Apollo BioSciences is focuses on making cancer a more manageable disease via Pharmefex™, an acid-prepared mesoporous silica. Pharmefex™ currently is available in two forms, Pharmefex™ + DOX and Pharmefex™ + DTIC, both cytotoxic drugs.
While cytotoxic agents are very effective in targeting cancer cells, the have an unfortunate side effect: they also kill normal proliferating cells, such as those in bone marrow, hair follicles and in the intestinal tract, causing severe side effects. These side effects, including vomiting, diarrhea and anemia, limit the dosage of standard cytotoxic agents. Thus, these drugs often are not administered at levels needed to achieve their maximum anti-cancer effect.
But combining Pharmefex™ with DOX and DTIC, both standard cytotoxic drugs, changes the picture. Pharmefex™ enables chemotherapy agents to be administered in concentrated form to cancer cells, yet exposing normal cells to minimal toxicity. The end result: improved chemotherapy efficiency and potentially the expansion of chemotherapy to earlier stages of cancer, without side effects.
Pharmefex™ is a monodispersed, spherical particle with a disordered pore structure with a surface that can be modified to facilitate selective uptake. Preliminary research showed Pharmefex™ increased the effectiveness of the chemotherapy drug doxorubicin by approximately 700 percent in the apoptosis of mesothelioma cells.
Pharmefex™'s sphere size and pore size can be optimized for a specific drug or biomolecule. Its exceptionally large pore volume and surface area gives Pharmefex™ the potential ability to trap and ultimately deliver large amounts of small interfering RNA (siRNA) and short hairpin RNA (shRNA).
As with all forms of amorphous silica, Pharmefex™ is easily modified by reaction with organosilanes. Selective functionalization of the external surface of APMS should provide for enhanced, targeted uptake of Pharmefex™ by cells. In comparison, the types of macroporous (pore diameters > 50 nm) solids that are commercially available have surface areas of approximately 350 m2/g and pore volumes of 0.5 cm3/g.
The synthesis of Pharmefex™ can be completed in less than 2 hours and does not require extensive equipment. In contrast, most mesoporous silica syntheses require extensive stirring times, sometimes as long as one week.