A Phase II, Investigator-Initiated Exploratory Study of Sacituzumab Tirumotecan for Previously Treated Unresectable Thymic Carcinomas

NCT07750353 | Not Yet Recruiting Phase 2 DMC

• 1 other identifier: NCCH2506/MK017/ATLAS2503
• Study Type: interventional
• Target: 35
• Locations: 1 country
• Sites: 3

Brief Summary

This is a non-randomized, open-label, investigator-initiated phase II clinical trial designed to evaluate the efficacy and safety of sacituzumab tirumotecan (hereafter referred to as sac-TMT) in patients with unresectable thymic carcinoma who have a history of platinum-based combination chemotherapy.

Conditions

Unresectable Thymic Carcinoma

Keywords

sacituzumab tirumotecan; thymic carcinoma

Outcome Measures

Primary Outcomes (1)

• Objective response rate based on central image review

  The primary endpoint is the objective response rate based on central image review. It is defined as the proportion of patients in the FAS who achieved either a CR or PR based on the best overall response determined by central imaging review.

  Baseline up to 3 years. Overall Response is assessed every 8 weeks until 24 weeks after initiation of protocol treatment, and every 12 weeks after 25 weeks and after termination. It continues until PD confirmation or post-study treatment initiation.

Secondary Outcomes (6)

• Objective response rate based on investigator assessment

  Baseline up to 3 years. Overall Response is assessed every 8 weeks until 24 weeks after initiation of protocol treatment, and every 12 weeks after 25 weeks and after termination. It continues until PD confirmation or post-study treatment initiation.

• Progression-free survival

  From date of enrollment until disease progression or death, whichever occurs first, through study completion, approximately 3 years.

• Overall survival

  From date of enrollment until death, through study completion, approximately 3 years.

• Duration of response

  From date of enrollment until death, through study completion, approximately 3 years.

• Disease control rate

  From date of enrollment until disease progression, initiation of post-study treatment, or study completion, approximately 3 years.

Study Arms (1)

sacituzumab tirumotecan

EXPERIMENTAL

Drug: Sacituzumab Tirumotecan (Sac-TMT)

Interventions

Sacituzumab Tirumotecan (Sac-TMT) DRUG

Sacituzumab tirumotecan at 4 mg/kg is administered intravenously on Day 1 and Day 15 of each 28-day cycle and continued until disease progression, unacceptable toxicity, withdrawal of consent, or other protocol-defined discontinuation criteria are met. The maximum exposure period for sacituzumab tirumotecan is 78 cycles (approximately 3 years).

sacituzumab tirumotecan

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Pathologically diagnosed (histological or cytological examination) as thymic carcinoma originating in the thymus or from a metastatic site Immunohistochemical staining including diagnostic marker testing is recommended. If performed prior to registration, the timing is not restricted. However, if histological examination was conducted at another institution, the pathological diagnosis must generally be obtained by a pathologist at the study site, e.g., by requesting the pathological specimen.)
• Meets any of the following criteria:
• Thymic carcinoma was classified as Stage IV by the Masaoka-Koga staging at initial diagnosis
• Thymic carcinoma was classified as Stage III by the Masaoka-Koga staging at initial diagnosis and was judged to be unresectable with curative resection
• The disease is a postoperative recurrence of thymic carcinoma
• The patients do not have symptomatic brain metastases, carcinomatous meningitis, or spinal metastases requiring radiation therapy or surgical intervention
• The patients do not have pericardial effusion, pleural effusion, or ascites requiring treatment
• Age ≥ 18 years at registration
• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) of 0 or 1
• At least one measurable lesion on contrast-enhanced CT (brain, neck, chest, abdomen, pelvis: slice thickness ≤ 5 mm) performed within 14 days prior to registration (same day of the week 2 weeks prior to registration date is acceptable; same applies below)
• History of combination chemotherapy including platinum agents for unresectable thymic carcinoma (treatment in this study will be second-line or later)
• No administration of anticancer drugs (chemotherapy, molecularly targeted therapy, immunotherapy, etc.) or other investigational drugs within 28 days prior to the registration date (same day of the week 4 weeks prior to registration date is acceptable; same applies below)
• No surgery under general anesthesia within 28 days prior to the registration date
• No radiation therapy (including gamma knife, cyberknife) within 14 days prior to the registration date
• Laboratory tests performed within 14 days prior to the registration date meet the following criteria #1 to #8. However, no administration of granulocyte colony-stimulating factor (G-CSF) or blood transfusion within 14 days prior to the blood draw date

