Apple - Is there a way to remove App from iTunes Connect?

There is no way to do it. To delete an app, this must be approved first.

Apps that have not been approved yet can't be deleted.

Transferring and Deleting Apps

New feature is added by Apple to delete an app from iTunesConnect. For details, refer to this help document:

Delete an app from your account

While you can't delete an app that has not been approved, you can edit and reuse the same app record for a new app.

When I talked to Apple's Developer Support team about a previously rejected and abandoned app in our account, this is the method they suggested as it is possible to edit the bundle identifier, app name and all existing assets prior to submitting for review, essentially making a new app record out of the old one.

We did this, noting the circumstances of the previous rejection in the App Review section and that they did not apply to the new app, and were able to successfully reuse the old record.