Weekly Dose of Parathyroid Hormone Thickens Spine

PHILADELPHIA — Weekly parathyroid hormone increases bone mineral density and bone formation biomarkers, but only slightly, Dennis M. Black, Ph.D., reported at the annual meeting of the American Society for Bone and Mineral Research.

Spine bone mineral density (BMD) increased 2.1% in women on parathyroid hormone (PTH) at the end of 1 year, compared with women receiving no treatment, a significant finding. Trabecular spine volumetric BMD assessed with quantitative CT increased 3.8% in women in the treatment group, compared with those in the control group, though this result was not significant, Dr. Black said. There also were trends toward increases in trabecular number and cortical thickness, though these were not statistically significant.

In the PTH Once Weekly Research (POWR) study, 50 women were randomized evenly to treatment with PTH (1–84) at a dosage of 100 mcg daily for 1 month followed by 11 months of once weekly PTH (also 100 mcg) or no treatment. All women also received 500 mg calcium and 400 IU vitamin D per day, reported Dr. Black, professor of epidemiology and biostatistics at the University of California, San Francisco. Women had to be postmenopausal and aged between 45 and 70 years, with minimal previous use of bisphosphonates. They also had to have a femoral neck BMD T score between −1 and −2 and a spine BMD T score greater than −2.5.

The primary end point was spine BMD measured by dual-energy x-ray absorptiometry (DXA). Secondary end points included BMD at the hip, trabecular, and cortical bone measured by quantitative CT at the spine and hip and bone biomarkers. Based on injection diaries, 94% of the women were found to have at least an 80% compliance with the injection regimen, he said.

Bone formation during daily treatment with PTH, as measured by procollagen type 1 N-propeptide (P1NP) levels, increased roughly 100% compared with untreated women. However, levels slowly decreased during weekly injections, remaining 15% greater than for untreated women at 12 months. There were no significant changes in resorption markers in either group.

He compared the results of this pilot study with those for daily PTH treatment at 12 months from the Parathyroid Hormone and Alendronate (PaTH) study (N. Engl. J. Med. 2005;353:555–65).

Once-weekly PTH following daily PTH for 1 month significantly increased spine BMD. However, compared with daily PTH in the PaTh study, “there was no significant increase in trabecular BMD, a small increase in DXA spine BMD, a smaller increase in bone formation markers, and generally a smaller anabolic response,” he said.

Once weekly PTH may not be frequent enough. A longer loading period may be necessary, he noted. In terms of adverse events, there was one case of chest pain in the placebo group, and there were four mild cases of hypercalcemia in the PTH group.

Dr. Black disclosed that he has significant financial relationships with Novartis, Merck & Co., Hoffmann-La Roche Inc., and GlaxoSmithKline.

PHILADELPHIA — Weekly parathyroid hormone increases bone mineral density and bone formation biomarkers, but only slightly, Dennis M. Black, Ph.D., reported at the annual meeting of the American Society for Bone and Mineral Research.

Spine bone mineral density (BMD) increased 2.1% in women on parathyroid hormone (PTH) at the end of 1 year, compared with women receiving no treatment, a significant finding. Trabecular spine volumetric BMD assessed with quantitative CT increased 3.8% in women in the treatment group, compared with those in the control group, though this result was not significant, Dr. Black said. There also were trends toward increases in trabecular number and cortical thickness, though these were not statistically significant.

In the PTH Once Weekly Research (POWR) study, 50 women were randomized evenly to treatment with PTH (1–84) at a dosage of 100 mcg daily for 1 month followed by 11 months of once weekly PTH (also 100 mcg) or no treatment. All women also received 500 mg calcium and 400 IU vitamin D per day, reported Dr. Black, professor of epidemiology and biostatistics at the University of California, San Francisco. Women had to be postmenopausal and aged between 45 and 70 years, with minimal previous use of bisphosphonates. They also had to have a femoral neck BMD T score between −1 and −2 and a spine BMD T score greater than −2.5.

