ADCs are so 2013 as Immunogen and CytomX team up on PDCs

Immunogen has inked a deal to use probodies from CytomX with its own cytotoxics and linker technology, to create probody-drug conjugates (PDCs).

Amongst the numerous players in the antibody-drug conjugate (ADC) field, Immunogen has demonstrated a degree of success with recent licensing deals penned with Novartis and Eli Lilly and regulatory approval for Genentech’s drug Kadcyla, which uses its technology.

Now the Massachusetts-headquartered firm is looking to take its proven platform and use it with CytomX’s fully recombinant, protease-activated monoclonal antibodies - known as Probodies - in order to create a new less toxic class of therapy, called PDCs.

“Monoclonal antibodies are constructed to bind selectively to antigens. However, most antigens are expressed not only in diseased tissue, but also in healthy tissue,” a CytomX spokesperson told Biopharma-Reporter.com.

“Toxicity due to off-target binding has limited the pool of accessible disease targets for monoclonal antibodies to-date. However, CytomX’s Probody features an antibody-masking technology to ensure binding to the target only at the site of disease.”

The partnership allows Immunogen access to the patent protected platform in order to use probodies to create PDCs, whilst CytomX will be provided with PDC compounds to its target(s) with alternative ImmunoGen linker/payload formats.

“This strategic collaboration gives us access to one of the most validated drug conjugate technologies on the market today,” CytomX said. “Additionally, it allows us to leverage the expertise and knowledge of one of the world’s leading ADC companies.”

Financial details have not been disclosed.

Pfizer's pro-probodies

As well as Immunogen, the “unparalleled targeting and efficacy” of probodies has attracted the attention of pharma giant Pfizer who last June entered a partnership with CytomX to develop and commercialize multiple PDCs in Oncology.

On top of a $25m (€18m) upfront payment, CytomX could receive up to $610m in regulatory and sales milestones, as well as future royalties in the deal.

At the time Pfizer’s Senior VP and CSO Robert Abraham said the investment was: “An important component of our overall strategic focus to advancing the next generation of ADCs and reflects the disruptive potential of this approach.”

CytomX told us it would continue to evaluate opportunities for strategic collaborations with “high quality partners” in the future, as well as continue to develop its own pipeline which - on top of PDCs - uses the platform to investigate probodies, bispecifics and multispecifics to address previously undruggable targets in cancer, cancer immunotherapy and inflammation.