I have uploaded an improved version of this font the following site, version which basically corrects the metadata:

https://fontlibrary.org/en/font/radis-sans

The original website from this font is no longer available. You will want to make the above page the new one, and build this package from there in case there are further updates.

Also fixes:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=805987

The new font version has a Reserved Font Name. At Debian we would rather
not include a RFN when there is a font version without RFN, which is
already packaged.