In the burgeoning RNAi sector, a handful of companies are working to develop the technology into a source of human therapeutics. Only one — Sirna Therapeutics — has said that it expects to have an RNAi drug ready for clinical trials next year.
But now, a Philadelphia-based start-up is pushing into the foreground with a seasoned biotech player in front and a even more ambitious timeline than its bigger rival.
The company, Acuity Pharmaceuticals, is a six-employee shop founded in October last year by Michael Tolentino, a retinal surgeon and faculty member at the University of Pennsylvania’s Scheie Eye Institute, and Samuel Reich, a UPenn researcher. Its goal is to commercialize an age-related macular degeneration and diabetic retinopathy drug known as Cand5 within the next seven years — a process that it expects to include the initiation of a phase I trial in 2004.
To help it in its effort, Acuity has brought on as president and CEO Dale Pfost, formerly the founding CEO of both Oxford GlycoSciences and Orchid BioSciences.
Pfost told RNAi News that Acuity expects to be able to meet its development timeline for a number of reasons — chief among them the indications the company is pursuing.
Arguably the biggest problem facing RNAi therapeutics is delivery, but the hurdle gets lower when dealing with certain kinds of tissue, such as hepatic or ophthalmic, that are more amenable to drug uptake.
“The molecular target we’re going after is VEGF, which is a reasonably well-validated target for anti-vascularization,” he said. “The wonderful thing is that the cells [in the eye] that are responsible for releasing the vascularization factor are phagocytitic. So, you provide the drug molecule [and it] is taken up by exactly the cells that you need. We’ve demonstrated in those cells that it works, that it silences VEGF.
“You couldn’t ask for a better pathogenesis to go after or organ to deliver the drug in.”
Pfost also noted that Acuity is well along the road to the clinic, having already begun studying Cand5 in a primate model. Data from this effort are expected to be available in the latter part of 2003, he said, and will hopefully be robust enough to convince investors to chip in the $7 million to $9 million Acuity is seeking in an ongoing Series A financing round.
“We’re targeting a very select group of top-tier names in venture capital, a lot of people that I’ve known for awhile,” Pfost said. “So far it’s going very well.”
He added that the proceeds of the financing are expected to carry Acuity through phase I testing. After that, the company — which intends to go it alone on the development and commercialization of Cand5 in the US and possibly overseas — will look again to raise cash through investments.
But Acuity doesn’t expect private financing to be its only source of capital. Pfost stressed the significance of the firm’s IP portfolio — which includes a patent application covering RNAi in mammalian cells that he believes supercedes other similar patent applications — and said that the company would consider selling sublicenses to the technology in fields outside of ophthalmology.
The patent application, number 20020173478, describes the use of RNAi to disrupt “cell expression at the mRNA level in mammalian cells.” Key to the filing is its self-described “demonstration of a RNAi technique that is applicable to human cells and cell lines, as well as for administration to human patients.”
“Biotechnology these days it is an uncertain art,” Pfost said. “And the uncertain art means that the speculative application of technol-
ogy is not being accepted as sufficient to grant claims within a patent. So, the absence of an enabling disclosure and the absence of data to support evidence that [an experiment] was actually performed are fatal missing parts to [other patent] filings that are there.
“Does a patent filing have data to support the claims being made, and…does it include an enabling disclosure that actually would have allowed someone skilled in the art of biology to actually undertake the practice? Those two thresholds are exceedingly important in the patent office. The patent estate that we have is very strongly bolstered with in vivo data and mammalian cell data that is supported with enabling disclosures and data to show that we actually undertook the project.”
Whether Acuity will beat its competitors to the punch, and whether its IP can withstand a legal challenge, remains to be seen. But as RNAi drugs look more and more viable, and the potential for blockbuster revenues grows, it probably won’t be long until we find out.
—DM