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Cernaro V, Longhitano E, Casuscelli C, Peritore L, Santoro D. Hyperphosphatemia in Chronic Kidney Disease: The Search for New Treatment Paradigms and the Role of Tenapanor. Int J Nephrol Renovasc Dis 2024; 17:151-161. [PMID: 38831770 PMCID: PMC11144652 DOI: 10.2147/ijnrd.s385826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 05/14/2024] [Indexed: 06/05/2024] Open
Abstract
Hyperphosphataemia represents a significant challenge in the management of chronic kidney disease, exerting a pronounced influence on the pathogenesis of cardiovascular complications and mineral bone disorders. Traditional approaches to address hyperphosphataemia involve implementing dietary phosphate restrictions, administering phosphate binders, and, in cases of end-stage renal disease, resorting to dialysis. Unfortunately, these interventions frequently prove inadequate in maintaining phosphate levels within recommended ranges. Additionally, commonly employed pharmacological agents are not immune to eliciting adverse events, thereby limiting their prescription and therapeutic adherence. There is a growing focus on exploring novel therapeutic strategies in this context. The current discussion centres on tenapanor, a pharmacological agent predominantly acting as a selective inhibitor of sodium/hydrogen exchanger isoform 3 (NHE3). Its mechanism of action involves modulating tight junctions, resulting in reduced sodium absorption and intestinal paracellular permeability to phosphate. Furthermore, tenapanor downregulates sodium-dependent phosphate 2b transport protein (NaPi2b) expression, thereby impeding active transcellular phosphate transport. Clinical trials have elucidated the efficacy and safety profile of tenapanor. This evidence hints at a potential paradigm shift in the management of hyperphosphataemia. However, the burgeoning optimism surrounding tenapanor warrants tempered enthusiasm, as further research remains indispensable. The imperative lies in meticulously delineating its efficacy and safety contours within the crucible of clinical practice. In this review, we synthesize the intricate interplay between hyperphosphataemia and Chronic Kidney Disease-Mineral Bone Disorder, and we discuss the existing pharmacological interventions for hyperphosphataemia and explore emerging treatment paradigms that offer novel perspectives in managing elevated phosphate levels in CKD patients.
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Affiliation(s)
- Valeria Cernaro
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Elisa Longhitano
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Chiara Casuscelli
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Luigi Peritore
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Domenico Santoro
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
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Sprague SM, Weiner DE, Tietjen DP, Pergola PE, Fishbane S, Block GA, Silva AL, Fadem SZ, Lynn RI, Fadda G, Pagliaro L, Zhao S, Edelstein S, Spiegel DM, Rosenbaum DP. Tenapanor as Therapy for Hyperphosphatemia in Maintenance Dialysis Patients: Results from the OPTIMIZE Study. KIDNEY360 2024; 5:732-742. [PMID: 38323855 PMCID: PMC11146652 DOI: 10.34067/kid.0000000000000387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 02/01/2024] [Indexed: 02/08/2024]
Abstract
Key Points Tenapanor, a first-in-class local inhibitor of sodium/hydrogen exchanger isoform 3, acts as a phosphate absorption inhibitor by decreasing paracellular phosphate absorption. Tenapanor alone or with phosphate binders achieved P ≤ 5.5 mg/dl over 10 weeks in 34%–38% of patients taking phosphate binders at baseline. Tenapanor can help adults with CKD on maintenance dialysis achieve normal serum phosphate concentrations. Background OPTIMIZE was a randomized, open-label study evaluating different tenapanor initiation methods. OPTIMIZE evaluated tenapanor alone and in combination with phosphate binders (PBs) to achieve target serum phosphate (P) ≤5.5 mg/dl. Methods Patients with inadequately controlled P receiving maintenance dialysis from 42 US locations who were taking