According to a new study, potential savings realized from transitioning to treatment with biosimilar filgrastim-sndz from reference filgrastim are not only significant, but these savings can also be applied to expand access to novel immunotherapies or supportive care.
Cancer patients undergoing myelosuppressive chemotherapy are at significant risk for developing chemotherapy-induced (febrile) neutropenia (CIN/FN), which is treated prophylactically with recombinant granulocyte colony stimulating factors (G-CSFs) that stimulate the production of neutrophils in the bone marrow. According to a new study published in Future Oncology, potential savings realized from converting to treatment with biosimilar filgrastim-sndz (Sandoz’s Zarxio) from reference filgrastim (Amgen’s Neupogen) are not only significant, but these savings can also be applied to expand access to novel immunotherapies or supportive care. The study received funding from Sandoz.
Ali McBride, PharmD, MS, (an Advisory Board member of The Center for Biosimilars®) and colleagues performed a comparative cost-minimization study for reference filgrastim; its pegylated form, pegfilgrastim (Amgen’s Neupogen); and biosimilar filgrastim-sndz for prophylaxis periods ranging from 1 to 14 days. Filgrastim is given as a daily injection for a maximum of 14 days; pegfilgrastim requires only a single injection.
The simulation study was a cost-of-medicines—based analysis from the perspective of a US payer and focused on the expanded access enabled by converting a hypothetical panel of 20,000 cancer patients receiving G-CSF treatment with either reference filgrastim or pegfilgrastim to prophylaxis with filgrastim-sndz to 2 novel immunotherapy agents: obinutuzumab (Roche’s Gazyva) in combination with bendamustine for patients with relapsing/refractory follicular lymphoma, and pembrolizumab (Merck’s Keytruda) as a single agent for treatment of non—small-cell lung cancer (NSCLC). The study assumed that cost-savings from using biosimilars should be reallocated on a budget-neutral basis to provide more patients with access to either therapeutic or supportive cancer care.
The study showed savings potentially ranging from $7 million to $56 million in base-case analyses with fixed prophylaxis duration—and ranging from $6 million to $59 million in sensitivity analyses based on likely clinical regimens—could provide significant expanded access to recently introduced immunotherapy regimens, the authors said. Between 52 and 544 patients with relapsing/refractory follicular lymphoma could be treated budget-neutrally with obinutuzumab and between 18 and 192 patients with metastatic NSCLC with pembrolizumab. The potential savings could provide significant expanded access to supportive care with filgrastim-sndz to between 860 and 9017 patients with 5 days of filgrastim-sndz prophylaxis in each of the cycles of a 6-cycle chemotherapy regimen.
The researchers also concluded that treating 1 additional patient with obinutuzumab is possible by converting as few as 37 patients from pegfilgrastim and as few as 118 from reference filgrastim to biosimilar filgrastim-sndz. Providing 1 additional patient with access to pembrolizumab requires as few as 104 patients to be converted to biosimilar filgrastim-sndz from pegfilgrastim, and as few as 336 from reference filgrastim. Providing 1 additional patient with biosimilar filgrastim-sndz support during a 6-cycle course of chemotherapy could be achieved with as few as 2 out of 20,000 patients converted from pegfilgrastim and only 7 patients converted from reference filgrastim, the researchers found.
“It is not surprising that the greatest efficiencies and the highest expanded access rates are achieved with converting patients from pegfilgrastim to filgrastim-sndz, as pegfilgrastim is the more expensive agent,” they note. “This is important because of the anecdotal evidence of US payers declining prophylaxis with pegfilgrastim and instead authorizing up to 7 days of prophylaxis with daily filgrastim.” The potential savings generated by 7 days of filgrastim-sndz instead of single-administration pegfilgrastim for 20,000 patients in only 1 cycle of chemotherapy totals $47,177,600—savings that would provide an additional 7217 patients with CIN/FN prophylaxis over a 6-cycle course of chemotherapy, an additional 435 patients with treatment with obinutuzumab, or an additional 153 patients with access to pembrolizumab on a budget-neutral basis without further cash demand.
The researchers believe their results may help clinicians see biosimilars as a cost-responsible alternative and help increase their adoption of biosimilars.