Study to Assess the Effect of OCT-598 in Patients With Advanced Solid Tumors

January 13, 2026 updated by: Oscotec Inc.

A Phase 1 Dose-Escalation Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Efficacy of OCT-598 as a Single Agent and in Combination With Standard-of-Care Treatment in Patients With Advanced Solid Tumors

This is a Phase 1 study intended to determine the MTD of OCT-598 following multiple-dose therapy and to establish the RP2D for OCT-598 as a single agent, by assessing its safety and tolerability as monotherapy and in combination with standard-of-care treatments in patients with advanced solid tumors.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

51

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • South Korea
      • Goyang-si, South Korea
        • Recruiting
        • National Cancer Center
        • Contact:
      • Seongnam-si, South Korea
        • Recruiting
        • Seoul National University Bundang Hospital (SNUBH)
        • Contact:
      • Seoul, South Korea
        • Not yet recruiting
        • Asan Medical Center
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Female or male, ≥18 years of age (or ≥19 years according to according to the local regulatory guidance), at the time of screening
  • Signed informed consent prior to any study-related procedures that are not considered standard of care
  • Life expectancy >12 weeks in the opinion of the investigator

  • Adequate organ and marrow function, defined as follows:

    • Absolute neutrophil count ≥1.5 × 109/L
    • Platelets ≥100,000/μL
    • Hemoglobin ≥9.0 g/dL
    • Total bilirubin <1.5 × ULN
    • ALT or AST ≤2.5 × ULN
    • Creatinine clearance calculated using the Cockcroft-Gault formula ≥60 mL/min (In equivocal cases, a 24-hour urine collection test can be used to estimate the creatinine clearance more accurately)
  • LVEF >50% or within institutional values
  • At least 1 measurable lesion based on RECIST version 1.1

  • Cohort-specific disease requirements:

    1. Part A: patients with advanced solid tumors and no effective standard therapy option or for whom standard-of-care treatment is not available or not appropriate as per the investigator's discretion
    2. Part B: patients with advanced solid tumors who are candidates for receiving docetaxel as a single agent for their cancer treatment, including but not limited to: advanced human epidermal growth factor receptor 2-negative breast cancer, recurrent/metastatic head and neck cancer, non-small cell lung cancer, prostate cancer, or gastric/gastroesophageal cancer
  • Docetaxel-appropriate (Part B): patients who have not received prior docetaxel in the advanced setting are eligible

Exclusion Criteria:

  • Treatment with any IP or other anticancer therapy (including chemotherapy, antibody-drug conjugates, targeted agents, and immunotherapy) within 28 days or 5 half-lives, whichever is longer, of the first dose of study drug.
  • Prior clinically significant treatment-related toxicities not resolved to Grade ≤1 or baseline (per CTCAE version 5.0) except for alopecia. Participants with stable Grade 2 peripheral neuropathy or endocrinopathies with stable endocrine replacement therapy are eligible. Patients with irreversible toxicity that is not reasonably expected to be exacerbated by study treatment (eg, vitiligo or hearing loss) may be eligible after discussion with the Sponsor.
  • Prior treatment with an EP2 and/or EP4 antagonist.
  • Major surgery or wide-field radiation within 28 days or limited field palliative radiation within 7 days prior to the first dose of the study drug.
  • Known active central nervous system metastasis. Patients with asymptomatic previously treated brain metastasis are eligible if they are clinically stable for at least 4 weeks prior to enrollment and do not require treatment with corticosteroids.
  • Treatment with systemic corticosteroids at a dose of >10 mg of prednisone or equivalent at the time of enrollment, or any other immunosuppressive medication 7 days before the first dose of the study drug. Premedication with corticosteroids prior to chemotherapy administration in the combination phase is allowed, as per the site standard of care. Systemic treatment with NSAIDs, COX2 inhibitors, or synthetic prostaglandins within 5 half-lives prior to the first dose of study drug (acetylsalicylic acid ≤160 mg/day, or 325 mg ≤3 times/week is permitted).
  • Patients who are pregnant, breastfeeding, or planning to become pregnant during the study .
  • Concomitant active malignancy or previous malignancy within 2 years of the time of enrollment. Patients with adequately resected basal or squamous cell carcinoma of the skin, carcinoma in situ or the cervix or breast, stage 1 prostate cancer, or other malignancy deemed to be cured by prior therapy in the judgment of the investigator may enroll regardless of the time of diagnosis.
  • History of bleeding disorders, including gastrointestinal bleeding. Subjects with prior gastrointestinal bleeding due to the primary tumor, that is currently controlled, are allowed to participate.
  • Mean resting corrected QT (QTc) interval using Fridericia's formula (QTcF) >470 ms, regardless of gender, or history of additional risk factors for torsades de pointes (eg, heart failure, hypokalemia, family history of long QT syndrome). Patients with left bundle block or atrial fibrillation are eligible if QTc cannot be accurately calculated provided that there is no prior history of prolonged QTc.
  • For patients in Part B only: AST and/or ALT >1.5 × ULN concomitant with alkaline phosphatase >2.5 × ULN.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: PART A. OCT-598 100mg QD
Administered orally
Drug: OCT-598
OCT-598 will be administered orally once daily.
Experimental: PART A. OCT-598 200mg QD
Administered orally
Drug: OCT-598
OCT-598 will be administered orally once daily.
Experimental: PART A. OCT-598 300mg QD
Administered orally
Drug: OCT-598
OCT-598 will be administered orally once daily.
Experimental: PART A. OCT-598 500mg QD
Administered orally
Drug: OCT-598
OCT-598 will be administered orally once daily.
Experimental: PART A. OCT-598 800mg QD
Administered orally
Drug: OCT-598
OCT-598 will be administered orally once daily.
Experimental: PART A. OCT-598 1200mg QD
Administered orally
Drug: OCT-598
OCT-598 will be administered orally once daily.
Experimental: PART B. OCT-598 DL1 QD
Administered orally, Combination with Docetaxel
Drug: OCT-598
OCT-598 will be administered orally once daily.
Combination product: Docetaxel
Docetaxel will be provided for Part B only to support the combination therapy with the standard-of-care regimen.
Experimental: PART B. OCT-598 DL2 QD
Administered orally, Combination with Docetaxel
Drug: OCT-598
OCT-598 will be administered orally once daily.
Combination product: Docetaxel
Docetaxel will be provided for Part B only to support the combination therapy with the standard-of-care regimen.
Experimental: PART B. OCT-598 DL3 QD
Administered orally, Combination with Docetaxel
Drug: OCT-598
OCT-598 will be administered orally once daily.
Combination product: Docetaxel
Docetaxel will be provided for Part B only to support the combination therapy with the standard-of-care regimen.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
To evaluate the safety and tolerability by measuring the frequency and severity of adverse events, as assessed by CTCAE v5.0
Time Frame: Approximately 2 years
Approximately 2 years
Incidence of Dose-Limiting Toxicities (DLTs) for Determination of the Maximum Tolerated Dose (MTD)
Time Frame: Approximately 2 years
Approximately 2 years
Incidence of adverse events and dose-limiting toxicities used to determine the recommended Phase 2 dose (RP2D) of OCT-598 (PART B only)
Time Frame: Approximately 1 years
Approximately 1 years

Secondary Outcome Measures

Outcome Measure
Time Frame
To assess the maximum observed plasma concentration (Cmax) of OCT-598.
Time Frame: Approximately 2 years
Approximately 2 years
To evaluate the effect of food on the pharmacokinetics of OCT-598 by comparing Cmax under fed and fasted conditions.
Time Frame: From enrollment to Cycle 1 Day -3 (PART A only)
From enrollment to Cycle 1 Day -3 (PART A only)
To measure time of maximum plasma concentration (Tmax)
Time Frame: Approximately 2 years
Approximately 2 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Oscotec Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 18, 2025

Primary Completion (Estimated)

December 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

December 7, 2025

First Submitted That Met QC Criteria

January 13, 2026

First Posted (Actual)

January 22, 2026

Study Record Updates

Last Update Posted (Actual)

January 22, 2026

Last Update Submitted That Met QC Criteria

January 13, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • OSCO-P1401

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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