Fluvastatin does not prevent the acute-phase response to intravenous zoledronic acid in post-menopausal women

Prediction of musculoskeletal pain after the first intravenous zoledronic acid injection in patients with primary osteoporosis: development and evaluation of a new nomogram

OBJECTIVE

To construct a new prediction nomogram to predict the risk of musculoskeletal pain in patients with primary osteoporosis who receive zoledronic acid intravenously for the first time.

METHOD

Clinical data of 368 patients with primary osteoporosis who received the first intravenous injection of zoledronic acid in our hospital from December 2019 to December 2022 were studied. Patients were divided into a musculoskeletal pain group (n = 258) and a non-musculoskeletal pain group (n = 110) based on the presence or absence of musculoskeletal pain 3 days after injection. Statistically significant predictors were screened by logistic regression analysis and the minimum absolute contraction and selection operator (LASSO) to construct a nomogram. The nomogram was evaluated by the receiver operating characteristic (ROC) curve, the calibration curve, the C-index, and the decision curve analysis (DCA) and verified in a validation cohort.

RESULTS

The independent predictors of the nomogram were age, serum 25-hydroxyvitamin D, NSAIDs, prior Vitamin D intake, and BMI. The area under the ROC curve (AUC) was 0.980 (95% CI, 0.915-0.987), showing excellent predictive performance. The nomogram c index was 0.980, and the nomogram c index for internal verification remained high at 0.979. Moreover, calibration curves show that the nomogram has good consistency. Finally, the DCA showed that the net benefit of the nomogram was 0.20-0.49.

CONCLUSION

Musculoskeletal pain is a common symptom of APR in OP patients treated with intravenous zoledronic acid. Risk factors for musculoskeletal pain after zoledronic acid injection in OP patients were: non-use of NSAIDs, youth (<80 years old), serum 25 (OH) D<30ng /mL, no prior intake of vitamin D, BMI<24 kg /m2. A nomogram constructed from the above predictors can be used to predict musculoskeletal pain after the first zoledronic acid injection.

Reduction effect of oral pravastatin on the acute phase response to intravenous zoledronic acid: protocol for a real-world prospective, placebo-controlled trial

INTRODUCTION

Zoledronic acid (ZA) has been used as a first-line treatment in patients with osteoporosis (OP) who receive an annual injection of 5 mg. However, side effects of bone pain and fever, known as the acute phase response (APR), have often been observed after clinical usage. A meta-analysis reported that the incidence of APR was 49.4% among patients with OP who received ZA for the first time and that 30% of patients with these adverse effects refused treatment in the following year. As a clinically used hypolipidaemic drug, statins can inhibit 3-hydroxy-3-methylglutaryl coenzyme A reductase to block the pathway upstream of farnesyl pyrophosphate synthase. This process can decrease the accumulation of isopentenyl pyrophosphate to prevent γδT-cell activation and inflammatory factor production, blocking APR occurrence. The aim of this study is to determine the reduction effect of oral pravastatin on APR and investigate the possible mechanisms underlying the effect in vivo.

METHODS AND ANALYSIS

This will be a single-centre, placebo-controlled trial. Female participants will be allocated at a 1:1 ratio to receive either oral pravastatin or a placebo at 1-hour predose and 24 and 48 hours post-administration of ZA. The primary outcome will be the incidence of APR within 72 hours after ZA infusion. The secondary outcomes will include the occurrence time and severity of APR and the frequency and amount of acetaminophen usage within 72 hours after ZA infusion. This study will determine the preventive effect of oral pravastatin on APR in Chinese patients with OP, supporting the clinical application of ZA to alleviate concerns regarding safety and increase patient compliance.

ETHICS AND DISSEMINATION

This study protocol has been registered with ClinicalTrials.gov. This study protocol was reviewed and approved by the Peking University Third Hospital Medical Science Research Ethics Committee. The results will be published in scientific peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04719481.

