Background: Biosimilars not only have the potential to reduce the cost of prophylaxis of CIN/FN but such savings could be reallocated to provide access to anti-neoplastic treatment. To demonstrate this, we simulated in a 20,000-patient panel: 1) the savings that could be realized from CIN/FN prophylaxis with biosimilar pegfilgrastim-cbqv over reference pegfilgrastim with or without on-body injector (PEG/PEG-OBI), 2) a model of expanded access to adjuvant chemotherapy with doxorubicin/cyclophosphamide for localized breast cancer from cost-savings achieved from conversion from PEG/PEG-OBI, and 3) the number-needed-to-convert (NNC) to biosimilar pegfilgrastim-cbqv from PEG/PEG-OBI to purchase one additional treatment of doxorubicin/cyclophosphamide chemotherapy. Methods: Simulation modeling from the US payer perspective utilizing:average selling price (ASP) derived from CMS Q1 2020 reimbursement limits for PEG/PEG-OBI, pegfilgrastim-cbqv, doxorubicin and cyclophosphamide;between one and six cycles of prophylaxis in a panel of 20,000 cancer patients at risk for CIN/FN; and conversion rates from PEG/PEG-OBI to biosimilar pegfilgrastim-cbqv ranging from 10% to 100%. Results: Using current ASP, cost-savings of biosimilar pegfilgrastim-cbqv over PEG/PEG-OBI in a panel of 20,000 breast cancer patients range from $445,163 (for one cycle of prophylaxis at 10% conversion) to $26,709,788 (6 cycles at 100% conversion). In a single cycle of chemotherapy, these savings translate into expanded access to doxorubicin/cyclophosphamide ranging from 1,286 cycles at 10% conversion from PEG/PEG-OBI to 12,861 cycles at 100% conversion. The savings over six cycles could provide between 7,717 additional cycles of doxorubicin/cyclophosphamide (at 10% conversion) to 77,166 cycles (at 100% conversion). The NNC from PEG/PEG-OBI to purchase one additional cycle of doxorubicin/cyclophosphamide is 2. Conclusions: These models demonstrate that CIN/FN prophylaxis with biosimilar pegfilgrastim-cbqv can generate significant cost savings for supportive cancer care. Further, these savings could be reallocated to provide access to curative anti-neoplastic treatment on a budget-neutral basis, thus enhancing the value of cancer care to both payers and patients.