A Medical Device Daily

This year's annual meeting of the American Association for Cancer Research (AACR; Philadelphia) in Los Angeles this week is themed "A Century of Leadership in Science — a Future of Cancer Prevention and Cures" in recognition, the organization said, of its progress in the understanding and eradication of cancer.

Given that theme, it is not surprising that many companies in the sector are using the meeting as an opportunity to present data on emerging anticancer therapies or to exhibit their latest developments.

One such company, Arrowhead Research (Pasadena, California) reported that two of its majority-owned subsidiaries, Insert Therapeutics (Pasadena, California) and Calando Pharmaceuticals (also Pasadena), are presenting the latest research findings on two anticancer therapies under development at the meeting. Both therapies employ a delivery system called Cyclosert, developed at the California Institute of Technology (Pasadena, California) and exclusively licensed to Insert and, through Insert, to Calando.

According to Arrowhead, Cyclosert is the first nanoparticle drug transport platform to be designed de novo and synthesized specifically to overcome limitations in existing technologies used for the systemic transport of therapeutics to targeted sites within the body.

Based on small cyclic repeating molecules of glucose called cyclodextrins, Cyclosert promotes the ability of cytotoxic drugs to inhibit the growth of human cancer cells while reducing toxicity and remaining non-immunogenic at therapeutic doses. In particular, the system is designed to reduce the toxicity of the drugs until they actually reach the targeted tumor cells where the active drug is released in a controlled fashion.

Insert's chief scientific officer, Thomas Schluep, will present data from in vitro and animal studies using the Cyclosert system to deliver tubulysin A, a potent, but highly toxic, antitumor agent. In vitro studies have shown the tubulysin-Cyclosert conjugate to be effective against multiple human cancer cell lines. The conjugate was found to be stable and 100 times more water-soluble than the free drug, the company said.

Calando's chief scientific officer, Jeremy Heidel, PhD, will present data from animal studies using the Cyclosert system augmented by Calando's technology. Calando is developing a type of ribonucleic acid (RNA) called small interfering RNA, or siRNA, for anticancer use.

In the tests, this siRNA-containing formulation, using Cyclosert as a delivery system, showed significant anti-tumor activity and was well-tolerated.

"We are pleased that our companies have outstanding data to present at this prestigious conference," said R. Bruce Stewart, CEO and chairman of Arrowhead. "We see great promise going forward for the treatment of cancer using our delivery system."Arrowhead is a nanotechnology company commercializing new technologies in the areas of life sciences, electronics, and energy.

In other news from the AACR meeting:

• Immunicon (Huntingdon Valley, Pennsylvania) will exhibit its Immunicon Pharma ServicesSM, the new CellCapture CTC Mouse/Rat Kit and the new EasyCount System at its exhibit booth.

The CellCapture CTC Mouse/Rat Kit is designed to enable preclinical studies using animal models. It uses a manual test procedure to capture CTCs in a few drops of mouse blood and the cells are counted and characterized using the CellTracks Analyzer II. This kit is intended to enable scientists to conduct efficacy studies in very early drug studies and may streamline this phase of drug development.

The EasyCount System is a fluorescent microscopy-based imaging system designed to accurately count dead and live nucleated cells and automatically calculate cell viability, in a single test.

Immunicon develops cell- and molecular-based human diagnostic and life science research products and is providing certain analytical services to pharmaceutical and biotechnology companies to assist them in developing new therapeutic agents, with an initial focus on cancer disease management.

• Introgen Therapeutics (Austin, Texas) reported updated Advexin biomarker data over the weekend at AACR. The company is developing molecular therapeutics, immunotherapies, vaccines and nano-particle tumor suppressor therapies to treat a range of cancers using tumor suppressors, cytokines and genes.

Abnormality of the p53 tumor suppressor is one of the most common and fundamental molecular defects in cancer, according to Introgen. Advexin is targeted to restoring p53 tumor suppressor function and the detection of abnormal p53 is a logical predictive biomarker for Advexin efficacy, the company noted. In a study of 28 recurrent head and neck cancer patients in Phase II clinical trials, abnormal p53 was shown to correlate with increased survival and tumor responses following Advexin treatment.

Also at the conference, data was presented regarding Introgen's other Phase III product, INGN 241, indicating that inhibitors of a class of stress proteins called heat shock proteins enhances INGN 241-mediated tumor cell death.

The company said that these preclinical data provide insight into INGN 241 mechanisms of action and identify future strategies to enhance its activity.