PHILADELPHIA - Researchers at the University of Pennsylvania School of Medicine and Immunocore Limited, Oxford, UK, today announced that a targeted agent that may have a role in treating advanced metastatic melanoma in the future has received Investigational New Drug (IND) approval and is opening enrollment for clinical trials in the UK and USA.
Melanoma is a form of skin cancer that accounts for approximately five percent of cases but causes the vast majority of skin-cancer deaths. The American Cancer Society estimates that over 68,000 new melanomas will be diagnosed in the US during 2010 and 8,700 deaths from this disease will occur. Incidence rates for melanoma have increased in the last thirty years, and unlike other common cancers, melanoma has a wide age distribution.
Patients with melanoma who are diagnosed early are treatable with surgery, although in many the disease will recur within a few years. If melanoma continues to later stages and becomes metastatic, the prognosis is poor, with average survival times of six to nine months. Chemotherapy is the most common treatment, but the response rate is very low, so physicians are looking for more effective therapies.
Engineered to Kill
Tumor cells often express low levels of their signature surface molecules and thereby hide from the immune system. Immunocore has developed a process that allows it to isolate and manipulate human T cell receptors to enhance – by several million fold -- their ability to recognize and bind to specific tumors.
These engineered, disease-specific receptors are fused to an antibody fragment that binds a cell-surface protein called CD3, which is found on the surface of killer T cells of the immune system. ImmTACs, as the new class of drugs are called, target melanoma tumor cells and redirect any T cell touching them to kill tumors.
Unlike traditional immunotherapies such as cancer vaccines or immune-stimulating agents, ImmTACs have been specifically designed to overcome the limited effectiveness of immunotherapies to date. Pre-clinical tests indicate they can achieve potent T-cell redirection against cancer cells that have lost almost all of their cell-surface antigens.
Mobilizing the Immune System
In the US, the Food and Drug Administration has authorized a Phase 0 or exploratory trial of the study agent. A Phase 0 trial involves giving a sub-therapeutic dose or doses of the study drug to a small number of subjects to gather preliminary data on how the drug is processed by the body.
The US study, in which the agent will be injected directly into one melanoma tumor, is designed to complement the UK study by shedding light on how the drug works and at what concentration.
“This is a novel approach to the challenge of mobilizing the immune system's ability to recognize and disable cancer cells. In this study we will assess their effectiveness by analyzing tumor samples from melanoma patients for evidence of local immune stimulation,” explains Carl June, MD, director of translational research at the Abramson Family Cancer Research Institute (AFCRI) at Penn, which will conduct the US trial.
“The number of melanoma cases in the US is increasing and although early-stage melanoma can be treated surgically, we urgently need effective therapies to manage late stage metastatic disease,” notes Leslie Fecher MD, assistant professor of Medicine and principal investigator on the trial. “As a novel targeted immunotherapy, IMCgp100 may be a promising new approach to tackle this intractable disease.”
The Penn investigators in this study have no financial interest or other relationship with Immunocore Ltd, apart from their scientific collaboration in conducting laboratory experiments and planning human clinical trials.
Further details of both trials are available at www.clinicaltrials.gov.
Patients with melanoma interested in learning more about the trial should contact Lester Lledo, MSN, CRNP assistant director, Translational Research Program, AFCRI, at 215.746.6040 or firstname.lastname@example.org