Becotatug Vedotin Plus PD-1 Monoclonal Antibody and Radiotherapy for Unresectable Locally Recurrent Nasopharyngeal Carcinoma

An Open-Label, Single-Arm, Single-Center Phase II Study of Induction Becotatug Vedotin Plus a PD-1 Inhibitor Followed by Radiotherapy With PD-1 Maintenance in Patients With Unresectable Locally Recurrent Nasopharyngeal Carcinoma

This exploratory clinical study will enroll patients with unresectable locally recurrent nasopharyngeal carcinoma to receive two cycles of becotatug vedotin plus a PD-1 monoclonal antibody, followed by sequential radiotherapy and PD-1 monoclonal antibody maintenance until disease progression or unacceptable toxicity. The study aims to evaluate the efficacy and safety of this treatment strategy.

Study Overview

• Status: Not yet recruiting
• Conditions: Nasopharyngeal Carcinoma
• Intervention / Treatment: Drug: Becotatug Vedotin; Drug: Toripalimab; Drug: Camrelizumab; Drug: Intensity-Modulated Radiotherapy

Detailed Description

**Detailed Description**

This is an open-label, single-arm, single-center Phase II clinical study. The study will enroll patients with unresectable locally recurrent nasopharyngeal carcinoma. Eligible patients will receive two cycles of induction therapy with becotatug vedotin plus a PD-1 monoclonal antibody, followed by intensity-modulated radiotherapy. During and after radiotherapy, patients will continue PD-1 monoclonal antibody maintenance treatment until disease progression, unacceptable toxicity, withdrawal of consent, or other protocol-defined discontinuation criteria.

The study is designed to evaluate the efficacy and safety of this sequential treatment strategy. The primary endpoint is objective response rate assessed by RECIST v1.1. Secondary endpoints include locoregional recurrence-free survival, progression-free survival, distant metastasis-free survival, 12-month and 24-month progression-free survival rates, overall survival, disease control rate, duration of response, treatment-related adverse events assessed according to NCI-CTCAE v5.0, and quality of life.

• Study Type: Interventional
• Enrollment (Estimated): 28
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Yi-Jun Hua, MD; Phone Number: 18820019088; Email: huayj@sysucc.org.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Voluntarily participates in the study and provides written informed consent.
• Aged 18-70 years, male or non-pregnant female, with an expected survival of ≥3 months and an ECOG performance status of 0 or 1.
• Histologically or cytologically confirmed locally recurrent nasopharyngeal carcinoma, differentiated or undifferentiated carcinoma, corresponding to WHO type II or III, with clinical stage rT2-4N0-3M0, rIA-III according to the AJCC 9th edition.
• Recurrence occurring more than 12 months after completion of initial radiotherapy, with no systemic or local antitumor treatment during this interval.
• At least one measurable lesion according to RECIST v1.1.
• Hemoglobin ≥90 g/L, white blood cell count ≥4.0 × 10⁹/L, and platelet count ≥100 × 10⁹/L.
• Adequate liver function: total bilirubin <2.0 × ULN; AST and ALT ≤2.5 × ULN in the absence of liver metastasis, or ALT or AST ≤3.0 × ULN in the presence of liver metastasis; ALP ≤1.5 × ULN, or ≤2 × ULN in the presence of liver metastasis; serum albumin ≥30 g/L.
• Adequate coagulation function: INR or PT and APTT ≤1.5 × ULN, except for patients receiving anticoagulant therapy, whose anticoagulation level should be within the therapeutic range. These laboratory parameters should be closely monitored by the investigator if the patient is receiving anticoagulant therapy.
• Adequate renal function, defined as serum creatinine ≤1.5 × ULN, or creatinine clearance ≥50 mL/min if serum creatinine is >1.5 × ULN. Creatinine clearance should be calculated using the corrected Cockcroft-Gault formula.
• Female and male patients of childbearing potential must agree to use adequate contraception during treatment and for 180 days after the last dose.

Exclusion Criteria:

• Patients with surgically resectable locally recurrent disease, including rT2 disease limited to the superficial parapharyngeal space and located more than 0.5 cm from the internal carotid artery, or rT3 disease limited to the floor of the sphenoid sinus and located more than 0.5 cm from the internal carotid artery and cavernous sinus.
• Nasopharyngeal necrosis, radiation-induced brain injury, severe cervical fibrosis, or other CTCAE v5.0 Grade ≥3 radiation-related complications, with extremely high radiotherapy risk as assessed by the investigator.
• Grade ≥2 peripheral neuropathy according to CTCAE v5.0.
• Receipt of systemic chemotherapy within 3 weeks before the first dose of study drug; small-molecule targeted therapy within 2 weeks or 5 half-lives, whichever is longer, before the first dose; antitumor biologic therapy, macromolecular targeted therapy, immunotherapy, or major surgery within 4 weeks before the first dose, except for minor surgery within 2 weeks with complete recovery.
• Residual toxicity from prior antitumor therapy, including immunotherapy, targeted therapy, chemotherapy, or radiotherapy, except alopecia, fatigue, and Grade 2 hypothyroidism, or clinically significant laboratory abnormalities greater than Grade 1 according to CTCAE v5.0.
• Uncontrolled or poorly controlled cardiac disease, including congestive heart failure (CHF) Grade ≥2 according to CTCAE v5.0 or New York Heart Association classification, myocardial infarction, unstable angina, history of ventricular tachycardia or torsades de pointes, or arrhythmia requiring treatment within 6 months before enrollment; QTcF >450 ms in males or >470 ms in females; complete left bundle branch block; or third-degree atrioventricular block. QTcF = QT/(RR^0.33).
• Pulmonary embolism or deep vein thrombosis within 3 months before the first dose of study drug, except catheter-related thrombosis from an infusion port or PICC line.
• Known history of malignancy, except for radically treated basal cell carcinoma of the skin, superficial bladder cancer, squamous cell carcinoma of the skin, carcinoma in situ, or papillary thyroid carcinoma, unless the patient has received potentially curative treatment and has had no disease recurrence within 5 years after treatment initiation.
• Any severe or uncontrolled systemic disease, including uncontrolled or poorly controlled hypertension, such as systolic blood pressure >160 mmHg or diastolic blood pressure >100 mmHg, or diabetes mellitus with HbA1c >8%.
• Active bleeding, history of coagulation disorder, or treatment with coumarin anticoagulants.
• Known hypersensitivity to any component or excipient of becotatug vedotin, including citric acid monohydrate, sodium citrate dihydrate, trehalose dihydrate, sodium chloride, and polysorbate 80; or known Grade ≥3 hypersensitivity reaction to prior anti-EGFR drugs, including investigational study drugs, or other monoclonal antibodies.
• Known active hepatitis B or hepatitis C. Active hepatitis B is defined as known HBsAg positivity and HBV DNA ≥500 IU/mL. Active hepatitis C is defined as known hepatitis C antibody positivity and quantitative HCV RNA above the lower limit of detection. Other severe liver diseases, including chronic autoimmune liver disease, primary biliary cirrhosis or sclerosing cholangitis, alcoholic liver disease, or nonalcoholic steatohepatitis (NASH), are also excluded.
• Severe uncontrolled infection; known human immunodeficiency virus (HIV) infection with positive HIV antibody; diagnosis of acquired immunodeficiency syndrome (AIDS); active autoimmune disease, except type 1 diabetes mellitus, hypothyroidism controlled by replacement therapy, and skin diseases not requiring systemic therapy, such as vitiligo, psoriasis, or alopecia; prior allogeneic tissue or organ transplantation, stem cell or bone marrow transplantation, or prior solid organ transplantation.
• Active bacterial, viral, fungal, rickettsial, or parasitic infection requiring systemic anti-infective therapy, unless treated and resolved before study drug administration.
• Receipt of a live viral vaccine within 30 days before the first dose of study drug.
• History of or concurrent interstitial pneumonia, severe chronic obstructive pulmonary disease with respiratory failure, severe pulmonary insufficiency, symptomatic bronchospasm, or similar pulmonary conditions.
• Receipt of immunology-based therapy for any reason, including chronic systemic steroid therapy equivalent to >10 mg/day prednisone within 7 days before the first dose of study drug or at any time during the study. Inhaled or topical steroids, systemic corticosteroids equivalent to ≤10 mg/day prednisone, and short-term corticosteroids equivalent to >10 mg/day prednisone, such as premedication before contrast administration, are permitted.
• Uncontrolled pleural, abdominal, pelvic, or pericardial effusion requiring drainage at least once per month.
• Positive pregnancy test or breastfeeding. Female and male patients who do not plan to use adequate contraception during treatment and for 180 days after the last dose are excluded.
• Any other disease, clinically significant laboratory abnormality, severe medical or psychiatric condition, or substance abuse including alcoholism that, in the investigator's opinion, may compromise patient safety, study integrity, patient participation, or interfere with the study objectives and outcome analysis.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Experimental group; Becotatug Vedotin Plus PD-1 Monoclonal Antibody Induction Followed by Radiotherapy With Concurrent and Maintenance PD-1 Monoclonal Antibody

