Adding mixtures to the mix
DARMSTADT, Germany—Pharmaceutical powerhouse Merck KGaA has acquired exclusive worldwide licensing rights to the oncology drug candidate Sym004 by its originator, Denmark-based biopharmaceutical company Symphogen.
Under the terms of the agreement, Merck will make an upfront payment of $26 million to Symphogen for Sym004. Symphogen is also eligible to receive up to $289 million for clinical development and regulatory milestones, another $322 million in potential combined sales performance milestones, as well as additional royalties on net worldwide sales. In exchange, Merck will assume exclusive rights to the product and all future development responsibilities.
Sym004 is a recombinant antibody mixture comprised of two antibodies that are intended to simultaneously block ligand binding, receptor activation and subsequent downstream signaling while also removing epidermal growth factor receptor (EGFR) receptors from cancer cells' surfaces by inducing EGFR internalization and degradation. The mixture also stimulates the body's immune system to target cancer cells by triggering a reaction known as antibody-dependent cellular cytotoxicity.
Recombinant antibody mixtures are a class of antibody therapeutics under investigation for the treatment or prophylaxis of illnesses including cancer, infectious diseases and autoimmune diseases.
"This approach offers a wide variety of opportunities, the most obvious of which are for patient groups with no treatment options available to them today," says Symphogen CEO Dr. Kirsten Drejer.
Drejer sees great potential in the antibody mixture approach to cancer treatment in particular, as opposed to the antibody therapeutic approaches of the past that have focused on closing a single receptor.
"If you hit several targets at the same time, we're finding it's a more effective way to treat cancer," she says. "You get a more unique mechanism of action, and the cancers actually integrate the receptors rather than blocking them."
Symphogen is a relatively small biotech company, but the company saw tremendous promise in its Sym004 antibody mixture as it proceeded into a Phase I/II clinical trial for patients with advanced KRAS wild-type metastatic colorectal cancer, and into a single-arm, open-label Phase II trial in patients with squamous cell carcinoma of the head and neck.
"We see an extremely nice consistency between our preclinical results and what we're observing in clinical trials," says Drejer.
Eighty-eight patients have been treated with Sym004 in clinical trials as of July 2012.
Unable to pursue development of the product on a large scale by itself, the company reached out to larger pharmaceutical groups, speaking to several potential partners before ultimately accepting Merck's bid.
"This partnering agreement with Symphogen offered the opportunity to complement Merck's existing Erbitux franchise," says Dr. Gangolf Schrimpf, Merck's manager of group external communications. Erbitux (cetuximab)—a chimeric monoclonal antibody—is an EGFR Merck is developing for use in the treatment of metastatic colorectal cancer as well as cancer of the head and neck.
"You couldn't ask for a better validation of the attractiveness of the antibody mixture approach than having a company such as Merck take over the development," says Drejer.
"Sym004 further strengthens our early development pipeline by adding a product that is thought to act via a proposed synergistic mechanism of action not previously studied," Dr. Susan Jane Herbert, head of global business development and strategy for Merck Serono, said in a press release announcing the agreement. "More specifically, it has the potential to become a key asset complementing our already highly successful Erbitux franchise."
"Merck is very well placed to develop Sym004 based on our deep knowledge of the EGFR area from Erbitux," says Schrimpf.
Merck is a global pharmaceutical and chemical company with total revenues of $1 billion in 2011. Merck Serono is the biopharmaceutical division of Merck KGaA, headquartered in Darmstadt, Germany. Merck Serono's portfolio includes products designed to treat cancer, multiple sclerosis, infertility, endocrine and metabolic disorders and cardiovascular diseases.
Symphogen is a private biopharmaceutical company headquartered in Copenhagen, Denmark, that is developing a diverse pipeline of products to treat cancer and autoimmune and infectious diseases. Its lead product is Rozrolimupab (dubbed Sym001), a polyclonal antibody used to treat autoimmune thrombocytopenic purpura, as well as having applications in preventing isoimmunization in Rh-negative pregnant women.