Amgen to Use Xencor’s Bispecific Antibody Platform

Amgen will pay Xencor an upfront payment of $45 million to license Xencor’s XmAb bispecific technology platform for the development of a total of six targets, according to a press release dated Sept. 16, 2015. Xencor’s platform will be used to develop and commercialize five programs for Amgen involving bispecific antibodies and/or T-cell engagers, as well as a “preclinical bispecific T-cell engager (BiTE) program directed at CD38 and CD3 for multiple myeloma,” that originated from Xencor.

In addition to the upfront payment, Xencor will be eligible for milestone payments of up to $1.7 billion for the six programs and royalties for the candidates it develops with Amgen. Sean E. Harper, MD, executive vice-president of research and development at Amgen, said of the partnership: “We are especially excited about the T-cell engaging bispecific antibody directed against CD38, which complements Amgen's BiTE platform, while growing our hematology and oncology portfolio that includes two bispecific T-cell engager antibodies, Blincyto (blinatumomab) and AMG 330, as well as Kyprolis (carfilzomib) for relapsed multiple myeloma."

Amgen’s Blincyto (blinatumomab) is the only bispecific CD19-directed CD3 T-cell engager (BiTE) drug approved by FDA. Blincyto, which is meant to treat refractory B-cell precursor acute lymphoblastic leukemia (ALL), targets cell-surface proteins CD19 and CD3 simultaneously, helping bring T cells to targeted cancer cells via dual targets. The New York Times reported in August 2015 that, according to a final rule from the Federal Register published in the same month, Blincyto represents a “substantial clinical improvement over existing treatment options” for ALL. As a result, the drug-which is $178,000 for two 28-day cycles of treatment-will be partially covered by Medicare through a “new technology payment,” according to the newspaper.

The key to Xencor’s platform lies in its Fc domains, which Xencor has engineered to selectively direct T-cell killing of cancer cells. Xencor says its Fc-domain variants produces bispecific antibodies that can be “made and purified with standard antibody-production methods.” AMG 330 is an investigational product targeting CD33 and CD3 at the same time, and is in clinical trials to test its effectiveness against CD33-expressing acute myeloid leukemia (AML) target cells.

Amgen isn’t Xencor’s only partner in the bispecific development space. Xencor also has licensing partnerships with Morphosys AG for the treatment of ALL and non-Hodgkin’s lymphoma, as well as other partnerships with Merck (on a combination product involving Keytruda [pembrolizumab]), Janssen, Alexion, Novo Nordisk, Roche, Kite Pharma, and Boehringer Ingelheim. Internally, Xencor will continue to pursue its own investigational products, including XmAb14045 for AML and XmAb13676 for the treatment of B-cell malignancies.

Source: Xencor