Denosumab specifically targets RANK Ligand, an essential regulator of osteoclasts (the cells that break down bone).
By targeting RANK Ligand regulator, denosumab has shown the ability to prevent the spread of cancer to the bone.
Under the agreement, AstraZeneca will be responsible to co-promote denosumab after it is approved for use in Japan.
Previously, Daiichi Sankyo has taken over denosumab rights in 2007 from Amgen.
AstraZeneca Global Commercial Organisation executive vice president Tony Zook said collaborations like this are a key part of their strategy to bring medicines to patients.