It's generally better to test using a proxy, or to have your application deployed on the target environment (to rule out any CORS and/or authentication issues)
But anyway, if your application runs on a local webserver, in IE open the Internet Options, go to Security tab, and for the current zone click 'Custom Level', find the entry 'Access data sources across domains' and set to 'Enable'.
But after testing, make sure you disable it again, since it makes you vulnerable to all sorts of attacks!