To explore a more effective treatment for newly diagnosed, advanced-stage extranodal natural killer/T-cell lymphoma, nasal type (ENKTL), we conducted a phase 4 study of the cisplatin, dexamethasone, gemcitabine, pegaspargase (DDGP) regimen. The primary end point was the 2-year progression-free survival (PFS) after the protocol treatment. Secondary endpoints included response rate (RR), overall survival (OS) and median survival time (MST). The interim analysis included data only from March 2011 to September 2013, who received six cycles of DDGP chemotherapy. A total of 25 eligible patients were enrolled. Seventeen patients (17/24, 70.83%) achieved complete response (CR) and four (4/24, 16.67%) achieved partial response (PR), three (3/24, 12.50%) had progressive disease (PD). The RR after treatment was 87.50%. After a median follow-up duration of 24.67 months (range 4-48 months). The 2-year PFS and OS rate were 61.80% (95% CI, 42.00% to 81.60%) and 68.50 % (95% CI, 48.70% to 88.30%), respectively. The MST was 36.55 months (95% CI, 29.41 months to 43.70 months). Grade 3/4 leukopenia occurred in fourteen patients (58.33%) and grade 3/4 thrombocytopenia occurred in eleven patients (45.83%). Twelve patients (50.00%) experienced Activated Partial Phromboplastin Ptime (APTT) elongation and fourteen patients (58.33%) experienced hypofibrinogenemia. In conclusion, DDGP regimen is an effective and tolerated treatment for newly diagnosed, advanced-stage ENKTL. This trial was registered at www.ClinicalTrials.gov as #NCT01501149.
Keywords: DDGP; chemotherapy; efficacy; extranodal natural killer/T-cell lymphoma; safety.