Positive results for new multiple myeloma treatment

Biopharmaceutical company Patrys (ASX:PAB) has announced positive early results for its new drug (PAT-SM6), a human antibody-based therapy, to treat multiple myeloma.

The results are for a first cohort of three patients taking part in an ongoing Phase I/IIA clinical trial. The patients had advanced disease and had failed or were resistant to multiple courses of chemotherapy. Therapeutic options for such patients with this bone marrow cancer are usually limited to clinical trials.

Patrys began the Phase II trial at two sites last year, having successfully conducted a Phase I safety and tolerability study earlier in 2012.

Each patient received four doses of PAT-SM6 (each dose at 0.3 mg/kg) given intravenously over a 2-week period and were followed up for 36 days. All of the doses of PAT-SM6 were well tolerated and no serious adverse events or dose-limiting toxicities were reported. None of these patients have gone on to receive additional doses of PAT-SM6.

Prior to treatment with PAT-SM6, multiple myeloma cells were extracted from the bone marrow of each patient and tested in vitro for their ability to bind the antibody. In all three patients, between 80-100% of their cancer cells specifically bound to PAT-SM6. There was no binding of the antibody to non-malignant cells confirming the specificity of PAT-SM6 for cancer cells.

All patients had significantly reduced numbers of white blood cells, red blood cells and platelets prior to their inclusion in the trial. Post treatment with PAT-SM6, these blood counts improved significantly and more rapidly than expected for this group of patients.

As part of their follow-up post treatment, the overall status of the patient’s immune system was monitored. The results of these tests indicate that PAT-SM6 is active in patients and stimulates the immune system.

After inclusion in this trial, two of the three patients went on to receive additional chemotherapy due to advancing disease. Both patients had an unexpectedly positive response to drugs that they had previously been resistant to. This may suggest that PAT-SM6 had an influence on the sensitivity of the malignant cells.

Patrys CEO Dr Marie Roskrow said, “Our clinical trial is progressing as planned and we are very excited by this early data. Stimulating the immune system of patients with end-stage multiple myeloma is not easy and we look forward to treating patients with higher doses of PAT-SM6 in the hope that we will induce some positive clinical responses.”

A second cohort of patients is currently being recruited.

Based in Melbourne, Australia, Patrys (ASX:PAB) shares were trading at $0.04 at close of business on Friday.