Methods for the treatment of CD30-expressing cancers are provided. The methods comprise administering to a subject in need thereof a weekly dose of from about 0.8 mg/kg to about 1.8 mg/kg of an antibody-drug conjugate compound having formula (I); or a pharmaceutically acceptable salt thereof; wherein: mAb is an anti-CD30 antibody unit, S is a sulfur atom of the antibody, A- is a Stretcher unit, and p is from about 3 to about 5.