PBs with baseline P > 5.5 mg/dl and ≤ 10.0 mg/dl, or were PB-naive with baseline P > 4.5 mg/dl and ≤ 10.0 mg/dl, were included in OPTIMIZE. Participants taking PBs at baseline were randomized to switch from PBs to tenapanor (Straight Switch ; n =151) or reduce PB dosage by ≥50% and add tenapanor (Binder Reduction ; n =152); PB-naive patients started tenapanor alone (Binder-Naive ; n =30). Participants received tenapanor 30 mg twice a day for 10 weeks (part A), followed by an elective, 16-week open-label extension (part B). Outcomes included changes from baseline in P, intact fibroblast growth factor 23, parathyroid hormone, serum calcium, and medication burden; patient-reported outcomes; and safety. Results By part A end point, 34.4% (Straight Switch ), 38.2% (Binder Reduction ), and 63.3% (Binder-Naive ) of patients achieved P ≤ 5.5 mg/dl. Mean P reduction and median pill burden reduction from baseline to part A end point were 0.91±1.7 mg/dl and 4 pills/d for the Straight Switch and 0.99±1.8 mg/dl and 1 pill/d for the Binder Reduction group. The mean P reduction for Binder-Naive patients was 0.87±1.5 mg/dl. Among Straight Switch and Binder Reduction patients who completed patient experience questionnaires, 205 of 243 (84.4%) reported an improved phosphate management routine. Diarrhea was the most common adverse event (133 of 333 [39.9%]). Conclusions Tenapanor as monotherapy or in combination with PBs effectively lowered P toward the target range in patients who were PB-naive or who were not at goal despite PB use. Clinical Trial registration number NCT04549597 .
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Affiliation(s)
- Stuart M. Sprague
- NorthShore University Health System, Evanston, Illinois
- University of Chicago Pritzker School of Medicine, Chicago, Illinois
| | | | | | | | - Steven Fishbane
- Zucker School of Medicine at Hofstra & Northwell Health, Great Neck, New York
| | | | | | - Stephen Z. Fadem
- Kidney Associates, PLLC and Baylor College of Medicine, Houston, Texas
| | | | - George Fadda
- Balboa Nephrology Medical Group, La Mesa, California
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Nakayama M, Kobayashi S, Kusakabe M, Ohara M, Nakanishi K, Akizawa T, Fukagawa M. Tenapanor for peritoneal dialysis patients with hyperphosphatemia: a phase 3 trial. Clin Exp Nephrol 2024; 28:153-164. [PMID: 37910313 PMCID: PMC10808471 DOI: 10.1007/s10157-023-02406-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 09/10/2023] [Indexed: 11/03/2023]
Abstract
BACKGROUND Tenapanor is a novel selective inhibitor of intestinal sodium/hydrogen exchanger 3 transporter. This is the first trial to assess the efficacy and safety of tenapanor in Japanese patients with hyperphosphatemia who are undergoing peritoneal dialysis. METHODS This phase 3, open-label, multicenter, single-arm clinical trial targeted patients whose serum phosphorus was within 3.5-7.0 mg/dL with phosphate binders at screening. After phosphate binder washout, tenapanor was orally administered twice-daily, stepwise from 5 to 30 mg/dose for 16 weeks. The primary endpoint, mean change in serum phosphorus level, was evaluated at week 8. The 16-week treatment period was completed with tenapanor alone, and only one phosphate binder type was allowed for combined use after the primary endpoint. RESULTS Of the 54 patients enrolled, 34 completed the study. At week 8, the primary endpoint, mean change in serum phosphorus level (last observation carried forward), was - 1.18 mg/dL (95% confidence interval: - 1.54, - 0.81 mg/dL) with tenapanor. From a baseline value of 7.65 mg/dL, serum phosphorus decreased to 6.14 and 5.44 mg/dL at weeks 8 and 16, respectively, and 46.3% and 76.5% of patients achieved serum phosphorus within 3.5-6.0 mg/dL at week 8 and week 16, respectively. The most common adverse event, diarrhea, occurred in 74.1% of patients; the severity of diarrhea was mild or moderate. Thus, the discontinuation percentage due to diarrhea was low at 5.6%. CONCLUSIONS Administration of tenapanor resulted in a sufficient reduction in serum phosphorus level at week 8 and was considered safe and tolerable. TRIAL REGISTRATION NCT04766385.
