With three of the four sustained-release drug delivery products commercially available in the U.S. and Europe, pSivida just might prove Wall Street pundits correct and score some big wins in the ophthalmic space.
The Watertown, Mass.-based company’s Durasert technology can deliver drugs to the posterior segment for a predetermined amount of time ranging from months to years.
Most recently, the technology received approval as part of Iluvien (fluocinolone) for the treatment of diabetic macular edema; Iluvien is designed to be a 3-year implant and is licensed to Alimera Sciences. pSivida’s other two FDA-approved products, Retisert for noninfectious uveitis and Vitrasert for cytomegalovirus, are both licensed to Bausch + Lomb and use earlier generations of the Durasert technology system. Medidur (fluocinolone acetonide, [FA]) consists of a 180 μg FA core surrounded by a 3.5-mm polyimide cylinder, also designed for 36-month implantation; it’s currently in Phase 3 studies for noninfectious posterior uveitis. Medidur and Iluvien are the same drug, delivered on the same platform, just for different indications.
The company recently secured more than $25 million in financing, triggered by the U.S. approval of Iluvien—enough to keep it solvent well into 2017, when pSivida expects to file Medidur for U.S. approval.
Potential blockbusters? pSivida’s got `em.
pSivida may begin to collaborate with Pfizer to use the Durasert technology as a platform for the sustained delivery of latanoprost (a leading medication for the treatment of glaucoma). According to the companies’ worldwide collaborative agreement, pSivida would be due a milestone payment of $20 million in the event that Phase 2 trials are initiated for the latanoprost product and succeed in proof of concept; Pfizer already owns 6.3% of the company. Back in 2011, the deal called for a $146.6 million payout to pSivida in combined milestone payments and royalties on any sales of the sustained-release product.
Medidur may be the company’s first potential blockbuster. It targets posterior uveitis, which has no known cause but affects 175,000 people in the U.S. and leaves 30,000 permanently blind each year making it the nation’s third leading cause of blindness. At three months, only 4% more study eyes (2/3 of which received Medidur) experienced elevated intraocular pressure (IOP) than the fellow non-study eyes (none of which received Medidur). The assessment of masked data compared the elevation of IOP over 21mmHg at three months study eyes and fellow eyes for the 105 out of 129 enrolled subjects with at least a 3-month follow-up. The FDA has conceded that safety data can be taken from the previous Phase 3 trials for Iluvien, given that it’s the same product.
“We are very pleased that we have a clear regulatory path that should permit us to file the NDA for Medidur with only a short delay from the timing we anticipated based on a single Phase 3 trial. We had budgeted for the second trial pending FDA guidance, so the second trial does not change our liquidity projections,” said Paul Ashton, Ph.D., President and CEO of pSivida. During pSivida’s fiscal third quarter, it completed enrollment in the first Phase 3 trial with the longer 12-month primary endpoint, and top-line data in the expected during second quarter of 2016. A second Phase 3 trial has already begun, which will enroll up to 150 patients in India.
Retisert (also for posterior uveitis) has not been commercially successful as it requires a full surgical procedure; Medidur will be injected in one office visit which should boost sales, comparatively speaking.
Newer, smaller technologies
But it’s the company’s nanotechnology Tethadur that has some analysts believing this company has the potential to be the next ophthalmic blockbuster. Dr. Ashton has called Tethadur “a molecular honeycomb, with each comb between 20 and 300 angstroms wide.” Each of the honeycombs can be customized by size, thereby controlling the rate of drug release. Further, each comb encompasses only one molecule so concern about deactivation as a result of clumping is alleviated.
In theory, Tethadur is considered small enough to be placed anywhere in the body, which could have significant implications for companies with monoclonal antibody compounds close to patent expiry.