Entyvio, PML and other side effects

Sure I can explain what it's all about and let's start with a brief history lesson.

The first medication of this type of biologic was known as TYSABRI (natalizumab) which blocked both MADCAM1 and MADCAM2. It was discovered that by blocking MADCAM2, it had a rare side effect of PML that affect the brain and a black-box label was added to the medication.

Subsequently, a new Entyvio (vedolizumab) was specifically developed to only block MADCAM1 and thus not have any chance of the PML side effect. MADCAM1 was shown to be gut-specific, and only affects the gut as intended. There has been no instances of PML with entyvio either during clinical trials and while the medication has been available on the market. As entyvio is within the same class of medications as Tysabri (both MADCAM-inhibitors), the FDA mandates that the PML black box warning appears on both medications labels.

So entyvio patients aren't typically tested for the JCV virus, there's no incidences of PML with it, and in theory there should be zero chance of ever getting a PML on entyvio. As entyvio was developed to avoid the possibility of it. Takeda Pharmaceuticals developed both medications, and entyvio is an improved, safer medication.

Edit: Added Details
Generally you are not going to see TYSABRI prescribed at all for UC. Rather, it's pretty much limited to MS patients, who as a generalization have a broader acceptance of risk due to the severe debilitating nature of MS.

From here:

https://www.healio.com/gastroenterology/inflammatory-bowel-disease/news/online/%7bef9c33ea-2cf9-41fa-81eb-fd29e380e0d1%7d/entyvio-safe-effective-for-uc-in-real-world-study

"The 12-month cumulative rate of clinical remission was 51% and for endoscopic remission it was 41%. Also at 12 months, investigators found that 37% of patients experienced steroid-free remission, and 30% experienced deep remission."

These numbers are really good considering most people who use Vedo (Entyvio) have already failed other biologics, which skews the results. If Entyvio was used as a first line treatment, these already good numbers would certainly be even higher.

PML has been a total non-issue for the reasons iPoop pointed out.

Sepsis is something that happens when an infection spreads beyond its initial site, generally not a worry as long as you are prompt on treating major infections. Pretty much if you have symptoms of an infection requiring antibiotics (like an UTI, sinus infection, or bronchitis) then seek out antibiotics earlier on, rather than trying to wait it out Normal cuts, scrapes and bruises are of no worries.

FlowersGal, that's great you had such a positive experience with Entyvio! Was it the first biologic you tried?

What I don't understand is - if this medication suppresses only the immune system of the gut, why is there still an increased risk of infections in other parts of the body. I heard that respiratory infections are common for example.

Entyvio suppresses the gut side of the immune system, which can include some things you/I might not include in that definition. The lungs have a physical connection to the GI tract and therefore share similar cells, and entyvio reacts on them.

Keep in mind that a lot of the people in the study were likely very sick and weak from flaring, and many (probably a majority) started Entyvio when they were already on long-term high doses of prednisone. That confounds the results. Also they don't define what a "serious adverse event" is, my guess is mostly allergic reaction.

Katerina FWIW Entyvio has been a life changer for me. It was not my first biologic. I was on Simponi first, then tried 6mp but had a bad reaction to it. I have asthma and two small kids and I’ve had no issues with infections or respiratory issues. Are you on a biologic now? If you can get blood tests to check your current immunity levels. I came here to post about my fear of measles since I have no immunity to it so I dearly wish I had been tested when I could have been vaccinated.