AbbVie has decided to take a chance on STING, an emerging immuno-oncology target that has proved a tough challenge for drug developers.
It’s buying three-year-old Seattle start-up Mavupharma to claim ownership of its STING agonist programme, joining the fray of companies hoping to use this class of drugs to rev up the immune system against cancer. Terms of the deal haven’t been disclosed.
There has been a rush to bring STING agonists forward into clinical trials, in the hope that they could enhance the activity of checkpoint inhibitors like the PD-1/PD-L1 antagonists which remove a brake on immune responses to malignant cells.
There’s also hope that combination therapy could improve the proportion of patients who respond to cancer immunotherapy.
Despite the enthusiasm, the first candidates – most of which are large-molecule compounds that require direct injection into tumours – have failed to make a big impact in early clinical trials.
For instance, Merck & Co/MSD reported disappointing results in a phase 1 study of its MK-1454 drug at last year’s ESMO congress, revealing little activity on its own but some when combined with Merck’s checkpoint inhibitor Keytruda (pembrolizumab).
Shortly afterwards, Aduro reported data for its ADU-S100, which seemed to far a little better than MK-1454 in its phase 1 trial but was still a long way from showing proof-of-concept for the STING agonist hypothesis. Novartis paid $200m upfront for rights to Aduro’s STING programme in 2015.
Mavupharma has a different approach to its peers however, targeting ENPP1, an enzyme that regulates the STING pathway and can be modulated using small-molecule drugs. That could make dosing much easier and boost the chances of a successful clinical programme.
Its lead clinical candidate is MAVU-104, which the privately-held biotech says “allows for highly controlled enhancement of STING signalling in tumours without the need for injections.”
“AbbVie’s vision in oncology is to advance breakthrough areas of science leading to a strong pipeline of innovative cancer therapies,” said Steve Davidsen, the firm’s vice president of oncology discovery.
“Mavupharma’s platform has the potential to further our immuno-oncology portfolio and assist in the development of transformative medicines for patients.”
AbbVie is still in the throes of the biggest acquisition in its history – the $63bn takeover of Allergan – but clearly still has aspirations to do bolt-on deals to boost its pipeline.
Meanwhile, Mavupharma isn’t the only company trying to develop small-molecule STING agonists.
GlaxoSmithKline is also working in this area, for example, and in a high-throughput screening programme has discovered a number of small-molecule candidate, headed by GSK3745417, but so far these can only be delivered intravenously or subcutaneously.