No, at least not normally or without serious modifications. The line 6 Spider IV 75 does not have a way to connect to a cab.
However, it does have a 1/4 stereo direct out, which can be hooked up to a console that accepts stereo 1/4 connectors. or headphones if you have an adapter. It basically shuts down the power-amp section of the amp and uses the preamp. The obvious use for this are headphones, recording, hooing it up to a mixer -> PA
I have tried it, and the sound was extremely different (obviously) comapared to using the built in speakers, leaning towards the worse. So I personally recommend just micing your amp up old school style.