Our friends at PharmaCircle recently published an interesting and provocative piece entitled Injectables: The New Oral? The PDF is available here.
The article notes that, in 2014, seven of the top ten pharmaceuticals were parenteral products, with products such as Humira, Remicade, and Enbrel achieving $9-12+ billion in sales.
This is a huge change from ten years previously, where only one parenteral product (Epogen) was in the top ten.
The article discusses some of the key reasons why this change has taken place:
So where do parenterals go from here? We think there are a few areas where parenterals could indeed approach the levels of usage of oral therapies:
Lower Dosing – Highly potent peptides and proteins which can be dosed at ~2 milligrams or less are perfect for any number of self-injection devices, skin-permeating patches, and other delivery devices which can greatly expand their use.
We think low-dose, higher frequency regimens, via novel devices will become more common in the future.
Smaller Large Molecules – Scanning the list of top 10 drugs for 2014, seven are large molecules, and only two (Lantus and Enbrel) are not monoclonal antibodies. Even with Enbrel, we are looking at a molecular weight of roughly 50,000 daltons, while Lantus checks in at a svelte ~6,000 daltons.
As our collective understanding of both disease and drug-target interactions improve, might we see these molecular weights decline? Maybe. Maybe not. But if they do, then self-dosing becomes increasingly possible.
Novel Combinations – Lower doses with small molecules opens up the theoretical possibility of parenteral combination therapies via self-injection. Perhaps small molecules and large peptides/small proteins can be combined in single, self-injection systems for severe inflammation (i.e., later-stage Crohn’s Disease), for maintaining cancer remission, and other medical needs.
Stability issues aside, patients who are using both oral and parenteral therapies could benefit from combining them into a single parenteral. While increasing Rx cost, it could increase compliance and improve overall therapeutic benefit.
So will parenterals ever become as common as orals? Probably not. But the premise of the article is quite sound, in the sense that parenteral products will continue to become more routine, thanks in part to easy-to-use self injection systems and devices.