Merck KGaA signs $750m deal for late-stage cancer drug

Merck KGaA will partner with Threshold Pharmaceuticals to develop and commercialise an investigational cancer treatment that is activated by lack of oxygen in the tumour.

Threshold Pharmaceuticals will receive an upfront payment of $25m as well as potential milestone payments of up to $525m for the rights to TH-302, a hypoxia-targeted drug currently in phase III investigation in patients with soft tissue sarcoma and near the end of phase II for pancreatic cancer.

TH-302 is designed to work by creating a 'radical anion prodrug' when taken by a patient, which has no effect in tissue with normal levels oxygen.

However, in areas of tissue with a low level of oxygen, a condition known as hypoxia, the radical anion prodrug is broken down, releasing its active ingredient.

Hypoxia is common in solid tumours because of poor blood vessel growth and also occurs in the bone marrow of patients with haematological cancers.

“The addition of TH-302 to our pipeline provides an important opportunity in several different tumour types to expand our oncology development programme,” said Susan Jane Herbert, head of global business development and strategy at Merck Serono.

“Given the fact that pancreatic cancer is a very difficult to treat indication, successful phase II results could represent important upside for our company.”

In its current studies, TH-302 plus doxorubicin is being compared with doxorubicin alone in patients with first-line advanced soft tissue sarcoma with overall survival the primary efficacy endpoint.

Results from a phase II trial comparing the drug's use, in combination with chemotherapeutic gemcitabine, to gemcitabine alone in patients with first-line pancreatic cancer are expected to be announced later this month.

If approved by the relevant authorities, Merck will initially be responsible for commercialisation of TH-302 in the US, although Threshold has the option to co-promote TH-302 in the country.

Outside of the US, Merck KGaA will be solely responsible for the commercialisation of TH-302 with Threshold receiving a tiered, double-digit royalty on sales in these territories.

Merck KGaA will also pay 70 per cent of worldwide development costs.