ENKTL occurs predominantly in Asian populations and data is limited in North America. We performed a retrospective analysis to define treatment patterns and outcomes for North American ENKTL patients to assess the impact of asparaginase (ASP) use and toxicity based on patient age.
We included 134 ENKTL patients from 8 academic institutions. Clinical, pathologic, treatment, and survival characteristics were collected. Survival was analyzed using the Kaplan-Meier method. Cox proportional hazard regression assessed the relationship of ASP exposure and outcome. A total of 84 of 134 (63%) patients received ASP. Patient age groups included 42 patients 61 years.
Adverse events were more common in ASP-receiving patients including ≥grade 3 transaminase elevation in 23/84(27%) ASP patients vs 3/50(6%) in non-ASP. Other notable toxicities in ASP vs non-ASP patients included hypertriglyceridemia (24% vs 0%), hypofibrinogenemia (24% vs 2%), neutropenic fever (20% vs 8%), hypersensitivity reactions (10% vs 2%). Treatment complications resulted in frequent unplanned hospitalizations (31% vs 10%); 28% of patients discontinued ASP, but there was no increase in therapy-associated death.
Overall and Complete (CR) response rates were 80% (62% CR) in the ASP group and 54% (46%) in the non-ASP group. This trend was similar across all age groups. We did not detect a statistically significant difference in overall survival by ASP-receipt (p=0.44).
This analysis supports that ASP use was associated with higher response rates, but increased toxicity and no advantage in overall survival. The toxicity of ASP may differ in North American vs Asian populations.
