Blackwell, K., Donskih, R., Jones, C.M., Nixon, A., Vidal, M.J., Nakov, R., . . . Harbeck, N. (2016). A comparison of proposed biosimilar LA-EP2006 and reference pegfilgrastim for the prevention of neutropenia in patients with early-stage breast cancer receiving myelosuppressive adjuvant or neoadjuvant chemotherapy: Pegfilgrastim randomized oncology (supportive care) trial to evaluate comparative treatment (PROTECT-2), a phase III, randomized, double-blind trial. Oncologist, 21, 789–794. 

To compare the efficacy and safety of a pegfilgrastim biosimilar to reference pegfilgrastim

Patients were randomized to receive 6 mg of either reference pegfilgrastim or a biosimilar. The colony-stimulating factor (CSF) was given on day 2 of each cycle. ANC was measured on day 1 of cycle 1, then daily until recovery after nadir or until day 15. A margin of one day of neutropenia was established as the margin for noninferiority analysis.

• N = 275   
• MEAN AGE = 48.9 years
• FEMALES: 100%
• CURRENT TREATMENT: Chemotherapy
• KEY DISEASE CHARACTERISTICS: Patients with breast cancer receiving docetaxel, doxorubicin, and cyclophosphamide (TAC) chemotherapy 

• SITE: Multi-site   
• SETTING TYPE: Not specified    
• LOCATION: European countries

• PHASE OF CARE: Active antitumor treatment

• Noninferiority, randomized, controlled trial

• Consecutive days of neutropenia 
• Depth of absolute neutrophil count (ANC) nadir
• Days to ANC recovery
• Infections

All study outcomes were similar in both groups. Over 95% of both groups had musculoskeletal adverse events, including bone pain, myalgia, arthralgia, and back pain (13.7%–16.1% of patients).

The CSF biosimilar evaluated here demonstrated similar efficacy and safety to that of the reference pegfilgrastim.

Pegfilgrastim and the CSF biosimilar evaluated were shown to be therapeutically equivalent.