Characteristics Associated with Acute-Phase Response following First Zoledronic Acid Infusion in Brazilian Population with Osteoporosis

We aimed to evaluate characteristics associated with acute-phase response (APR) following first zoledronic acid infusion in a Brazilian cohort. This retrospective cohort study enrolled all adults with osteoporosis who underwent a first zoledronic acid infusion at our centre between June 2015 and June 2019. Clinical demographics (age, sex, diabetes, smoking, body mass index, and previous oral bisphosphonate use) and laboratory data (calcium, parathyroid hormone, renal function, and serum 25-hydroxyvitamin D and carboxy-terminal crosslinked telopeptide of type 1 collagen [CTX], both before and after infusion) were compared between patients with and without APR. We evaluated association magnitude between the presence of APR and clinical variables through logistic regression. This study enrolled 400 patients (women, 80%). APR was observed in 24.5% (n = 98) of patients. The mean symptom duration in days was 3.5 ± 2.8. Patients with APR were younger (67 ± 12 vs. 71 ± 11 years; p=0.001), used oral bisphosphonates less frequently (34% × 50%; p=0.005), and had greater baseline CTX (0.535 ng/mL [0.375, 0.697] × 0.430 [0.249, 0.681]; p=0.03) and ΔCTX (-69 [-76; -50] × -54 [-72; -23]; p=0.002) than those without APR. The other variables were similar between the groups. Only ΔCTX was associated (OR, 0.62; 95% CI 0.41-0.98) with APR after accounting for age and bisphosphonate use. APR occurred in 24.5% of the cohort. Younger age and absence of prior oral bisphosphonate use were associated with APR following first zoledronic acid infusion. APR was associated with ΔCTX (but no other variables) after adjusting for these factors.

Molecular mechanisms of action of bisphosphonates and new insights into their effects outside the skeleton

Bisphosphonates (BP) are a class of calcium-binding drug used to prevent bone resorption in skeletal disorders such as osteoporosis and metastatic bone disease. They act by selectively targeting bone-resorbing osteoclasts and can be grouped into two classes depending on their intracellular mechanisms of action. Simple BPs cause osteoclast apoptosis after cytoplasmic conversion into toxic ATP analogues. In contrast, nitrogen-containing BPs potently inhibit FPP synthase, an enzyme of the mevalonate (cholesterol biosynthesis) pathway. This results in production of a toxic metabolite (ApppI) and the loss of long-chain isoprenoid lipids required for protein prenylation, a process necessary for the function of small GTPase proteins essential for the survival and activity of osteoclasts. In this review we provide a state-of-the-art overview of these mechanisms of action and a historical perspective of how they were discovered. Finally, we challenge the long-held dogma that BPs act only in the skeleton and highlight recent studies that reveal insights into hitherto unknown effects on tumour-associated and tissue-resident macrophages.

Preventive Role of Vitamin D Supplementation for Acute Phase Reaction after Bisphosphonate Infusion in Paget's Disease

CONTEXT

Intravenous aminobisphosphonates (N-BPs) can induce an acute phase reaction (APR) in up to 40% to 70% of first infusions, causing discomfort and often requiring intervention with analgesics or antipyretics.

OBJECTIVE

Our aim was to explore the risk factors of APR in a large sample of patients with Paget's disease of bone (PDB) and to assess the possible preventive effects of vitamin D administration.

METHODS

An observational analysis was performed in 330 patients with PDB at the time of N-BP infusion. Then, an interventional study was performed in 66 patients with active, untreated PDB to evaluate if vitamin D administration (oral cholecalciferol 50 000 IU/weekly for 8 weeks before infusion) may prevent APR.

RESULTS

In a retrospective study, APR occurred in 47.6% and 18.3% of naive or previously treated patients, respectively. Its prevalence progressively increased in relation to the severity of vitamin D deficiency, reaching 80.0% in patients with 25-hydroxyvitamin D (25OHD) levels below 10 ng/mL (relative risk (RR) = 3.7; 95% confidence interval (CI) 2.8-4.7, P < .0001), even in cases previously treated with N-BPs. Moreover, APR occurred more frequently in patients who experienced a previous APR (RR = 2.8; 95% CI 1.5-5.2; P < .001) or in carriers of SQSTM1 mutation (RR = 2.3; 95% CI 1.3-4.2; P = .005). In the interventional study, vitamin D supplementation prevented APR in most cases, equivalent to a RR of 0.31 (95% CI 0.14-0.67; P < .005) with respect to prevalence rates of the observational cohort. A similar trend was observed concerning the occurrence of hypocalcemia.

CONCLUSIONS

The achievement of adequate 25OHD levels is recommended before N-BP infusion in order to minimize the risk of APR or hypocalcemia in PDB.