Drug: Becotatug Vedotin; Becotatug vedotin will be administered at 2.0 mg/kg intravenously on Day 1 every 3 weeks for 2 cycles as induction therapy, in combination with a PD-1 monoclonal antibody.; Drug: Toripalimab; Toripalimab will be administered at 240 mg intravenously on Day 1 every 3 weeks. Toripalimab is one of the optional PD-1 monoclonal antibodies in this study and will be used as an alternative to camrelizumab, not in combination with camrelizumab. It will be given during induction therapy, concurrently with radiotherapy, and as maintenance therapy after radiotherapy until disease progression or unacceptable toxicity.; Drug: Camrelizumab; Camrelizumab will be administered at 200 mg intravenously on Day 1 every 3 weeks. Camrelizumab is one of the optional PD-1 monoclonal antibodies in this study and will be used as an alternative to toripalimab, not in combination with toripalimab. It will be given during induction therapy, concurrently with radiotherapy, and as maintenance therapy after radiotherapy until disease progression or unacceptable toxicity.; Drug: Intensity-Modulated Radiotherapy; Intensity-modulated radiotherapy will be delivered once daily, 5 days per week. Prescribed doses are 60 Gy in 27 fractions to PTVnx, 60-64 Gy in 27 fractions to PTVnd, and 54 Gy in 27 fractions to PTV1.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective response rate	The proportion of participants who achieve a complete response (CR) or partial response (PR), as assessed by the investigator according to RECIST v1.1, from the first dose until disease progression, initiation of new anticancer therapy, death, or the last tumor assessment, whichever occurs first.	Baseline; end of 2 induction cycles (21 days/cycle); 8-12 weeks after radiotherapy; every 12 weeks through Month 24; then every 24 weeks thereafter until progression, new anticancer therapy, death, or study completion, up to 36months.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of Response (DoR)	For participants who achieve a confirmed complete response (CR) or partial response (PR), duration of response is defined as the time from the first documented CR or PR to the first documented disease progression or death from any cause, whichever occurs first.	From first documented CR or PR until first documented disease progression or death, whichever occurs first, assessed up to 36 months.
Locoregional Recurrence-Free Survival (LRFS)	Locoregional recurrence-free survival is defined as the time from the first dose to the first documented locoregional recurrence/progression or death from any cause, whichever occurs first.	From the first dose until the first documented locoregional recurrence/progression or death from any cause, whichever occurs first, assessed up to 36 months.
Treatment-Related Adverse Events	Treatment-related adverse events will be assessed and graded according to NCI-CTCAE v5.0. The incidence and severity of adverse events, Grade 3 or higher adverse events, serious adverse events, and adverse events leading to dose modification, treatment interruption, or treatment discontinuation will be summarized.	From first dose to 90 days after last study treatment; late radiotherapy-related toxicities followed until Month 24 or study completion.
Overall Survival (OS)	OS is defined as the time from the first dose to death from any cause. Participants who are alive will be censored at the date of last confirmed survival status.	From the first dose until death from any cause, assessed up to 36 months.
12-Month Progression-Free Survival Rate	The 12-month PFS rate is defined as the proportion of participants who remain alive and progression-free at 12 months, estimated using the Kaplan-Meier method based on PFS.	From the first dose to 12 months.
24-Month Progression-Free Survival Rate	The 24-month PFS rate is defined as the proportion of participants who remain alive and progression-free at 24 months, estimated using the Kaplan-Meier method based on PFS.	From the first dose to 24 months.
Progression-Free Survival (PFS)	Progression-free survival is defined as the time from the first dose to the first documented disease progression according to RECIST version 1.1 or death from any cause, whichever occurs first.	From the first dose until the first documented disease progression according to RECIST version 1.1 or death from any cause, whichever occurs first, assessed up to 36 months.
Disease Control Rate (DCR)	The proportion of participants who achieve a best overall response of complete response (CR), partial response (PR), or stable disease (SD), as assessed by the investigator according to RECIST version 1.1.	Baseline; end of 2 induction cycles (21 days/cycle); 8-12 weeks after radiotherapy; every 12 weeks through Month 24; then every 24 weeks thereafter until progression, death, or study completion, up to 36 months.
Distant Metastasis-Free Survival (DMFS)	DMFS is defined as the time from the first dose to the first documented distant metastasis or death from any cause, whichever occurs first. Distant metastasis will be assessed by imaging examinations, including chest CT, abdominal imaging, bone scan, PET/CT, or other clinically indicated examinations.	From first dose until first documented distant metastasis or death, whichever occurs first, assessed up to 36 months.
Quality of Life (QoL)	Quality of life will be assessed using the EORTC QLQ-C30 questionnaires. Scores for each domain and health status will be calculated according to the questionnaire scoring manuals, and changes from baseline will be summarized.	Baseline; end of 2 induction cycles (21 days/cycle); end of radiotherapy; 8-12 weeks after radiotherapy; every 12 weeks through Month 24; then every 24 weeks thereafter until study completion, up to 36 months.

Collaborators and Investigators

• Sponsor: Sun Yat-sen University
• Investigators: Principal Investigator: Yi-Jun Hua, MD, Sun Yat-sun University Cancer Center

Study record dates

Study Major Dates

• Study Start (Estimated): April 20, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2029

Study Registration Dates

• First Submitted: April 14, 2026
• First Submitted That Met QC Criteria: April 21, 2026
• First Posted (Actual): April 29, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Stomatognathic Diseases; Neoplasms by Site; Neoplasms; Neoplasms by Histologic Type; Head and Neck Neoplasms; Neoplasms, Glandular and Epithelial; Carcinoma; Otorhinolaryngologic Diseases; Pharyngeal Neoplasms; Otorhinolaryngologic Neoplasms; Nasopharyngeal Diseases; Pharyngeal Diseases; Nasopharyngeal Neoplasms; Nasopharyngeal Carcinoma; Therapeutics; Radiotherapy; Radiotherapy, Conformal; Radiotherapy, Computer-Assisted; toripalimab; Radiotherapy, Intensity-Modulated; camrelizumab
• Other Study ID Numbers: 2025-FXY-540-NPC

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Researchers who has been approved can share.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No