OBJECTIVES: The GENESIS trial demonstrated that motixafortide (M) + G-CSF (G, growth factor) mobilized significantly more stem cells for autologous transplantation (ASCT) in patients with multiple myeloma (MM) versus G alone. This study analyzed resource use (HRU) alongside the GENESIS trial and used the findings to assess cost-effectiveness of M+G vs G.

METHODS: HRU items collected included number of drug doses, number of apheresis sessions in primary and rescue mobilization, percentage of patients needing rescue mobilization, hospitalization for conditioning, ASCT and serious adverse events. 2021 Medicare unit costs and drug wholesale acquisition cost were used. The de novo cost-effectiveness model has two parts: a 6-month decision tree describing management of patients undergoing ASCT populated with GENESIS clinical and HRU data followed by a lifetime Markov model (alive-dead). Maintenance costs including subsequent therapy lines were based on large US claims databases. Published utility scores in MM were applied. A disutility was deducted per mobilization/apheresis day. Discounting of 3%/year was applied. Sensitivity analyses were performed to identify key drivers.

RESULTS: Patients receiving M+G needed less drug doses and less apheresis sessions, achieved significantly more optimal mobilization in ≤4 days (96.3% vs. 47.6%) and required less rescue therapy (1.3% vs. 23.8%). More patients in M+G vs G underwent ASCT. The model yielded a QALY gain of 0.06 (5.56 vs. 5.50, respectively) and cost savings of $6,152 with M+G vs G (total savings $19,024 minus $12,872 for motixafortide cost, assuming $12,000/vial). Thus, M+G is dominant vs G. Key drivers were probability of undergoing ASCT, of having successful and shorter time to engraftment, and long-term maintenance costs. M+G was dominant in half of the simulations.

CONCLUSIONS: The trial findings, combined with model estimates, suggest that upfront use of M+G in ASCT is a cost-effective option in the US, based on usual willingness-to-pay values.