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Affiliation(s)
- Masaaki Nakayama
- Kidney Center, St. Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo, 104-8560, Japan.
| | | | | | - Meiko Ohara
- R&D Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | | | - Tadao Akizawa
- Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan
| | - Masafumi Fukagawa
- Division of Nephrology, Endocrinology, and Metabolism, Department of Internal Medicine, Tokai University School of Medicine, Kanagawa, Japan
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Abstract
Inorganic phosphate (Pi) is an essential component of many biologically important molecules such as DNA, RNA, ATP, phospholipids, or apatite. It is required for intracellular phosphorylation signaling events and acts as pH buffer in intra- and extracellular compartments. Intestinal absorption, uptake into cells, and renal reabsorption depend on a set of different phosphate transporters from the SLC20 (PiT transporters) and SLC34 (NaPi transporters) gene families. The physiological relevance of these transporters is evident from rare monogenic disorders in humans affecting SLC20A2 (Fahr's disease, basal ganglia calcification), SLC34A1 (idiopathic infantile hypercalcemia), SLC34A2 (pulmonary alveolar microlithiasis), and SLC34A3 (hereditary hypophosphatemic rickets with hypercalciuria). SLC34 transporters are inhibited by millimolar concentrations of phosphonoformic acid or arsenate while SLC20 are relatively resistant to these compounds. More recently, a series of more specific and potent drugs have been developed to target SLC34A2 to reduce intestinal Pi absorption and to inhibit SLC34A1 and/or SLC34A3 to increase renal Pi excretion in patients with renal disease and incipient hyperphosphatemia. Also, SLC20 inhibitors have been developed with the same intention. Some of these substances are currently undergoing preclinical and clinical testing. Tenapanor, a non-absorbable Na+/H+-exchanger isoform 3 inhibitor, reduces intestinal Pi absorption likely by indirectly acting on the paracellular pathway for Pi and has been tested in several phase III trials for reducing Pi overload in patients with renal insufficiency and dialysis.
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Affiliation(s)
- Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland.
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Gan L, Xing L, Xu Y, Zhou L, Jiang H, Sun X, Guan T, Luo P, Wang J, Sun F, Guo Z, Guo M, Gao J, Wei G, Zhong W, Zhou Y, Zuo L. Tenapanor in Chinese ESRD patients with hyperphosphatemia on haemodialysis: a randomised, phase 3 trial. Clin Kidney J 2024; 17:sfad216. [PMID: 38186905 PMCID: PMC10768776 DOI: 10.1093/ckj/sfad216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Indexed: 01/09/2024] Open
Abstract
Background The efficacy and safety of tenapanor has not been confirmed in Chinese end-stage renal disease (ESRD) patients with hyperphosphatemia on haemodialysis (HD). Methods This was a randomised, double blind, phase 3 trial conducted at 26 dialysis facilities in China (https://www.chictr.org.cn/index.aspx; CTR20202588). After a 3-week washout, adults with ESRD on HD with hyperphosphatemia were randomised (1:1) using an interactive web response system to oral tenapanor 30 mg twice a day or placebo for 4 weeks. The primary endpoint was the change in mean serum phosphorous level from baseline to the endpoint visit (day 29 or last serum phosphorus measurement). Efficacy was analysed in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of the study drug. Results Between 5 March 2021 and 8 June 2022, 77 patients received tenapanor and 73 received placebo. Tenapanor treatment (n = 75) resulted in a significantly greater least squares (LS) mean reduction in serum phosphate at the endpoint visit versus placebo (n = 72): LS mean difference -1.17 mg/dl (95% CI -1.694 to -0.654, P < .001). More patients receiving tenapanor achieved a serum phosphorous level <5.5 mg/dl at the endpoint visit (44.6% versus 10.1%). The most common treatment-related adverse event was diarrhoea [tenapanor 28.6% (22/77), placebo 2.7% (2/73)], which was mostly mild and led to treatment discontinuation in two patients receiving tenapanor. Conclusions Tenapanor significantly reduced the serum phosphorous level versus placebo in Chinese ESRD patients on HD and was generally well tolerated.
