Entyvio hcp (Vedolizumab) is a humanized monoclonal antibody that stops the migration of memory T-lymphocytes across the endothelium into inflamed gastrointestinal parenchymal tissue by binding to the alpha-4 beta-7 integrin. This step is considered as the hallmark of inflammation in IBDs (inflammatory bowel diseases). It is usually administered at a dose of 300 mg as an intravenous infusion over 30 minutes in patients with moderately to severely active ulcerative colitis and Crohn's colitis who have an inadequate response to TNF inhibitors (e.g. Certolizumab and infliximab) and other immunomodulators.

Serious Side effects of Entyvio hcp:

Like most other biologic agents, Entyvio hcp (Vedolizumab) is associated with some serious side effects.

Most of the biologic agents including Entyvio (vedolizumab) have one or more of the following serious side effects:

• Serious infusion-related allergic reactions,
• Reactivation of serious infections like tuberculosis, fungal, bacterial, and viral infections.
• Neurological side effects such as headache and progressive multifocal leukoencephalopathy.
• Liver injury

Regarding the negative experiences of the use of biologics in patients with inflammatory bowel diseases, most patients showed their concerns for the following adverse events:

• Increased risk of cancers
• Safety of the drugs in pregnancy
• Immune suppressant effects
• Fatigue
• Rashes
• Skin lesions
• infections
• headache, and
• hair loss 

Hair loss, as a side effect of Entyvio hcp (vedolizumab), has not been mentioned in the manufacturer's labeling.

A study by Joseph Meserve et al titled "Retrospective Analysis of Safety of Vedolizumab in Patients With Inflammatory Bowel Diseases" evaluated more than 1000 patients for safety and adverse drug reactions. Out of a total of 1080 patients, only one patient reported hair loss as a side effect. Compared to Entyvio (vedolizumab), azathioprine and mercaptopurine are more likely to cause severe hair loss (A Phase 1, Multiple‐Dose Study of Vedolizumab in Japanese Patients With Ulcerative Colitis)

Most other studies have not reported hair loss as a side effect of the Entyvio. However, individuals have reported hair loss with the use of Entyvio.

Two patients reported hair loss while using Entyvio. One patient reported marked hair loss which the doctor thought was a consequence of disease severity.

The same patient had intestinal resection which might have led to decreased absorption of certain vitamins such as folic acid, biotin, and vitamin B12.

Folic acid, vitamin C, Biotin, and Vitamin B12 are important for hair growth.

The other patient reported thinning of hair, dryness, and brittle hair with Entyvio use but hair loss was not the primary complaint.

Skin manifestations of inflammatory bowel diseases:

Skin manifestations are among the common extraintestinal manifestations of inflammatory bowel diseases. Common skin manifestations of IBDs include:

• Erythema nodosum

[caption id="attachment_10555" align="aligncenter" width="600"] erythema nodosum[/caption]

• Pyoderma gangrenosum

• Sweet syndrome
• Necrotizing cutaneous vasculitis
• Psoriasis
• Epidermolysis bullosa acquisita
• Ulcerating skin nodules termed as metastatic Crohn's disease
• Increased risk of skin cancers

In conclusion:

Most studies have not reported hair loss as a side effect of Entyvio (vedolizumab). However, rare individual patients have reported hair loss as a side effect.