ALBERT

Description: BACKGROUND: Extranodal natural killer/T-cell lymphoma, nasal type (ENKTL) is an aggressive form of non-Hodgkin lymphoma. up to now, optimal therapeutic strategies for ENKTL have not been fully defined yet. However, approximately 25-50% patients experience local relapse or systemic failure who receive RT alone. The addition of chemotherapy is emphasized to reduce the risk of recurrence. Therefore, we evaluated efficacy and safety of P-GEMOX regimen in patients with newly diagnosed stage I/II ENKTL. METHODS: We conducted this pilot study to evaluate the efficacy and safety of pegaspargase combined with gemcitabine and oxaliplatin (P-GEMOX) followed by extensive involved-field radiotherapy(EIFRT) in patients with stage I/II ENKTL. We enrolled 56 newly diagnosed stage I/II patients. All patients received P-G GEMOX chemotherapy. The P-GEMOX dosage was as follows: gemcitabine 1000 mg/m2 intravenous infusion in 30 minutes ondays 1 and 8; oxaliplatin 100 mg/m2 intravenous infusion in 2 hours on day 1; pegaspargase deep intramuscular injection of 2000 U/m2 at two different sites on day 1. The regimen was repeated every 3 weeks. Patients underwent 4 cycles of induction chemotherapy, followed by EIFRT. After achieving complete response (CR), partial response (PR), or stable disease (SD). EIFRT was 56 Gy in 28 fractions over 4 weeks. Primary EIFRT was delivered using 6-MeV linear accelerator using 3-dimensional conformal treatment planning. Clinical target volume (CTV) included gross tumor volume with a margin of at least 20mm and the bilateral nasal cavity, bilateral parasinusess. Planning target volume (PTV) included CTV with a 5mm margin. For stage IIE disease, CTV and PTV also included the involved the cervical lymph node area. RESULTS: The median follow-up was 35.2 months (range: 10.6-51.4 months). The objective response rates(ORR) of P-G GEMOX regimen was 89.3% (50/56), 35(62.5%) patients achieved CR and 15 (26.8%) patients achieved PR, respectively. After EIFRT, ORR increased to 94.6% (53/56), CR rate increased to 89.3% (50/56). The 4-year overall survival(OS) and progression-free survival(PFS) rate was 90.7¡À4.0% and 89.1¡À4.2% for the whole cohort. The OS and PFS of stage I patients were superior to patients with stage II (Figure1A,B). No treatment-related death was observed. No allergic reactions occurred. Common toxicities (〉50%) were neutropenia (80.3%), thrombocytopenia (55.3%), hypoproteinemia (75.0%). Fibrinogen decrease rate was 44.6%. The most common grade III/IV toxicities (〉10%) were granulocytosis (23.2%), thrombocytopenia (19.6%) and hypoproteinemia (10.7%). CONCLUSION: The P-GEMOX regimen followed by radical radiotherapy yielded very promising longterm survival for patients with stage I/II ENKTL with good tolerance. Further investigation of P-GEMOX in a larger series of patients, is required. Figure 1. Survival for different stage. (A) Overall survival(P =0.056). (B) Progression free survival (P =0.023). A. B. Figure 1. Survival for different stage. (A) Overall survival(P =0.056). (B) Progression free survival (P =0.023). / A. B. Figure 2. Figure 2. Disclosures No relevant conflicts of interest to declare.

