CUSP9 [Coordinated Undermining of Survival Paths] is one of several cancer treatment protocols using re-purposed older drugs to interfere with cancer cell's growth signaling rather than directly killing them with cytotoxic drugs. CUSP9 is a treatment specifically targeted to glioblastoma that adds to a traditional cancer cell killing drug, temozolomide, nine older, non-cytotoxic drugs to block growth factors that enhance or drive glioblastoma growth [aprepitant blocks NK-1, auranofin inhibits thioredoxin reductase, captopril inhibits angiotensin converting enzyme, celecoxib blocks cyclooxygenase-2, disulfiram blocks aldehyde dehydrogenase, itraconazole blocks Hedgehog signaling, minocycline inhibits metalloproteinase-2 and -9, quetiapine inhibits RANKL, sertraline inhibits Tissue Factor]. These targets have been shown to be active in glioblastoma.
CUSP9 is related several other trials using a similar conceptual approach: The COMBAT regimen for treating various advanced pediatric cancers that uses two re-purposed non-cytotoxic drugs to augment two traditional cytotoxic drugs, or the GLAD regimen that uses one traditional anti-cancer drug, gefitinib, with three re-purposed non-cancer drugs. Or the MEMMAT regimen, in a current trial of A.Peyrl et al. using a 7 drug cocktail, (ClinicalTrials.gov Identifier: NCT01356290)- non-cytotoxic drugs bevacizumab, thalidomide, celecoxib, and fenofibric acid to augment traditional cytotoxic drugs etoposide, cyclophosphamide, and cytarabine to treat progressive medulloblastoma.
The ReDO project and many others [7] also follow this line of thought as in CUSP9 - repurposing older drugs for their anti-cancer effect and simultaneous use of several of them] in cancer treatment.
None of these treatment regimens have been proven to be safe or effective in human cancers but are occasionally tried on compassionate-use basis in patients who have exhausted all other options. A formal trial of the CUSP9 protocol in recurrent glioblastoma [ClinicalTrials.gov Identifier: NCT02770378] is starting in Ulm, Germany.