The drug delivery firm was due to receive the payment from its development partner Procter & Gamble (P&G) Pharmaceuticals.
US-based Nastech has now announced plans to start an additional Phase II dose ranging study of its Parathyroid Hormone (PTH) nasal spray in the second half of next year, after P&G requested the additional clinical study.
As a result, the two firms have had to amend their 10-month agreement last Monday. Under the terms of the new deal, the $15m payment Nastech expected to receive this year has been deferred to a $5m payment at the beginning of the additional clinical trial and another $10m payment on the initiation of a phase III clinical study.
A Phase III trial was expected to begin at the end of this year, following the completion of the biomarker study and the original $15m milestone payment. But that study is taking longer than originally thought and the Phase III trial could be pushed to the beginning of 2008.
"We are fully supportive of the clinical pathway moving forward on PTH1-34," said Mark Collar, president, P&G Global Pharmaceuticals.
"P&G has a long history in the osteoporosis field, and we are leveraging this expertise to bring the best development efforts possible to this new potential therapeutic product."
P&G is currently conducting a biomarker study of the new drug in patients with low bone mass to measure blood markers of both bone formation and bone resorption. This study is expected to be completed during the second quarter of 2007.
"The PTH1-34 nasal spray clinical development programme has made significant progress in 2006 and we are pleased with P&G's commitment to advancing the clinical development program in a manner that maximises the potential for regulatory approval and successful commercialisation of this important product candidate," said Steven Quay, chairman, president and CEO of Nastech.
"A patient-friendly, non-invasive nasal spray dosage form of PTH1-34 would provide osteoporosis patients and their doctors with a preferred alternative to the currently required daily injections."
Indeed, the company's expectation is that a more patient-friendly delivery formulation of the drug would make the use of PTH more widespread.
In addition, PTH is of real interest for osteoporosis patients because it builds bone, rather than just blocking the bone destruction that characterises the disease. Osteoporosis is a bone disease in which the amount of bone is decreased and the structural integrity of trabecular bone is impaired. As a result, cortical bone becomes more porous and thinner which this makes the bone weaker and more likely to fracture.
In the US only, about 45 per cent of postmenopausal women have low bone density.
According to the National Osteoporosis Foundation, in the US, one in two women and one in four men over age 50 will have an osteoporosis-related fracture in her/his lifetime and it is estimated that the disease accounts for more than 1.5m fractures each year.
Eli Lilly is already a player in the osteoporosis market and has already launched a drug - Forteo (teriparatide) - to treat the condition that is delivered intravenously, so a nasal spray has the potential to take the competition even further, although Forteo is already a nice earner for Lilly, with revenues of $149m in the third quarter of 2006.
Nastech and P&G's new formulated drug will be tested in the forthcoming Phase III trial against Lilly's injected form.
P&G and Nastech signed their $577m partnership agreement for PTH1-34 in February. Under the terms of the deal Nastech will receive increasing royalties and co-promotion rights for the new drug.
Since the first agreement was signed, Nastech has received $17m in payments, and P&G has started the ongoing Phase II biomarker study in patients with low bone mass.
P&G has also completed a pharmacokinetic study in post-menopausal women and elderly men which showed a positive safety profile over a range of doses and produced similar exposure levels compared to the approved injected drug Forteo.