Are different methotrexate regimens as first line therapy for low risk gestational trophoblastic neoplasia more cost effective than the dactinomycin regimen used in GOG 0174?

OBJECTIVES

Gynecologic Oncology Group (GOG) 0174 compared weekly intramuscular methotrexate (MTX) with biweekly pulsed intravenous dactinomycin (Act-D) as single-agent chemotherapy for low-risk gestational trophoblastic neoplasia (GTN). Act-D had a higher rate of initial complete response (CR) (70% vs. 53%, p=0.01), but multi-day regimens of MTX have higher historic success rates. We assessed the cost-effectiveness of Act-D vs. MTX per GOG 0174 and explored multi-day MTX regimens.

METHODS

A cost effectiveness decision model was constructed with data from GOG 0174. Outcome was cost per first-line treatment success expressed in terms of incremental cost-effectiveness ratio (ICER). Front-line failures were assumed to receive cross-over single agent therapy, second line failures; multi-agent chemotherapy. GOG 0174 had no quality of life (QOL) evaluation, so equal QOL (utility 1.0) was assumed but varied in sensitivity analysis. A second exploratory model included 5-day and 8-day MTX regimens.

RESULTS

Act-D ($18,505) was more expensive compared to weekly MTX ($8950) with an ICER of $56,215 per first-line treatment success compared to weekly MTX. Small decreases in QOL dramatically increased the ICER during sensitivity analysis. Models with multi-day MTX regimens were also more cost-effective than Act-D. If effectiveness was redefined as avoidance of multi-agent chemotherapy, weekly MTX was more effective.

CONCLUSIONS

With a complete cure rate for low-risk GTN regardless of initial agent, our model supports provider hesitation toward first line Act-D for low risk GTN. While Act-D is more effective for first line treatment success, it is more costly, and does not decrease rate of multi-agent chemotherapy use.