Tekmira’s stable nucleic acid-lipid particles (SNALP) encapsulate small interfering RNA (siRNA) and deliver their cargo to target organs, minimising systemic toxicity.
A product using SNALP, which has been developed in collaboration with Alnylam Pharmaceuticals, is due to enter clinical trials in the next few months.
While Alnylam has been developing the drug candidate Tekmira has continued to work on SNALP and has now published data indicating that potency and tolerability have significantly improved.
Mark Murray, Tekmira’s President and CEO, said: “These new improvements have the potential to expand the opportunity of systemic RNAi drugs and supports Tekmira as a leader in the field.
“We expect our research efforts will continue to make these technology advances critical to the success of systemic RNAi therapeutics.”
The capsules consist of a layer of cationic and neutral lipids, which serve to encase the siRNA, with peg-lipids on the outer surface. Tekmira claim that this arrangement gives the capsules a long circulation time in the blood, resulting in “enhanced permeability and retention effect”.
This leads to the particles accumulating at areas of vascular leak, for example the site of tumour cell growth, where they enter cells through endocytosis to deliver the siRNA.
In addition to the product developed with Alnylam, Tekmira also has two in-house products that the company is preparing to submit investigational new drug applications (INDs) for.
These include PLK1 SNALP, which is being developed for the treatment of cancer, and ApoB SNALP for combating elevated cholesterol.