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Affiliation(s)
- Liangying Gan
- Department of Nephrology, Peking University People's Hospital, Beijing, China
| | - Li Xing
- Hemodialysis Room, People's Hospital of Zhengzhou, Zhengzhou, China
| | - Yan Xu
- Department of Nephrology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Linghui Zhou
- Department of Nephrology, First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Hong Jiang
- Division of Nephrology, Department of Internal Medicine, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - Xiuli Sun
- Department of Nephrology, Baotou Central Hospital, Baotou, China
| | - Tianjun Guan
- Department of Nephrology, Zhongshan Hospital Xiamen University, Xiamen, China
| | - Ping Luo
- Department of Nephrology, Second Hospital of Jilin University, Changchun, China
| | - Junxia Wang
- Blood Purifying Center, First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
| | - Fuyun Sun
- Department of Nephrology, Cangzhou Center Hospital, Cangzhou, China
| | - Zhiyong Guo
- Department of Nephrology, Shanghai Changhai Hospital, Shanghai, China
| | - Minghao Guo
- Department of Nephrology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Ju Gao
- Panjin Liaohe Oilfield Baoshihua Hospital, Panjin, China
| | - Gang Wei
- R&D Center, Fosun Pharma, Shanghai, China
| | - Wen Zhong
- R&D Center, Fosun Pharma, Shanghai, China
| | | | - Li Zuo
- Department of Nephrology, Peking University People's Hospital, Beijing, China
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Koiwa F, Sato Y, Ohara M, Nakanishi K, Fukagawa M, Akizawa T. Long-term safety and decrease of pill burden by tenapanor therapy: a phase 3 open-label study in hemodialysis patients with hyperphosphatemia. Sci Rep 2023; 13:19100. [PMID: 37925471 PMCID: PMC10625594 DOI: 10.1038/s41598-023-45080-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 10/16/2023] [Indexed: 11/06/2023] Open
Abstract
Phosphate binders (PBs) generally have a high pill burden. Tenapanor selectively inhibits sodium/hydrogen exchanger isoform 3, reducing intestinal phosphate absorption. Tenapanor is a novel drug administered as a small tablet, twice daily. This multicenter, open-label, single-arm, phase 3 study aimed to evaluate the long-term safety of tenapanor and its efficacy in decreasing PB pill burden. Tenapanor 5 mg twice daily was administered to hemodialysis patients with serum phosphorus level 3.5-7.0 mg/dl at baseline; the dose could be increased up to 30 mg twice daily. Patients could also switch from PBs. The primary endpoint was safety during 52-week administration. The key secondary endpoint was a ≥ 30% reduction in the total pill number of daily PBs and tenapanor from baseline. Of 212 patients starting treatment, 154 completed the study. Diarrhea was the most frequent adverse event, occurring in 135 patients (63.7%); most events were classified as mild (74.8%). No clinically significant changes occurred other than serum phosphorus level. At Week 52/discontinuation, 158/204 patients (77.5%) achieved the key secondary endpoint. Complete switching from PBs to tenapanor was achieved in 50-76 patients (26.7%-41.5%), and 80 patients (51.9%) at Week 8-12 and Week 50, respectively. Serum phosphorus remained generally stable within the target range (3.5-6.0 mg/dl). These findings suggest the long-term safety and tolerability of tenapanor. Tenapanor could reduce or eliminate PB pill burden while controlling serum phosphorus levels.Trial registration: NCT04771780.
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Affiliation(s)
- Fumihiko Koiwa
- Division of Nephrology, Department of Internal Medicine, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-Ku, Yokohama, 227-8501, Japan.
