AstraZeneca to buy biotech company Spirogen in $440 mn deal

British pharmaceutical giant AstraZeneca today said that its global biologics research and development arm MedImmune would buy biotech company Spirogen for up to $440 million in order to acquire the London-based company's antibody-drug conjugate technology used in oncology.

The deal comes just a week after MedImmune completed its acquisition of Amplimmune, a privately-held, US-based biologics company focused on developing novel therapeutics in cancer immunology in a $500 million deal.

MedImmune will pay privately-held Spirogen an initial amount of $200 million and deferred consideration of up to $240 million based on reaching predetermined development milestones.

MedImmune has also entered into a collaboration agreement with Swiss-based ADC Therapeutics to jointly develop two of ADC Therapeutics' antibody-drug conjugate programmes in preclinical development.

MedImmune will also make an equity investment of $20 million in ADC Therapeutics, which has an existing licensing agreement with Spirogen.

The Spirogen group was founded in 2001 as a spin-out from several institutions including University College London and with partial funding by Cancer Research UK.

Majority owned by Auven Therapeutics, Spirogen has developed a novel class of highly potent cytotoxic warheads based on its proprietary pyrrolobenzodiazepines (PBDs), DNA minor groove binding agents, which bind and cross-link specific sites of DNA of the cancer cell.

This blocks the cancer cells' division without distorting its DNA helix, thus potentially avoiding the common phenomenon of emergent drug resistance.

Spirogen has been developing its PBD technology for more than ten years, including a standalone PBD agent in a Phase II study in acute myeloid leukemia.

Its business model has been to partner its technology with pharma and biotech for use in the development of novel drugs. It has a number of industry collaborations, including collaborations with Genentech and with ADC Therapeutics.

Antibody-drug conjugates are a clinically-validated cancer drug technology that offers both high potency and selective targeting of cancer cells. Spirogen's proprietary PBD technology attaches highly potent cytotoxic agents, or 'warheads' to specific cancer-targeting antibodies using biodegradable 'linkers'.

This targetting optimises the delivery of the cancer drug to the tumour cells only and provides the greatest degree of tumour killing while minimising the toxicity to the patient.

''Antibody-drug conjugates are ground-breaking technologies with the potential for directly targeting many types of cancer tumours while safeguarding healthy cells. The cutting-edge technologies developed by Spirogen and ADC Therapeutics complement MedImmune's innovative antibody engineering capabilities, enabling us to accelerate antibody-drug conjugates into the clinic,'' said Dr. Bahija Jallal, executive vice president at MedImmune.

MedImmune is developing a comprehensive portfolio with an emphasis on two key areas in oncology development: antibody-drug conjugates and immune-mediated cancer therapy, which aims to harness the power of the patient's own immune system to fight cancer.