The last decade has brought a totally new class of systemic anticancer treatment options, the so-called cancer (cell)-specific (CCS) anticancer agents. Until recently, this treatment modality has been referred to as 'targeted therapy' but as all existing systemic anticancer therapies have a clearly defined target, this seems to be a misnomer. Despite impressive results of several CCS drugs, the present set up of drug development is ill suited for CCSs due to the nature of the majority of these compounds. The authors focus on specific aspects of how to design early clinical trials with this new class of anticancer agents with focus on pharmacodynamic behaviour in relation to response, optimal dose and treatment duration.