Etelcalcetide (Parsabiv)_Dosage, benefits & legal status
Also known as Parsabiv, AMG 416, KAI-4169, ONO-5163, velcalcetide, telcalcetide, etelcalcetide hydrochloride
A short chain of mirror-image amino acids that makes the parathyroid glands sense more calcium than is there. FDA-approved in 2017 for overactive parathyroid glands in adults on hemodialysis.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Etelcalcetide (Parsabiv)?
Plain language first. The technical label stays, but it never stands alone.Overview
People on hemodialysis often develop overactive parathyroid glands that make too much parathyroid hormone (PTH), a condition called secondary hyperparathyroidism. Given into the dialysis line three times a week, etelcalcetide cut PTH by more than 30% in 77% and 79% of patients in two 26-week trials, against 11% on placebo, and beat the cinacalcet tablet head to head (68.2% against 57.7%). It lowers blood calcium in most patients (64% against 10% on lab tests), sometimes enough to cause symptoms, and its trials measured PTH, not fractures, heart events or survival.
Etelcalcetide is a seven-residue chain of D-amino acids (Ac-D-Cys-D-Ala-D-Arg-D-Arg-D-Arg-D-Ala-D-Arg-NH2) whose D-cysteine carries a separate L-cysteine through a disulfide bond. It is a calcimimetic: its cysteine forms a disulfide bond with cysteine 482 on the outside of the calcium-sensing receptor of parathyroid cells and makes the receptor respond more strongly to calcium, so parathyroid hormone (PTH) secretion falls. KAI Pharmaceuticals discovered it as KAI-4169, Amgen bought KAI in 2012 and sells it as Parsabiv, the first calcimimetic given into a vein, and Ono holds the Japanese rights.
What it's used for
An injection given by dialysis staff at the end of each hemodialysis session to treat secondary hyperparathyroidism in adults with kidney failure. It is not for people who are not on hemodialysis.
How does Etelcalcetide (Parsabiv) work?
What it does in the body, and where.Etelcalcetide makes the parathyroid glands read blood calcium as higher than it is, so they release less parathyroid hormone.
- 01Into the dialysis lineIt is pushed into the dialysis line as a session ends and travels in the blood mostly attached to albumin, by swapping disulfide bonds. Dialysis is the main way it leaves the body, so its effect carries over from one session to the next.
- 02Locking onto the calcium sensorParathyroid cells measure calcium with the calcium-sensing receptor. Etelcalcetide's cysteine forms a disulfide bond with cysteine 482 on the outside of this receptor and makes it respond more strongly to calcium; in lab work, receptors lacking that cysteine, such as the pig receptor, did not respond.
- 03Less hormoneThe glands release less PTH within 30 minutes of a dose, and calcium and phosphate fall. It is not a PTH analog: teriparatide and palopegteriparatide act like PTH at the PTH1 receptor, while etelcalcetide lowers the body's own PTH.
What else is it used for?
Each group carries its own evidence level.Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
Against placebo (two phase 3 trials)
FDA-approved- Human trial1,023 adults on hemodialysis over 26 weeks: PTH fell by more than 30% in 77% and 79% against 11% on placebo in the label, and in 74.0% and 75.3% against 8.3% and 9.6% in the JAMA analysis.
- Human trialPTH reached 300 pg/mL or less in 49.6% and 53.3% against 5.1% and 4.6%.
Against cinacalcet
FDA-approved- Human trial683 patients, double-blind with dummy tablets and injections: PTH down more than 30% in 68.2% against 57.7% (superiority P=.004), and more than 50% in 52.4% against 40.2%.
- Human trialDecreased blood calcium in 68.9% against 59.8%. Days with nausea or vomiting over the first 8 weeks did not differ significantly, so the injection did not prove easier on the stomach than the tablet.
Japan
FDA-approved- Human trial155 patients over 12 weeks: iPTH within the Japanese target of 60 to 240 pg/mL in 59.0% against 1.3% on placebo, and down by 30% or more in 76.9% against 5.2%; low calcium was described as mild.
Heart muscle (ETECAR-HD)
Early research- Human trial62 patients with a thickened left ventricle, 12 months against alfacalcidol: left ventricular mass index 6.9 g/m² lower with etelcalcetide (95% CI 1.2 to 12.6, P=0.022).
- No dataA small trial against another drug, measured on MRI rather than in heart events.
Safety signals
FDA-approved- No dataQTcF above 500 ms in 4.8% against 1.9% on placebo, and heart failure needing a hospital stay in 2% against 1%.
- No dataUpper GI bleeding was noted at death in 2 patients over 1,253 patient-years on etelcalcetide against none in 384 patient-years on control; the cause was not determined.