Zoledronate rescues immunosuppressed monocytes in sepsis patients

Severe sepsis is often accompanied by a transient immune paralysis, which is associated with enhanced susceptibility to secondary infections and poor clinical outcomes. The functional impairment of antigen‐presenting cells is considered to be a major hallmark of this septic immunosuppression, with reduced HLA‐DR expression on circulating monocytes serving as predictor of mortality. Unconventional lymphocytes like γδ T‐cells have the potential to restore immune defects in a variety of pathologies including cancer, but their use to rescue sepsis‐induced immunosuppression has not been investigated. Our own previous work showed that Vγ9/Vδ2⁺ γδ T‐cells are potent activators of monocytes from healthy volunteers in vitro, and in individuals with osteoporosis after first‐time administration of the anti‐bone resorption drug zoledronate in vivo. We show here that zoledronate readily induces upregulation of HLA‐DR, CD40 and CD64 on monocytes from both healthy controls and sepsis patients, which could be abrogated by neutralising the pro‐inflammatory cytokines interferon (IFN)‐γ and tumour necrosis factor (TNF)‐α in the cultures. In healthy controls, the upregulation of HLA‐DR on monocytes was proportional to the baseline percentage of Vγ9/Vδ2 T‐cells in the peripheral blood mononuclear cell population. Of note, a proportion of sepsis patients studied here did not show a demonstrable response to zoledronate, predominantly patients with microbiologically confirmed bloodstream infections, compared with sepsis patients with more localised infections marked by negative blood cultures. Taken together, our results suggest that zoledronate can, at least in some individuals, rescue immunosuppressed monocytes during acute sepsis and thus may help improve clinical outcomes during severe infection.

Prevention of Vγ9Vδ2 T Cell Activation by a Vγ9Vδ2 TCR Nanobody

Vγ9Vδ2 T cell activation plays an important role in antitumor and antimicrobial immune responses. However, there are conditions in which Vγ9Vδ2 T cell activation can be considered inappropriate for the host. Patients treated with aminobisphosphonates for hypercalcemia or metastatic bone disease often present with a debilitating acute phase response as a result of Vγ9Vδ2 T cell activation. To date, no agents are available that can clinically inhibit Vγ9Vδ2 T cell activation. In this study, we describe the identification of a single domain Ab fragment directed to the TCR of Vγ9Vδ2 T cells with neutralizing properties. This variable domain of an H chain-only Ab (VHH or nanobody) significantly inhibited both phosphoantigen-dependent and -independent activation of Vγ9Vδ2 T cells and, importantly, strongly reduced the production of inflammatory cytokines upon stimulation with aminobisphosphonate-treated cells. Additionally, in silico modeling suggests that the neutralizing VHH binds the same residues on the Vγ9Vδ2 TCR as the Vγ9Vδ2 T cell Ag-presenting transmembrane protein butyrophilin 3A1, providing information on critical residues involved in this interaction. The neutralizing Vγ9Vδ2 TCR VHH identified in this study might provide a novel approach to inhibit the unintentional Vγ9Vδ2 T cell activation as a consequence of aminobisphosphonate administration.

Synergistic Antiproliferative Effects of Zoledronic Acid and Fluvastatin on Human Pancreatic Cancer Cell Lines: An in Vitro Study

Bisphosphonates and statins are known to have antitumor activities against different types of cancer cell lines. In the present study, we investigated the antiproliferative effects of the combination of zoledronic acid (ZOL), a bisphophosphonate, and fluvastatin (FLU), a statin, in vitro on two types of human pancreatic cancer cell lines, Mia PaCa-2 and Suit-2. The pancreatic cancer cell lines were treated with ZOL and FLU both individually and in combination to evaluate their antiproliferative effects using WST-8 cell proliferation assay. In this study, we demonstrated a potent synergistic antiproliferative effect of both drugs when used in combination in both cell lines. Moreover, we studied the molecular mechanism behind this synergistic effect, which was inhibited by the addition of the mevalonate pathway products, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). Furthermore, we aimed to determine the effect of ZOL and FLU combination on RhoA and Ras guanosine 5'-triphosphate (GTP)-proteins. The combination induced a marked accumulation in RhoA and unprenylated Ras. GGPP and FPP reversed the increase in the amount of both proteins. These results indicated that the combination treatment impaired RhoA and Ras signaling pathway by the inhibition of geranylgeranylation and/or farnesylation. This study provides a potentially effective approach for the treatment of pancreatic cancer using a combination treatment of ZOL and FLU.

