Treatment patterns and outcomes in patients with non-small cell lung cancer receiving biosimilar filgrastim for prophylaxis of chemotherapy-induced/febrile neutropaenia: Results from the MONITOR-GCSF study

Leveraging G-CSF prescribing in the outpatient setting: considerations beyond clinical factors-a questionnaire study

PURPOSE

This study aims to delineate G-CSF treatment practices, assess decision criteria, and measure their implementation in ambulatory settings for patients with breast (BC), lung (LC), or gastrointestinal cancers (GIC), beyond standard recommendations.

METHODS

In this non-interventional, cross-sectional, multicenter study, clinical cases were presented using conversational interfaces (chatbots), simulating a conversation with one or more virtual interlocutors through voice or text exchange. The clinical simulations were configured by four parameters: types of cancer, risk of FN related to chemotherapy and comorbidities, access to care, and therapy setting (adjuvant/neoadjuvant/metastatic).

RESULTS

The questionnaire was completed by 102 physicians. Most practitioners (84.5%) reported prescribing G-CSF, regardless of tumor type. G-CSF was prescribed more frequently for adjuvant/neoadjuvant therapy than for metastatic cases. The type of chemotherapy was cited as the first reason for prescribing G-CSF, with access to care being the second. Regarding the type of chemotherapy, physicians do not consider this factor alone, but combined with comorbidities and age (56.7% of cases). Pegfilgrastim long-acting was prescribed in most cases of BC and LC (70.1% and 86%, respectively), while filgrastim short-acting was named in the majority of cases of GIC (61.7%); 76.3% of physicians prescribed G-CSF as primary prophylaxis.

CONCLUSIONS

Our findings suggest that recommended practices are broadly followed. In the majority of cases, G-CSF is prescribed as primary prophylaxis. In addition, physicians seem more inclined to prescribe G-CSF to adjuvant/neoadjuvant patients rather than metastatic patients. Finally, the type of chemotherapy tends to be a more significant determining factor than the patient's background.

Uptake and cost of biosimilar filgrastim among Medicare and Medicaid populations in 2015-2018

BACKGROUND: The first biosimilar product filgrastim-sndz was approved by the FDA in 2015, but real-world evaluations of its uptake and cost in nationally representative populations are limited. OBJECTIVE: To evaluate the uptake and cost of filgrastim-sndz, relative to its originator filgrastim and alternative biologic tbofilgrastim, among Medicare and Medicaid populations. METHODS: Using the annually aggregated, product-level utilization and cost data of biologic and biosimilar filgrastim products in 2015-2018 from CMS drug spending data, total number of claims and costs for all 3 filgrastim products were identified and extracted for Medicare Part B, Part D, and Medicaid reimbursement. Annual average cost per claim and per beneficiary of individual filgrastim products were also extracted, and their annual growth rates were calculated. RESULTS: Three years after entering the US market, use of filgrastim-sndz increased to 49.1% and 46.0% of all filgrastim claims paid by Medicare Parts B and D, respectively, and to 38.7% of filgrastim Medicaid claims in 2018. Total cost for filgrastim-sndz also reached 42.8%, 41.8%, and 26.9% of all filgrastim products paid by Medicare Parts B and D and Medicaid, respectively. Significant reductions in average cost per claim for filgrastim-sndz in 2017 and 2018 were observed in Medicare Part B and Medicaid. CONCLUSIONS: Significant uptake of biosimilar filgrastim in Medicare and Medicaid programs occurred during the first 3 years of marketing. Policymakers may use the evidence to evaluate existing barriers and policies regarding biosimilar adoption. DISCLOSURES: No outside funding supported this work. The author has no conflicts of interest to disclose.

Extrapolation in Practice: Lessons from 10 Years with Biosimilar Filgrastim

Biosimilar filgrastim (Sandoz) was approved in Europe in 2009 and, in 2015, was the first biosimilar approved in the USA. These authorizations were based on the "totality of evidence" concept, an approach that considers data from structural and functional characterization and comparability analysis and non-clinical and clinical studies. For biosimilar filgrastim, phase III confirmatory clinical studies were performed in the most sensitive population, patients with breast cancer undergoing myelosuppressive chemotherapy. In Europe and the USA, approval was granted for all indications of the reference biologic. Hence, stem cell mobilization and severe chronic neutropenia indications were approved on the basis of extrapolation, with no clinical data available at the time of market authorization in the EU. Although extrapolation is well-accepted in biologic development and regulatory contexts, it remains a misunderstood part of the biosimilarity concept in the medical community. Since approval, more than a decade of obtained clinical experience supports the totality of evidence and reassures clinicians regarding the efficacy and safety of biosimilar filgrastim. This includes real-world data from MONITOR-GCSF, a multicenter, prospective, observational study describing treatment patterns and clinical outcomes of patients with cancer (n = 1447) receiving biosimilar filgrastim for the prophylaxis of chemotherapy-induced neutropenia in solid tumors and hematological malignancies. Evidence is also available from unrelated healthy donors and those with severe chronic neutropenia. Together, the experience from a decade of use of biosimilar filgrastim includes over 24 million patient-days of exposure, which can help reassure oncologists that extrapolation is based on strong scientific evidence and works in practice.