Daily Endocrinology Research Analysis
Three studies stand out today in endocrinology and metabolic medicine: a phase II randomized trial shows a novel anti-RANKL antibody (narlumosbart) increases bone mineral density in postmenopausal osteoporosis; a double-blind RCT in infertile men reveals seminal fluid phosphate is extraordinarily high, correlates inversely with sperm motility/morphology, and is not altered by vitamin D/calcium; and a pooled analysis from CANVAS/CREDENCE demonstrates canagliflozin provides greater cardio-renal be
Summary
Three studies stand out today in endocrinology and metabolic medicine: a phase II randomized trial shows a novel anti-RANKL antibody (narlumosbart) increases bone mineral density in postmenopausal osteoporosis; a double-blind RCT in infertile men reveals seminal fluid phosphate is extraordinarily high, correlates inversely with sperm motility/morphology, and is not altered by vitamin D/calcium; and a pooled analysis from CANVAS/CREDENCE demonstrates canagliflozin provides greater cardio-renal benefit in type 2 diabetes patients with elevated NT-proBNP-defined heart stress.
Research Themes
- New antiresorptive therapies in osteoporosis
- Male reproductive endocrinology and seminal biomarkers
- Cardio-renal risk stratification in diabetes using NT-proBNP
Selected Articles
1. Efficacy and safety of narlumosbart, an anti-RANKL monoclonal antibody, in postmenopausal women with osteoporosis: a multi-center, randomized, double-blind, placebo- and active-controlled, phased II study.
In a multicenter, double-blind phase II RCT (n=207), the anti-RANKL antibody narlumosbart increased lumbar spine BMD by 4.8–6.5% at 12 months versus 0.6% with placebo, with a safety profile comparable to denosumab over 12 months. These data support narlumosbart as a promising antiresorptive candidate warranting fracture-endpoint phase III trials.
Impact: A new anti-RANKL monoclonal antibody shows robust, dose-responsive BMD gains versus placebo with short-term safety, potentially expanding antiresorptive options beyond denosumab.
Clinical Implications: If confirmed in phase III trials with fracture outcomes, narlumosbart could offer an alternative antiresorptive therapy for postmenopausal osteoporosis, particularly in settings of denosumab intolerance, supply issues, or specific payer/regulatory contexts.
Key Findings
- Narlumosbart increased lumbar spine BMD at 12 months by 4.83%, 6.52%, and 5.74% (45, 60, 90 mg) versus 0.63% with placebo (all P<0.001).
- Safety over 12 months was comparable to placebo and denosumab; common TEAEs included decreased vitamin D and increased PTH.
- Study included an active comparator (denosumab 60 mg) and was double-blind across five arms, strengthening interpretability.
Methodological Strengths
- Multicenter, randomized, double-blind, placebo- and active-controlled design
- Pre-registered trial (NCT05278338) with clear primary endpoint (lumbar spine BMD)
Limitations
- Phase II duration (12 months) with surrogate endpoint (BMD) rather than fractures
- High TEAE incidence typical of antiresorptives; long-term safety and immunogenicity require further study
Future Directions: Conduct phase III trials powered for fracture reduction and long-term safety, head-to-head comparisons with denosumab/zoledronate, and subgroup analyses (e.g., CKD, glucocorticoid-induced osteoporosis).
