Prima encouraged by Biomira result

Prima Biomed (ASX:PRR) has been cheered by clinical trial results from commercial partner Biomira.

The trial results are said to provide validation of the use of the mucin-1 (MUC1) antigen in dendritic cell therapy, a technique under development by Prima subsidiary CancerVac.

Biomira recently announced that preliminary data from a Phase IIb trial of a MUC1-derived peptide vaccine, delivered via liposomes, demonstrated improved median survival times in patients with stage IIIb and IV non-small cell lung cancer, although results were not statistically significant due to the numbers of patients enrolled in the trial.

Prima CEO Marcus Clark said the results of the trial further demonstrated that MUC1, which is expressed at high levels on the surface of certain cancer types, was a suitable target for cancer treatment.

"It's starting to get momentum -- it's widely expressed and immunogenic. We can really see we're on a hot target with MUC1," Clark said.

CancerVac's MUC1-mannan fusion protein therapeutic vaccine is delivered ex vivo to patients' dendritic cells, which are transplanted back into the patient after stimulation with the vaccine.

Last year, Prima reported that CancerVac was able to show in a Phase I trial involving patients with a variety of cancers that strong immune responses were generated against MUC1 as a result of ex vivo dendritic cell therapy with the MUC1-mannan therapeutic vaccine, and in some patients disease progression was slowed.

Last month, Prima and CancerVac signed a commercial agreement with Biomira, providing the Austin Research Institute spin-off with exclusive access to the MUC1 protein for dendritic cell therapy.

In return, Biomira took a 10 per cent equity stake in CancerVac and gained a seat on the board, in addition to an option on worldwide rights excluding Australia and New Zealand for commercialisation of the MUC1 dendritic cell therapy, with CancerVac to receive upfront and milestone payments worth up to AUD$20 million, and royalties if the therapy is successfully commercialised.

Now the two companies are awaiting the start of CancerVac's Phase IIa trial of the MUC1 dendritic cell therapy on 20 patients with metastatic ovarian cancer. The trial is expected to start recruiting patients in late April, said Clark, and if results generated by the trial are positive, Biomira will plan larger Phase II trials to support registration of the therapy in North America.