| | - Yu Sato
- R&D Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | - Meiko Ohara
- R&D Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | | | - Masafumi Fukagawa
- Division of Nephrology, Endocrinology, and Metabolism, Department of Internal Medicine, Tokai University School of Medicine, Kanagawa, Japan
| | - Tadao Akizawa
- Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan
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Silva AL, Chertow GM, Hernandez GT, Lynn RI, Tietjen DP, Rosenbaum DP, Yang Y, Edelstein S. Tenapanor Improves Long-Term Control of Hyperphosphatemia in Patients Receiving Maintenance Dialysis: the NORMALIZE Study. KIDNEY360 2023; 4:1580-1589. [PMID: 37853560 PMCID: PMC10695649 DOI: 10.34067/kid.0000000000000280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 10/11/2023] [Indexed: 10/20/2023]
Abstract
Key Points Tenapanor is a first-in-class, minimally systemic sodium–hydrogen exchanger 3 inhibitor with a mechanism of action distinct from phosphate binders. Tenapanor alone or with phosphate binders led to 35%–49% of patients achieving serum phosphate ≤4.5 mg/dl over an 18-month period versus 22% at baseline. Tenapanor alone or with phosphate binders may help adults with CKD on maintenance dialysis achieve normal serum phosphate concentrations. Background Most patients with ESKD and hyperphosphatemia have difficulty controlling serum phosphate (sP) concentrations despite maintenance dialysis, dietary restriction, and phosphate binder treatment. NORMALIZE evaluated the efficacy and safety of tenapanor 30 mg twice daily alone or in combination with phosphate binders to achieve sP within the adult population reference range (2.5–4.5 mg/dl). Methods Patients who completed the Phase 3 PHREEDOM study could enroll in NORMALIZE. Patients enrolled in NORMALIZE who had received tenapanor during the PHREEDOM study (n =111) added sevelamer carbonate if sP was >4.5 mg/dl. Patients who had received sevelamer carbonate during the PHREEDOM study (n =61) added tenapanor and decreased sevelamer carbonate if sP was ≤4.5 mg/dl, per protocol titration schedule. Patients were followed in NORMALIZE for up to 18 months. We assessed efficacy in the full analysis set, defined as patients who received ≥1 dose of study drug and had ≥1 post-treatment sP measurement (n =171). We assessed safety in all patients who received ≥1 dose of study drug (n =172). Results At the end point visit, 57 of 171 patients (33%) in the full analysis set achieved sP between 2.5 and 4.5 mg/dl. Eight of 23 patients (35%) who were on tenapanor alone at the end point visit achieved sP between 2.5 and 4.5 mg/dl. The mean reduction from PHREEDOM baseline to end of NORMALIZE in sP was 2.0 mg/dl. Serum intact fibroblast growth factor-23 was significantly reduced; serum intact parathyroid hormone was significantly reduced among patients with intact parathyroid hormone ≥300 pg/ml at PHREEDOM baseline. The most commonly reported treatment-emergent adverse event was diarrhea in 38 of 172 patients (22%), which led to tenapanor discontinuation in four patients (2%). Conclusions Tenapanor alone or in combination with phosphate binders helped adult patients on maintenance dialysis achieve normal sP concentrations. Safety was consistent with previous studies of tenapanor. Clinical trial registry name and registration number A Long-Term Study to Evaluate the Ability of Tenapanor Alone or in Combination With Sevelamer to Treat to Goal Serum Phosphorus in Patients With ESKD on Dialysis (NORMALIZE), NCT03988920 .
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Affiliation(s)
| | - Glenn M. Chertow
- Departments of Medicine and Epidemiology and Population Health, Stanford University School of Medicine, Stanford, California
| | | | | | | | | | - Yang Yang
- Ardelyx, Inc., Waltham, Massachusetts
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Wish JB. Tenapanor as Add-on Treatment for Hyperphosphatemia in Dialysis Patients: Enough Bang for the Buck? Kidney Int Rep 2023; 8:2194-2197. [PMID: 38025212 PMCID: PMC10658425 DOI: 10.1016/j.ekir.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023] Open
Affiliation(s)
- Jay B. Wish
- Division of Nephrology, Indiana University School of Medicine, IU Health University Hospital, Indianapolis, Indiana, USA
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Kalantar-Zadeh K, Forfang D, Bakris G, Martin KJ, Moe SM, Sprague SM. Managing Phosphate Burden in Patients Receiving Dialysis: Beyond Phosphate Binders and Diet. KIDNEY360 2023; 4:1650-1656. [PMID: 37870525 PMCID: PMC10695651 DOI: 10.34067/kid.0000000000000262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 09/07/2023] [Indexed: 10/24/2023]
Abstract
Most patients receiving dialysis rely on dietary restriction and phosphate binders to minimize the risk of hyperphosphatemia, which is associated with increased mortality. However, dietary restriction is difficult because of hidden phosphate additives in processed foods and medications. Restriction of dietary phosphate sources such as protein may increase the risk of malnutrition. Phosphate binders, the only pharmacologic option for phosphate management since aluminum salts were introduced several decades ago, are often insufficient for binding the 1400-2500 mg of phosphate potentially consumed daily. Over the last decade, serum phosphate levels in the United States have risen, and >69% of patients receiving dialysis exhibited a most recent phosphate level >4.5 mg/dl (above the normal range), indicating an urgent need for new, more effective therapies to manage phosphate burden. Novel, nonbinder therapies such as transcellular and paracellular phosphate absorption inhibitors may be used for phosphate management, and future studies should examine whether they allow fewer dietary restrictions for patients receiving dialysis, potentially improving patient quality of life and nutritional status. It is imperative that we collaborate to move beyond the restrictive approaches available today and provide patients and clinicians with an array of strategies so that they may choose the most appropriate patient-centered therapy.
