Bayer signs €250m pact with India’s Curadev for STING drugs

The immune checkpoint STING has seen some popularity as a target for cancer drug development, but Bayer and India’s Curadev have started working on STING drugs with potential in auto-immune and inflammatory diseases.

The German drugmaker is paying up to €250m ($267m) for rights to a series of small-molecule antagonists of the STING (Stimulator of Interferon Genes) pathway, focusing on inflammatory diseases of the lung, cardiovascular and other systems.

Bayer gets exclusive access to novel molecules from Curadev and the partners will now collaborate to bring these and others into clinical development.

STING – or cGAS-STING  as it is sometime known – is a mechanism in the body designed to detect DNA and activate the innate immune system, a first line of defence against pathogens, cancer and cell damage.

Excessive signalling through cGAS–STING has been linked to a range of chronic and rare diseases, including neurodegenerative conditions like Parkinson’s, pulmonary fibrosis and non-alcoholic steatohepatitis (NASH).

More than a dozen biopharma companies have been looking at STING agonists as potential treatments for cancer by switching on the inflammatory response against tumour cells, including Merck & Co and Novartis.

The approach has been fraught with difficulty because of side effects – notably pancreatic inflammation – as well as lacklustre efficacy in cancer trials.

With its Curadev deal, Bayer has now joined a smaller group of companies that have switched gears, looking at using antagonists of STING to reduce innate immunity and inflammation.

Eli Lilly, for example, paid $12m upfront in a $620 million deal with Aduro Biotech at the end of 2018 for STING inhibitors, focusing on autoimmune diseases.

Novartis meanwhile agreed a $840m deal with IFM Therapeutics for STING drugs that could be used to target rare diseases such as Aicardi-Goutières syndrome (AGS), STING-associated vasculopathy with onset in infancy (SAVI) and a subset of systemic lupus erythematosus (SLE).

There’s still interest in STING agonists, despite disappointing results for Novartis/Aduro’s ADU-S100 at last year’s ASCO meeting – which resulted in Novartis handing back rights to the project in December – as well as for Merck’s MK-1454 at ESMO in 2018.

Last July, AbbVie acquire Mavupharma and its cancer-focused STING programme headed by MAVU-104 which targets ENPP1 – an enzyme involved in the regulation of the STING pathway – and is being developed for solid tumours.