These enzymes promote inflammation, and they are involved in some diseases.
Inflammation is limited when the enzyme signaling pathways are interrupted, which can help some autoimmune diseases.
It will also discuss promising JAK inhibitors coming down the pipeline.
Verywell / Jiaqi Zhou
Verywell / Jiaqi Zhou
JAK Inhibitor Drugs
JAK inhibitors come in oral and topical forms.
Several others currently in the development pipeline are selective for certain JAK enzymes.
JAK inhibitors can help reduce inflammation.
Cytokinesare inflammatory proteins that attach to receptors on immune cells.
The STAT proteins further increase inflammation.
Overactivity of this process can make you susceptible toautoimmune diseasesconditions in which yourimmune systemattacks healthy, normal tissues.
JAk inhibitors interrupt this process so that STAT proteins can’t lead to increased inflammation.
Can JAK Inhibitors Regrow Hair?
Oral JAK inhibitors approved by the FDA to treat alopecia areata include Litfulo, Olumiant, and Opzelura.
These treatments have been shown to help regrow hair in patients with the autoimmune hair loss condition alopecia areata.
Those living with alopecia areata would need to stay on the medication for the results to be maintained.
Both types of drugs belong to thedisease-modifying antirheumatic drugs(DMARDs) family.
Biologics are made from animal or plant cells, and JAK inhibitors are synthetic.
Biologics are older and, therefore, have more data backing their use.
Biologics are administered via an infusion or intramuscular injection.
Biologics are also generally less expensive.
However, JAK inhibitors are in pill form or a topical utility, which makes them more convenient.
Some patients will do best with a combination of both biologics and JAK inhibitors.
Further, participants who took 10 mg per day showed greater improvement than those taking 5 mg daily.
Olumiant (baricitinib)
The FDA approved Olumiant in 2018.
It carries an FDAboxed warningfor cardiovascular issues, malignancy, and thrombosis.
Olumiant has also been studied as a psoriasis treatment.
Olumiant is available as a 1 mg, 2 mg, and 4 mg tablet taken once daily.
Jakafi (ruxolitinib)
Jakafi was FDA-approved in 2011.
It is designed to inhibit JAK1 and JAK2.
Rinvoq; Rinvoq LQ (upadacitinib)
Rinvoq was initially approved by the FDA in 2019.
Rinvoq LQ is available as a 1mg/mL solution, which is taken twice daily.
Results have generally been positive for Rinvoq as a treatment for the unapproved uses listed above.
The authors recommended further investigation of the drug for axial spondyloarthritis types.
This drug is available as 50 mg, 100 mg, and 200 mg tablets for oral administration.
Litfulo (ritlecitinib)
Litfulo was approved by the FDA in 2023.
Litfulo is approved by the FDA for the treatment of severe alopecia areata in people ages 12 and older.
This drug is available in a 50 mg capsule form to be taken once a day.
Opzelura is approved for treating nonsegmental vitiligo in adult and pediatric patients 12 years of age and older.
It is also approved to treat mild to moderate atopic dermatitis.
Opzelura is available as a 1.5% cream applied twice daily.
The maximum dose is 60 g per week or 100 g every two weeks.
Whats in the Pipeline?
Pipeline drugs are currently being developed and tested but aren’t FDA-approved for any use.
Researchers hypothesize this could mean fewer side effects.
Status
Phase 3 trials have been concluded.
In August 2020, the FDA rejected the drug due to toxicity.
It was approved for medical use in both the European Union and Japan in September 2020.
Research Highlights
Here’s a sample of takeaways from research on filgotinib thus far.
Phase 3 trials are concluded, and the manufacturer has submitted a new drug software to the FDA.
This drug is approved for treating rheumatoid arthritis in Japan under the brand name Smyraf.
Phase 2 trials are currently underway for testing the efficacy and safety of Itacitinib for treating plaque psoriasis.
Research Highlight
A phase 2 study published in 2016 demonstrated significant improvement in an assessment of plaque psoriasis symptoms.
Other potential uses are in earlier stages of study.
SHR0302
SHR0302 is believed to be a highly selective JAK1, JAK2, and JAK3 inhibitor.
It’s being investigated as a possible treatment for:
This drug is not approved for any use.
In June 2020, phase 2 and 3 trials for ankylosing spondylitis began.
Phase 3 trials for rheumatoid arthritis are expected to conclude in 2022.Preliminary research has begun for lupus.
Little research on this drug has been concluded and published.
Why Do Pipeline Drugs Have Code-Like Names?
In its earliest stages, a new drug is given an alpha-numeric name.
Later, it’s assigned a generic name.
Once it’s approved by the FDA, the manufacturer gives it a brand name.
Typically, drug names are written with the brand name first and the generic name in parentheses.
Some common ones may go away once your body gets used to the medication.
Others may persist and have serious effects.
Some can be managed through lifestyle and medication, while others require a medication change.
Immune-System Suppression
Similar to biologics and traditional DMARDs, JAK inhibitors suppress the immune system.
While that makes them beneficial, it increases vulnerability to severe infectionsespeciallyupper respiratoryandurinary tract infections.
If you stop using these drugs, your immune system should return to normal and begin preventing infections again.
Contraindications and Warnings
JAK inhibitors can also causeanemiain some people.
This is due to how they affect proteins the body needs to make red blood cells.
JAK inhibitors are also known for lowering white blood cell counts, a condition calledlymphopenia.
Liver damage is a possible adverse reaction of JAK inhibitor use.
These drugs are contraindicated in patients with diverticulitis, as they can lead to viscous perforation.
They work by interrupting a chain of reactions that lead to inflammation.
However, these medications are relatively new, and researchers are still learning more about their long-term safety.
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