Efbemalenograstim Alfa (Ryzneuta)

Efbemalenograstim alfa is a fourth engineered G-CSF joining this site's existing filgrastim/pegfilgrastim/sargramostim cluster — a dimeric Fc-fusion protein built without PEGylation or polysorbate 80, dosed once per chemotherapy cycle. FDA-approved in November 2023 on two real Phase 3 trials — one placebo-controlled, one head-to-head against pegfilgrastim — it's now commercially available in both the US and EU.

A fourth engineered G-CSF, built without PEG

Efbemalenograstim alfa (F-627, developed by Evive Biotech) is a recombinant human granulocyte colony-stimulating factor (G-CSF) engineered as a dimeric Fc-fusion protein — two copies of the G-CSF molecule linked through an antibody Fc fragment — rather than the PEGylated monomer structure used in pegfilgrastim (Neulasta). The Fc fusion extends its half-life enough for once-per-cycle dosing, the same clinical goal pegfilgrastim already achieves by attaching a polyethylene-glycol chain to filgrastim, but through a structurally different engineering route that avoids PEG and polysorbate-80 altogether — components some patients and manufacturers would rather avoid. Like every G-CSF on this site, its job is the same: reduce the depth and duration of the neutrophil drop that follows myelosuppressive chemotherapy, cutting the risk of a febrile-neutropenia infection.

GC-627-04: beating placebo

The first pivotal trial, GC-627-04, randomized 122 women with breast cancer receiving doxorubicin-and-docetaxel chemotherapy 2:1 to a single 20 mg dose of efbemalenograstim alfa or placebo in cycle 1 (with all patients receiving efbemalenograstim alfa in cycles 2-4). The mean duration of severe (grade 4) neutropenia in cycle 1 was 1.3 days on efbemalenograstim alfa versus 3.9 days on placebo, and febrile neutropenia occurred in 4.8% of the efbemalenograstim alfa group versus 25.6% on placebo (p=0.0016) (Glaspy J, Bondarenko I, Burdaeva O, et al., "Efbemalenograstim alfa, an Fc fusion protein, long-acting granulocyte-colony stimulating factor for reducing the risk of febrile neutropenia following chemotherapy: results of a phase III trial," Support Care Cancer 2023;32(1):34, DOI: 10.1007/s00520-023-08176-6, PMC10725375).¹ That's a real, statistically significant, placebo-controlled result on the same primary endpoint the entire G-CSF class is judged on.

GC-627-05: matching pegfilgrastim head-to-head

A second, larger Phase 3 trial (GC-627-05) randomized 393 patients with early-stage (I-III) breast cancer receiving docetaxel-and-cyclophosphamide chemotherapy to a single 20 mg dose of efbemalenograstim alfa or a single 6 mg dose of pegfilgrastim per cycle, across four cycles. The trial met its prespecified noninferiority margin on duration of severe neutropenia in cycle 1, with a comparable safety profile between arms (Glaspy JA, Bondarenko I, Tjulandin S, et al., "Efbemalenograstim Alfa, a Long-Acting Granulocyte Colony-Stimulating Factor Fusion Protein Without PEGylation, Versus Pegfilgrastim for Management of Chemotherapy-Induced Neutropenia in Patients With Breast Cancer: Results of a Phase III Randomized Noninferiority Trial," JCO Oncol Adv 2025;2:e2400074, DOI: 10.1200/OA-24-00074).² That's a genuine, adequately powered noninferiority result against the established comparator, not a claim of outperforming it — the trial was designed to show "at least as good," and that's exactly what it reported.

Approval and a two-continent launch

The FDA approved efbemalenograstim alfa-vuxw on 16 November 2023 (publicly announced by Evive Biotech and its US commercialization partner, Acrotech Biopharma, on 22 November 2023) to decrease the incidence of infection manifesting as febrile neutropenia in adults with non-myeloid malignancies on myelosuppressive chemotherapy. The European Commission followed with its own marketing authorization on 21 March 2024, and Evive Biotech launched the product in Germany, through a partnership with Apogepha, in November 2024. Acrotech Biopharma handles US commercialization under the Ryzneuta brand name.

Current status

Ryzneuta is commercially available in the US, distributed by Acrotech Biopharma under NDC 72893-016, with an active HCPCS billing code (J9361) and payer coverage policies in place as of 2026 — a routine, prescribed specialty-pharmacy oncology-supportive-care product, not an investigational or discontinued one. It's marketed alongside filgrastim, pegfilgrastim and other established G-CSF options as an alternative once-per-cycle choice for oncologists managing chemotherapy-induced neutropenia risk.