Disclosed herein are amplification systems that are dynamically biased based on a signal indicative of differential envelope of an input radio-frequency (RF) signal being amplified. The amplification systems include a cascode amplifier configured to amplify the RF signal to generate an output RF signal when one of the transistors of the cascode amplifier is biased by a combination of the input RF signal and a biasing signal while the other transistor of the cascode amplifier is biased by a processed differential envelope signal. The cascode amplifier also receives a combination of a processed differential envelope signal and a supply voltage to generate the output RF signal. The biasing signal can improve or enhance the linearity of amplification systems.