Quantitative peripheral blood perturbations of γδ T cells in human disease and their clinical implications

Human γδ T cells, which play innate and adaptive, protective as well as destructive, roles in the immune response, were discovered in 1986, but the clinical significance of alterations of the levels of these cells in the peripheral blood in human diseases has not been comprehensively reviewed. Here, we review patterns of easily measurable changes of this subset of T cells in peripheral blood from relevant publications in PubMed and their correlations with specific disease categories, specific diagnoses within disease categories, and prognostic outcomes. These collective data suggest that enumeration of γδ T cells and their subsets in the peripheral blood of patients could be a useful tool to evaluate diagnosis and prognosis in the clinical setting.

Severe polyarthritis secondary to zolendronic acid: a case report and literature review

Intravenous zolendronic acid is an established anti-resorptive treatment for post-menopausal osteoporosis and is usually well tolerated. Common side effects, including the classical 'acute phase response', are consented for prior to treatment. However, rare but serious adverse reactions to zolendronic acid have been described. We report the case of an older patient with osteoporosis and osteoarthritis who presented within 12 hours of her first zolendronic acid infusion with evidence of a severe acute polyarthritis affecting her peripheral appendicular skeleton, in joints affected by pre-existing osteoarthritis. Despite the prevalence of osteoarthritis, this is the most severe case of polyarthritis following intravenous zolendronic acid to date and only the second reported case. We remind prescribing physicians treating patients with intravenous bisphosphonates, to bear in mind possible rare serious adverse reactions as well as common benign side effects. We postulate age-associated frailty may reduce tolerability to even milder acute phase reactions.

Intravenous bisphosphonates for postmenopausal osteoporosis: safety profiles of zoledronic acid and ibandronate in clinical practice

BACKGROUND

Intravenous bisphosphonates are widely used for treatment of postmenopausal osteoporosis. They are associated with transient influenza-like symptoms, predominantly after the first zoledronic acid (up to 32 %) or ibandronate (up to 5 %) administration. The experience in clinical practice suggests that the incidence of post-dose symptoms is higher than has been reported in clinical trials. We assessed the safety of annual infusions of zoledronic acid and 3-monthly injections of ibandronate in women with postmenopausal osteoporosis.

METHODS

In this retrospective study we analysed safety data from 272 postmenopausal women treated with zoledronic acid (n = 127; mean age 68.6 ± 9.4 years) or intravenous (IV) ibandronate (n = 145; mean age 69.1 ± 9.0 years). Safety data (including occurrence of acute-phase reactions and osteonecrosis of the jaw) were gathered in phone call interviews by using a standardized questionnaire.

RESULTS

The number of patients with adverse events was significantly higher in zoledronic acid as compared to ibandronate-treated patients, primarily because of a larger number of post-dose symptoms after bisphosphonate administrations (54.3 % vs. 33.1 %, p < 0.001). Except for occurrence of fever (more common after zoledronic acid infusion), other influenza-like symptoms (myalgia, arthralgia, headache) appeared in a similar proportion of patients after IV treatment (within 24-36 h). Symptoms lasted for >3 days in approximately 50 % of patients. The incidence of symptoms decreased after subsequent infusions. The rate of influenza-like symptoms was more frequent after zoledronic acid than after IV ibandronate in bisphosphonate-naïve patients but comparable in patients pretreated with oral bisphosphonates. There were no spontaneous reports of osteonecrosis of the jaw, arrhythmia or delayed fracture healing.

CONCLUSION

Although IV bisphosphonates are generally safe, the occurrence of transient influenza-like symptoms after IV bisphosphonates seems to be more frequent in clinical practice than has been reported in clinical trials.

