P-Gemox Regimen(Pegaspargase, Gemcitabine, oxaliplatin) for Extranodal Natural Killer Cell Lymphoma: 10 Years' Real-World Clinical Experience from China
Authors: Yan Gao , Huang Hui-qiang , Xiaoxiao Wang , Bing Bai , Li Pengfei , Zhou Hui , Peng Zhi-gang , Ke Xiao-yan , Ding Kai-yang , Yang Yu , Min Sha-dong , Shuang Yue-rong , Zhiming Li , Qingqing Cai , Li Bingzong , Jiang Wenqi 
Published: October 2019

Backgroud and Purpose:

Extranodal natural killer/T-cell lymphoma (ENKTL) is an uncommon, aggressive form of non-Hodgkin's lymphoma. Optimal therapeutic strategies have not been fully defined yet. We reported the outcome of P-Gemox for the treatment of chemotherapy-naïve, refractory ENKTL in 2013 ASH meeting at the first time. Although several clinical trials have demonstrated the efficacy and tolerability of P-Gemox, we collected and anlyzed the real-world data of P-Gemox in Chinese patients with ENKTL.

Patients and methods

All cases with ENKTL from 2008 to 2017 were analyzed retrospectively P-Gemox were as follows: gemcitabine 1000 mg/m2; day 1,8; oxaliplatin 130 mg/m2 day 1, pegaspargase 2000-2500 U/m2 im day1. The regimen was repeated every 3 weeks. For newly diagnosed stage I/II patients, P-Gemox regimen was administered as induction chemotherapy for 4-6cycles and followed by involved-field radiotherapy or with"sandwiched" radiotherapy/chemotherapy. Furthermore autologous haematopoietic stem cell transplantation (ASCT) was recommended to chemo-sensitive refractory/relapsed patients as consolidation. All patients come to hospital regularly.

Results:

267 patients with ENKTL were treated at the 10 institutions, in the department of Oncology or hematology in China between 2008 and 2017. Patient characteristics are summarized in Table 1. All patients received P-Gemox regimen, 209 patients (78.2%) as first-line therapy and 46 patients (22.0%) as second-line therapy. The median number of treatment cycles was 4.6(1-8) in the first line, 3.3 (2-6) in the second line, 243 patients were evaluable for response. The overall response (OR) rate was 84.8% (206/243), with a complete remission (CR) rate of 59.3% (144/243) (Table2).

After the median follow-up time was 43.5 months (range, 1.5-101 months). The median OS of whole group was not reached, the median PFS was 61.0 months. The OS and PFS of the newly diagnosed patients is superior to refractory and relapsed patients (Fig1 A, B, P<0.001). Newly diagnosed stage I/II patients got better OS than stage III/IV patients (Figure 2, P<0.001). Fifteen (8 newly diagnosed stage IV, 3 refractory and 4 relapsed) patients accepted ASCT. They achieved satisfied OS than other patients (Fig 3,P=0.004). The incidence (>50%) of rates of grade 1 and 2 adverse events were as follows: hypoproteinemia, 74.1%, neutropenia, 64.4%, fibrinogenopenia 56.2%, transaminase elevated, 52.8%. Grade 3 and 4 adverse reactions (>10%) were thrombocytopenia, 29.2%, neutropenia, 27.7%(Table 3) .

Conclusion:

P-Gemox regimen followed by EIFRT yielded promising results for patients with stage I/II ENKTL. While for advanced or refractory/relapsed patients, P-Gemox was still unsatisfied . ASCT consolidation for good responders may improve the longterm outcom. Toxicity was moderate and tolerable.

Disclosures

No relevant conflicts of interest to declare.