Some effective medicines are remarkably simple in their chemical structure and others are extraordinarily complex. Biologics, drugs derived from biological sources, can have tremendous complexity that is heavily dependent on the specific circumstances of their production, raising some interesting challenges when companies attempt to reproduce existing biologics. 

For more than a century, we’ve been using biologics to treat, and immunize against, a wide variety of medical conditions. The number of biologics on the market skyrocketed in the 1980s and 1990s as new genetic recombination technologies allowed researchers to tap into a vast array of previously unexplored molecules. As the patents on these often expensive drugs begin to expire, competitors are rushing to offer alternate versions of these biologics, but their deep complexity means that perfect reproduction can be impossible. “Biologic drugs are much more complex molecules than standard small molecule drugs,” says Dr. Mark Silverberg, a gastroenterologist and Professor of Medicine at the Inflammatory Bowel Disease Centre at Mount Sinai Hospital, University of Toronto. “They are proteins with primary, secondary, and tertiary structures, so it’s not really possible to copy it exactly the way you can with a small molecule generic. What you can do is create another molecule that is very similar, and that’s what biosimilars are.”

Different molecule, same effectiveness

Now that biosimilars are entering the market for conditions ranging from rheumatoid arthritis to inflammatory bowel disease, there are important questions to ask about how close is close enough. When a patient or doctor opts for a generic small molecule drug like a painkiller in place of a name brand, they know that the two drugs are chemically identical, so the exact same effect can be expected. With biosimilars, it is quite a bit more complicated. “The risk is that the molecule won’t behave exactly as the originator biologic would,” says Dr. Silverberg. “For the most part, however, what we’ve seen has been very reassuring.”

In practice, the regulation process requires that a biosimilar be demostrated to have the same safety and efficacy as the originator drug, as well as having a substantially similar chemical structure. In other words, manufacturers are expected to show that the small chemical variations between the two drugs do not affect patient outcomes. For patients with conditions that are treated by expensive biologics, effective new alternatives can provide a huge boon. “Biosimilars potentially provide access to a less expensive version of the originator drug,” says Dr. Silverberg. “This means that more patients have access to it, and it brings down the cost to the health care system.”

New treatment options for those who need it most

Inflammatory bowel disease is one of the newest conditions to see a biosimilar approved for its treatment in Canada. The hundreds of thousands of Canadians who live with this painful condition are always eager for any new treatment alternative, especially as the effectiveness of existing treatment can vary wildly from one patient to another.

Inflammatory bowel disease is in fact a constellation of similar conditions, including ailments like Crohn’s disease and ulcerative colitis, with a diverse selection of different drugs that can attack the illness from different vectors. There is currently no cure, so patients are dependent on medications taken on an ongoing basis to control symptoms and inflammation. This means that the pricetag of costly drugs can balloon quickly.

Biologics have been helping people with hard-to-treat inflammatory bowel disease since 1999, but they can be phenomenally expensive. Now, biosimilars are providing a possible route to more affordable care without sacrificing efficacy.

The importance of informed choice

For patients who are just starting on a biologic, biosimilars provide a more cost-effective alternative with the same overall effectiveness. For patients who are already on a biologic, however, the question of whether or not to switch is more nuanced. “For a patient who is new to biologics, the data generally points to biosimilars being safe and effective,” says Dr. Silverberg. “There’s a little more controversy regarding switching, when a patient who is responding well to a biologic is forced to switch to a biosimilar for no reason other than cost savings. We don’t yet have strong data supporting switching in these cases.”

Over time, that data will accumulate and doctors will be able to make a more confident decision regarding whether patients can be safely switched to more affordable biosimilars in a similar fashion to the way patients are often transitioned from name-brand small molecule drugs to generics. Until the research delivers a clear picture, however, patient advocacy groups are rightfully insistent that switching should be a choice, not a mandate.

Overall, biosimilars are simply providing a greater choice of treatment options for patients with inflammatory bowel disease and other conditions. In medicine, as in most things, more choice is unequivocally better, so long as people are properly educated about the options. “Patients should know what their alternatives and options are,” says Dr. Silverberg. “We can’t just discuss the drug and not address the fact that it’s a biosimilar. Patients need to ask their doctors about the products, how long they’ve been on the market, and what the data says on safety and efficacy. As long as people are having a good discussion about what their options are, then they will be able to make an educated choice.”