August 30, 2017
By Alex Keown, BioSpace.com Breaking News Staff
SAN FRANCISCO – Two years after forging a collaborative and licensing agreement with Southern California-based Inhibrx LLC, Five Prime Therapeutics is walking away from the deal that includes an early cancer drug candidate.
In a filing with the U.S. Securities and Exchange Commission, Five Prime announced it issued a notice of termination to Inhibrx on Aug. 28. The deal between the two companies will officially come to an end on Dec. 27. The company did not provide information as to why it was cutting Inhibrx loose.
In 2015, the two companies entered into the partnership. Five Prime sought to harness Inhibrx’s novel glucocorticoid-induced tumor necrosis factor receptor (GITR) antibody program. Five Prime provided $10 million in upfront funding as part of the deal. Inhibrx stood to gain up to an additional $442.5 million in milestone payments under the terms of the agreement. In addition to the GITR antibody program, Five Prime also gained the option to license other antibody programs in the Inhibrx pipeline.
The Five Prime partnership with Inhibrx has produced on experimental candidate, INBRX-110. The drug candidate is an engineered GITR antibody. INBRX-110 is designed to multimerize and activate GITR independent of Fc binding. This is in contrast to conventional GITR antibodies, where efficacy is dependent upon binding and the presence of Fc-receptor bearing cells and may be dampened by competing serum IgG, according to the Inhibrx website.
In April, Five Prime presented data on INBRX-110, which it calls FPA154, at the American Association for Cancer Research. The company said early data indicates FPA154 is superior to conventional bivalent antibodies. Luis Borges, head of Five Prime’s R&D, said in a statement that the company’s “GITR agonist antibody has potent anti-tumor activity for the treatment of cancer, including in combination with PD-1 blockade, which suggests the potential for combination therapy.”
The company appeared headed to filing for an Investigational New Drug Application for FPA154, but has since scrapped that plan, according to FierceBiotech. In an email to that publication a Five Prime spokesperson said the company was looking to “strike an appropriate balance” when it comes to company programs and finances.
“Terminating this program is such an example and there were many factors to consider. As a company, we have multiple pre-clinical and clinical opportunities to pursue and are judicious about our allocation of resources. As such, we made the decision to terminate the FPA154 program,” Five Prime said in its email to FierceBiotech.
Five Prime also has other products in development. Last year at the American Association for Cancer Research, Five Prime showed off in vivo data for its monoclonal antibody FPA144. Five Prime’s FPA144 is being used in preclinical trials for patients with solid tumors, including gastric cancer. Five Prime’s FPA144 is an anti-FGF receptor 2b (FGFR2b) humanized monoclonal antibody in clinical development as a targeted immune therapy for tumors that over-express FGFR2b. The treatment is designed to block tumor growth through two distinct mechanisms. First, it binds specifically to FGFR2b and prevents the binding of certain fibroblast growth factors that promote tumor growth. Second, it has been engineered to drive immune-based killing of tumor cells by antibody-dependent cell-mediated cytotoxicity (ADCC) and the recruitment of natural killer (NK) cells, according to Five Prime.
In addition to the deal with Five Prime, Inhibrx also has a collaboration with Celgene for the development of INBRX-103, which targets CD47 on cancer cells. INBRX-103 blocks the CD47-SIRPa interaction thereby facilitating efficient phagocytosis and elimination of cancer cells, the company said.
