Cost-efficiency analysis of conversion to biosimilar filgrastim for supportive cancer care and resultant expanded access analysis to supportive care and early-stage HER2+ breast cancer treatment in Saudi Arabia: simulation study

Abstract

Aims

This study estimated, for Saudi Arabia, the cost-efficiency of converting patients from reference Neupogen and Neulastim to one of two filgrastim biosimilars (Nivestim, Zarzio); the budget-neutral expanded access to supportive care with biosimilar filgrastim and therapeutic care to ado-trastuzumab emtansine thus afforded; and the number-needed-to-convert (NNC) to provide supportive or therapeutic treatment to one patient.

Materials and methods

Replicating prior studies, we modeled the cost-efficiencies gained from converting varying proportions of a hypothetical panel of 4,000 patients undergoing six cycles of cancer treatment from Neupogen or Neulastim to one of the two biosimilar G-CSF formulations, using national cost inputs. Cost-savings in USD were used to estimate the additional doses of biosimilar G-CSF and expanded access to ado-trastuzumab emtansine on a budget-neutral basis, and NNC to purchase one additional dose of supportive or therapeutic treatment.

Results

Savings from conversion from reference to a biosimilar filgrastim were $3,086,400 (Nivestim) and $3,460,800 (Zarzio). With reference pegfilgrastim, savings from conversion were $11,712,240 (Nivestim) and $12,086,640 (Zarzio). Biosimilar conversion from reference to biosimilar filgrastim enabled expanded access to ado-trastuzumab emtansine ranging from 61 patients (5 days, Nivestim) to 191 patients (14 days, Zarzio). For supportive care, biosimilar conversion enabled expanded access ranging from 8,244 patients (5 days, Nivestim) to 25,882 patients (14 days, Zarzio). For biosimilar conversion from daily filgrastim, the NNC for treatment with ado-trastuzumab emtansine decreased as days of injections increased [5 days: 395 (Nivestim), 352 (Zarzio); 14 days: 141(Nivestim), 126 (Zarzio)]. Alternately, for biosimilar conversion from single-injection pegfilgrastim to daily biosimilar filgrastim, the NNC for treatment with ado-trastuzumab emtansine rose as days of injections increased, being highest under the 14-day scenario (146, Nivestim; 130, Zarzio).

Conclusion

This simulation study demonstrated significant potential cost-savings from biosimilar conversion. These savings provide budget-neutral increased access to supportive and therapeutic cancer care.

Keywords:

• Biosimilar
• cost-efficiency
• cost savings
• febrile neutropenia
• granulocyte colony-stimulating factor
• ado-trastuzumab emtansine
• filgrastim
• pegfilgrastim

JEL CLASSIFICATION CODES:

• I10
• I19

Transparency

Declaration of funding

This study was conducted independently and was not funded by an external authority.

Declaration of financial/other relationships

IA is the Deputy Editor in Chief of the Journal of Medical Economics. IA holds equity in Matrix45, LLC, which provides scientific and consulting services to biopharmaceutical, diagnostics, and medical device companies on a non-exclusivity basis; government and international agencies; and academic or health care institutions. By company policy, owners, employees, and associates are prohibited from holding equity in client and sponsor organizations (except through mutual funds or other independently administered collective investment instruments), contracting independently with client and sponsor organizations, or receiving compensation independently from such organizations. Any compensation related to the provision of services to government and international agencies, academic institutions, and healthcare institutions by equity owners is collected by Matrix45. All other authors report there are no competing interests to declare. With regards to the products mentioned in this article, Matrix45 has provided services to the following manufacturers of licensees of originator and biosimilar granulocyte colony stimulating factors: Amgen, Roche, Sandoz/Novartis, Teva, Hospira/Pfizer, Mylan/Viatris/Biocon, and Coherus Biosciences.

Author contributions

All authors meet the ICMJE criteria for authorship.

Conceptualization: All authors

Study design: CCY, MAK, IA

Acquisition of data: CCY, IA

Data curation: CCY, IA

Data analysis: CCY, MAK, IA

Data interpretation: CCY, MAK, IA

Manuscript drafting: CCY, MAK, IA

Critical revision of the manuscript for intellectual content: All authors

Acknowledgements

None reported.

Data availability statement

Requests will be considered by the corresponding author in consultation with other authors as necessary.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Geolocation

Saudi Arabia; Gulf Cooperation Council member countries; Eastern Mediterranean; Middle East.

Notes

1 Neupogen, filgrastim; Neulastim, pegfilgrastim.

2 KSA does not differentiate between biosimilars as the US does with its 4-letter suffixes, hence we are obliged to use the proprietary drug name for biosimilars in this paper. Nivestim and Zarzio are biosimilars referencing standard filgrastim.