Monocytes and γδ T cells control the acute-phase response to intravenous zoledronate: insights from a phase IV safety trial

Aminobisphosphonates (NBPs) are used widely against excessive bone resorption in osteoporosis and Paget's disease as well as in metastatic bone disease and multiple myeloma. Intravenous NBP administration often causes mild to severe acute-phase responses (APRs) that may require intervention with analgesics and antipyretics and lead to treatment noncompliance and nonadherence. We here undertook a phase IV safety trial in patients with osteoporosis to investigate the APR of otherwise healthy individuals to first-time intravenous treatment with the NBP zoledronate. This study provides unique insight into sterile acute inflammatory responses in vivo, in the absence of confounding factors such as infection or cancer. Our data show that both peripheral γδ T cells and monocytes become rapidly activated after treatment with zoledronate, which ultimately determines the clinical severity of the APR. Our study highlights a key role for IFN-γ in the zoledronate-induced APR and identifies pretreatment levels of monocytes and central/memory Vγ9/Vδ2 T cells as well as their responsiveness to zoledronate in vitro as predictive risk factors for the occurrence of subclinical and clinical symptoms. These findings have diagnostic and prognostic implications for patients with and without malignancy and are relevant for Vγ9/Vδ2 T-cell-based immunotherapy approaches.

Long-term effects of amino-bisphosphonates on circulating γδ T cells

The aim of this study was to explore whether desensitization to the occurrence of the acute-phase response (APR) in patients previously treated with amino-bisphosphonates (N-BPs) is due to a long-lasting reduction in the number of circulating γδ T cells. Circulating lymphocyte subpopulation counts were obtained from 63 patients with postmenopausal or senile osteoporosis at baseline and after 2 days and 12 months of the first intravenous (IV) 5 mg zoledronic acid (ZOL) infusion. At baseline both the proportion and absolute number of circulating γδ T cells were significantly higher in patients who had never used N-BPs vs. previous users, either oral or IV. A typical APR was observed in none of the patients given IV ZOL a year earlier, in 6 (22 %) of the patients previously treated with oral N-BPs, and in 13 (57 %) of the patients naive to any N-BP treatment. In patients naive to N-BPs, a significant reduction in both total lymphocytes and their subsets was observed 2 days after ZOL infusion; all these changes returned to baseline values 1 year later with the exception of γδ T cells, which remained significantly lower in terms of both proportion and absolute number. These results indicate for the first time that both IV and oral N-BP treatments are associated with a long-lasting decrease in circulating γδ T cells, and this may explain the lower incidence of APR in patients previously exposed to N-BPs. Other clinical implications of this sustained effect of N-BPs on immune-regulatory cells might be important.

Acute phase response following intravenous zoledronate in postmenopausal women with low bone mass

An acute phase response (APR) is frequently observed in patients treated with intravenous (i.v.) zoledronate (ZOL). We aimed to define clinical and laboratory parameters that may predict ZOL-induced APR in women with low bone mass. Fifty-one postmenopausal women with low bone mass were given a single i.v. infusion of ZOL 5mg. APR was clinically defined by the visual analog pain scale (VAS) for the musculoskeletal symptoms and body temperature. White blood cell count (WBC), leucocyte subpopulations, C-reactive protein (CRP), parathyroid hormone (PTH), 25-hydroxyvitamin D [25(OH)D], interleukins (IL)-1b and -6, tumor necrosis factor (TNF)α and interferon (IFN)γ were measured before and 48 h following the infusion. Subsequently, patients were divided into those experiencing APR (APR+) or not (APR-). WBC, granulocytes, CRP, IL-1b and IL-6 were significantly increased, whereas lymphocytes, eosinophils, calcium, phosphate and 25(OH)D decreased 48h after ZOL infusion. Twenty-eight of the 51 patients (54.9%) experienced an APR. APR+ patients were younger and had higher baseline lymphocytes compared to APR- patients. There was no difference (p=0.405) in the development of APR between treatment-naive patients (19/32, 59.4%) and patients previously treated with another oral nitrogen-containing bisphosphonate (9/19, 47.4%). In conclusion, our data suggest that pre-treatment higher lymphocyte number increases the risk of APR while previous treatment with another nitrogen-containing bisphosphonate does not significantly reduce the risk. Serum 25(OH)D concentrations decrease significantly after the infusion, possibly as part of the inflammatory response to ZOL.

