Oncothyreon and Celldex Therapeutics have started a combined open-label Phase Ib trial of ONT-10 and varlilumab to treat advanced breast or ovarian cancer patients.
ONT-10 is a therapeutic vaccine targeting the tumour-associated antigen MUC1, while varlilumab is a fully human monoclonal antibody that targets CD27, a critical molecule in the activation pathway of lymphocytes.
CD27 can be effectively manipulated with activating antibodies to induce potent anti-tumour responses and it may result in less toxicities due to its restricted expression and regulation.
The trial is designed to evaluate ONT-10 administered at the recommended single agent dose in combination with varlilumab at two dose levels in about 42 patients with advanced breast or ovarian cancer.
The trial's primary objective is to determine the safety and tolerability of the combined treatment, while additional objectives include evaluations of the impact of combination therapy on MUC1-specific humoral and cellular immune responses, T-cell activation markers and levels of regulatory T-cells, and anti-tumour effects.
The trial will be carried out by Oncothyreon under the terms of a previously announced collaboration agreement between Oncothyreon and Celldex.
The two parties will jointly own the data from the trial and will make any plans for potential future development of the combination therapy together.
As part of the deal, neither company has granted the other a licence, or any other rights, to its product candidate.
ONT-10 contains a glycosylated antigen designed to mimic the hypoglycosylated state of tumour-associated MUC1 and is intended to stimulate both the humoral and cellular arms of the immune response.
In addition, ONT-10 contains the adjuvant PET-Lipid A, a fully synthetic toll like receptor 4 (TLR4) agonist proprietary to Oncothyreon.
The company said that in an ongoing Phase I trial ONT-10 has been well-tolerated and it led to a robust anti-MUC1 antibody response.
Oncothyreon is continuing the Phase I trial and is currently enrolling two disease-specific groups in patients with advanced breast or ovarian carcinoma.