What long-term side effects can happen with Cosentyx (secukinumab)?
Cosentyx (secukinumab) targets interleukin-17A and is used for chronic inflammatory conditions such as plaque psoriasis, psoriatic arthritis, and ankylosing spondylitis. The main long-term safety issues clinicians watch for are infections, effects on the immune system, and rare but important longer-term risks.
The most consistent long-term concern is infection risk, because IL-17 blockade can affect how the body responds to certain bacteria and skin/mucosal infections. Long-term use also keeps patients exposed to ongoing immunomodulation, so infections can recur or become more serious than expected in people who develop them [2].
Other longer-running risks that need monitoring include:
- Serious infections (including tuberculosis reactivation risk in people with prior TB, which is why screening is standard) [2]
- Mucocutaneous fungal infections such as candida/thrush [2]
- Inflammatory bowel disease (new onset or worsening) has been reported with IL-17 pathway inhibitors, and symptoms may need ongoing attention over time [2]
Do people get immune problems or more cancers from long-term Cosentyx?
Cosentyx can change immune signaling for as long as it’s used. Over the long term, this creates ongoing concern about whether immune suppression could raise malignancy risk. The available long-term clinical experience for IL-17 inhibitors has not shown a clear, definitive cancer signal in the way some older immunosuppressants did, but risk is still monitored because the mechanism is immunomodulatory and because rare events take years to detect [2].
Patients who have a personal history of cancer or who develop new, unexplained symptoms during treatment should discuss risk and monitoring with their prescriber [2].
What infections should patients monitor for while staying on Cosentyx long-term?
For long-term users, the practical infection question is less “Will I get infections?” and more “What kinds, and when should I stop and call my clinician?”
Common infection patterns to report promptly include:
- Fever or signs of a bacterial infection (pneumonia, skin infection, urinary infection)
- Thrush or other fungal symptoms (mouth sores, persistent yeast infections) [2]
General guidance is that if a serious infection develops, clinicians typically reassess whether Cosentyx should be held until the infection is controlled [2].
What about inflammatory bowel disease (IBD) and long-term use?
Some patients may develop new IBD symptoms or see worsening of existing IBD during IL-17 inhibitor therapy. That matters for long-term treatment decisions because IBD is chronic and can require long-term management.
People with Crohn’s disease or ulcerative colitis, or those with new symptoms like persistent abdominal pain, diarrhea, or blood/mucus in stool, should contact their clinician quickly so treatment can be reevaluated [2].
Are there long-term cardiovascular or neurological side effects?
For IL-17 inhibitors like Cosentyx, long-term safety monitoring focuses mainly on immune-related outcomes (infections, hypersensitivity, IBD signals, and fungal infections). The provided source information does not point to a specific, established pattern of long-term cardiovascular or neurological side effects as the dominant issue compared with immune-related risks [2].
When should patients consider stopping or switching because of long-term side effects?
In real-world practice, long-term side effects usually trigger action when they are:
- Serious (hospitalization-level infections, severe allergic reactions)
- Recurrent or difficult to treat (repeated significant infections)
- Consistent with IBD symptoms (persistent GI complaints that fit IBD) [2]
The decision to stop or switch should be individualized with the prescribing clinician; do not stop Cosentyx without discussing the reason, since stopping can allow the underlying disease to flare.
Do biosimilars or switching affect the long-term risk profile?
Switching within the same drug class (IL-17 pathway) or to a different biologic can change which long-term risks a patient is exposed to (for example, IBD-related caution is class-relevant but not identical across all agents). The key is matching the drug choice to a patient’s history (recurrent infections, prior TB, prior IBD/IBS symptoms, fungal infection history) [2].
If you tell me which condition you’re treating (psoriasis vs psoriatic arthritis vs ankylosing spondylitis) and how long you’ve been on Cosentyx, I can tailor which long-term effects people most commonly report for that specific use.
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Sources cited:
1. https://www.drugs.com/cosentyx.html
2. https://www.drugs.com/sfx/cosentyx-side-effects.html