Circulating γδ T cells and the risk of acute-phase response after zoledronic acid administration

The use of intravenous nitrogen-containing bisphosphonates (N-BPs) is associated with the appearance of an acute phase response (APR) in a proportion of the patients for reasons that are poorly understood. The APR was attributed to the indirect activation of γδ T cells with the release of interferon-γ and tumor necrosis factor (TNF). Forty patients with postmenopausal or senile osteoporosis (age range = 53-91 years) never previously treated with intravenous (i.v.) bisphosphonate, received a single 5-mg zoledronic acid (ZOL) iv infusion over 15 minutes. White blood cells were counted and analyzed with an automated hematology analyzer (ADVIA 2120i Siemens, New York, USA) and by flow cytometer (BD FACSCanto, Becton Dickinson). The occurrence of APR was defined by the occurrence of fever (>37 °C) during the next 2 days. Forty-two percent of patients (17 of 40) receiving the infusion of ZOL experienced an APR. Compared with the others they were younger (69 ± 7 years versus 74 ± 8 years; p = 0.06), and both the proportion and absolute number of γδ T cells were significant higher (p = 0.02 and p = 0.013, respectively). Nonsignificant differences were found between the two groups for white blood cells and for the other circulating lymphocyte subpopulations. Age was inversely correlated with circulating γδ T cells (p = 0.003) but the difference between the two groups in circulating γδ T cells persisted for age-adjusted values and vice versa. In conclusion, the results of this study indicate that the number of circulating γδ T cells, together with age, are important determinant of the occurrence of APR after intravenous infusion of ZOL and possibly of any other N-BPs.

Role of bisphosphonates in the management of postmenopausal osteoporosis: an update on recent safety anxieties

Following their introduction in the 1990s, bisphosphonates have become the mainstay of treatment in the management of postmenopausal osteoporosis, and their use continues to rise. Commonly noted adverse effects in clinical practice include gastrointestinal side-effects, acute phase reactions (predominately seen with intravenous preparations) cutaneous reactions and more rarely, ocular side-effects. However, recent reports of potentially serious adverse effects of bisphosphonate therapy, including atypical subtrochanteric and femoral shaft fractures, atrial fibrillation, oesophageal carcinoma and osteonecrosis of the jaw, have prompted concerns regarding the long-term safety of this class of drugs. This review summarizes the benefits and potential adverse effects of bisphosphonates used in the treatment of postmenopausal osteoporosis. Although evidence of a definitive casual relationship between bisphosphonate therapy and serious adverse effects is lacking, concern remains particularly in relation to atypical subtrochanteric and femoral shaft fractures. This has important consequences in terms of determining optimum duration of therapy and how best to target therapy at those most at risk. Recently, attention has focused on individual fracture risk assessment in order to optimize the risk-benefit ratio of treatment for individual patients. A review of the role of hormone replacement therapy in younger women with significant risk of osteoporotic fractures may be timely in these circumstances.

No effect of rosuvastatin in the zoledronate-induced acute-phase response

The acute-phase response (APR) is frequently observed in patients treated with intravenous (iv) zoledronate (ZOL). We investigated whether a short course of rosuvastatin (ROSU) could attenuate the ZOL--induced APR through blocking the mevalonate pathway at a proximal level. Twenty-eight osteoporotic postmenopausal women with no prior bisphosphonate use (mean age 65.3 ± 1.9 years) were subjected to ZOL iv infusion. Patients were randomly assigned into either a ROSU+ group (n = 12), which received ROSU 10 mg/day starting 5 days before the infusion of ZOL for a total period of 11 days, or a ROSU- group (n = 16), which did not receive ROSU. The visual analog pain scale (VAS) for musculoskeletal symptoms and body temperature was used to define clinically APR. In addition, white blood cell (WBC) count, leukocytic subpopulations, and C-reactive protein (CRP) were obtained before and 48 h following the infusion. Seven (58.3%) patients in the ROSU+ group and 13 (81.3%) in the ROSU- group experienced APR (P = not significant). No difference was found in fever and VAS measurements. CRP and granulocytes increased significantly in both groups; WBC count increased, while lymphocytes and eosinophils decreased significantly only in the ROSU- group. In a post hoc analysis of only patients with an APR, all laboratory parameters exhibited a similar significant change solely within the ROSU- group. In conclusion, our data suggest that a short course of ROS at this dose cannot prevent the ZOL-induced APR among osteoporotic women. Milder changes in acute-phase laboratory parameters in ROSU+ patients suggest that studies with higher doses may be warranted.