BACKGROUND: This study aimed to preliminarily explore the efficacy and safety of narlumosbart, an anti-RANKL monoclonal antibody, in treating postmenopausal women with osteoporosis. METHODS: This multi-center, randomized, double -blind, placebo- and active-controlled study was conducted at 23 clinics across China between April 21, 2022 and April 19, 2023. Eligible patients were randomly assigned (1:1:1:1:1) to receive either 45 mg. 60 mg, 90 mg of narlumosbart, 60 mg of denosumab, or placebo, administered once every 6 months over a 12-month period, with the treatment allocation masked for participants, sponsors, and clinical investigators. The primary efficacy endpoint was the percentage change in lumbar spine bone mineral density (BMD) from baseline to 12 months. The secondary measures were percentage changes in lumbar spine, total hip, and femoral neck BMD, height changes, bone turnover markers, safety, and immunogenicity. Study registration: www.clinicaltrials.gov (NCT05278338). FINDINGS: 207 postmenopausal women with osteoporosis were enrolled and randomly assigned to received narlumosbart 45-90 mg (n = 41 in each group), denosumab (n = 42), or placebo (n = 42). At month 12, patients receiving narlumosbart 45 mg, 60 mg, and 90 mg had the percentage change in lumbar spine BMD from baseline (least-squares [LS] mean [standard error]) of 4.83% (0.65), 6.52% (0.62), and 5.74% (0.64), respectively, and all showed significant increases compared with the placebo group (0.63% [0.67]), with LS mean differences (99% confidence interval [CI]) of 4.20% (1.92∼6.48), 5.90% (3.63∼8.16), and 5.11% (2.84∼7.39), respectively (all P < 0.001). Treatment-emergent adverse events (TEAEs) were observed in 91.9% of patients in the pooled narlumosbart groups, and 92.9% in both the placebo and the denosumab groups. Most common TEAEs were decreased vitamin D levels (34.1% [pooled narlumosbart] vs. 35.7% [placebo] vs. 33.3% [denosumab]), COVID-19 (38.2% vs. 40.5% vs. 35.7%), and increased serum parathyroid hormone (22.8% vs. 14.3% vs. 19.0%). INTERPRETATION: In this phase II trial of postmenopausal women with osteoporosis, narlumosbart demonstrated superiority over placebo in increasing BMD at 12 months following administration at 6-month intervals, with a tolerable safety profile in the short term, consistent with that of anti-RANKL monoclonal antibodies. FUNDING: This study was supported by Shanghai JMT-Bio Technology Co., Ltd.; National Key R&D Program of China [2021YFC2501700]; CAMS Innovation Fund for Medical Sciences (CIFMS) [2021-I2M-1-002]; National High Level Hospital Clinical Research Funding [2022-PUMCH-D-006]; the National Natural Science Foundation of China [No. 82270938, No. 81970757]; and the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences [2023-PT320-10].
2. Phosphate concentration is exceptionally high in seminal fluid and is linked with semen quality but not influenced by vitamin D and calcium supplementation.
In a double-blind RCT of 307 infertile men, seminal phosphate was ~25-fold higher than serum and inversely associated with sperm motility and normal morphology; serum phosphate did not correlate with seminal phosphate. High-dose vitamin D plus calcium for 150 days did not alter seminal phosphate concentrations.
Impact: This trial identifies seminal phosphate as a stable, locally regulated biomarker linked to semen quality and shows it is not modifiable by systemic vitamin D/calcium, informing male infertility assessment and therapeutic targeting.
Clinical Implications: Consider measuring seminal phosphate in male infertility workups as a potential indicator of semen quality; vitamin D/calcium supplementation should not be expected to modulate seminal phosphate or improve semen parameters via this pathway.
Key Findings
- Seminal phosphate concentration (median 24.0 mmol/L) was ~25-fold higher than serum and independent of serum phosphate.
- Higher seminal phosphate (≥29 mmol/L) associated with fewer motile sperm (median AB% 27% vs 37%; P=0.007) and fewer morphologically normal sperm (1.9% vs 2.5%; P=0.014).
- High-dose cholecalciferol plus calcium for 150 days did not change seminal phosphate concentrations versus placebo.
Methodological Strengths
- Double-blind, randomized, placebo-controlled design with adequate sample size (n=307)
- Predefined seminal phosphate endpoint and rigorous semen parameter assessment
Limitations
- Single-center trial may limit generalizability
- Seminal phosphate-semen quality associations are observational within the RCT; causality not established and no pregnancy/live-birth outcomes reported
Future Directions: Elucidate mechanisms of local phosphate regulation in seminal fluid, assess seminal phosphate as a predictive biomarker for fertility outcomes, and explore targeted local interventions.
OBJECTIVE: This study aims to determine the link between seminal fluid (SF) concentrations of phosphate with semen quality parameters, corresponding serum phosphate concentration, and possible influence of high-dose cholecalciferol and calcium supplementation. MATERIALS AND METHODS: In a single-center, double-blinded, randomized clinical trial (NCT01304927), 307 infertile men were assigned to receive a single dose of vitamin D (cholecalciferol) 300 000 IU initially followed by 1400 IU and 500 mg of calcium daily for 150 days or placebo. Change in SF phosphate was a predefined secondary endpoint while effect on semen parameters was the primary endpoint. RESULTS: At baseline, SF phosphate concentration was 25-fold higher but not associated with serum phosphate concentration (median 24.0 mmol/L [IQR 17, 30] vs 0.93 mmol/L [IQR 0.83, 1.05]). Men with the highest concentration of SF phosphate (≥29 mmol/L) had fewer motile spermatozoa (AB%: median 27% [IQR 14, 39] vs 37% [IQR 17, 56]; P = .007) and morphologically normal spermatozoa (1.9% [IQR 0.8, 3.8] vs 2.5% [IQR 1.4, 6.5]; P = .014) than men having SF phosphate < 19 mmol/L. Seminal fluid concentrations of phosphate remained stable and were unaffected by vitamin D and calcium supplementation (SF phosphate in placebo median 21.4 [IQR 15.9, 28.4] vs treatment 21.1 [IQR 14.5, 29.8]). CONCLUSION: Seminal fluid phosphate concentration may be of importance for reproductive function as infertile men with the lowest SF phosphate concentration had higher percentage of motile and morphologically normal spermatozoa. Serum phosphate concentration was not associated with seminal phosphate levels, and cholecalciferol and calcium supplementation did not influence SF phosphate.
