# Have we hit the JAK‐pot? Success of selective JAK 1 inhibitor following failure of pan‐JAK inhibitor in refractory pediatric ulcerative colitis

## TL;DR

A child with severe ulcerative colitis who failed multiple treatments achieved remission with a selective JAK1 inhibitor after a broader JAK inhibitor failed.

## Contribution

This case highlights the potential effectiveness of selective JAK1 inhibition over pan-JAK inhibition in refractory pediatric ulcerative colitis.

## Key findings

- The patient achieved rapid clinical remission with upadacitinib after failing multiple therapies.
- Failure of tofacitinib (a pan-JAK inhibitor) was followed by a response to upadacitinib (a selective JAK1 inhibitor).
- Selective JAK1 inhibition may offer a new treatment option for refractory pediatric UC.

## Abstract

The treatment options available for pediatric ulcerative colitis (UC) are challenging due to few with Federal Drug Administration approval. Newer medications approved for adults include additional biologics with differing mechanisms of action and small molecule drugs, such as Janus kinase (JAK) inhibitors. Our case outlines a patient with refractory UC who failed mesalamine, adalimumab, tofacitinib, and vedolizumab. She was evaluated for colectomy, but upadacitinib was trialed. She achieved rapid clinical remission and avoided surgery. This case demonstrates the failure of a pan‐JAK inhibitor (tofacitinib) and response to a more selective JAK 1 inhibitor (upadacitinib).