PaTH Forward: A Randomized, Double-Blind, Placebo-Controlled Phase 2 Trial of TransCon PTH in Adult Hypoparathyroidism.

CONTEXT: Hypoparathyroidism is characterized by insufficient levels of parathyroid hormone (PTH). TransCon PTH is an investigational long-acting prodrug of PTH(1-34) for the treatment of hypoparathyroidism. OBJECTIVE: This work aimed to investigate the safety, tolerability, and efficacy of daily TransCon PTH in adults with hypoparathyroidism. METHODS: This phase 2, randomized, double-blind, placebo-controlled 4-week trial with open-label extension enrolled 59 individuals with hypoparathyroidism. Interventions included TransCon PTH 15, 18, or 21 µg PTH(1-34)/day or placebo for 4 weeks, followed by a 22-week extension during which TransCon PTH dose was titrated (6-60 µg PTH[1-34]/day). RESULTS: By Week 26, 91% of participants treated with TransCon PTH achieved independence from standard of care (SoC, defined as active vitamin D = 0 µg/day and calcium [Ca] ≤ 500 mg/day). Mean 24-hour urine Ca (uCa) decreased from a baseline mean of 415 mg/24h to 178 mg/24h by Week 26 (n = 44) while normal serum Ca (sCa) was maintained and serum phosphate and serum calcium-phosphate product fell within the normal range. By Week 26, mean scores on the generic 36-Item Short Form Health Survey domains increased from below normal at baseline to within the normal range. The Hypoparathyroidism Patient Experience Scale symptom and impact scores improved through 26 weeks. TransCon PTH was well tolerated with no treatment-related serious or severe adverse events. CONCLUSION: TransCon PTH enabled independence from oral active vitamin D and reduced Ca supplements (≤ 500 mg/day) for most participants, achieving normal sCa, serum phosphate, uCa, serum calcium-phosphate product, and demonstrating improved health-related quality of life. These results support TransCon PTH as a potential hormone replacement therapy for adults with hypoparathyroidism.

Weekly Lonapegsomatropin in Treatment-Naïve Children With Growth Hormone Deficiency: The Phase 3 heiGHt Trial.

CONTEXT: For children with growth hormone deficiency (GHD), treatment burden with daily somatropin injections [human growth hormone (hGH)] is high, which may lead to poor adherence and suboptimal overall treatment outcomes. Lonapegsomatropin (TransCon hGH) is an investigational long-acting, once-weekly prodrug for the treatment of GHD. OBJECTIVE: The objective of this study was to evaluate the efficacy and safety of once-weekly lonapegsomatropin vs daily somatropin. DESIGN: The heiGHt trial was a randomized, open-label, active-controlled, 52-week Phase 3 trial (NCT02781727). SETTING: This trial took place at 73 sites across 15 countries. PATIENTS: This trial enrolled and dosed 161 treatment-naïve, prepubertal patients with GHD. INTERVENTIONS: Patients were randomized 2:1 to receive lonapegsomatropin 0.24 mg hGH/kg/week or an equivalent weekly dose of somatropin delivered daily. MAIN OUTCOME MEASURE: The primary end point was annualized height velocity (AHV) at week 52. Secondary efficacy end points included change from baseline in height SD scores (SDS). RESULTS: Least squares (LS) mean (SE) AHV at 52 weeks was 11.2 (0.2) cm/year for lonapegsomatropin vs 10.3 (0.3) cm/year for daily somatropin (P = 0.009), with lonapegsomatropin demonstrating both noninferiority and superiority over daily somatropin. LS mean (SE) height SDS increased from baseline to week 52 by 1.10 (0.04) vs 0.96 (0.05) in the weekly lonapegsomatropin vs daily somatropin groups (P = 0.01). Bone age/chronological age ratio, adverse events, tolerability, and immunogenicity were similar between groups. CONCLUSIONS: The trial met its primary objective of noninferiority in AHV and further showed superiority of lonapegsomatropin compared to daily somatropin, with similar safety, in treatment-naïve children with GHD.

A Randomized Double-Blind Placebo-Controlled First-In-Human Phase 1 Trial of TransCon PTH in Healthy Adults.

