For the Success of Oncolytic Viruses: Single Cycle Cures or Repeat Treatments? (One Cycle Should Be Enough)

Oncolytic viruses (OVs) should be aggressively pursued as single cycle therapies to replace the protracted and poorly tolerated cancer treatment regimens currently offered to patients with surgically incurable cancers. Patients want single cycle therapies, clinical proof of concept exists for the efficacy of the approach, and OVs can be further engineered to increase their virulence, at the same time controlling their capacity to cause collateral damage by targeting their tropisms. Long-term repeat dosing regimens give diminishing returns with each successive OV administration, there are no preclinical or clinical studies demonstrating superiority of repeat dosing versus single cycle OV therapy and, even if harmless, it would be wasteful to continue OV therapy once patients are no longer deriving benefit.