Less than 50% of Osteoporosis Patients Adhere to Current Bisphosphonate Therapy Regimens

Main Category: Bones / Orthopedics
Article Date: 06 Oct 2004 - 15:00 PDT


More than half of women with postmenopausal osteoporosis do not stay on their prescribed bisphosphonate therapy,1,2 resulting in lesser gains in bone mineral density (BMD) and, potentially, an increased risk for fractures compared to women who stay on therapy as directed,3 according to findings presented at the 26th Annual Meeting of the American Society for Bone Mineral Research (ASBMR). The findings showed that adherence to therapy was better with oral weekly-dosed than with daily-dosed bisphosphonates, but was suboptimal for both dosage regimens.1,2

"Osteoporosis is a chronic condition that requires patients to take their medication as directed over the long term to gain full therapeutic benefit," said lead investigator Joyce Cramer, associate research scientist, Department of Psychiatry, Yale University School of Medicine, New Haven, Conn. She said the new findings are consistent with other data showing that poor patient adherence occurs with bisphosphonate therapy.4,5 Poor adherence with osteoporosis therapies results in less gain in bone strength,6 an increased risk for fractures and greater healthcare costs.7

Many patients do not adhere to bisphosphonate therapy, she said, in part because osteoporosis is an asymptomatic, chronic condition. Many patients see no obvious evidence of the disease, unless they experience a bone fracture, and consequently may not accept the need for therapy.

An additional barrier to treatment adherence is that current oral bisphosphonates need to be administered according to strict treatment guidelines, including remaining upright and not eating, drinking (except plain water) or taking other medications for a period of time after the bisphosphonate therapy is taken.

"These study findings suggest that a less frequent dosing regimen improves adherence with bisphosphonate therapy. However, adherence with even once-weekly dosing is suboptimal, so alternative dosing regimens should be explored," she said.

Studies and Findings

Adherence to therapy involves both persistence (staying on a medication) and compliance (taking the medication as directed). In one of the studies presented,1 only one-third (33.3 percent) of patients prescribed daily bisphosphonate therapy and just less than half (44.8 percent) on weekly bisphosphonate therapy had adequate persistence. The study was based on data from prescriptions dispensed from U.S. pharmacies, and assessed persistence over one year in more than 200,000 women 50 years and older taking either daily (33,767 women) or weekly (177,552 women) bisphosphonate therapy for osteoporosis. Persistence was measured by determining, for each woman, the total days of supply from all bisphosphonate prescriptions filled or refilled during the year, and dividing by 365 potential days of therapy; a value of 80 percent or greater was considered "adequate" persistence.

Similar findings from another study were presented2 showing that weekly bisphosphonate users had better adherence (persistence and compliance) than daily bisphosphonate users, but rates remained suboptimal for both dosing regimens. The analysis showed that at the end of 12 months, 31.7 percent of patients prescribed daily therapy and 44.2 percent on weekly therapy persisted with the therapy. The study was based on five years of administrative claims from 30 health plans and 2,741 postmenopausal women newly-prescribed a once-weekly or once-daily bisphosphonate.

The negative clinical impact of poor adherence was shown in a third presentation,3 based on data taken over three years on 1,041 patients with osteoporosis who were either "inconsistent" (discontinued early or reported taking the medication less than 80 percent of the time) or "consistent" users of daily bisphosphonate therapy. In consistent users, lumbar spine BMD increased significantly from baseline after one, two and three years; in inconsistent users, no significant improvement in BMD occurred until the third year, when a modest gain occurred.

The increased BMD among consistent users was significantly greater than those for inconsistent users each of the three years. In addition, there was a trend of a 27 percent greater 10-year fracture risk in inconsistent compared with consistent users (p = 0.18; not statistically significant).

About Osteoporosis

Osteoporosis (porous bones) is a disease in which bones become brittle and more likely to break. Common and chronic conditions, osteoporosis and low bone mass (osteopenia) pose a major public health threat to more than 44 million Americans over age 50.8 In the U.S. today, ten million individuals, eight million of whom are women, are estimated to already have osteoporosis, and almost 34 million more are estimated to have osteopenia, placing them at increased risk for osteoporosis.8 Unfortunately, the prevalence of osteoporosis is growing, especially as the number of postmenopausal women in the population continues to rise.

An estimated 52 million women and men age fifty plus are expected to be affected by osteoporosis and osteopenia by 2010 and 61 million are expected to be affected by 2020.8

About Roche

Hoffmann-La Roche Inc. (Roche), based in Nutley, N.J., is the U.S. prescription drug unit of the Roche Group, a leading research-based health care enterprise that ranks among the world's leaders in pharmaceuticals and diagnostics. Roche discovers, develops, manufactures and markets numerous important prescription drugs that enhance people's health, well-being and quality of life. Among the company's areas of therapeutic interest are: dermatology; genitourinary disease; infectious diseases, including influenza; inflammation, including arthritis and osteoporosis; metabolic diseases, including obesity and diabetes; neurology; oncology; transplantation; vascular diseases; and virology, including HIV/AIDS and hepatitis C.

For more information on the Roche U.S. pharmaceuticals business, visit the company's web site at: http://www.rocheusa.com.

About GSK

GSK, one of the world's leading research-based pharmaceutical and healthcare companies, is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For company information, visit GSK on the World Wide Web at http://www.gsk.com.

For further information contact:

Roche:
Terence Hurley (973) 562-2882
GSK:
Veronica Grosshandler (919) 483-2839

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References

1 Recker RR, Gallagher R, Amonkar M, Smith JC, MacCosbe PE. Medication persistence is better with weekly bisphosphonates, but it remains suboptimal. Poster SA407, presented at: 26th Annual Meeting of the American Society for Bone Mineral Research, October 1-5, 2004, Seattle, WA.

2 Cramer JA, Amonkar MM, Hebborn A, Suppapanya. Does dosing regimen impact persistence with bisphosphonate therapy among postmenopausal osteoporotic women. Poster M434, presented at: 26th Annual Meeting of the American Society for Bone Mineral Research, October 1-5, 2004, Seattle, WA.

3 Sebaldt RJ, Shane LG, Pham BZ, Cook RJ, Thabane L, Petrie A, Olszynski WP, Hanley DA, Brown J, Adachi1 JD, Murray T, Josse R, Papaioannou A. Impact of non-compliance and non-persistence with daily bisphosphonates on longer-term effectiveness outcomes in patients with osteoporosis treated in tertiary specialist care. Poster M423, presented at: 26th Annual Meeting of the American Society for Bone Mineral Research, October 1-5, 2004, Seattle, WA.

4 Lombas C, Hakim C, Zanchetta JR. Compliance with alendronate treatment in an osteoporosis clinic. J Bone Miner Res 2001;15: S529, Abstract M406.

5 Roldán EJA, Negri AL, Gador SA. Short-term compliance to daily alendronate treatment in 1,877 patients with osteoporosis - the ECMO study. J Bone Miner Res 2000; 15:SU411.

6 Yood RA, Emani S, Reed JI, Lewis BE, Charpentier M, Lydick E. Compliance with pharmacologic therapy for osteoporosis. Osteoporos Int. 2003 Dec;14(12):965-8.

7 Caro JJ, Ishak KJ, Huybrechts KF, Raggio G, Naujoks C. Clinical and economic impact of adherence to osteoporosis medication. Osteoporos. Int. 2003;14(7). Abstr PL6.

8 America's Bone Health: The State of Osteoporosis and Low Bone Mass in Our Nation. The National Osteoporosis Foundation. February 2002.

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