Knife defense 101:
There's something called the primary weapon rule. If you're getting attacked by a knife and you have a gun obv you want to make space, you want to be more than 20 feet away. You can throw the good old push kick/front snap/teep to make space but you'll probably not make enough to draw unless your kick disables the attacker.
If you're in knife range and currently getting stabbed and your gun is not out, then drawing is not the right move. There's something called the Primary Weapon Rule. All your attention needs to be on that knife, you're not protecting anyone else, you're not doing anything but trying to get two-on-one, two hands on the attacking hand. You don't move to anything else until you control the knife. You always want to move off of the angle of attack, get your feet out of the way. Keep your hands up, shoulders shrugged, body crunched. Try and cover all your vital organs and your neck and face. Don't extend your hands, keeping them close to your body will help you not get cut. If I'm stabbing and you reach out you open a nice space for me to put the knife into, usually liver, kidneys, or pancreas. Keep the backs of your hands and arms towards the attacker, if you're good you're probably going to only get cut in the hands but you don't want to get cut in the inside of your wrist because you'll bleed out. Crash into the attacker off the line of attack to the outside and get your two on one. You can't have a knife between two people fighting over it, we call this 50/50 because nobody has an advantage, bad news for knife fighting. What you can do is attach the knife to something, the ground, a wall, the ceiling. The best for me is the ground. If someone stabs down and you can crash the knife into the ground, you can step on it freeing your hands, satisfying the primary weapon rule. You can then go to town with knees or elbows or whatever.
There's some really cool drills built around two-on-one fighting. You really want to microtrain that so it's instinctive.
So basically, if you have good open handed skills, within stabbing range you're better off with nothing if your hands.