Cost-effectiveness Of Travoprost Followed By Travoprost/timolol Fixed-combination Treatment Sequence (T-TTFC) Compared To Latanoprost Followed By Latanoprost/timolol Fixed-combination (L-LTFC) In Thailand

Robert Tan

Alcon R&D International, Singapore

PURPOSE: To assess the cost-effectiveness of T-TTFC compared with L-LTFC treatment sequences using a payer perspective in Thailand.

METHODS: A Markov model simulated the disease progression of open angle glaucoma and ocular hypertension (OHT) patients. Transition probabilities were obtained from Denis (2008), and extrapolated from 2 phase III clinical trials (Topouzis, 2007; Netland 2001). Probabilities to develop new visual field defect (VFD) was estimated from literature (Denis 2004). Unit costs were obtained from list prices. The time horizon was five years and sensitivity analyses were performed on key parameters.

RESULTS: At five years, fewer T-TTFC patients switched to third line treatment, and 65.5% of patients showed no disease progression (no new VFDs) compared to 61.4% for L-LTFC Thus initiation of treatment in an OHT patient with T followed by TTFC if needed would avoid one incidence of VFD in every 24 incident cases (Number Needed to Treat - NNT). In Thailand, T-TTFC results in a cost-savings of 5,507 Baht (US$180) against L-LTFC with additional QALY gain of 0.00625 of a 5 year period. Sensitivity analyses have demonstrated the robustness of these findings.

CONCLUSIONS: T-TTFC yielded cost-savings, fewer treatment switches and additional QALY gain. Poor IOP control results in therapy changes and increases the probability of patients experiencing new VFDs (Denis 2004), which in turn adversely impacts patient quality of life. T-TTFC economically dominates L-LTFC. With these findings policy-makers and clinicians should consider the use of T-TTFC for glaucoma patients as potential cost-saving medications.