Wind Against the Wrist
Meyer's dagger section provides a number of precepts; general principles for dagger fighting.
The fifth precept describes what to do if he grabs our arm in a parry (though is useful in all wrist grabbing scenarios).
If we attack the high openings with a reverse grip and he grabs our wrist with his free hand in a reverse grip, wind clockwise with our dagger under his wrist so our hand is toward his inner arm. From here we can wrench upward and stab down, or if strong enough we can stab straight in (assisting with our left hand as the Third Precept advises if we need to; hand on our pommel/right-wrist/hand). If his grab is not with reversed grip, we are advised to turn in against his palm, again using our left hand as needed.
Alternatively if he has gripped your right wrist with his left hand reverse grip, grab his left wrist with your left hand and pull his wrist down toward you in a kind of wrist lock to overbalance him. Experience tells us that if we do this with a spiral motion toward our left hip/thigh, and step back and around with our left, his balance will be broken. From here we can achieve the straight arm break from our Joint locking techniques. We can also step forward across him and move into the rear bent arm break from the same set of actions.
The general rule is that we should twist out of his attacks against his natural angle of motion, locking, escaping, then counterattacking.