SIMPLE Chemotherapy for NK Lymphoma/Leukaemia

Natural killer (NK)/T-cell malignancies comprise two related entities, extranodal NK/T cell lymphoma and aggressive NK leukaemia. The disease occurs world-wide but Asian and South American populations are particularly affected, NK/T cell malignancies carry poor prognosis, the response rate is low with conventional CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) or CHOP-like regimen even for newly diagnosed disease. These regimens are typically ineffective for relapsed disease.

In the last 10 years the investigators have employed two different regimen sequentially. The former SMILE regimen (Dexamethasone, methotrexate, ifosfamide, L-asparaginase and etoposide) harness the combination of P-gp independent chemotherapy in management of NK/T cell malignancies with great success. However, nephrotoxicity remained a major concern with the use of this regimen. The SMILE regimen was later modified as PIGLETS regimen (cisplatin, ifosfamide, gemcitabine, L-asparaginase, etoposide, dexamethasone) to reduce the risk of nephrotoxicity while preserving the treatment efficacy. The study with the use of PIGLETS was approved by IRB. The preliminary results of phase II clinical trial with PIGLETS at Queen Mary Hospital resulted in an overall response rate (ORR) of 80% in newly diagnosed disease.

The recruitment was completed with previous PIGLETS phase II trial. The problems with the PIGLETS regimen are:

1. The term 'PIGLETS' may appear to be offensive in some of the ethnicities/religions.

2. Significant nausea and vomiting, which may be delayed after completion of chemotherapy.

In addition, there is a need of further subject recruitment for comparison with SMILE therapy for non-inferiority. In the current study, the regimen was renamed as 'SIMPLE' and aprepitant (a substance P antagonist) was added in the regimen to reduce the incidence of nausea and vomiting. The current study aims to compare SIMPLE to SMILE in a 'non-inferiority' design.