Baumer wrote:If Avonex and Rebif are the same drug (interferon beta 1a) and the difference is the way it is injected (IM vs. SC), then why couldn't someone buy a months supply of Rebif (which is approximately the same price as Avonex) and simply inject 2/3 of the 44mcg dose IM? For the same price (appoximately) you would have 3 months worth of drugs?
Well, they are in different buffers and that might make a difference when injecting Rebif intramuscularly. But you have a good question and, unfortunately, I don't have a good answer. Clearly, if the quantity of Ifn-B was the critical determinant, then the pricing would reflect that. However, it appears as though there are likely arbitrary factors built into the price of the medications.
30 mcg Lyophilized Powder Vial
Each vial of reconstituted AVONEX ® contains 30 mcg of Interferon beta-1a; 15 mg Albumin (Human), USP; 5.8 mg Sodium Chloride, USP; 5.7 mg Dibasic Sodium Phosphate, USP; and 1.2 mg Monobasic Sodium Phosphate, USP, in 1.0 mL at a pH of approximately 7.3.
30 mcg Prefilled Syringe
Each 0.5 mL (30 mcg dose) of AVONEX ® in a prefilled glass syringe contains 30 mcg of Interferon beta-1a, 0.79 mg Sodium Acetate Trihydrate, USP; 0.25 mg Glacial Acetic Acid, USP; 15.8 mg Arginine Hydrochloride, USP; and 0.025 mg Polysorbate 20 in Water for Injection, USP at a pH of approximately 4.8.
"Each 0.5 mL (0.5 cc) of Rebif® contains either 22 mcg or 44 mcg of
interferon beta-1a, 2 or 4 mg albumin (human) USP, 27.3 mg mannitol
USP, 0.4 mg sodium acetate, Water for Injection USP.