Editor's Note: This was updated on 6/21 to reflect that Upadacitinib was not licensed from Galapagos.

Being the first drugmaker to develop a therapy attacking a new target in cells can result in blockbuster sales. But other companies can wrestle that market share away from the first-in-class drugs with follow-on drugs going after the same targets if the new drugs can provide better safety, efficacy, or dosing than the current offerings.

Here are three follow-on drugs that have proven their worth in clinical trials and are waiting for FDA approvals before the companies can start the competition with the current standard of care.




FDA Decision Expected


AbbVie (ABBV 1.00%)

Rheumatoid arthritis

Mid-August 2019*


Novartis (NVS 2.19%)

Wet age-related macular degeneration

Mid-October 2019*


Celgene (CELG)

Relapsing forms of multiple sclerosis

March 25, 2020

Source: Company press releases. *Estimated based on announcement of filing the marketing application and the FDA accepting it.

Doctor sitting at a table with a patient.

Image source: Getty Images.

JAK of all trades

Upadacitinib is a Janus kinase 1 (JAK1) inhibitor that AbbVie is developing for a range of diseases in which an overactive immune system leads to inflammation. JAK1 and its siblings, JAK2 and JAK3, are signal transducers that work in the immune cell stimulation pathway. Inhibiting the pathway dampens the immune reaction that causes diseases such as rheumatoid arthritis, Crohn's disease, ulcerative colitis, atopic dermatitis, and psoriatic arthritis.

Pfizer's Xeljanz, which targets JAK3, brought in $423 million in sales in the first quarter, a jump of 34% as the drug moves beyond rheumatoid arthritis and into psoriatic arthritis and ulcerative colitis, which it was recently approved to treat.

While AbbVie has some work to do to take away market share from Pfizer and Eli Lilly's (LLY 0.70%) JAK inhibitor Olumiant -- and additional upcoming competition from Gilead Sciences' (GILD) filgotinib -- there's some evidence that upadacitinib might work better than Xeljanz based on their respective studies comparing the drugs to Humira. AbbVie also has a dominant position in the rheumatoid arthritis space since it sells Humira, and it may be able to get a preferred position on insurers' lists of covered drugs.

Man getting an eye exam.

Image source: Getty Images.

Seeing better efficacy

Brolucizumab targets vascular endothelial growth factor (VEGF), which promotes the blood vessel growth in patients with wet macular degeneration in the eye. The drug will compete directly with Regeneron Pharmaceuticals' (REGN 0.33%) megablockbuster Eylea, which also targets VEGF and brought in $1.7 billion in sales in the first quarter.

In two head-to-head studies, brolucizumab was deemed noninferior to Eylea, with the drugs improving patients' ability to see letters on an eye chart at about the same levels. But brolucizumab beat Eylea in measurements of disease activity with 23.5% and 21.9% of patients having disease activity at the end of the studies compared to 33.5% and 31.4% of patients taking Eylea having disease activity in the two respective late-stage clinical trials.

Brolucizumab may also have some dosing benefit because the clinical trials compared 12-week dosing of brolucizumab with 8-week dosing of Eylea. Patients obviously would prefer to have fewer injections into their eyes, and that goes double for older patients who may need assistance getting to the doctor. Eylea has since been approved by the FDA for 12-week dosing, although the 8-week dosing may still provide better results, leading doctors to prefer brolucizumab's 12-week scheme.

Second time's a charm

This is ozanimod's second time in front of the FDA, although the first stint was fairly short-lived. After submitting the marketing application, Celgene received a refuse-to-file letter from the FDA because it hadn't fully characterized a metabolite -- breakdown product -- of the drug. Celgene ran the required studies, and the FDA accepted the marketing application earlier this month. Nevertheless, the regulatory history of the drug makes an approval less certain than the other two drugs.

Ozanimod modulates sphingosine 1-phosphate (S1P) receptor 1 and 5 on immune cells, which attack myelin, the protective sheath that covers nerve fibers in multiple sclerosis patients. By modulating the activity of the immune cells, ozanimod and other S1P modulators, such as Novartis' Gilenya, can slow the disease progression.

Celgene, which is in the process of being purchased by Bristol-Myers Squibb (BMY 0.54%), has set up ozanimod as a safer version of Gilenya, which racked up $766 million in sales in the first quarter. For example, the first dose of Gilenya has to be monitored in a doctor's office because it can slow the heart rate in some patients, but ozanimod doesn't appear to have the heart issue. While ozanimod's activity may not be as strong as Gilenya's, doctors are likely to prescribe the safer drug even if it means giving up some disease-slowing activity.