Response rates for the two placebo-controlled trials appear in two versions: the US label reports a PTH fall of more than 30% in 77% and 79% of patients against 11% on placebo, while the JAMA paper on the same trials reports 74.0% and 75.3% against 8.3% and 9.6%, from a different analysis; this page uses the label. The 64% often quoted as the rate of hypocalcemia is the share with lower blood calcium on lab tests (against 10% on placebo); low calcium with symptoms occurred in 7% against 0.2%. It is often described as a D-amino-acid peptide: the seven-residue chain is all D, but the cysteine attached to it is ordinary L-cysteine. It was not the first calcimimetic, since the cinacalcet tablet came first; it is the first given into a vein. US approval on February 7, 2017 came third, after the EU (November 11, 2016) and Japan (December 19, 2016), and followed a Complete Response Letter on August 24, 2016. The head-to-head difference is printed as -10.5% because it was calculated as cinacalcet minus etelcalcetide; etelcalcetide did better (68.2% against 57.7%). The 3 to 4 day half-life is an effective half-life in people on hemodialysis, where dialysis removes most of the drug; in healthy men a single dose had a half-life of about 18 to 20 hours. It lowers PTH and is not a PTH analog like teriparatide.
The published record
Papers and trials about Etelcalcetide (Parsabiv)
130 papers tagged human · 82 not reviews or lab · 24 clinical trial publications
23 registered trials · 16 with posted results
Furthest stage reached: Approved in the US
Counted from Europe PMC indexing, not read by a person; a human tag can land on reviews, commentary or lab papers; clinical trial publications is the narrower count.
At a glance
Four things to know about Etelcalcetide (Parsabiv)
Evidence
FDA-approved
Category
Healing and recovery
Common vial
Varies
Half-life
3 to 4 days in people on hemodialysis
How much, and do you cycle it?
The range, and whether you take breaks.5 mg to start, then 2.5 to 15 mg three times a week (label), three times a week, after each dialysis session. Continuous, three times a week with dialysis FDA label
Given at every dialysis session for as long as it keeps PTH and calcium in range, with dose changes no more often than every 4 weeks; missed doses are not made up.
How long does it stay in the body?
The half-life, and where the figure comes from.3 to 4 days in people on hemodialysisFDA label
An effective half-life in hemodialysis patients, where dialysis is the main route of removal (clearance 7.66 L an hour); in a radiolabel study about 60% was recovered in dialysate and about 7% in urine and feces over 175 days. Steady state takes 7 to 8 weeks, with 3- to 4-fold build-up. It is not broken down by liver CYP enzymes; it swaps disulfide bonds with thiols in the blood, mostly forming albumin conjugates. In a small single-dose study in healthy men with working kidneys, the half-life was about 18 to 20 hours.
Source: Parsabiv US prescribing information, section 12.3
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How is it given?
Dosing context and source notes.Given in hospital from a prepared product, so there is nothing to mix.
Label range: 2.5 up to 15 mg per dose. Parsabiv US prescribing information (revised January 2025), section 2
Given by the dialysis team three times a week as a bolus into the venous line of the dialysis circuit during rinse-back at the end of hemodialysis, or into a vein after rinse-back followed by at least 10 mL of saline. Corrected calcium must be at or above the lower limit of normal before starting, before each increase and before restarting. Start at 5 mg; increase in 2.5 or 5 mg steps no more often than every 4 weeks, up to 15 mg, with a maintenance dose of 2.5 to 15 mg set by PTH and calcium. Calcium is checked within 1 week of starting or changing the dose and then every 4 weeks, and PTH after 4 weeks. If PTH falls too low, the dose is reduced or paused. If calcium is below normal but at or above 7.5 mg/dL without symptoms, a lower dose, a pause or calcium-raising treatment is considered; below 7.5 mg/dL or with symptoms, it is stopped and restarted 5 mg lower once calcium is corrected (2.5 mg if the last dose was 2.5 or 5 mg). Missed doses are not made up; after more than 2 weeks off, it restarts at 5 mg (or 2.5 mg if that was the last dose). Cinacalcet is stopped at least 7 days before the first dose. No separate kidney or liver adjustment, since it is used only on hemodialysis. Supplied as ready-made single-dose vials of 2.5 mg/0.5 mL, 5 mg/mL and 10 mg/2 mL that are not diluted or mixed, kept in a fridge (out of the fridge, used within 7 days in the carton at up to 25°C). Given by dialysis staff from a ready-made vial, so there is nothing to mix or draw at home.
How do you store it?
Before mixing, and after.Given in a hospital or trial clinic, so the pharmacy stores it.
Etelcalcetide (Parsabiv) goes into a vein and is prepared by hospital, clinic or trial pharmacy staff, following the product label or the trial protocol. Some products like this are ready-made solutions and others are powders mixed just before use, often with hours rather than weeks of shelf life once prepared. It is not a medicine people store at home.
