Advanced Targeting Systems received $3 million from the NCI to advance SP-SAP over the next two years into clinical trials for cancer pain. SP-SAP is a conjugate between the pain-processing peptide substance P and the ribosome-inactivating protein saporin.
The mechanism of action of SP-SAP is well characterized, a rarity in pain therapeutics, according to Advanced Targeting Systems. A small number of cells that process pathological pain signals is removed, causing relief that appears to be permanent, the firm explains. Normal acute pain is unaffected.
FDA recommended that the first population to undergo treatment with SP-SAP is terminal cancer patients who are resistant to opioids such as morphine. In preclinical tests, a single treatment with SP-SAP alleviated pathologic pain perception without affecting other sensory signal pathways.