Our Pipeline

The product candidates in the Merus pipeline are based on the Multiclonics® format (full length human IgG antibodies). Our strategy employs the unique attributes of our proprietary bispecific antibodies and our patented screening technologies to engage and harness the power of the immune system to target tumor cells.

Zenocutuzumab (Zeno, MCLA-128)

Phase 1/2
NRG1+ cancer
Target: HER2, HER3

Zeno is a Biclonics® targeting the HER3 pathway. Zeno docks onto HER2, abundantly expressed on tumor cells, and subsequently binds to HER3, blocking heregulin-stimulated growth of tumor cells. Zeno is intended to overcome tumor cells inherent and acquired resistance to HER2-targeted therapies by both blocking tumor growth, survival pathways and recruiting immune effector cells to help eliminate tumors.

NRG1 fusions are associated with the activation of HER2/HER3 heterodimers and cancer cell growth. Fusions between NRG1 and partner genes are rare, tumorigenic genomic events occurring in patients with certain lung, pancreatic and other cancers. Merus has observed that Zeno is capable of blocking tumor cell growth harboring NRG1 fusions. Learn more at nrg1.com.

Learn how Zeno works.

Petosemtamab (Peto, MCLA-158)

Phase 1
Various solid tumors
Target: LGR5, EGFR

Peto is a Biclonics® that binds to cancer stem cells expressing leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) and epidermal growth factor receptor (EGFR) with two different mechanisms of action (MOA). The first MOA blocks growth and survival pathways in cancer stem cells; the second recruits/enhances immune cells to kill cancer stem cells that persist and cause relapse and metastasis.


Phase 1
Various solid tumors
Target: PD-L1, CD137

MCLA-145 is a Biclonics® T-cell agonist. MCLA-145 binds with high affinity and specificity to PD-L1 and CD137. A unique immunostimulatory profile of MCLA-145 derives from the ability to potently activate immune effector cells in the context of the tumor microenvironment while simultaneously blocking inhibitory signals in the same immune cell population.


Phase 1
Various solid tumors
Target: EGFR, c-MET

MCLA-129 is a Biclonics® binding to EGFR and c-MET. MCLA-129 blocks EGFR and c-MET signaling with the potential to inhibit tumor growth and survival and is expected to have less toxicity compared to agents targeting EGFR alone. MCLA-129 is subject to a collaboration and license agreement, which permits Betta Pharmaceuticals Co. Ltd., to exclusively develop MCLA-129 in China, while Merus retains full ex-China rights.


Phase 1
Autoimmune disease
Target: PD-1 x CD3

ONO-4685 is a Biclonics® designed to target PD-1 and CD3.

This program is wholly owned by Ono, with Merus receiving milestones and royalties upon advancement in development and approval.



To read more about Merus platform and its leading Multiclonics® technology, please follow the link below for access to Merus scientific publications.

View Publications