Trastuzumab shots for breast cancer deliver on cost savings

Subcutaneous (SC) trastuzumab may be a cost-saving alternative to the intravenous (IV) formulation in the treatment of breast cancer patients in Singapore, according to a study.

In a model-based cost-minimization analysis, the annual societal cost ranged between SGD 64,194 and SGD 65,135 per patient receiving IV trastuzumab as opposed to between SGD 25,865 and SGD 26,807 per patient receiving SC trastuzumab. SC trastuzumab reduced the annual cost burden by 58.8 percent per nonmetastatic breast cancer patient and by 59.7 percent per metastatic breast cancer patient. [Ther Adv Med Oncol 2024:16:17588359241293381]

As shown in the detailed cost breakdown, drug costs constituted more than 90 percent of the total cost. The next most significant contributors to cost were infusion chair time and pharmacist time, with patients receiving IV trastuzumab incurring additional annual costs of SGD 988 and SGD 244, respectively. However, patients receiving SC trastuzumab were estimated to incur higher costs at SGD 526 per year for nurses to travel to their homes.

The cost of absenteeism in the workplace due to travelling to the cancer centre was SGD 314 per patient receiving IV trastuzumab, while the costs of absenteeism due to receiving treatment were estimated at SGD 823 and SGD 185 per patient receiving IV and SC trastuzumab, respectively.

Even when excluding the cost of drugs, SC trastuzumab remained cheaper by SGD 1,912 annually. The cost reduction is approximately 60 percent compared with IV trastuzumab regardless of disease status, with a 100-percent probability that the decision to adopt the SC formulation leads to cost savings in Singapore.

“This study represents the first analysis of the economic value of SC versus IV trastuzumab in the Singapore setting. Our findings highlight cost-savings for consumables, infusion chair time, pharmacist time, and reduced absenteeism attributed to travelling or treatment time incurred. Increased costs associated with nursing time were observed, primarily due to additional travel time for nurses,” the investigators noted.

They stressed that the substantial decrease in chair time in the chemotherapy unit is especially advantageous. “This is important in a resource-limited setting such as the National Cancer Centre Singapore (NCCS), where wait times for chemotherapy unit chairs can extend to 4 weeks. Changing to home administration of SC trastuzumab allows for chemotherapy chairs to be allocated to patients in need of lengthier infusions for medications carrying a higher risk of hypersensitivity or acute toxicities.”

For the study, the investigators estimated and compared the per-patient annual costs associated with each treatment modality from a societal perspective. The target population was female patients from NCCS with early (nonmetastatic) and advanced (metastatic) stages of breast cancer who were prescribed trastuzumab treatment with curative and palliative intent, respectively. 

Direct cost comprised healthcare resources use including drug, consumables, manpower, facility, and cardiac assessment. Indirect cost was estimated using a human capital approach to account for productivity lost by patients. Parameter uncertainties were accounted for using Monte Carlo simulations with 1,000 iterations. Costs were reported in 2023 Singapore dollars.