Expanded Access to Obinutuzumab from Cost-Savings Generated By Biosimilar Filgrastim-Sndz in the Prophylaxis of Chemotherapy-Induced (Febrile) Neutropenia: US Simulation Study

BACKGROUND: Prophylaxis of chemotherapy-induced (febrile) neutropenia with biosimilar filgrastim-sndz (EP2006) may generate cost-savings over reference filgrastim and pegfilgrastim (incl. on-body injector). Such savings could be reallocated on a budget-neutral basis to provide other treatments to the same or different patients, including expensive, recently approved novel cancer therapies. To make this case, we estimated cost-savings that could be achieved from converting (febrile) neutropenia prophylaxis from reference filgrastim or pegfilgrastim to biosimilar filgrastim-sndz; and simulated a hypothetical reallocation of those savings to therapeutic care for follicular lymphoma (FL) patients with obinutuzumab, a humanized anti-CD20 monoclonal antibody approved in 2016 for relapsed/refractory follicular lymphoma. Specifically, we aimed to [1] simulate, for a 20,000 patient panel, cost-savings achieved from prophylaxis with filgrastim-sndz over filgrastim and pegfilgrastim; [2] estimate the budget-neutral expanded access to obinutuzumab (second line) treatment for follicular lymphoma afforded by these cost-savings; and [3] determine the number-needed-to-convert to purchase one additional course of obinutuzumab treatment. Note that we use obinutuzumab in FL as an exemplar of how conversion of patients from filgrastim or pegfilgrastim to filgrastim-sndz generates savings efficiencies that can be used by a payer to provide other patients with access to therapeutic cancer treatment on a budget-neutral basis.

METHODS: Under the assumption of therapeutic similarity of filgrastim, pegfilgrastim, and filgrastim-sndz, a simulation analysis was performed using the 3Q2016 average selling price (ASP) cost for one patient for one chemotherapy cycle with 5, 7, 11, and 14 days (d) of prophylaxis. Escalated to a 20,000-patient panel, we calculated [1] cost-savings accrued from 5/7/11/14d prophylaxis converted to filgrastim-sndz from filgrastim and pegfilgrastim; [2] expanded access afforded by these cost-savings to obinutuzumab for follicular lymphoma at $108,349 per treatment course (computed as the 3Q2016 ASP based on 1Q2017 payment allowance limits of Centers for Medicare and Medicaid Services for 3 doses in cycle 1, 1 dose in cycles 2-6 followed by 1 dose every 2 months for 2 years); and [3] number-needed-to-convert (NNC) for one additional course (6 cycles + 2 years) of obinutuzumab treatment.

RESULTS: Per-cycle cost-savings from utilizing filgrastim-sndz over filgrastim are $327.00 (5d), $457.80 (7d), $719.40 (11d), and $915.60 (14d). For 20,000 patients, conversion from filgrastim to filgrastim-sndz yields savings of (rounded) $6,540,000 (5d), $9,156,000 (7d), $14,388,000 (11d), and $18,312,000 (14d). These savings provide expanded access to obinutuzumab treatment to 60 (5d filgrastim-sndz regimen), 85 (7d), 133 (11d), and 169 (14d) patients. The NNC is 331 (5d), 237 (7d), 151 (11d), and 118 (14d). As conversion-related savings relative to pegfilgrastim decline as daily injections increase, for 20,000 patients, conversion from pegfilgrastim to filgrastim-sndz yields savings of $55,893,600 (5d), $47,177,600 (7d), $29,745,600 (11d), and $16,671,600 (14d). These savings provide expanded access to obinutuzumab treatment to 516 (5d filgrastim-sndz regimen), 435 (7d), 275 (11d), and 154 (14d) patients. The NNC from pegfilgrastim is 39 (5d), 46 (7d), 73 (11d), and 130 (14d).

CONCLUSION: Conversion from reference filgrastim and pegfilgrastim to filgrastim-sndz yields significant savings, especially when converting from pegfilgrastim. These savings can be applied to procure therapeutic cancer care with obinutuzumab for patients with relapsed/refractory follicular lymphoma on a budget-neutral basis. Considering the rising costs of novel cancer treatment (including obinutuzumab), conversion to biosimilar growth factors for prophylaxis of febrile neutropenia in large payer panels can create significant savings that could enable more patients with hematological malignancies to be treated without additional cost to payers.