Treatments such as these are suitable for use in only a sub-group of patients with a given disease, because they target or otherwise exploit a specific genetic feature of either the patient or the diseased cells. The most common application is in cancer, where for example the breast cancer therapeutic Herceptin (trastuzumab) is only effective in patients with breast tumours that overproduce the HER2 protein. Targeted medicines therefore typically require a ‘companion diagnostic’ test to identify which patients could benefit from the treatment
Now the FDA proposes that new stratified medicines would only gain regulatory approval for use if the relevant companion diagnostic is also approved, with two exceptions: new treatments for serious or life-threatening conditions for which there are no other effective therapeutics and where the new treatment produces significant benefits; and amendments to treatments that have already been approved.
Comment: The FDA hopes to “help stimulate early collaborations between drug and device makers”. Efforts to streamline the regulatory process are desirable, but may not solve one of the other major barriers to the use of stratified medicine: the cost of companion diagnostics, and who should pay. If the diagnostic and therapeutic form a package that may be regarded as the therapeutic then that problem may be masked, but it could also prevent competition from alternative providers and keep prices high.