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Affiliation(s)
- Kamyar Kalantar-Zadeh
- Division of Nephrology, Hypertension and Kidney Transplantation, University of California Irvine, Irvine, California
| | - Derek Forfang
- The Co-Chair of the National Forum of ESRD Network's Kidney Patient Advisory Council (KPAC), Henrico, Virginia
- National Kidney Foundation, Public Policy Committee, New York, New York
| | - George Bakris
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Chicago, Chicago, Illinois
| | - Kevin J. Martin
- Department of Internal Medicine, Division of Nephrology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Sharon M. Moe
- Division of Nephrology and Hypertension, Indiana University School of Medicine, Indianapolis, Indiana
| | - Stuart M. Sprague
- Division of Nephrology and Hypertension, NorthShore University Health System-University of Chicago Pritzker School of Medicine, Evanston, Illinois
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Cha RR, Park SY, Camilleri M. Constipation in Patients With Chronic Kidney Disease. J Neurogastroenterol Motil 2023; 29:428-435. [PMID: 37814433 PMCID: PMC10577456 DOI: 10.5056/jnm23133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 09/12/2023] [Indexed: 10/11/2023] Open
Abstract
Constipation is a frequent symptom in patients with chronic kidney disease (CKD). This review outlines the mechanisms and management of constipation in patients with CKD from a physician's perspective. Common causes of constipation in patients with CKD include concomitant medications, low dietary fiber intake, water-restricted diet, lack of physical activity, altered gut microbiota, and reduced gastrointestinal motility. Constipation has a negative impact on overall health, and, in particular, the presence of constipation has been associated with worsening kidney function and increased risk of developing advanced stages of CKD. Although lifestyle and dietary modifications may not always be practical for patients with CKD, they are recommended because they are beneficial as they lower mortality in patients with CKD. The use of laxatives containing magnesium salts, bulking agents, and osmotic laxatives may have insufficient efficacy and may be associated with adverse effects. In contrast, lactulose and lubiprostone have been shown to exhibit reno-protective effects. Linaclotide and plecanatide have very limited systemic absorption and appear safe in patients with CKD. Tenapanor reduces paracellular intestinal phosphate absorption in addition to blocking sodium uptake by enterocytes, and provides additional benefit in patients patients with CKD who have hyperphosphatemia and constipation. Prucalopride leads to improvements in bowel function and constipation-related symptoms in cases in which response to conventional laxatives are inadequate. However, the dose of prucalopride should be reduced to 1 mg once daily for patients with CKD. In conclusion, there are important advances on the impact and treatment of constipation in patients with CKD.