3. Impact of canagliflozin on heart stress and outcomes: Pooled insights from CREDENCE and CANVAS.
In 5,281 T2D participants without baseline HF from CANVAS/CREDENCE, age-adjusted NT-proBNP defined “heart stress” in 45% and predicted cardio-renal events. Canagliflozin conferred greater relative risk reductions in those with heart stress, including primary composite (HR 0.72), kidney composite (HR 0.65), and HF hospitalization (HR 0.68).
Impact: This pooled analysis operationalizes NT-proBNP thresholds to stratify T2D patients for SGLT2 inhibitor benefit, bridging biomarker-defined risk with therapeutic decision-making.
Clinical Implications: Age-adjusted NT-proBNP can aid in identifying T2D patients most likely to derive cardio-renal benefit from canagliflozin; consider systematic NT-proBNP screening and early SGLT2i initiation in those with heart stress.
Key Findings
- Heart stress by age-adjusted NT-proBNP present in 45% and independently predicted higher risks of cardio-renal outcomes.
- Canagliflozin reduced the primary composite (HR 0.72), kidney composite (HR 0.65), and HF hospitalization (HR 0.68) in those with heart stress.
- Persistent or rising NT-proBNP from baseline to year 1 identified patients at highest risk.
Methodological Strengths
- Large pooled dataset from two landmark RCT programs with centralized biomarker assessment at baseline and 1 year
- Multivariable Cox modeling and age-adjusted NT-proBNP thresholds enhance clinical interpretability
Limitations
- Post hoc pooled analysis; findings are associative and may not fully account for residual confounding
- Generalizability limited to T2D with cardio-renal disease and no baseline HF; NT-proBNP-guided treatment not prospectively tested
Future Directions: Prospective trials of NT-proBNP-guided SGLT2i initiation/intensification in T2D and exploration of dynamic NT-proBNP changes as a treat-to-target strategy.
AIMS: In individuals with type 2 diabetes with cardio-renal disease but no known heart failure (HF), elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP), a marker of heart stress, signals higher risk of HF and cardio-kidney complications. This analysis assesses canagliflozin impact on heart stress and outcomes using age-adjusted NT-proBNP thresholds from two major trials. METHODS AND RESULTS: This analysis included 5281 participants from the CANVAS and CREDENCE trials without HF at baseline. NT-proBNP was measured at baseline and year 1, with heart stress defined using age-adjusted NT-proBNP thresholds. Outcomes included a primary composite (end-stage kidney disease, doubling of serum creatinine, kidney or cardiovascular death), kidney composite, HF hospitalization, cardiovascular death, all-cause death, and HF hospitalization or cardiovascular death composite. Multivariable Cox models assessed heart stress, outcomes, and canagliflozin effects. At baseline, 45% of participants had heart stress. Heart stress independently predicted increased risks for all outcomes, with the highest risks in those with persistent or rising NT-proBNP at baseline and year 1. Rising NT-proBNP by year 1 was associated with higher risk as well. Canagliflozin significantly reduced risks in individuals with heart stress, including the primary composite (hazard ratio [HR] 0.72, 95% confidence interval [CI] 0.62-0.84), kidney composite (HR 0.65, 95% CI 0.53-0.79), and HF hospitalization (HR 0.68, 95% CI 0.54-0.85). Benefits were less pronounced in those without heart stress. CONCLUSIONS: Age-adjusted NT-proBNP thresholds effectively predict cardio-kidney events in at-risk type 2 diabetes individuals without HF. Canagliflozin offers strong cardiovascular and kidney protection, with the greatest benefits in those with heart stress, emphasizing the need for early identification and intervention. CLINICAL TRIAL REGISTRATIONS: CANVAS (NCT01032629), CREDENCE (NCT02065791).