Currently in Phase 2, Nastech's PTH(1-34) contains a naturally occurring human parathyroid hormone (PTH), an important regulator of calcium and phosphorus metabolism, and promises easy and convenient delivery in the form of a nasal spray.
Its competitor would be Eli Lilly's Forteo, a similar parathyroid hormone drug already in the market but administered by injection, thus making its appeal to patients less strong.
Moreover, Nastech hopes to submit an FDA application for its spray in 2007 and receive approval in 2008, around the same time Forteo is expected to lose patent protection.
But PTH(1-34) would not be the only nasal spray drug for osteoporosis available in the market, as Upsher-Smith' s Fortical and Novartis's Miacalcin are already available in nasal spray form.
However, both drugs contain a different hormone called calcitonin, which, as Jackie Parrington of the UK's National Osteoporosis Society explained to In-Pharmatechnologist.com, is not as effective as PTH.
"The evidence for fracture reduction, the ultimate aim of any osteoporosis treatment, is not as robust for calcitonin as it is for other treatments and so it is rarely used in the UK," she said.
"Although taking treatments via nasal spray is an accepted practice in many areas of health, the osteoporosis treatments via this method are limited."
Indeed, the main treatments for osteoporosis currently include bisphosphonates, the most successful family of drugs for osteoporosis to date, expanding from their launch in 1995 to 33 million prescriptions in the US in 2004, and selective estrogen receptor modulators (SERMs) for postmenopausal women.
Merck currently holds a 39 per cent market share with its bisphosphonate alendronate (Fosamax), Lilly 17 per cent of the market, thanks primarily to its SERM raloxifene (Evista), while Procter & Gamble holds a 13 per cent share with sales of its bisphosphonate risedronate (Actonel).
Procter hopes to increase its share with PTH(1-34), which it sees as complementary to Actonel and more appealing to users.
"PTH treatment offers considerable hope for those people with severe osteoporosis, particularly if other treatments have not worked," Ms Parrington said.
"At present PTH treatment is available in injection form as teriparatide (Forteo), which although given with community nursing support initially, may put some people off taking the treatment so if an easier and effective way of delivering PTH treatment can be found then people with severe osteoporosis could benefit greatly."
This is what Procter is betting on, although there are still challenges that need to be addressed in clinical trials, including the fact that prolonged PTH treatment reduces the efficacy of the drug.
Nevertheless, unlike bisphosphonates and all other drugs which are "anti-resorptives," exerting their action by slowing bone resorption and preserving what bone remains, PTH(1-34) actually grows bone, and therefore may be seen as a complementary product to an anti-resorptive.
"Recent experimental results published in the August 2005 New England Journal of Medicine demonstrate that PTH and bisphosphonates may be used in sequence, so that bone is built up by PTH and these gains in bone are preserved through the use of bisphosphonates," Gordon Brandt, Nastech's executive vice president of clinical research and medical affairs, told In-Pharmatechnologist.com.
"In this way, osteoporosis may ultimately be reversed, so Procter & Gamble and other companies in the osteoporosis market see PTH as the most potent drug and complementary to all other currently marketed drugs."
In its agreement with Nastech Procter is being cautious, offering the Bothell-based company just $10m in an upfront payment.
Yet if the project succeeds the rewards for Nastech could be huge, receiving double-digit royalties and possible additional payments of up to $22m in the first year.
Procter will assume responsibility for clinical and non-clinical studies and regulatory approval while Nastech will be responsible for the chemistry, manufacturing and controls (CMC) sections of regulatory submissions.
PTH1-34 will be jointly developed by Nastech and Procter, and if a supply agreement is reached between the companies Nastech will be responsible for all manufacturing of the drug and will supply clinical and commercial product to Procter, who will direct worldwide sales, marketing, and promotion.
"PTH1-34 nasal spray is an excellent strategic fit for P&G, particularly given our long and successful history in the osteoporosis category," said Mark Collar, global president of pharmaceuticals for Procter & Gamble.
"We are excited to have this opportunity to develop and deliver another innovative, patient-preferred therapy to provide physicians with an additional therapy to treat their osteoporosis patients."
When given by daily injection, PTH1-34 has been shown to increase bone mineral density and significantly reduce fractures in both women and men suffering from osteoporosis.
Studies will investigate whether the nasal formulation will produce the same results.
Research and Markets, a market research publisher, estimates that the osteoporosis market will grow at an annual rate of 5.3 per cent from 2004 to 2009.
They expect that bisphosphonates will remain the mainstay of osteoporosis treatment, with 6.9 per cent annual sales growth during this period, and that SERMs will remain the drug class with the second-highest sales.
However, they claim it will be novel agents that will drive growth after 2009, with Amgen's recombinant product AMG-162 and the cathepsin K inhibitors, led by Novartis's balicatib, standing out.
Affecting more than 150 million people around the world, osteoporosis is most commonly found in elderly, post-menopausal women, and associated with an increased risk of hip and vertebral fractures.