Eltrombopag

Eltrombopag

Clinical data
Trade names	Promacta, Revolade
AHFS/Drugs.com	Monograph
MedlinePlus	a609011
License data	EU EMA: Revolade US FDA: Eltrombopag
Pregnancy category	AU: B3 US: C (Risk not ruled out)
Routes of administration	Oral
ATC code	B02BX05 (WHO)
Legal status
Legal status	US: ℞-only
Pharmacokinetic data
Bioavailability	~52%[1]
Protein binding	>99%
Metabolism	extensive hepatic (through CYP1A2 and CYP2C8
Biological half-life	21–35 hours
Excretion	feces (59%), urine (31%)
Identifiers
IUPAC name 3'-{(2Z)-2-[1-(3,4-dimethylphenyl)-3-methyl-5-oxo-1,5-dihydro-4H-pyrazol-4-ylidene]hydrazino}-2'-hydroxy-3-biphenylcarboxylic acid
CAS Number	496775-61-2 496775-62-3 (olamine)
PubChem (CID)	9846180
ChemSpider	21106301
UNII	S56D65XJ9G
ChEMBL	CHEMBL461101
ECHA InfoCard	100.128.125
Chemical and physical data
Formula	C25H22N4O4
Molar mass	442.467 g/mol
3D model (Jmol)	Interactive image
SMILES CC1=C(C=C(C=C1)N2C(=O)C(=C(N2)C)NN=C3C=CC=C(C3=O)C4=CC(=CC=C4)C(=O)O)C
InChI InChI=1S/C25H22N4O4/c1-14-10-11-19(12-15(14)2)29-24(31)22(16(3)28-29)27-26-21-9-5-8-20(23(21)30)17-6-4-7-18(13-17)25(32)33/h4-13,26,30H,1-3H3,(H,32,33)/b27-22+ Key:XDXWLKQMMKQXPV-HPNDGRJYSA-N
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Eltrombopag (rINN, codenamed SB-497115-GR) is a medication that has been developed for certain conditions that lead to thrombocytopenia (abnormally low platelet counts). It is a small molecule agonist of the c-mpl (TpoR) receptor, which is the physiological target of the hormone thrombopoietin. Eltrombopag was discovered as a result of research collaboration between GlaxoSmithKline and Ligand Pharmaceuticals. Designated an orphan drug in the United States and European Union, it is being manufactured and marketed by GlaxoSmithKline under the trade name Promacta in the USA and is marketed as Revolade in the EU.

Approvals and indications

Eltrombopag was initially approved by the U.S. Food and Drug Administration on November 20, 2008, for the treatment of thrombocytopenia in patients with chronic immune (idiopathic) thrombocytopenic purpura who have had an insufficient response to corticosteroids, immunoglobulin therapy, or splenectomy.^[2]

Eltrombopag received FDA breakthrough treatment designation in February 2014 for patients with aplastic anemia for which immunosuppression has not been successful.^[3] It has been shown to produce a trilineage hematopoesis in some patients with aplastic anemia, resulting in increased platelet counts, along with red and white blood cell counts.^[4]

On August 24, 2015, the FDA approved eltrombopag (Promacta for oral suspension) for the treatment of thrombocytopenia in pediatric patients 1 year and older with idiopathic thrombocytopenia who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.^[5]

Development

In preclinical studies, the compound was shown to interact selectively with the thrombopoietin receptor, leading to activation of the JAK-STAT signaling pathway and increased proliferation and differentiation of megakaryocytes. Animal studies confirmed that it increased platelet counts. In 73 healthy volunteers, higher doses of eltrombopag caused larger increases in the number of circulating platelets without tolerability problems.^[6]

Clinical trials

Eltrombopag has been shown to be effective in two major clinical syndromes: idiopathic thrombocytopenic purpura^[7] and cirrhosis due to hepatitis C (in which low platelet counts may be a contraindication for interferon treatment).^[8]

After 6 weeks of therapy in a phase III trial, eltrombopag 50 mg/day was associated with a significantly higher response rate than placebo in adult patients with chronic ITP.^[9]

References

1. "Promacta^® (eltrombopag) Tablets, for Oral Use and for Oral Suspension. Full Prescribing Information" (PDF). GlaxoSmithKline, Research Triangle Park, NC 27709. Retrieved 13 September 2015.
2. "Approval Letter" (PDF). fda.gov. United States Food and Drug Administration. Retrieved 18 March 2016.
3. "Eltrombopag / Promacta". fda.gov. United States Food and Drug Administration. Retrieved 18 March 2016.
4. Desmond R, Townsley DM, Dumitriu B, Olnes MJ, Scheinberg P, Bevans M, Parikh AR, Broder K, Calvo KR, Wu CO, Young NS, Dunbar CE (March 2014). "Eltrombopag restores trilineage hematopoiesis in refractory severe aplastic anemia that can be sustained on discontinuation of drug". Blood. 123 (12): 1818–25. doi:10.1182/blood-2013-10-534743. PMID 24345753.
5. "FDA extends use of Promacta in young children with rare blood disorder". fda.gov. United States Food and Drug Administration. Retrieved 18 March 2016.
6. Jenkins JM, Williams D, Deng Y, Uhl J, Kitchen V, Collins D, Erickson-Miller CL (June 2007). "Phase 1 clinical study of eltrombopag, an oral, nonpeptide thrombopoietin receptor agonist". Blood. 109 (11): 4739–41. doi:10.1182/blood-2006-11-057968. PMID 17327409.
7. Bussel JB, Cheng G, Saleh MN, Psaila B, Kovaleva L, Meddeb B, Kloczko J, Hassani H, Mayer B, Stone NL, Arning M, Provan D, Jenkins JM (November 29, 2007). "Eltrombopag for the treatment of chronic idiopathic thrombocytopenic purpura". The New England Journal of Medicine. 357 (22): 2237–2247. doi:10.1056/NEJMoa073275. PMID 18046028.
8. McHutchison JG, Dusheiko G, Shiffman ML, Rodriguez-Torres M, Sigal S, Bourliere M, Berg T, Gordon SC, Campbell FM, Theodore D, Blackman N, Jenkins J, Afdhal NH (November 29, 2007). "Eltrombopag for thrombocytopenia in patients with cirrhosis associated with hepatitis C". The New England Journal of Medicine. 357 (22): 2227–2236. doi:10.1056/NEJMoa073255. PMID 18046027.
9. Garnock-Jones KP, Keam SJ (2009). "Eltrombopag". Drugs. 69 (5): 567–76. doi:10.2165/00003495-200969050-00005. PMID 19368418.