Oral delivery for osteoporosis drug

GSK has started a Phase I trial of an oral formulation of parathyroid hormone, a relatively new treatment for osteoporosis that is marketed as an injectable by Eli Lilly under the trade name Forteo (teriparatide).

Forteo was launched in December 2002 and is still the only treatment for osteoporosis based on PTH to be commercialised, despite the advantages of this approach.

PTH is the only treatment for the disease that actually replaces lost bone tissue. All other drugs on the market, including the top-selling bisphosphonate class, act by interrupting the decline in bone density experienced by patients with osteoporosis.

Under the terms of its April 2002 agreement with Unigene, GSK received an exclusive worldwide license to develop an oral formulation of PTH under Unigene's manufacturing and oral delivery patents. The agreement could have a value to Unigene before royalties, PTH sales and reimbursement for development activities, of up to $150 million.

Including the $4 million milestone payment, Unigene will have received an aggregate of $11.9 million from GSK, consisting of $8 million in up-front and milestone payments and an additional $3.9 million for development work and PTH production.

A recent report published by Datamonitor predicted that sales of drugs to treat osteoporosis will reach $10.4 billion by 2011, from approximately $5.0 billion in 2003.