TransCon PTH is a sustained-release, essentially inactive prodrug transiently bound to an inert carrier, designed to release PTH(1-34), and in development for hypoparathyroidism (HP). This phase 1, randomized, placebo-controlled, single and multiple ascending dose (SAD and MAD, respectively) trial evaluated safety, tolerability, pharmacodynamics (PD), and pharmacokinetics (PK) of TransCon PTH in healthy adults. SAD and MAD cohorts consisted of 10 subjects (eight active, two placebo) who received up to seven single or six multiple ascending doses of TransCon PTH, respectively. TransCon PTH doses ranged from 3.5 to 124 µg PTH(1-34) for the SAD cohorts and 3.5 to 24 µg PTH(1-34)/day for the MAD cohorts. The primary PK endpoint was Free PTH. The PD endpoints included albumin adjusted serum calcium (sCa), fractional excretion of calcium (FECa), intact endogenous PTH(1-84), bone turnover markers, renal tubular maximum reabsorption of phosphate/glomerular filtration rate (TMP/GFR), serum phosphate (sP) and magnesium, and 1,25 dihydroxyvitamin D. TransCon PTH was generally well tolerated; there were no drug-related serious adverse events (SAEs), and all AEs were transient in nature. Free PTH demonstrated an effective half-life of approximately 60 hours and a dose-dependent, sustained exposure with an infusion-like profile within the calculated physiologic range for active PTH at steady-state. Albumin-adjusted sCa demonstrated a dose-dependent, sustained response with complete control of FECa despite modest hypercalcemia at higher doses. Renal tubular maximum reabsorption of phosphate/glomerular filtration rate (TMP/GFR) showed a dose-dependent decrease, resulting in a dose-dependent decrease in sP. TransCon PTH administered daily for 10 days showed no increase in the osteoblastic bone formation markers, serum bone-specific alkaline phosphatase (BSAP) or P1NP, or the osteoclastic bone resorption marker, urine NTx, but modestly and transiently increased the osteoclast marker, serum CTx. These phase 1 data support TransCon PTH as a daily replacement therapy for HP providing physiological levels of PTH 24 hours per day and advancement into phase 2 clinical development. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Design and Preclinical Development of TransCon PTH, an Investigational Sustained-Release PTH Replacement Therapy for Hypoparathyroidism.

Hypoparathyroidism (HP) is a condition of parathyroid hormone (PTH) deficiency leading to abnormal calcium and phosphate metabolism. The mainstay of therapy consists of vitamin D and calcium supplements, as well as adjunct Natpara (PTH(1-84)). However, neither therapy optimally controls urinary calcium (uCa) or significantly reduces the incidence of hypercalcemia and hypocalcemia. TransCon PTH, a sustained-release prodrug of PTH(1-34) in development for the treatment of HP, was designed to overcome these limitations. To determine the pharmacokinetics and pharmacodynamics of TransCon PTH, single and repeat s.c. dose studies were performed in rats and monkeys. TransCon PTH demonstrated a half-life of 28 and 34 hours in rats and monkeys, respectively. After repeated dosing, an infusion-like profile of the released PTH, characterized by low peak-to-trough levels, was obtained in both species. In intact rats and monkeys, daily subcutaneous administration of TransCon PTH was associated with increases in serum calcium (sCa) levels and decreases in serum phosphate levels (sP). In monkeys, at a single dose of TransCon PTH that increased sCa levels within the normal range, a concurrent decrease in uCa excretion was observed. In 4-week repeat-dose studies in intact rats and monkeys, uCa excretion was comparable to controls across all dose levels despite increases in sCa levels. Further, in a rat model of HP, TransCon PTH normalized sCa and sP levels 24 hours per day. This was in contrast to only transient trends toward normalization of sCa and sP levels with an up to 6-fold higher molar dose of PTH(1-84). After repeated dosing to HP rats, uCa excretion transiently increased, corresponding to increases in sCa above normal range, but at the end of the treatment period, uCa excretion was generally comparable to sham controls. TransCon PTH was well tolerated and the observed pharmacokinetics and pharmacodynamics were in line with the expected action of physiological replacement of PTH. © 2019 American Society for Bone and Mineral Research.

The rationale and design of TransCon Growth Hormone for the treatment of growth hormone deficiency.