The primary end point was spine BMD measured by dual-energy x-ray absorptiometry (DXA). Secondary end points included BMD at the hip, trabecular, and cortical bone measured by quantitative CT at the spine and hip and bone biomarkers. Based on injection diaries, 94% of the women were found to have at least an 80% compliance with the injection regimen, he said.

Bone formation during daily treatment with PTH, as measured by procollagen type 1 N-propeptide (P1NP) levels, increased roughly 100% compared with untreated women. However, levels slowly decreased during weekly injections, remaining 15% greater than for untreated women at 12 months. There were no significant changes in resorption markers in either group.

He compared the results of this pilot study with those for daily PTH treatment at 12 months from the Parathyroid Hormone and Alendronate (PaTH) study (N. Engl. J. Med. 2005;353:555–65).

Once-weekly PTH following daily PTH for 1 month significantly increased spine BMD. However, compared with daily PTH in the PaTh study, “there was no significant increase in trabecular BMD, a small increase in DXA spine BMD, a smaller increase in bone formation markers, and generally a smaller anabolic response,” he said.

Once weekly PTH may not be frequent enough. A longer loading period may be necessary, he noted. In terms of adverse events, there was one case of chest pain in the placebo group, and there were four mild cases of hypercalcemia in the PTH group.

Dr. Black disclosed that he has significant financial relationships with Novartis, Merck & Co., Hoffmann-La Roche Inc., and GlaxoSmithKline.

PHILADELPHIA — Weekly parathyroid hormone increases bone mineral density and bone formation biomarkers, but only slightly, Dennis M. Black, Ph.D., reported at the annual meeting of the American Society for Bone and Mineral Research.

Spine bone mineral density (BMD) increased 2.1% in women on parathyroid hormone (PTH) at the end of 1 year, compared with women receiving no treatment, a significant finding. Trabecular spine volumetric BMD assessed with quantitative CT increased 3.8% in women in the treatment group, compared with those in the control group, though this result was not significant, Dr. Black said. There also were trends toward increases in trabecular number and cortical thickness, though these were not statistically significant.

In the PTH Once Weekly Research (POWR) study, 50 women were randomized evenly to treatment with PTH (1–84) at a dosage of 100 mcg daily for 1 month followed by 11 months of once weekly PTH (also 100 mcg) or no treatment. All women also received 500 mg calcium and 400 IU vitamin D per day, reported Dr. Black, professor of epidemiology and biostatistics at the University of California, San Francisco. Women had to be postmenopausal and aged between 45 and 70 years, with minimal previous use of bisphosphonates. They also had to have a femoral neck BMD T score between −1 and −2 and a spine BMD T score greater than −2.5.

The primary end point was spine BMD measured by dual-energy x-ray absorptiometry (DXA). Secondary end points included BMD at the hip, trabecular, and cortical bone measured by quantitative CT at the spine and hip and bone biomarkers. Based on injection diaries, 94% of the women were found to have at least an 80% compliance with the injection regimen, he said.

Bone formation during daily treatment with PTH, as measured by procollagen type 1 N-propeptide (P1NP) levels, increased roughly 100% compared with untreated women. However, levels slowly decreased during weekly injections, remaining 15% greater than for untreated women at 12 months. There were no significant changes in resorption markers in either group.

He compared the results of this pilot study with those for daily PTH treatment at 12 months from the Parathyroid Hormone and Alendronate (PaTH) study (N. Engl. J. Med. 2005;353:555–65).

Once-weekly PTH following daily PTH for 1 month significantly increased spine BMD. However, compared with daily PTH in the PaTh study, “there was no significant increase in trabecular BMD, a small increase in DXA spine BMD, a smaller increase in bone formation markers, and generally a smaller anabolic response,” he said.

Once weekly PTH may not be frequent enough. A longer loading period may be necessary, he noted. In terms of adverse events, there was one case of chest pain in the placebo group, and there were four mild cases of hypercalcemia in the PTH group.

Dr. Black disclosed that he has significant financial relationships with Novartis, Merck & Co., Hoffmann-La Roche Inc., and GlaxoSmithKline.