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Affiliation(s)
- Ra Ri Cha
- Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Gyeongsangnam-do, Korea
| | - Seon-Young Park
- Division of Gastroenterology, Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Michael Camilleri
- Clinical Enteric Neuroscience Translational and Epidemiological Research, Mayo Clinic, Rochester, MN, USA
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Luo H, Feng J, Zhang Y, Wang J, Xue G, Huang X, You S, Dong H, Li L, Li J, Xiao H, Ai X, Li X, Huang B. Efficacy and safety of tenapanor in hemodialysis patients with hyperphosphatemia: A systematic review and meta-analysis of randomized placebo-controlled trials. Ther Apher Dial 2023; 27:839-847. [PMID: 37349983 DOI: 10.1111/1744-9987.14028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/30/2023] [Accepted: 06/13/2023] [Indexed: 06/24/2023]
Abstract
BACKGROUND The effects of tenapanor in reducing serum phosphorus in hemodialysis patients with hyperphosphatemia are uncertain and no relevant meta-analysis has been conducted. We performed a meta-analysis of randomized placebo-controlled trials to evaluate the efficacy and safety of tenapanor. METHODS All randomized controlled trials of tenapanor were searched up to 1 August 2022. The primary endpoint was the change in serum phosphorus level from baseline with tenapanor and placebo. Data on drug-related adverse events (AEs), gastrointestinal AEs and diarrhea were collected to determine the safety of tenapanor. RESULTS There were 533 patients throughout five trials that were eligible. Tenapanor significantly lowered blood phosphorus level by 1.79 mg/dl in the mean difference than the placebo. Diarrhea, gastrointestinal AEs, and drug-related AEs were more severe than placebo. CONCLUSIONS This meta-analysis showed that although drug side effects were common, tenapanor significantly reduced serum phosphorus level in hemodialysis patients.
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Affiliation(s)
- Houli Luo
- Department of Radiology, Cheng du First People's Hospital, Chengdu, Sichuan, China
| | - Jian Feng
- Department of Critical Care Medicine, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Yanbiao Zhang
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Jie Wang
- Department of Critical Care Medicine, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Gang Xue
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Xi Huang
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Shuang You
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Hongfei Dong
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Lingfan Li
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Juncheng Li
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Hualin Xiao
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Xiang Ai
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Xianhui Li
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Bo Huang
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
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Cernaro V, Longhitano E, Calabrese V, Casuscelli C, Di Carlo S, Spinella C, Gembillo G, Santoro D. Progress in pharmacotherapy for the treatment of hyperphosphatemia in renal failure. Expert Opin Pharmacother 2023; 24:1737-1746. [PMID: 37527180 DOI: 10.1080/14656566.2023.2243817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 08/03/2023]
Abstract
INTRODUCTION Among the clinical and metabolic complications of progressive chronic kidney disease (CKD), CKD-mineral bone disorder (CKD-MBD) significantly contributes to morbidity and mortality. While overt and persistent hyperphosphatemia is typical of advanced CKD and requires treatment, other abnormalities of calcium/phosphate metabolism begin to occur since the early stages of the disease. AREAS COVERED We searched on the PubMed database, without restrictions for language or time range, for randomized clinical trials and meta-analyses investigating phosphate-lowering therapies. The various phosphate binders show different safety profiles and diverse effects on calcium/phosphate metabolism and vascular calcification. The in-depth knowledge of the characteristics of these drugs is crucial to ensure adequate treatment to CKD patients. EXPERT OPINION A proper control of serum phosphate can be achieved using phosphate binders. These medications may induce side effects. Moreover, data on their impact on clinical outcomes are partly controversial or scarce, especially for the new generation drugs. Hyperphosphatemia favors cardiovascular disease and increases the risk for CKD progression. These effects are partially mediated by fibroblast growth factor 23 (FGF23), a phosphaturic hormone that raises to maintain normal serum phosphate. Since there are no data supporting the use of phosphate-lowering agents when phosphataemia is normal, a key role is played by reducing dietary phosphate intake with the aim to control serum phosphate and the compensatory FGF23 and parathyroid hormone (PTH) increase.
