Calando Pharmaceuticals this week announced its first in-house therapeutic program: an siRNA-based treatment for solid tumors.
Although the company did not provide specific details about the program, it said that it would focus on a gene “implicated in a wide variety of solid tumors.”
“Our success in preclinical studies involving different types of cancer cells provides us with optimism about the prospects of treating numerous types of cancer patients with this therapeutic,” Jeremy Heidel, Calando’s CSO, said in a statement.
Calando said that the drug candidate would contain a targeting ligand against a cell-surface receptor over-expressed by many kinds of tumors.
The drug will be delivered using a proprietary technology that comprises a linear, cyclodextrin-containing polycation capable of binding to the anionic backbone of an siRNA. When mixed together, the polymer and siRNA self-assemble into nanoparticles, roughly 50 nanometers in diameter, which are protected from nuclease degradation in blood serum.
The therapeutic “combines synthetic delivery components with targeting agents and siRNAs that do not require chemical modification to create the first of its kind nanoparticulate therapeutic for cancer,” Mark Davis, a professor at the California Institute of Technology and a Calando co-founder, said. “The therapeutic is an 'intelligent' nanoparticle that has shown excellent safety and lack of immunostimulatory effects in rodent and non-human primate studies.”
Calando said it is currently preparing an investigational new drug application for its RNAi cancer drug candidate and expects to begin phase I testing at a Southern California cancer center before the end of 2007.
Should Calando meet this goal, it could be the first to move an RNAi-based cancer therapy into human testing.
Norwegian start-up siRNAsense is working on an siRNA-based oncology drug, but is targeting 2008 for possible phase I testing (see RNAi News, 5/25/2006). Japan’s GeneCare had said in January 2005 that it expected to have an RNAi-based cancer drug ready for phase I trials in 2007, but the company has been relatively silent since then (see RNAi News, 1/28/2005).
England’s IC-Vec is also eyeing the RNAi-for-cancer market, but that company has not publicly disclosed any development timelines (see RNAi News, 10/21/2005).
One firm that might beat Calando to the punch, however, is Atugen. Iain Ross, executive chairman of Atugen’s parent firm SR Pharma, told RNAi News earlier this year that Atugen was on track to getting a cancer drug into the clinic in “early 2007” (see RNAi News, 4/6/2006).
Calando’s decision to pursue oncology as its initial drug program comes as no surprise to those familiar with the company; cancer has long been a major focus of Calando’s research.
Early last year, the company released preclinical data demonstrating that siRNAs delivered with its cyclodextrin technology were able to inhibit tumor growth in a mouse model of Ewing's sarcoma without stimulating an interferon response (see RNAi News, 4/29/2005).
Less than a year later, Calando formed a collaboration with the National Cancer Institute to develop RNAi-based treatments for a form of pediatric cancer (see RNAi News, 2/9/2006). At the time, Calando CEO John Petrovich told RNAi News that the work with the NCI did not represent the company’s first pipeline project, which he said would most likely be in oncology.
Most recently, Calando announced that it has received a license to use Alnylam Pharmaceuticals’ intellectual property to discover, develop, and commercialize an siRNA-based therapeutic against an undisclosed cancer target.
As part of the deal, Calando has the option to acquire another license from Alnylam against a second, undisclosed gene target.
Specific terms of the licensing deal — which was formed under Alnylam’s InterfeRx program (see RNAi News, 12/12/2003) — were not disclosed, but the companies said it includes upfront, annual, and milestone payments.
Calando added that it hopes to announce a second pipeline candidate in the second half of next year.