If you visit Microsoft Endpoint Manager | Endpoint Security | Microsoft Defender for Endpoint and scroll down the page on the right you see the new section App Policy Protection Settings as shown above. Turning this ON will basically allow the state of Microsoft Defender on both Android and iOS to feed into your compliance policies.
Once you have enabled these settings visit Apps | App Protection policies and edit or create an policy. During this process you will find a Conditional launch section. If you then scroll down to the bottom of tat page you will the screen shown above where you can add the setting for Max allowed device threat option. This basically is the threat level you would allow on your device. If the threat level on a device goes above this then the selected action will take place. That action can either be Wipe or Block. Wipe is rather drastic, especially to start with, so Block is probably the best starting point.
You can read more about this new capability here:
It is a nice integration we are beginning to see more of between device management and Defender for Endpoints.