What are the side effects and cautions?
Known cautions and warnings for this compound.Solubility, computed: 86% charged residues, 43% hydrophobic. Water usually sufficient.
A first-pass rule from peptide manufacturers' guidance. It does not account for disulfide bridges, salt form or how the powder was dried, and it predicts what should be easy rather than what will happen in your vial.
Who should avoid it
- Known allergy to etelcalcetide or its ingredients (facial swelling and anaphylaxis have been reported)
- Corrected blood calcium below the lower limit of normal: it is not started, increased or restarted until calcium is corrected
- Kidney disease not on hemodialysis, primary hyperparathyroidism or parathyroid cancer: not studied and not recommended
- Cinacalcet or other oral calcimimetics: not combined; cinacalcet is stopped at least 7 days before the first dose
- Breastfeeding is not recommended because of a risk of low calcium in the infant; use in children is not established
Stop and get help
- Tingling, muscle cramps or spasms, or a seizure: possible severe low calcium, so the dose is held and calcium is checked
- Palpitations, fainting, or new breathlessness and swelling: possible QT prolongation, an abnormal heart rhythm or worsening heart failure
- Facial swelling, rash or trouble breathing after a dose: possible allergic reaction, including anaphylaxis
Common effects
- Blood calcium decreased on lab tests in 64% against 10% on placebo; low calcium with symptoms in 7% against 0.2%
- Muscle spasms 12% against 7%, tingling (paresthesia) 6% against 1% and muscle pain 2% against 0.2%
- Diarrhea 11% against 9%, nausea 11% against 6%, vomiting 9% against 5% and headache 8% against 6%
- Corrected calcium below 7.5 mg/dL in 27% against 5.5%, and heart failure needing a hospital stay in 2% against 1%; 1% stopped because of low calcium
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Etelcalcetide (Parsabiv) approved?
And where the numbers on this page come from.Yes. Etelcalcetide (Parsabiv) is FDA approved and available on prescription in the United States. It is also approved in the European Union and Japan.
- Approval statusFDA-approved
- RouteInto a vein (bolus into the dialysis line at the end of hemodialysis)
- Checked21 October 2026
- Approved outside the USEuropean Union, Japan: EU authorization of Parsabiv (Amgen Europe B.V.) on November 11, 2016, and Japanese approval of Parsabiv Intravenous Injection for Dialysis (Ono, as etelcalcetide hydrochloride) on December 19, 2016, both before the US approval. Also approved in the US.This does not change the United States position above.
- DoseFrom the drug label. The manufacturer tested this range and a regulator reviewed it.
- Vial sizeFrom what vendors typically list; not a recommendation.
- SourcesParsabiv US prescribing information (Amgen, revised January 2025)Drugs@FDA, NDA 208325 (Parsabiv)openFDA label record for Parsabiv (2026)FDA GSRS substance record, etelcalcetide (UNII 60ME133FJB)Block GA et al., JAMA 2017;317:146-155Block GA et al., JAMA 2017;317:156-164Fukagawa M et al., Nephrology Dialysis Transplantation 2017;32:1723-1730Dörr K et al., Circulation Research 2021;128:1616-1625 (ETECAR-HD)Molecular Pharmacology 2015;88:853-865 (AMG 416 receptor study)EMA, Parsabiv EPAROno, approval in Japan (December 19, 2016)Amgen, agreement to acquire KAI Pharmaceuticals (April 10, 2012)Amgen, update on the Parsabiv NDA (August 24, 2016)Amgen, FDA approves Parsabiv (February 7, 2017)
What has happened recently
KAI Pharmaceuticals of South San Francisco developed etelcalcetide as KAI-4169 and licensed the Japanese rights to Ono in September 2011; Amgen announced on April 10, 2012 that it would buy KAI for $315 million, and KAI, now an Amgen subsidiary, is still the US application holder of record. The EU authorized Parsabiv (Amgen Europe B.V.) on November 11, 2016, after a positive CHMP opinion on September 15, 2016, and Japan approved Ono's Parsabiv Intravenous Injection for Dialysis on December 19, 2016, with launch on February 15, 2017. In the US, NDA 208325 was submitted in August 2015 and accepted with an action date of August 24, 2016, when the FDA issued a Complete Response Letter, with no reason given in Amgen's announcement; it approved Parsabiv on February 7, 2017 as a new molecular entity under standard review. There are no US generics, and the current label was revised in January 2025. A US orphan designation for hyperparathyroidism in children (May 31, 2017) has not led to an approved use in children.
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What else is like Etelcalcetide (Parsabiv)?
Others in Healing and recovery, side by side.If you're weighing Etelcalcetide (Parsabiv), it's worth reading Danegaptide (ZP1609), Dolcanatide (SP-333), and Serelaxin (RLX030) in the same class.
