Eisai, the Tokyo-based drugmaker, and Merck entered into an oncology research collaboration agreement, the duo announced Wednesday. Terms of the deal were not disclosed.

The clinical trial agreement will explore a combination of Merck’s anti-PD 1 treatment Keytruda—that was approved for use in metastatic melanoma in September—along with Eisai’s Lenvima (lenvatinib) and Halaven (eribulin mesylate).

Lenvima was approved for use in thyroid cancer this past February. Halavan received orphan designation from the FDA in May 2012 for advanced tissue sarcoma and is also currently approved for use in patients with metastatic breast cancer.

The two drugmakers have planned a Phase-Ib/II study to evaluate the oncology combo of Keytruda and Lenvima as well as Keytruda and Halavan in treatment of select solid tumors as well as for triple-negative metastatic breast cancer. Both studies are expected to start in the second half of 2015.