Immunotherapy With Adaptive Pulse Radiotherapy in Solid Tumors (I-APT)

January 23, 2026 updated by: Nalee Kim, Samsung Medical Center

A Prospective Phase II Study of Immunotherapy With Adaptive Pulse Radiotherapy in Solid Tumors

The goal of this clinical trial is to find out whether Adaptive Pulse Radiotherapy (Pulse RT) combined with immune checkpoint inhibitors (ICIs) helps treat advanced solid tumors.

It will also check how safe this combined treatment is and how it affects the immune system and quality of life.

The main questions the study will try to answer are:

Does adding Pulse RT to ICIs improve tumor response and survival? What side effects occur when participants receive Pulse RT with ICIs? How does the treatment change immune-related blood and tissue markers? Does the treatment affect participants' quality of life?

Researchers will compare this new approach to usual ICI treatment to see whether Pulse RT makes a difference.

Participants will:

Continue to receive their standard ICI treatment. Receive 2-3 sessions of high-dose Pulse RT (8-10 Gy each) given about every 3 weeks.

Have the treatment volume adjusted based on how their tumors respond. Visit the clinic regularly for check-ups, imaging, blood tests, and quality-of-life questionnaires.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

35

Phase

  • Phase 2

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

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:

  • Eastern Cooperative Oncology Group (ECOG) performance status 0-2
  • Histologically confirmed solid tumor (radiologic diagnosis allowed for hepatocellular carcinoma)
  • Currently receiving or planned to receive immune checkpoint inhibitor (ICI) therapy
  • Presence of at least one lesion suitable for radiotherapy and measurable disease per RECIST version 1.1
  • Ability and willingness to provide written informed consent

Exclusion Criteria:

  • Pregnant or breastfeeding women
  • Presence of brain metastasis or leptomeningeal metastasis
  • Prior radiotherapy to the intended treatment site
  • Significant comorbid conditions that may interfere with study participation or treatment (e.g., uncontrolled infection, heart failure, arrhythmia, psychiatric disorder)
  • Inability or unwillingness to comply with study procedures
  • Considered inappropriate for study participation by the principal investigator or treating physician

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: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Pulse RT
Radiation: Pulse radiation therapy
Adaptive Pulse Radiotherapy (Pulse RT) is a personalized radiotherapy strategy designed to enhance anti-tumor immunity when combined with immune checkpoint inhibitors (ICIs). Patients receive 2-3 fractions of 8-10 Gy at 3-4-week intervals, with adaptive modification of target volumes according to tumor response. This approach aims to induce repeated immunogenic cell death and expand tumor-specific T-cell repertoires, thereby amplifying the efficacy of concurrent immunotherapy while maintaining safety within standard dose constraints. Both photon and proton modalities may be used, depending on lesion location and clinical judgment.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Progression-Free Survival at 6 Months
Time Frame: 6 months after first radiation therapy
Progression-free survival (PFS) is defined as the time from the start of Adaptive Pulse Radiotherapy (first radiation treatment) to the date of disease progression according to RECIST version 1.1 or death from any cause, whichever occurs first.
6 months after first radiation therapy

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Progression-Free Survival (PFS)
Time Frame: 3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy
Progression-free survival (PFS) will be assessed using Kaplan-Meier analysis.
3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy
Local Recurrence-Free Survival (LRFS)
Time Frame: 3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy
Local recurrence-free survival (LRFS) is defined as the time from initiation of Adaptive Pulse Radiotherapy to local tumor recurrence within the irradiated field or death from any cause, whichever occurs first.
3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy
Overall Survival (OS)
Time Frame: 3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy
Overall survival (OS) is defined as the time from initiation of Adaptive Pulse Radiotherapy to death from any cause.
3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy
Objective Response Rate (ORR)
Time Frame: 3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy
Objective response rate is defined as the proportion of participants achieving complete or partial response according to RECIST version 1.1 criteria.
3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy
Immune Response Profiling and Biomarker Analysis
Time Frame: Baseline, during treatment, 1 month after last radiation therapy
Changes in circulating immune biomarkers, including cytokine levels (e.g., IL-6, IL-8, IL-10, TNF-β, IFN-γ) and immune cell subsets (e.g., CD3, CD4, CD8, NK cells, regulatory T cells), will be assessed in peripheral blood samples collected at specified time points.
Baseline, during treatment, 1 month after last radiation therapy
Change in Patient-Reported Quality of Life
Time Frame: Baseline, During treatment, 3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy
Patient-reported outcomes will be evaluated using the PRO-CTCAE core set at baseline and during follow-up. Changes over time will be analyzed using linear mixed models to assess treatment-related symptom burden and overall quality of life trends.
Baseline, During treatment, 3, 6, 12, 24, and 36 months after initiation of Adaptive Pulse Radiotherapy

Collaborators and Investigators

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

Sponsor

Samsung Medical Center

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)

September 26, 2025

Primary Completion (Estimated)

September 30, 2028

Study Completion (Estimated)

September 30, 2031

Study Registration Dates

First Submitted

December 1, 2025

First Submitted That Met QC Criteria

January 23, 2026

First Posted (Actual)

February 2, 2026

Study Record Updates

Last Update Posted (Actual)

February 2, 2026

Last Update Submitted That Met QC Criteria

January 23, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SMC 2025-08-014
  • 2025-08-014 (Other Identifier: Samsung medical center)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

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.

Subscribe