What is the Onpro Neulasta (on‑body injector) system for delivering pegfilgrastim (Neulasta)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: September 28, 2026 • View editorial policy

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.

Ask Question

What is Onpro Neulasta?

Onpro Neulasta is an automated on-body injector device that delivers a 6 mg dose of pegfilgrastim (Neulasta) subcutaneously approximately 27 hours after it is applied to the skin by a healthcare provider. 1

Device Description and Mechanism

The Onpro system is a timed automated-injection device designed to deliver pegfilgrastim without requiring patients to return to the clinic the day after chemotherapy 2. The device consists of:

  • A prefilled syringe containing pegfilgrastim that is loaded by the healthcare provider
  • An on-body injector with self-adhesive backing
  • A programmable delivery mechanism that automatically injects the medication 27 hours post-application
  • The injection is delivered over approximately 45 minutes 1

Clinical Application

The device is applied by a healthcare provider to either the abdomen or back of the upper arm (the arm location requires a caregiver to monitor the device) 1. The application site must be intact, non-irritated skin without swelling, redness, cuts, wounds, or abrasions 1.

Key Timing Considerations:

  • Applied 1-3 days after chemotherapy administration 2
  • Automatically delivers pegfilgrastim 27 hours after application 1
  • This timing aligns with guideline recommendations for next-day pegfilgrastim administration

Clinical Advantages

The primary benefit is eliminating the need for patients to return to the clinic the day after chemotherapy for pegfilgrastim injection 2. This is particularly valuable for patients with:

  • Distance barriers to clinic access
  • Mobility limitations
  • Transportation challenges

Studies demonstrate that the OBI improves adherence (93.8% vs 69.8% for other G-CSF options) and compliance (90.5% vs 53.2%) with pegfilgrastim prophylaxis 3. A prospective study in breast cancer patients showed lower febrile neutropenia incidence with OBI (4.4%) compared to other prophylaxis options (7.4%) 3.

Important Safety Monitoring

Critical Device Monitoring Requirements:

During dose delivery and for 1 hour after, patients or caregivers must monitor the device to ensure complete dose delivery and watch for allergic reactions 1. The device has visual and audio indicators to confirm proper function.

Device Failure Indicators - Call Provider Immediately If:

  • Device comes off before or during delivery
  • Device is leaking fluid
  • Adhesive becomes saturated with fluid or dripping occurs
  • Status light is flashing red
  • Any of these situations may result in missed or incomplete dosing 1

Patient Activity Restrictions

While wearing the device, patients must avoid:

  • Traveling, driving, or operating heavy machinery during hours 26-29 after application
  • Sleeping on or applying pressure to the device
  • Bumping or knocking the device
  • Getting lotions, creams, oils near the device (may loosen adhesive)
  • Bath tubs, hot tubs, whirlpools, saunas, or direct sunlight
  • Keeping the device dry for the last 3 hours before expected delivery 1

Environmental Contraindications

Do not expose the device to:

  • Diagnostic imaging (CT, MRI, ultrasound, X-ray)
  • Radiation treatment
  • Oxygen-rich environments like hyperbaric chambers 1

Storage and Handling

  • Store at 36°F to 46°F (2°C to 8°C) until use
  • If stored at room temperature for more than 12 hours, discard and use new kit
  • Allow 30 minutes to reach room temperature before activation
  • Do not freeze or shake 1

Important Contraindications

The device is for adult patients only and should not be used in:

  • Infants, children, or adolescents weighing less than 45 kg 2
  • Patients with severe skin reactions to acrylic adhesives 1
  • Patients with latex allergy (needle cap contains dry natural rubber) 1

Bioequivalence Evidence

Recent studies confirm pharmacokinetic and pharmacodynamic bioequivalence between pegfilgrastim delivered via OBI versus prefilled syringe 4. The most common OBI-related adverse event is injection site erythema (31.7%), which is typically mild, transient, and self-limiting 4.

References

Related Questions

Can Neulasta (pegfilgrastim) be administered 72 hours after chemotherapy instead of 24 hours after?
How should pegfilgrastim be administered?
For a patient receiving Udenyca (pegylated liposomal doxorubicin) via daily syringe injections for two days, why choose the Udenyca On‑pro on‑body injector to avoid daily travel, and is there a major difference between the injector and syringe administration?
Can a 120‑mg tablet of fexofenadine (Allegra) be added to manage the rash or pruritus associated with pegfilgrastim therapy?
What is the mechanism of action of filgrastim?
In a 17-year-old male with juvenile idiopathic arthritis on adalimumab (Humira) who has a localized infected toe requiring IV antibiotics but no fever, should he receive his final meningococcal conjugate vaccine and inactivated influenza vaccine today before going to the emergency department?
What is the diagnosis and appropriate management for a patient with serum iron 20 µg/dL, transferrin saturation 5 %, and ferritin 5 ng/mL?
What is the appropriate weight‑based dose of low‑molecular‑weight heparin (LMWH) for a pregnant patient with atrial fibrillation?
What are the indications for red blood cell (RBC) transfusion in patients with epistaxis?
What is the recommended definitive therapy and overall management for juvenile nephronophthisis?
A 2‑day post‑lower segment caesarean section patient develops a seizure and remains irritable afterward, with blood pressure 140/90 mmHg. What is the appropriate acute management?

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.