Ultra-low-dose Radiation Therapy Followed by Orelabrutinib as First-line Treatment for Stage Ⅰ-Ⅱ MALT Lymphoma: A Prospective, Multicenter Phase Ⅱ Study
This is a prospective, multicenter Phase 2 clinical trial named the MALT-RO study, evaluating ultra-low-dose radiation therapy followed by orelabrutinib as first-line treatment for adults with Stage I-II MALT lymphoma. The study aims to determine the efficacy and safety profile of this sequential regimen. Eligible participants aged 18 years or older with histologically confirmed MALT lymphoma, measurable lesions, no prior systemic anti-lymphoma therapy, adequate organ function, and an ECOG performance status of 0-1 will receive 4Gy ultra-low-dose radiation (2Gy daily for 2 consecutive days) followed by oral orelabrutinib 150mg once daily for up to 6 cycles (28 days per cycle). Patients with partial response or stable disease after 6 cycles may continue orelabrutinib monotherapy for up to 12 cycles or until disease progression. All participants will undergo regular safety monitoring, tumor assessments, and long-term follow-up every 3 months to evaluate treatment durability. This treatment strategy is designed to improve efficacy and achieve more favorable outcomes compared with standard approaches for MALT lymphoma, while minimizing treatment-related toxicities such as long-term organ damage, xerostomia, cataracts, and other complications related to conventional standard-dose radiation, thereby offering a well-tolerated, convenient, targeted therapeutic option for patients with MALT lymphoma under strict ethical oversight in accordance with the Declaration of Helsinki and Chinese Good Clinical Practice guidelines.
• Age ≥ 18 years, all genders eligible;
• Histopathologically confirmed MALT lymphoma (extranodal marginal zone lymphoma) with at least one measurable lesion outside the spleen, with any diameter \> 1.0 cm;
• No prior systemic anti-tumor therapy after diagnosis (including chemotherapy, targeted therapy, rituximab, etc.).
• Note: For patients with primary gastric MALT lymphoma, Helicobacter pylori (HP) must be negative or the patient must have failed standard HP eradication therapy. Patients with MZL who progressed or relapsed after local treatment (including surgery, Helicobacter pylori eradication, and hepatitis C treatment) are eligible for enrollment.
• ECOG performance status score of 0-1;
• Presence of treatment indications as judged by the investigator (including symptoms, cytopenias, risk of end-organ damage, bulky disease, or persistent progression);
• Adequate major organ function, meeting the following criteria:
‣ Absolute neutrophil count (ANC) ≥ 1.5 × 10⁹/L, platelets ≥ 75 × 10⁹/L, hemoglobin ≥ 75 g/L; If bone marrow involvement is present: ANC ≥ 1.0 × 10⁹/L, platelets ≥ 50 × 10⁹/L, hemoglobin ≥ 50 g/L;
⁃ Total bilirubin ≤ 1.5 × ULN, AST or ALT ≤ 2 × ULN, serum creatinine ≤ 1.5 × ULN, serum amylase ≤ ULN;
⁃ International Normalized Ratio (INR) ≤ 1.5 × ULN.
• Expected survival ≥ 3 months;
• Voluntarily provide written informed consent before screening.