401 (Unauthorized) in Chrome, but not in IE

I recently moved from using jQuery to using isomorphic-fetch with Redux. When running in IE, it manages to fetch fine. However I get the below when running in Chrome.

Failed to load resource: the server responded with a status of 401 (Unauthorized)

It may be worth noting that the web api does have windows authentication enabled.

Here's the code that executes the fetch:

export const fetchSearchResults = (name) => {
  return (dispatch) => {
    dispatch(requestSearchResults(name))
    return fetch(API URI HERE)
      .then(response => response.json())
      .then(json => {
        console.log('Fetch: ' + json.message.features.length)
        dispatch(receiveSearchResults(json))
      })
  }
}