Description: Purpose Extranodal natural killer/T-cell lymphoma (ENKTL) is an aggressive form of non-Hodgkin's lymphoma. The prognosis for patients with advanced stages or relapsed/ refractory ENKTL is extremely poor. Optimal combined chemotherapy remain to be defined. Therefore, the purpose of this study is to evaluate efficacy and safety of P-GEMOX (Pegaspargase, Gemcitabine and Oxaliplatin) in patients with newly diagnosed stage III/IV or relapsed/refractory ENKTL. Patients and methods We retrospectively analyzed the effectiveness and toxicity of P-GEMOX in 60 patients with newly diagnosed stage III/IV and relapsed/refractory ENKTL between February 2008 and August 2014. The P-GEMOX dosage was as follows: Gemcitabine 1000 mg/m2 iv d1,d8; Oxaliplatin 100 mg/m2; d 1, Pegaspargase 2000 U/m2 im, two different sites. The regimen was repeated every three weeks for a maximum six cycles. Patients underwent autologous hematopoietic stem cell transplantation (ASCT) as consolidation if they achieved CR. Results 57 patients were available for evaluation of response. The objective response, complete remission(CR), of whole cohort were 73.7% (42/57), 36.8% (21/57), respectively. It can be easily administered in out-patients clinic. The median follow-up was 29.1 (range, 2.4¨C54.2 months). Median OS and PFS was 23.0 months (95% confidence interval [CI], 16.441-29.559) and 12.8 months(95% confidence interval [CI], 8.109-17.491), respectively. The 4-year OS and PFS rate was 43.0¡À7.3% and 36.5¡À6.9%, respectively (Figure1). There was no difference between newly diagnosed stage III/IV and relapsed/refractory in OS and PFS. The long term survival CR responders were superior to patients with other response, and there was significant difference between the three group(Figure 2, P50%): neutropenia (85.0%), thrombocytopenia (72.0%), hypoproteinemia (86.7%), and anorexia (63.3%). In addition, hypofibrinogenemia was 46.7%. The most common grade III/IV toxicities (〉10%) were granulocytosis (31.6%), thrombocytopenia (26.67%) and hypoproteinemia (13.3%)(Table 1). Intracranial bleeding occurred in one patient during the first cycle with discontinuation of pegaspargase in the consecutive cycles. No treatment related death confirmed. Conclusion The P-GEMOX regimen is a safe and effective combination for newly diagnosed advanced and relapsed/refractory ENKTL. Promising long term outcome can be expected by addition of ASCT consolidation after response to induction chemotherapy. In comparison to other combined regimen in literatures, P-GEMOX is effective with less toxic, simplified and high cost-effective. Further clinical trials urgently needed. Table 1. Toxicities of whole cohort All cases (%) Grade 1/2 (%) Grade 3/4 (%) Toxicities Neutropenia 51(85.0) 32(53.3) 19(31.6) Thrombocytopenia 22(36.7) 15(25.0) 7(11.7) Anemia 43(71.6) 18(66.7) 3(5.0) lymphocytoponia 14(23.3) 12(20.0) 2(3.3) AST/ALT elevated 26(43.3) 22(36.7) 4(6.7) Hypoproteinemia 53(88.3) 48(84.9) 8(13.3) Fbg decrease 41(68.3) 39(65.0) 2(3.3) APTT prolong 16(26.7) 16(26.7) 0 Hyperglycemia 7(11.6) 7(11.6) 0 Total bilirubin elevated 9(15.0) 9(15.0) 0 Nausea 21(35.0) 21(35.0) 0 Anorexia 32 (53.3) 32 (53.3) 0 Vomiting 19(31.6) 19(31.6) 0 Allergic reactions 1(1.7) 1(1.7) 0 herpes zoster 3(5.0) 3(5.0) 0 Figure 1. 4-year OS and PFS of whole patients Figure 1. 4-year OS and PFS of whole patients Figure 2. Survival of whole patients, based on response Figure 2. Survival of whole patients, based on response Figure 3. OS: patients with ASCT vs. Non-ASCT Figure 3. OS: patients with ASCT vs. Non-ASCT Disclosures No relevant conflicts of interest to declare.

Description: The genetic landscape of Natural killer/T-cell nasal-type lymphoma (NKTL) has been recently unraveled by discoveries describing recurring mutations altering the JAK-STAT pathway, epigenetic modifiers, the DDX3X gene and genetic predisposition in the HLA-DPB1 gene but none has employed whole-genome sequencing (WGS). Whole-genome sequencing was performed for 11 pairs of tumor-blood samples to study the association between somatic mutations and response to pembrolizumab. Interestingly, recurrent PD-L1 SRs were validated in four of the seven complete responders (CR) cases. JAK3-activating (p.A573V) mutations were also validated in another two pembrolizumab-treated patients who have achieved CR. Lastly, we also found a homozygous 3 bp insertion (p.Q131_H132insQ) in the ARID1B gene, a chromatin remodeler gene and a subunit in the SWI/SNF complex in the last remaining CR case. A recent study has also reported PBRM1-deficient and ARID2-deficient tumors correlated with better response to anti-PD1/PD-L1 therapy renal cell carcinoma. There seems to be a relationship between truncating alterations in the subunits of the SWI/SNF complex and response to PD1/PD-L1 therapy. However, the exact mechanisms behind these associations remain to be elucidated for NKTL. Analysis of the WGS data from the four remaining progressive disease (PD) patients' tumors did not reveal similar alterations in the PD-L1 and JAK3 genes. A careful inspection was also carried out on the genes associated with major histocompatibility complex and interferon gamma pathways, which are known to associate with resistance to immune checkpoint blockade in melanoma, but no further mutation in these groups of genes was found in our cohort. Furthermore, a TP53 (p.W14X) stop-gain mutation, a hallmark tumor suppressor gene, was detected in a patient who had progressive disease after given pembrolizumab. We went on to check if PD-L1 IHC staining could explain the response of these NKTL patients to pembrolizumab. In this study, tumors were stained and assessed for PD-L1 positivity by the same pathologist. All cases, except two cases, have greater than 20% of tumor cells stained positive for PD-L1. Interesting, both cases are CR. In addition, all four PD cases were strongly stained for PD-L1 with an average of 69% PD-L1 positive cells (range, 50% - 90%) but their outcomes were dismal. This suggests that there could be a companion biomarker that could be added to PD-L1 IHC positivity for better predictive power of response to PD1 blockade therapy. Here we report retrospectively, for the first time, the genomic mutational profiles of anti-PD1 blockade in 11 relapsed/refractory NKTL patients using WGS data, which provide proof-of-concept data that the response to anti-PD1 is relevant and correlates with recurrent PD-L1 and JAK3 genomic alterations in this malignancy. Disclosures No relevant conflicts of interest to declare.