What is a biosimilar?
A biosimilar medication is a biologic drug that is highly similar (but not identical) to an existing biologic medication that has already been authorized for use and for sale. A biosimilar medication is not a generic medication which is identical to the originator molecule.
The original biologic medication is referred to as the “reference biologic drug”.
Examples of biosimilars include:
- Jubbonti®: biosimilar of denosumab, reference drug: Prolia®)
- Osnuvo® (biosimilar of teriparatide, reference drug: Forteo®)
What is a biologic medication?
Biologic medications are made from living organisms or their cells and are complex large molecules.
Examples of biologic medications used for osteoporosis treatment include:
- Denosumab (Brand name Prolia®): A monoclonal antibody, with a specific target (RANK ligand).
- Teriparatide (Brand name Forteo®): A synthetic form of our natural parathyroid hormone.
- Romosozumab (Brand name Evenity®): A monoclonal antibody, which targets sclerostin.
Are Biosimilars the Same as Generics?
No. The medicinal ingredients of a generic drug are identical to that of the reference drug.
WHY ARE THERE BIOSIMILARS?
Once the patent of the reference biologic drug expires, other companies can produce biosimilars of the reference medication. The biosimilar requires less clinical research and is less costly to produce and hence will likely be less expensive to the consumer.
How do they work?
Biosimilar medications work in the same way as their reference medications. Biosimilars need to undergo vigorous testing, prior to receiving approval from Health Canada. In fact, since biosimilars are not identical to their reference medications, they need to undergo more studies prior to approval, as compared to generic medications. As compared to the reference biologic medication, biosimilars are tested to ensure that they are similar in structure, function, efficacy, and safety profile. For approval by Health Canada, clinical studies with biosimilars are required to be conducted in subjects who are affected by the disease they treat.
HOW EFFECTIVE ARE THEY?
A biosimilar drug is highly similar to the reference biologic drug, but not identical. Studies with the reference biologic and the biosimilar show the same clinical efficacy and safety profile and the chemical structure of the biosimilar is very similar to the reference medication.
As an analogy, the reference biologic drug is your key, and the biosimilar is a copy of that key, made at your local hardware store. The keys may look a little bit different, but they will both perform the same function adequately well – to unlock your lock.
WHO CAN TAKE THEM?
Indications for biosimilars have been granted on the basis of similarity between the biosimilars and their reference biologic drugs.
Jubbonti®, the biosimilar of Prolia® can be used to reduce the risk of fractures in postmenopausal women with osteoporosis and in men with osteoporosis at high risk of fracture.
Similar to Prolia®, Jubbonti® is also indicated as a treatment to increase bone mass in men with nonmetastatic prostate cancer receiving androgen deprivation therapy (ADT), who are at high risk for fracture, and as a treatment to increase bone mass in women with nonmetastatic breast cancer receiving adjuvant aromatase inhibitor (AI) therapy, who have low bone mass and are at high risk for fracture.
Jubbonti® is also indicated as a treatment to increase bone mass for the treatment and prevention of glucocorticoid (steroid) induced osteoporosis in women and men at high risk for fracture, similar to Prolia®.
Similar to Forteo®, Osnuvo® is used for the treatment of postmenopausal women with severe osteoporosis who are at high risk of fracture. It is also used in postmenopausal women who did not tolerate or do well with other osteoporosis medications. Osnuvo® is used to increase bone mass in men with osteoporosis associated with low testosterone levels, who have failed or are intolerant to previous osteoporosis therapy. For both men and women, Osnuvo® can also be used for the treatment of glucocorticoid (steroid) induced osteoporosis for those who are at increased risk of fracture.
HOW ARE THEY TAKEN?
Biosimilars are taken in the same way as their reference medications. The administration devices may be similar but not the same.
Osnuvo®, a biosimilar of teriparatide, is taken as an injection just under the skin (subcutaneous injection) into the thigh or abdominal wall. The injection is 20 mcg (micrograms) once a day. The injections are self-administered. One course of teriparatide should not last longer than 24 months. No one should take more than 24 months of teriparatide therapy, whether it is Forteo ®, Apo-Teriparatide (generic), Teva-teriparatide (generic) or Osnuvo® (biosimilar).
Jubbonti®, a biosimilar of denosumab is administered in the same way as Prolia, as an injection under the skin (subcutaneous injection), 60 mg/mL solution, by a trained healthcare professional or self-administered twice yearly.