The fundamental challenge of developing a long-acting growth hormone (LAGH) is to create a more convenient growth hormone (GH) dosing profile while retaining the excellent safety, efficacy and tolerability of daily GH. With GH receptors on virtually all cells, replacement therapy should achieve the same tissue distribution and effects of daily (and endogenous) GH while maintaining levels of GH and resulting IGF-1 within the physiologic range. To date, only two LAGHs have gained the approval of either the Food and Drug Administration (FDA) or the European Medicines Agency (EMA); both released unmodified GH, thus presumably replicating distribution and pharmacological actions of daily GH. Other technologies have been applied to create LAGHs, including modifying GH (for example, protein enlargement or albumin binding) such that the resulting analogues possess a longer half-life. Based on these approaches, nearly 20 LAGHs have reached various stages of clinical development. Although most have failed, lessons learned have guided the development of a novel LAGH. TransCon GH is a LAGH prodrug in which GH is transiently bound to an inert methoxy polyethylene glycol (mPEG) carrier. It was designed to achieve the same safety, efficacy and tolerability as daily GH but with more convenient weekly dosing. In phase 2 trials of children and adults with growth hormone deficiency (GHD), similar safety, efficacy and tolerability to daily GH was shown as well as GH and IGF-1 levels within the physiologic range. These promising results support further development of TransCon GH.

Effects of the PPAR-δ agonist MBX-8025 on atherogenic dyslipidemia.

OBJECTIVE: Determine the effects of treatment with a selective PPAR-δ agonist±statin on plasma lipoprotein subfractions in dyslipidemic individuals. METHODS: Ion mobility analysis was used to measure plasma concentrations of subfractions of the full spectrum of lipoprotein particles in 166 overweight or obese dyslipidemic individuals treated with the PPAR-δ agonist MBX-8025 (50 and 100 mg/d)±atorvastatin (20 mg/d) in an 8-week randomized parallel arm double blind placebo controlled trial. RESULTS: MBX-8025 at both doses resulted in reductions of small plus very small LDL particles and increased levels of large LDL, with a concomitant reduction in large VLDL, and an increase in LDL peak diameter. This translated to reversal of the small dense LDL phenotype (LDL pattern B) in ∼90% of the participants. Modest increases in HDL particles were confined to the smaller HDL fractions. Atorvastatin monotherapy resulted in reductions in particles across the VLDL-IDL-LDL spectrum, with a significantly smaller reduction in small and very small LDL vs. MBX-8025 100 mg/d (-24.5±5.3% vs. -47.8±4.9%), and, in combination with MBX-8025, a reversal of the increase in large LDL. CONCLUSION: PPAR-δ and statin therapies have complementary effects in improving lipoprotein subfractions associated with atherogenic dyslipidemia.

MBX-8025, a novel peroxisome proliferator receptor-delta agonist: lipid and other metabolic effects in dyslipidemic overweight patients treated with and without atorvastatin.

CONTEXT: Preclinical and clinical studies suggest that peroxisome proliferator-activated receptor (PPAR)-δ agonists favorably affect multiple metabolic parameters that are otherwise proatherogenic, many that are not optimally managed with statins alone. OBJECTIVE: The aim of this study was to evaluate the effects of MBX-8025 (a novel PPAR-δ agonist) on lipid and other metabolic parameters associated with increased atherosclerotic risk, administered alone and in combination with atorvastatin. DESIGN AND SETTING: This was a randomized, double-blind, placebo-controlled, parallel group proof-of-concept study conducted at 30 U.S. research sites. PARTICIPANTS: This study evaluated 181 overweight men and women with mixed dyslipidemia. INTERVENTION(S): Subjects were administered once daily placebo, atorvastatin 20 mg, or MBX-8025 at 50 or 100 mg alone or combined with atorvastatin for 8 wk. MAIN OUTCOME MEASURES: The main efficacy measures included change from baseline in apolipoprotein B-100, lipid levels, high-sensitivity C-reactive protein, and additional metabolic parameters, as well as the effect on the metabolic syndrome and LDL particle size. RESULTS: Compared to placebo, MBX-8025 alone and in combination with atorvastatin significantly (P < 0.05) reduced apolipoprotein B-100 20-38%, LDL 18-43%, triglycerides 26-30%, non-high-density lipoprotein cholesterol 18-41%, free fatty acids 16-28%, and high-sensitivity C-reactive protein 43-72%; it raised high-density lipoprotein cholesterol 1-12% and also reduced the number of patients with the metabolic syndrome and a preponderance of small LDL particles. MBX-8025 was safe and generally well-tolerated. MBX-8025 also reduced liver enzyme levels. CONCLUSION: MBX-8025, a novel PPAR-δ agonist, favorably affected multiple metabolic parameters with and without atorvastatin. A more complete understanding of MBX-8025 requires a larger future study.

