A Phase 2 interventional study of Pembrolizumab and Involved Field Radiation Therapy in Lymphoma, Extranodal NK-T-Cell, sponsored by International Extranodal Lymphoma Study Group (IELSG). Active, not recruiting at 2 sites in China. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-07.
Sponsored by International Extranodal Lymphoma Study Group (IELSG) · Phase 2, Interventional, and Treatment
Aim of the trial is to evaluate the activity and tolerability of the anti PD1 agent Pembrolizumab in combination with RadioTherapy for the initial treatment of previously untreated patients with limited stage NK/T cell lymphoma who are not eligible to chemotherapy.
It is planned to enroll 30 patients in chinese sites.
All eligible patients will be treated with standard radiotherapy and concurrent pembrolizumab administered intravenously every 3 weeks. After 6 cycles of pembrolizumab patients with complete remission, partial response and stable disease will continue with pembrolizumab maintenance up to 2 years.
Patients will be followed up to 4 years from treatment start.
This is an interventional, phase II, open label, single arm, multicentric clinical trial to be conducted in China.
The primary objective is to test the efficacy of concurrent RT-Pembrolizumab in patients with limited stage NK/T cell lymphoma and who are not eligible to receive chemotherapy.
The secondary objectives are to further explore the efficacy and safety of a the combination of RT and Pembrolizumab as initial treatment of the patients population.
All eligible patients will be treated with standard IFRT and concurrent pembrolizumab administered intravenously, over 30 minutes starting on day 1 of RT (C1D1, at the dose of 200 mg, every 3 weeks). After 6 cycles of pembrolizumab patients will undergo restaging imaging. Patients with complete remission (CR), partial response (PR) and stable disease (SD) will continue with pembrolizumab maintenance up to 2 years that will be administered intravenously, at the dose of 200 mg, over 30 minutes on day 1 every 3 weeks up to 34 cycles.
The follow-up period will last up to 4 years from treatment start.
179 studies on the registry are indexed under Lymphoma, Extranodal NK-T-Cell; 32 are open to participants now.
This study's enrollment of 30 is below the median of 34 across 161 interventional studies indexed under Lymphoma, Extranodal NK-T-Cell.
Browse Lymphoma, Extranodal NK-T-Cell studies →International Extranodal Lymphoma Study Group (IELSG) is the lead sponsor of 29 studies on the registry; 4 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Induction Phase: Standard Involved Field Radiation Therapy (IFRT) and pembrolizumab. Pembrolizumab 200 mg IV will be given over 30 minutes on day 1 of each 21 day cycle for a total of 6 cycles. IFRT will start at first cycle of Pembrolizumab and will be delivered concurrently. Patients with complete remission (CR), partial response (PR) and stable disease (SD) after Induction Phase will continue with pembrolizumab maintenance. Maintenance Phase: Pembrolizumab 200 mg IV will be given over 30 minutes on day 1 of each 21 day cycle up to 34 cycles or until disease progression or unaccepted toxicity
Drug: Pembrolizumab · Radiation: Involved Field Radiation Therapy
50 mg powder for concentrate for solution for infusion
Also known as: Keytruda
50-54 Gy Involved Field Radiation Therapy (IFRT) as proposed by the International Lymphoma Radiation Oncology Group (ILROG) guidelines. 50 Gy is recommended in patients without primary tumor invasiveness (invasion to adjacent tissue and/or organs), 54 Gy in locally advanced cases (invasion to adjacent tissue and/or organs) or with other risk factors (age \> 60 years, stage II, elevated serum LDH levels). Intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) are recommended but not mandatory; 3-dimensional conformal RT (3D-CRT) is allowed.
Progression Free Survival (PFS) rate at 2 years - The proportion of patients without disease progression after 2 years from treatment start
Response will be assessed using international criteria for response assessment in lymphomas (Cheson 2014) and their update for patients receiving checkpoint inhibitors (Cheson 2016 Lyric)
Time frame: 2 years from treatment start
Complete remission rate (CRR) - Proportion of patients with complete responses
CRR defined according to Cheson 2014 criteria
Time frame: After 4 months from treatment start (End of Induction phase), Maintenance Phase:every 4 months during the first year and then every 6 months until end of treatment. Follow up: every 4 months during first year, then every 6 months during second year
2-year Event-free survival - Proportion of patient without disease related events after 2 years from treatment start
Time frame: 2 years from treatment start
Treatment related mortality - Number of treatment related deaths
Time frame: From informed consent signature to 90 days after the last study treatment administration
2-year Overall survival - Proportion of patients alive after 2 years from treatment start
Time frame: 2 years from treatment start
Rate of adverse events - Analysis of incidence, severity and relationship of adverse events
Adverse Events severity will be classified according to the National Cancer Institute - Common Terminology Criteria for Adverse Events (NCI-CTCAE) V. 5.0
Time frame: From Informed Consent signature to 30 days for AEs or 90 for SAEs after end of treatment
Overall Response Rate (ORR) - calculated as the sum of the complete and partial remission rates
ORR defined according to Cheson 2014 criteria
Time frame: After 4 months from treatment start (End of Induction phase) Maintenance Phase: every 4 months during the first year and then every 6 months until end of treatment. Follow up: every 4 months during first year, then every 6 months during second year
This study is active, not recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Lymphoma, Extranodal NK-T-Cell→
International Extranodal Lymphoma Study Group (IELSG)