DESIGNER DRUGS - PIPE-DREAMS OR REALITIES

New chemotherapies are urgently needed for the parasitic infections of animals and for the tropical diseases of man. Rational molecular desi gn approaches to attempt to discover such products require a massive i nvestment of resources up-front of actual chemical synthesis. However, such investment is justified, since chemical synthesis itself is high ly resource-consuming. The fact that few targets have yet been validat ed to justify a rational approach is an argument only to get on and va lidate more. Not all the components of molecular design can yet be don e totally rationally, but this is not an argument against applying thi s approach where it is possible. Absence of a successful track record is inevitable for any newly emerging technology. It is too early to dr aw conclusions about the relative costs of rational design versus empi rical synthesis, since the former is only now beginning to become real ity and the latter is in the middle of a (combinatorial) revolution. S imilarly, it is too soon to predict with certainty which of these two approaches will prevail in the long run. However, they lend themselves to parallel tracks, so both may well continue for the foreseeable fut ure. Current concerns about who would develop successful discoveries a re not reasons for stopping discovery research. Indeed, a string of pu tative products held at the discovery/development interface would be u seful ammunition to those trying to develop partnerships such as a Tro pical Diseases R&D Alliance aimed at carrying out such work and sharin g costs.