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Affiliation(s)
- Valeria Cernaro
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Elisa Longhitano
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Vincenzo Calabrese
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Chiara Casuscelli
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Silvia Di Carlo
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Claudia Spinella
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Guido Gembillo
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Domenico Santoro
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
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Portales-Castillo I, Rieg T, Khalid SB, Nigwekar SU, Neyra JA. Physiopathology of Phosphate Disorders. ADVANCES IN KIDNEY DISEASE AND HEALTH 2023; 30:177-188. [PMID: 36868732 PMCID: PMC10565570 DOI: 10.1053/j.akdh.2022.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 12/24/2022] [Accepted: 12/29/2022] [Indexed: 03/05/2023]
Abstract
Intracellular phosphate is critical for cellular processes such as signaling, nucleic acid synthesis, and membrane function. Extracellular phosphate (Pi) is an important component of the skeleton. Normal levels of serum phosphate are maintained by the coordinated actions of 1,25-dihydroxyvitamin D3, parathyroid hormone and fibroblast growth factor-23, which intersect in the proximal tubule to control the reabsorption of phosphate via the sodium-phosphate cotransporters Npt2a and Npt2c. Furthermore, 1,25-dihydroxyvitamin D3 participates in the regulation of dietary phosphate absorption in the small intestine. Clinical manifestations associated with abnormal serum phosphate levels are common and occur as a result of genetic or acquired conditions affecting phosphate homeostasis. For example, chronic hypophosphatemia leads to osteomalacia in adults and rickets in children. Acute severe hypophosphatemia can affect multiple organs leading to rhabdomyolysis, respiratory dysfunction, and hemolysis. Patients with impaired kidney function, such as those with advanced CKD, have high prevalence of hyperphosphatemia, with approximately two-thirds of patients on chronic hemodialysis in the United States having serum phosphate levels above the recommended goal of 5.5 mg/dL, a cutoff associated with excess risk of cardiovascular complications. Furthermore, patients with advanced kidney disease and hyperphosphatemia (>6.5 mg/dL) have almost one-third excess risk of death than those with phosphate levels between 2.4 and 6.5 mg/dL. Given the complex mechanisms that regulate phosphate levels, the interventions to treat the various diseases associated with hypophosphatemia or hyperphosphatemia rely on the understanding of the underlying pathobiological mechanisms governing each patient condition.
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Affiliation(s)
- Ignacio Portales-Castillo
- Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA; Endocrine Unit, Massachusetts General Hospital, and Harvard Medical School, Boston, MA
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL; James A. Haley Veterans' Hospital, Tampa, FL; Center for Hypertension and Kidney Research, University of South Florida, Tampa, FL
| | - Sheikh B Khalid
- Department of Internal Medicine, The Indus Hospital, Lahore Pakistan
| | - Sagar U Nigwekar
- Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA
| | - Javier A Neyra
- Department of Internal Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL.
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Tan X, Kini A, Römermann D, Seidler U. The NHE3 Inhibitor Tenapanor Prevents Intestinal Obstructions in CFTR-Deleted Mice. Int J Mol Sci 2022; 23:ijms23179993. [PMID: 36077390 PMCID: PMC9456459 DOI: 10.3390/ijms23179993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 11/30/2022] Open
Abstract
Mutations in the CFTR chloride channel result in intestinal obstructive episodes in cystic fibrosis (CF) patients and in CF animal models. In this study, we explored the possibility of reducing the frequency of obstructive episodes in cftr−/− mice through the oral application of a gut-selective NHE3 inhibitor tenapanor and searched for the underlying mechanisms involved. Sex- and age-matched cftr+/+ and cftr−/− mice were orally gavaged twice daily with 30 mg kg−1 tenapanor or vehicle for a period of 21 days. Body weight and stool water content was assessed daily and gastrointestinal transit time (GTT) once weekly. The mice were sacrificed when an intestinal obstruction was suspected or after 21 days, and stool and tissues were collected for further analysis. Twenty-one day tenapanor application resulted in a significant increase in stool water content and stool alkalinity and a significant decrease in GTT in cftr+/+ and cftr−/− mice. Tenapanor significantly reduced obstructive episodes to 8% compared to 46% in vehicle-treated cftr−/− mice and prevented mucosal inflammation. A decrease in cryptal hyperproliferation, mucus accumulation, and mucosal mast cell number was also observed in tenapanor- compared to vehicle-treated, unobstructed cftr−/− mice. Overall, oral tenapanor application prevented obstructive episodes in CFTR-deficient mice and was safe in cftr+/+ and cftr−/− mice. These results suggest that tenapanor may be a safe and affordable adjunctive therapy in cystic fibrosis patients to alleviate constipation and prevent recurrent DIOS.
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Affiliation(s)
| | | | | | - Ursula Seidler
- Correspondence: ; Tel.: +49-5115-329-427; Fax: +49-5115-328-428
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