Roche Announces Positive Results in Solid Tumors Using Human Monoclonal Antibody against IGF-1R (R1507)

Today, Roche announced positive results from a Phase I trial of R1507, a human monoclonal antibody to target IGF-1R (insulin-like growth factor receptor), in patients with solid tumors. IGF-1 is one of the most potent natural activators of the AKT and MAPK signaling pathways, which promote cell growth and cell survival. The IGF-1R pathway has also been shown to have an important role in mediating the resistance to cytotoxic drugs and EGFR/HER2-targeted agents. The results were reported during the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics, held in San Francisco.

Study Results
In the Phase I study, R1507 was administered by intravenous infusion. Nine of 34 adult patients with advanced solid tumors experienced disease stabilization. Four of the seven heavily pretreated patients with Ewing’s sarcoma demonstrated clinical benefit with two of these patients achieving durable, objective partial responses.

Once a week administration of R1507 was well tolerated with very few side effects. Treatment with R1507 was not associated with the typical side-effects normally observed with cancer therapy (e.g., low blood counts, infection, hair loss, severe nausea and vomiting). The most frequent side effects observed were fatigue, anorexia and weight loss, symptoms that are commonly observed in patients with advanced cancer.

“We are very encouraged by these early results with R1507 in patients with refractory Ewing’s sarcoma,” said Kapil Dhingra, MD, Head, Oncology Disease Biology Area at Roche. “As a result, we have given this program a very high priority as we believe this molecule has the potential to be very beneficial in treating patients with sarcoma as well as a variety of other solid tumors.”

The antibody (R1507) was initially developed under Roche’s broad antibody development collaboration with Genmab, which began in 2001.

The Phase I study is being conducted at four sites in the U.S., including the University of Colorado Cancer Center (Aurora, CO), The University of Texas M.D. Anderson Cancer Center (Houston, TX), Cancer Institute of New Jersey (New Brunswick, NJ) and The Institute for Drug Development (San Antonio, TX). R1507 has also been investigated in 26 patients on a three week schedule in the Phase I study. This treatment schedule was also generally well tolerated with a side effect profile similar to the weekly schedule.

“This drug attacks the IGF pathway and may provide a new class of drugs to treat a variety of cancers, including breast, prostate, colon, melanoma, myeloma and a variety of sarcomas, which could greatly add to the way that we currently treat these patients,” says Stephen Leong, M.D., assistant professor of Medical Oncology at the University of Colorado Cancer Center and lead author of the abstract.

Razelle Kurzrock, MD, investigator at the M.D. Anderson Cancer Center and the senior author of the abstract, noted that some of the responses were very impressive. For instance, one 28 year-old Ewing’s sarcoma patient with large tumors unresponsive to many other treatments showed dramatic tumor shrinkage within six weeks, without side effects. “This is one of the best responses I’ve seen in over 20 years of oncology experience,” stated Dr. Kurzrock.

Based on these initial results with R1507, Roche plans to conduct additional trials and work with a global consortium of sarcoma experts, including the Sarcoma Alliance for Research through Collaboration (SARC). “We are very excited about our collaboration with SARC, which represents a new approach to sarcoma clinical trials, and we look forward to combining our expertise with that our colleagues at SARC to expedite new sarcoma treatments,” added Dhingra.

“We are excited to be partnering with Roche on the development of a new treatment against an important target, which could result in a potential breakthrough treatment for sarcoma as well as other cancers,” said Laurence Baker, DO, professor of Medicine and Pharmacology at the University of Michigan and the Executive Director, SARC. “With Roche’s considerable expertise in oncology and SARC’s vast network of physicians and institutions, we look forward to determining the potential of R1507 in this important disease area.”