Researchers at the University of Illinois (U of I) in the US have initiated a Phase Ib clinical trial to assess a new experimental cancer drug PAC-1 in patients with anaplastic astrocytoma and glioblastomamultiforme, types of brain cancer.
Claimed to cross the blood-brain barrier, PAC-1 is being developed to target procaspase-3 enzyme and stimulate cancer cells to destroy themselves.
In the new trial, the investigational drug will be evaluated to determine its safety when used in combination with temozolomide, a standard chemotherapy drug for brain cancer.
The Phase Ib trial, which is an extension of an ongoing Phase I oncology trial of PAC-1 monotherapy, will include subjects whose disease has progressed following first-line therapy.
University of Illinois chemistry professor Paul Hergenrother said: “Most cancers have elevated levels of procaspase-3. When it is turned on, procaspase-3 kills cells.
"PAC-1 restores the activation of procaspase-3 and, because this enzyme is elevated in cancer cells, targets cancer cells over non-cancerous cells.”
During the Phase Ib trial, patients will be initially administered with a 375mg once-a-day dose of PAC-1, followed by incrementally increased doses.
As per results from the Phase I trial, once daily 450mg PAC-1 dose was found to be well-tolerated in patients suffering from late-stage solid tumours and lymphoma.
Following favourable data from an evaluation in human cell lines and rodents, the researchers investigated the drug candidate in pet dogs with naturally occurring osteosarcoma, lymphoma and glioma.
PAC-1 was found to be safe in dogs with few observable side effects and is being further evaluated in them.