A short chain of mirror-image amino acids that makes the parathyroid glands sense more calcium than is there. FDA-approved in 2017 for overactive parathyroid glands in adults on hemodialysis.
- Dose
- 5 mg to start, then 2.5 to 15 mg three times a week (label)
- How often
- Three times a week, after each dialysis session
A tiny modified peptide that strengthens the channels linking neighboring cells. It did not protect the heart in a 585-patient trial, and Breye Therapeutics is now taking an oral form into diabetic retinopathy.
- Dose
- 75 mg once daily to 150 mg twice daily for 28 days (phase 1b trial)
- How often
- Once or twice daily (phase 1b trial)
The same atoms as plecanatide, with the first and last amino acids switched to their mirror-image forms to resist digestion. It reached phase 2 for opioid-induced constipation; Bausch Health bought it in 2019 and has reported no development since 2020.
- Dose
- 3 or 6 mg once daily (phase 2 trial)
- How often
- Once daily (phase 2 trial)
Recombinant human relaxin-2, a two-chain hormone that relaxes arteries, given as a 48-hour drip in acute heart failure. In RELAX-AHF-2 cardiovascular deaths were 8.7% against 8.9% on placebo, and Novartis ended development in 2017.
- Dose
- 30 mcg/kg per day by continuous infusion for 48 hours (phase 3 trials)
- How often
- Once, as a single 48-hour infusion
Guides for this compound
- How to Reconstitute a Peptide
Mix peptide powder with bacteriostatic water, step by step.
- How to Read an Insulin Syringe
Read the units, convert to millilitres, and draw the exact dose.
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
Sources
- Parsabiv US prescribing information (Amgen, revised January 2025)(2025)Dosing and titration; pooled side effects in 503 against 513 patients (blood calcium decreased 64% against 10%); warnings; effective half-life 3 to 4 days; PTH response 77% and 79% against 11%.
- Drugs@FDA, NDA 208325 (Parsabiv)(2021)Approved February 7, 2017 as a new molecular entity under standard review; sponsor KAI Pharms; labeling supplements in 2018, 2019 and 2021.
- openFDA label record for Parsabiv (2026)(2026)Chemical name with seven D-amino acids and a disulfide-linked L-cysteine; calcium-sensing receptor mechanism; anaphylaxis and seizures after marketing.
- FDA GSRS substance record, etelcalcetide (UNII 60ME133FJB)(2026)C38H73N21O10S2, average MW 1048.25; other names velcalcetide and telcalcetide and codes KAI-4169, AMG-416 and ONO-5163; free-base CAS 1262780-97-1 (the hydrochloride, UNII 72PT5993DU, CAS 1334237-71-6, has its own GSRS record).
- Block GA et al., JAMA 2017;317:146-155(2017)Two placebo-controlled trials, 1,023 patients: PTH down more than 30% in 74.0% and 75.3% against 8.3% and 9.6%.
- Block GA et al., JAMA 2017;317:156-164(2017)683 patients against cinacalcet: PTH down more than 30% in 68.2% against 57.7% (superiority P=.004); more than 50% in 52.4% against 40.2%.
- Fukagawa M et al., Nephrology Dialysis Transplantation 2017;32:1723-1730(2017)155 Japanese hemodialysis patients over 12 weeks: iPTH in the 60 to 240 pg/mL target in 59.0% against 1.3% on placebo.
- Dörr K et al., Circulation Research 2021;128:1616-1625 (ETECAR-HD)(2021)62 patients with a thickened heart muscle, 12 months: left ventricular mass index 6.9 g/m² lower than with alfacalcidol (P=0.022).
- Molecular Pharmacology 2015;88:853-865 (AMG 416 receptor study)(2015)AMG 416 binds cysteine 482 of the calcium-sensing receptor by a disulfide bond; receptors without that cysteine did not respond.
- EMA, Parsabiv EPAR(2024)EU authorization November 11, 2016 after a CHMP opinion on September 15, 2016; holder Amgen Europe B.V.; ATC H05BX04.
- Ono, approval in Japan (December 19, 2016)(2016)Parsabiv Intravenous Injection for Dialysis approved as ONO-5163; license from KAI in September 2011.
- Amgen, agreement to acquire KAI Pharmaceuticals (April 10, 2012)(2012)$315 million in cash; KAI-4169 in phase 2; Japanese rights with Ono.
- Amgen, update on the Parsabiv NDA (August 24, 2016)(2016)The FDA issued a Complete Response Letter; no reason given, and other regions not affected.
- Amgen, FDA approves Parsabiv (February 7, 2017)(2017)US approval; 1,023 patients in two placebo-controlled trials; PTH, calcium and phosphate reductions kept for up to 78 weeks.
Beyond these, 185 records are indexed. Browse the records