Febrile neutropenia hospitalization due to pegfilgrastim on-body injector failure compared to single-injection pegfilgrastim and daily injections with reference and biosimilar filgrastim: US cost simulation for lung cancer and non-Hodgkin lymphoma.

Background: Guidelines recommend febrile neutropenia (FN) prophylaxis following myelotoxic chemotherapy with either daily injections of filgrastim (Neupogen®) or biosimilar filgrastim-sndz (Zarzio/Zarxio®), single-injection pegfilgrastim (Neulasta®), or pegfilgrastim administered through an on-body injector (PEG-OBI; Neulasta® Onpro®). PEG-OBI failure rates up to 6.9% have been reported, putting patients at incremental risk for FN and FN-related hospitalization. Our objective was to estimate, from a US payer perspective, the incremental costs of FN hospitalizations and the total incremental costs associated with PEG-OBI prophylaxis at varying device failure rates over assured FN prophylaxis with daily injections of filgrastim or filgrastim-sndz or a single injection of pegfilgrastim.Methods: Cost simulations comparing prophylaxis with PEG-OBI at failure rates of 1-10% versus assured prophylaxis in cycle 1 of chemotherapy were performed for panels of 10,000 patients with lung cancer treated with cyclophosphamide, doxorubicin, and etoposide (1 analysis) or non-Hodgkin lymphoma (NHL) treated with CHOP or CNOP (2 analyses). Daily injection scenarios were 4.3, 5, and 11 injections for lung cancer and 5, 6.5, and 11 for NHL. The analyses are from the US payer perspective.Results: For lung cancer, the total incremental cost of PEG-OBI prophylaxis at varying failure rates and durations ranged from $6,691,969‒$31,765,299 over filgrastim and $18,901,969‒$36,538,299 over filgrastim-sndz. For NHL, in scenario 1, the total incremental costs ranged from $6,794,984‒$30,361,345 over filgrastim and $19,004,984‒$35,911,345 over filgrastim-sndz; in scenario 2, the incremental costs ranged from $7,003,657‒$32,448,067 over filgrastim and $19,213,657‒$37,998,067 over filgrastim-sndz.Conclusions: In this simulation, the incremental costs of FN-related hospitalization due to PEG-OBI failure in cycle 1 compared to assured prophylaxis with reference pegfilgrastim, reference filgrastim, and biosimilar filgrastim-sndz varied depending upon the PEG-OBI failure rate and the alternative G-CSF prophylaxis option. Biosimilar filgrastim-sndz offers the greatest cost-efficiency.

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.

Antitumor effects of guanosine-analog phosphonates identified by molecular modelling.

Aiming to address new drug targets, molecular modelling is gaining increasing importance although the prediction capability of the in silico method is still under debate. For an improved treatment of actinic keratosis and squamous cell carcinoma, inhibitors of human DNA polymerase alpha (pol alpha) are developed by docking nucleoside phosphonate diphosphates into the active site of pol alpha. The most promising prodrugs OxBu and OxHex were then prepared by total synthesis and tested in the squamous cancer cell line SCC25. OxBu and OxHex proved cytotoxic and antiproliferative in the nanomolar concentration range and thus exceeded activity of aphidicolin, the relevant model compound, and 5-fluorouracil, the current standard for the therapy of actinic keratosis. Interestingly, the cytotoxicity in normal human keratinocytes with OxHex was clearly less pronounced and even not detectable with OxBu. Moreover, cytotoxicity of OxBu in particular with the colorectal carcinoma cell line HT29 even surmounted cytotoxicity in SCC25, and other tumor cell lines were influenced, too, by both agents. Taken together, OxBu and OxHex may offer a new approach to cancer therapy, given the agents are sufficiently well tolerated in vivo which is to be suspected beside their chemical structure.