Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
  • Adequate organ function.

Exclusion Criteria:

  • Prior use of PTK7 targeting treatment (Phase 1a) or prior use of PTK7 targeting treatments and/or topoisomerase 1 (TOP1) inhibitors (Phase 1b).
  • Phase 1b disease-specific exclusion criteria:

1. Cohort 1: Neuroendocrine tumors or endometrial sarcoma (eg, stromal sarcoma, leiomyosarcoma, or other types of pure sarcomas)
2. Cohort 2: Nasopharyngeal primary tumors.
3. Cohort 3: Ovarian cancer that progressed >6 months after the last dose of platinum-based chemotherapy (platinum-sensitive disease), or disease that did not respond (PR or complete response \[CR\]) to or progressed ≤91 days after the last dose of first-line platinum-based chemotherapy (primary platinum-refractory disease) .- 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.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Study Design

Enrollment

300 participants

Anticipated

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: DAY301 intravenous (IV) infusion

DAY301 will be administered at different dose levels in dose escalation and at the RD in dose expansion cohorts.

Interventions

DAY301

DAY301 will be administered as IV infusion

Primary outcome measure

  • Phase 1a: Dose Escalation: Number of participants with reported Dose Limiting Toxicities (DLTs) [ Time Frame: Within 21 days of first infusion (Day 1) ]
  • Phase 1a: Dose Escalation: Number of participants with reported adverse events (AEs) and serious AEs (SAEs) [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1a: Dose Escalation: Frequency of dose interruptions [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1a: Dose Escalation: Duration of dose interruptions [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1a: Dose Escalation: Frequency of dose reductions [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1a: Dose Escalation: Duration of dose reductions [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1b: Dose Expansion: Objective response rate [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1b: Dose Expansion: Number of participants reporting AEs and SAEs [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1b: Dose Expansion: Frequency of dose interruptions [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1b: Dose Expansion: Duration of dose interruption [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1b: Dose Expansion: Frequency of dose reductions [ Time Frame: through the duration of treatment, up to approximately 12 months ]
  • Phase 1b: Dose Expansion: Duration of dose reductions [ Time Frame: through the duration of treatment, up to approximately 12 months ]

Central Contacts and Locations

Central contacts

Day One Clinical Trials Information

650-484-0899clinicaltrials@dayonebio.com

Locations

Site: 001-058

Recruiting

New Haven, Connecticut, United States, 06511

Site: 001-064

Recruiting

Sarasota, Florida, United States, 34232

Site: 001-060

Recruiting

Avon, Indiana, United States, 46202

Site: 001-059

Recruiting

Grand Rapids, Michigan, United States, 49546

Site: 001-039

Recruiting

New York, New York, United States, 10065

Site: 001-073

Recruiting

Oklahoma City, Oklahoma, United States, 73104

Site: 001-065

Recruiting

Nashville, Tennessee, United States, 37203

Site: 001-069

Recruiting

Houston, Texas, United States, 77030

Site: 001-057

Recruiting

San Antonio, Texas, United States, 78240

Site: 011-013

Recruiting

Vancouver, British Columbia, Canada, V5Z 4E6

Site: 011-005

Recruiting

Toronto, Ontario, Canada, M5G 2M9

More Information

Sponsor

Day One Biopharmaceuticals, Inc.

Last update posted

Jul 22, 2026

Last verified

Jul, 2026

Keywords

  • Advanced or metastatic solid tumors
  • Dose Escalation
  • Dose Expansion
  • DAY301
  • PTK7-Targeted Antibody-drug Conjugate

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Day One Biopharmaceuticals, Inc. on 2026-07-22.