Nivestym Shortage: What Providers and Prescribers Need to Know in 2026

For oncologists, hematologists, and other prescribers who rely on filgrastim products to protect patients during myelosuppressive chemotherapy, navigating the current biosimilar landscape requires current knowledge about availability, formulary preferences, and patient access resources. This guide provides a practical overview of Nivestym (filgrastim-aafi) availability in 2026, along with clinical and operational guidance.

Current Nivestym Supply Status (2026)

As of 2026, Nivestym is not listed on the FDA's official drug shortage database. Pfizer continues to manufacture and distribute Nivestym for the U.S. market. However, clinicians and pharmacy teams are still reporting localized access challenges driven by:

• Specialty pharmacy-only distribution requirements imposed by payers
• Prior authorization delays, particularly at initial prescribing
• Formulary competition from other preferred biosimilars (e.g., Zarxio or Releuko)
• Localized inventory variation around chemotherapy cycle dates

Nivestym Indications: Clinical Reminders

Nivestym (filgrastim-aafi) is FDA-approved for the following indications, which are the same as Neupogen:

• Prophylaxis of febrile neutropenia in patients with nonmyeloid malignancies receiving myelosuppressive chemotherapy (5 mcg/kg/day SC or IV, starting ≥24 hours after chemo)
• Reduction of time to neutrophil recovery and duration of fever following induction or consolidation chemotherapy for AML (5 mcg/kg/day SC or IV)
• Reduction of neutropenia duration following myeloablative chemotherapy followed by BMT (10 mcg/kg/day IV)
• Mobilization of autologous peripheral blood progenitor cells (PBPC) for leukapheresis (10 mcg/kg/day SC for ≥4 days before first apheresis)
• Chronic administration in severe chronic neutropenia (SCN): congenital neutropenia (6 mcg/kg twice daily SC), cyclic or idiopathic neutropenia (5 mcg/kg once daily SC)

Note: Nivestym is NOT approved for hematopoietic syndrome of acute radiation syndrome (H-ARS). For that indication, prescribe Neupogen, Zarxio, Releuko, or Nypozi.

Biosimilar Alternatives When Nivestym Is Unavailable

When Nivestym is not available or not covered by a patient's plan, the following alternatives should be considered. All are biosimilars to Neupogen with no clinically meaningful differences for shared indications:

• Zarxio (filgrastim-sndz, Sandoz) — Approved for the same indications as Nivestym; often preferred by many insurance plans; prefilled syringes can be stored at room temperature up to 4 days vs. 24 hours for Nivestym
• Releuko (filgrastim-ayow) — FDA-approved February 2022; suitable for chemo, AML, BMT, and SCN but NOT approved for PBPC mobilization
• Nypozi (filgrastim-txid) — Approved June 2024; broadest indication set including H-ARS
• Neupogen (filgrastim, Amgen) — Reference product; available across all indications; typically higher cost

For most chemotherapy-related indications, switching among these products is clinically appropriate. Be aware that the switch requires a new prescription, as biosimilars are not automatically interchangeable under current law.

Navigating Prior Authorization for Nivestym

Prior authorization is required by most commercial payers and Medicare Advantage plans for Nivestym. Documentation requirements typically include:

• ICD-10 diagnosis code (e.g., C-codes for malignancy, D70.x for neutropenia)
• Documentation of chemotherapy regimen and cycle schedule
• Clinical rationale if not the payer's preferred G-CSF agent
• History of febrile neutropenia or ANC documentation for chronic neutropenia claims

Tip: For time-sensitive oncology situations, submit PA requests with an urgent/expedited designation. Most commercial insurers and Medicare Advantage plans must respond to urgent PA requests within 72 hours.

Medicare Part B Billing for Nivestym

When Nivestym is administered in a physician office or hospital outpatient setting, it is billed under Medicare Part B using HCPCS code Q5110 (Injection, filgrastim-aafi, biosimilar, [Nivestym], 1 microgram). Each microgram of administered dose represents one billing unit. Medicare typically reimburses at the ASP + 6% for Part B drugs. Be sure to document the JW modifier for any discarded doses and the JZ modifier when there is no waste, per CMS requirements effective July 1, 2023.

Patient Assistance and Copay Resources

For patients with cost or access barriers, the following programs are available:

• Pfizer Oncology Together Copay Program: Commercially insured eligible patients may pay as little as $0 per treatment, with a maximum savings of $25,000 per calendar year. Providers can submit copay claims on behalf of patients.
• Pfizer Patient Assistance Program: Uninsured or underinsured patients who meet income eligibility criteria may qualify for Nivestym at no cost. Contact 800-675-8416.
• medfinder for providers:

medfinder.com/providers helps practices find which pharmacies near a patient can fill their Nivestym prescription. See the full provider guide to helping patients find Nivestym for practical workflow tips.

Key Takeaways for Providers

• No active FDA shortage for Nivestym as of 2026, but localized access barriers persist
• Biosimilar alternatives (Zarxio, Releuko, Nypozi) are clinically interchangeable for most indications — require a new prescription
• Nivestym is NOT approved for H-ARS — use Neupogen, Zarxio, Releuko, or Nypozi for that indication
• Expedited PA requests are available for urgent oncology situations
• Pfizer's copay and patient assistance programs can significantly reduce patient out-of-pocket costs