You may not qualify if:

• Patients with thymoma and immune complications associated with thymoma (such as myasthenia gravis, aplastic anemia, hypogammaglobulinemia (Good syndrome), etc.)
• Patients with intestinal paralysis or intestinal obstruction
• Patients with a history of severe dry eye syndrome, severe meibomian gland disease, or severe corneal disease (impeding or delaying corneal healing)
• Uncontrolled major cardiovascular or cerebrovascular disease (NYHA Class III or IV heart failure, unstable angina, myocardial infarction, uncontrolled symptomatic arrhythmia, QTcF interval \>480 ms, or other major cardiovascular or cerebrovascular disease within 6 months prior to enrollment
• Patients with unresolved stomatitis greater than Grade 1 at the time of registration are excluded. Prophylactic supportive care measures for stomatitis are permitted, provided there are no active stomatitis-related symptoms.
• Previous treatment history with a TROP2-targeted ADC (such as sacituzumab govitecan)
• Previous treatment history with topoisomerase I inhibitors (irinotecan, topotecan) or ADCs containing topoisomerase I inhibitors (e.g., trastuzumab deruxtecan)
• Received a live or live-attenuated vaccine within 30 days prior to the registration date. Inactivated vaccines may be administered.
• Currently receiving a strong CYP3A4 inducer/inhibitor (Appendix 18.4) that cannot be discontinued during the treatment period of the protocol treatment. The required washout period prior to the registration date is 14 days.
• Known malignancy that has progressed or required active treatment within the past 3 years.
• Note: Patients with basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or carcinoma in situ (except carcinoma in situ of the bladder) who have undergone curative resection are not excluded.
• Note: Untreated patients with low-risk early-stage prostate cancer (T1-T2a, Gleason score ≤ 6, PSA \< 10 ng/mL) who have undergone curative treatment or whose disease is stable under active surveillance are not excluded.
• Active infection requiring systemic therapy.
• Positive for HIV antibody, HBs antigen, or HCV-RNA (HCV-RNA measured only if HCV antibody is positive).
• HBs antigen negative, HBs antibody or HBc antibody positive, and HBV-DNA quantitative positive (not excluded if below detection limit).

Sponsors & Collaborators

• National Cancer Center, Japan: lead

Study Sites (3)

Kanagawa Prefectural Hospital Organization Kanagawa Cancer Center

Yokohama, Kanagawa, Japan

Location

Osaka International Cancer Institute

Chuo-ku, Osaka, Japan

Location

National Cancer Center Hospital

Chuo-ku, Tokyo, 104-0045, Japan

Location

MeSH Terms

Conditions

Thymoma

Condition Hierarchy (Ancestors)

Neoplasms, Complex and Mixed; Neoplasms by Histologic Type; Neoplasms; Thymus Neoplasms; Thoracic Neoplasms; Neoplasms by Site; Lymphatic Diseases; Hemic and Lymphatic Diseases

Central Study Contacts

Yusuke Okuma, M.D., Ph.D.

CONTACT

+81-3-3542-2511; NCCH2506_office@ml.res.ncc.go.jp

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 2, 2026
• First Posted: August 6, 2026
• Study Start (Estimated): February 1, 2027
• Primary Completion (Estimated): December 1, 2029
• Study Completion (Estimated): June 1, 2030
• Last Updated: August 6, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

JP (3)