New safe and affordable drugs to halt the spread of drug-resistant malaria parasites are urgently needed. In this issue, Fidock and colleagues comment on the lack of standard in vitro and in vivo screens for malaria drug discovery, and recommend a streamlined process for evaluating drug efficacy. Cohen and Goedert review how efficacy is becoming evident for inhibitors of glycogen synthase kinase-3 (GSK3) in animal models of type 2 diabetes. GSK3 was ignored as a drug target by the pharmaceutical industry for more than 20 years, but new more potent and specific inhibitors show promise for treating diabetes and neurodegenerative diseases. CNS drug delivery carries both the challenge of circumventing the blood–brain barrier and avoiding damage to healthy tissue. Lesniak and Brem discuss progress in the delivery of drugs directly to tumours in the CNS, whereas Milenic and colleagues report on the clinical development of an alternative method for targeted cancer therapy: radionuclide-labelled monoclonal antibody therapies. Monoclonal antibodies look set to have a huge impact on healthcare, and this month's 'From the Analyst's Couch' speculates on how monoclonal antibodies will affect the US colorectal cancer market, while 'Fresh from the Pipeline' profiles efalizumab, a monoclonal antibody recently approved for the treatment of psoriasis. Approval of new biologics is often hindered by regulatory hurdles, just one of the factors cited by Preziosi in his 'Perspective' article on the increasing costs of drug development. Perhaps new imaging technologies, such as contrast-enhanced ultrasound described in this issue by Lindner, can be used to provide more detailed efficacy data that could smooth the approval process for new drugs.