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, andp is from about 3 to about 5.