The cost-effectiveness of therapy with teriparatide and alendronate in women with severe osteoporosis.

BACKGROUND: Teriparatide is a promising new agent for the treatment of osteoporosis. METHODS: The objective of this study was to evaluate the cost-effectiveness of teriparatide-based strategies compared with alendronate sodium for the first-line treatment of high-risk osteoporotic women. We developed a microsimulation with a societal perspective. Key data sources include the Study of Osteoporotic Fractures, the Fracture Intervention Trial, and the Fracture Prevention Trial. We evaluated postmenopausal white women with low bone density and prevalent vertebral fracture. The interventions were usual care (UC) (calcium or vitamin D supplementation) compared with 3 strategies: 5 years of alendronate therapy, 2 years of teriparatide therapy, and 2 years of teriparatide therapy followed by 5 years of alendronate therapy (sequential teriparatide/alendronate). The main outcome measure was cost per quality-adjusted life-year (QALY). RESULTS: For the base-case analysis, the cost of alendronate treatment was 11,600 dollars per QALY compared with UC. The cost of sequential teriparatide/alendronate therapy was 156,500 dollars per QALY compared with alendronate. Teriparatide treatment alone was more expensive and produced a smaller increase in QALYs than alendronate. For sensitivity analysis, teriparatide alone was less cost-effective than alendronate even if its efficacy lasted 15 years after treatment cessation. Sequential teriparatide/alendronate therapy was less cost-effective than alendronate even if fractures were eliminated during the alendronate phase, although its cost-effectiveness was less than 50,000 dollars per QALY if the price of teriparatide decreased 60%, if used in elderly women with T scores of -4.0 or less, or if 6 months of teriparatide therapy had comparable efficacy to 2 years of treatment. CONCLUSIONS: Alendronate compares favorably to interventions accepted as cost-effective. Therapy with teriparatide alone is more expensive and produces a smaller increase in QALYs than therapy with alendronate. Sequential teriparatide/alendronate therapy appear expensive but could become more cost-effective with reductions in teriparatide price, with restriction to use in exceptionally high-risk women, or if short courses of treatment have comparable efficacy to that observed in clinical trials.

Improvement in spine bone density and reduction in risk of vertebral fractures during treatment with antiresorptive drugs.

PURPOSE: To estimate how much the improvement in bone mass accounts for the reduction in risk of vertebral fracture that has been observed in randomized trials of antiresorptive treatments for osteoporosis. METHODS: After a systematic search, we conducted a meta-analysis of 12 trials to describe the relation between improvement in spine bone mineral density and reduction in risk of vertebral fracture in postmenopausal women. We also used logistic models to estimate the proportion of the reduction in risk of vertebral fracture observed with alendronate in the Fracture Intervention Trial that was due to improvement in bone mineral density. RESULTS: Across the 12 trials, a 1% improvement in spine bone mineral density was associated with a 0.03 decrease (95% confidence interval [CI]: 0.02 to 0.05) in the relative risk (RR) of vertebral fracture. The reductions in risk were greater than predicted from improvement in bone mineral density; for example, the model estimated that treatments predicted to reduce fracture risk by 20% (RR = 0.80), based on improvement in bone mineral density, actually reduce the risk of fracture by about 45% (RR = 0.55). In the Fracture Intervention Trial, improvement in spine bone mineral density explained 16% (95% CI: 11% to 27%) of the reduction in the risk of vertebral fracture with alendronate. CONCLUSION: Improvement in spine bone mineral density during treatment with antiresorptive drugs accounts for a predictable but small part of the observed reduction in the risk of vertebral fracture.