Biosimilars: Hope and concern.

As patents of the first introduced biologic therapeutics in oncology have begun to expire, competing pharmaceutical companies are allowed to produce and market the same protein as the original agent. These products are called biosimilars. Upon patent expiration, biosimilars would hopefully be a cheaper alternative to the original agent and that is the main reason for their existence. Although the financial aspect is similar to generics, the complex nature of these products generates the need for a distinct regulatory environment. Biosimilars are produced by DNA technology in bacteria, plant cells, or animal cells, while generics are produced by chemical synthesis. Details in the process of synthesis, selection of the microorganism, protein extraction, purification and manufacturing, affect the precise nature of the end product. Monoclonal antibodies are large proteins with four polypeptide chains and interact variably with each other and with the environment. It is important for payors to realize that biosimilars are different from generics; therefore, they need to develop different set of rules for approving, registering, and dispensing biosimilars. Regulators ought to respect the physicians' request for non-interchangeability and facilitate in any possible way of traceability. Such regulations along with a rigorous pharmacovigilance program will satisfy the concerns for true equivalence in activity and long-term safety. This is the only way to accumulate over time reliable safety information for new biosimilars. In conclusion, the wish born by the medical community and the society for a more affordable health system triggers the emergence of biosimilars, which could meet that goal if properly regulated.

Feasibility of rapid infusion of the initial dose of bevacizumab in patients with cancer.

PURPOSE: Bevacizumab is a monoclonal antibody against vascular endothelial growth factor (VEGF) widely used in clinical oncology. Bevacizumab is commonly co-adminis- tered with chemotherapy. It is recommended that the first infusion of the antibody last 90 min, the second 60 and all subsequent 30 min. Since there is no clear rationale for the proposed schedule of administration, our study assessed the feasibility of a 30 min initial infusion. METHODS: Cancer patients eligible for de novo bevacizumab treatment were enrolled. All patients received standard bevacizumab dose of 5, 7.5 or 10 mg/kg according to the indication, diluted in 250 ml normal saline, as a 30-min intravenous infusion. RESULTS: Thirty two patients were enrolled: male 18, female 14, median age 58 years, range 42-78. Oncologic diagnosis: lung cancer 16, colorectal 4, breast 3, ovarian 7, renal 2. All patients tolerated the infusion well. No hypersensitivity reactions were noted. Mean systolic and diastolic blood pressures were 122 and 73 mm/Hg respectively prior to the infusion and 125 and 75 mm/Hg 15 min after the infusion (p=0.3). During the observation period of 1 hour, blood pressure did not change. Transient grade 3 systolic hypertension was noted in 1 patient, with spontaneous regression in 45 min. CONCLUSION: Rapid administration of bevacizumab in 30 min, rather than the recommended in the package insert 90 min is feasible and safe. Such a practice limits the time of confinement in the treatment area to patients' satisfaction and would result in cost savings by reducing health resource utilization.