Algeta reveals targeted cancer-killing potential of alpha particle linked antibodies
Algeta ASA, a Norwegian cancer therapeutics company, has published a research paper showing the potential of its TH-1 technology for targeted cancer therapy, in Blood - the official journal of the American Society of Hematology.
Algeta ASA, a Norwegian cancer therapeutics company, has published a research paper showing the potential of its TH-1 technology for targeted cancer therapy, in Blood - the official journal of the American Society of Hematology.
Algeta's TH-1 technology links Thorium-227, which emits alpha particles, to cancer-targeting molecules such as antibodies. Alpha-emitting radionuclides are of considerable interest in the treatment of cancer as they are highly destructive to tumour cells but have very short range. Linking this radionuclide to tumour-seeking molecules creates a conjugate with the potential to specifically seek and destroy cancers while leaving surrounding healthy tissues undamaged.
The paper describes how researchers from the Norwegian Radium Hospital (Oslo) in collaboration with Professor Oliver Press at the Fred Hutchison Cancer Research Center (Seattle, USA) and Algeta have linked Thorium-227 to the monoclonal antibody rituximab to create 227Th-rituximab and demonstrated its potent anti-tumour effects.
Rituximab binds to a specific molecule on the cancer cell surface called CD20 and is marketed in the USA as Rituxan by Genentech and Biogen-Idec for the treatment of certain types of non-Hodgkin's lymphoma (NHL) and rheumatoid arthritis, and as MabThera by Roche for the treatment of certain types of NHL. Rituximab-based therapies generated global sales of nearly $6 billion in 2006.
In in vitro studies 227Th-rituximab killed CD20-positive lymphoma cells at low doses (Bq/ml) while in preclinical models, a single injection of 227Th-rituximab induced complete tumour regression in up to 60% of tumours without apparent toxicity.
Therapy with 227Th-rituximab was significantly more effective than the control radioimmunoconjugate 227Th-trastuzumab, which does not bind CD20, and the standard beta particle emitting radioimmunoconjugate for CD20-positive lymphoma, Zevalin (90Y-tiuxetan-ibritumomab), which is marketed by Biogen-Idec.
Dr Thomas Ramdahl, president and ceo of Algeta said the paper provides more evidence of the potential of alpha particle-based molecules for targeted cancer therapy and follows excellent Phase II clinical data for the product Alpharadin (radium-223) in prostate cancer.
"We are working with collaborators to validate our TH-1 technology and are looking for further partnering opportunities with companies that have interesting cancer-targeting molecules that would benefit from this approach," he said.