Casimersen (SRP-4045; Amondys 45) is an antisense oligonucleotide medication approved in 2021 for use in the treatment of Duchenne muscular dystrophy (DMD) in people who have a confirmed mutation of the dystrophin gene that is amenable to exon 45 skipping.

Physicochemical Properties

Molecular Formula	C22H40N7O9P
Molecular Weight	577.568265914917
Exact Mass	577.262
CAS #	1422958-19-7
PubChem CID	131842141
Appearance	White to off-white solid powder
LogP	-3.3
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	12
Rotatable Bond Count	15
Heavy Atom Count	39
Complexity	914
Defined Atom Stereocenter Count	2
SMILES	P(N(C)C)(N1CCN(C(=O)OCCOCCOCCO)CC1)(=O)OC[C@@H]1CNC[C@H](N2C(N=C(C=C2)N)=O)O1
InChi Key	KTQVJPYTGHFWJB-HCCSCLAOSA-N
InChi Code	InChI=1S/C22H40N7O9P/c1-26(2)39(33,37-17-18-15-24-16-20(38-18)29-4-3-19(23)25-21(29)31)28-7-5-27(6-8-28)22(32)36-14-13-35-12-11-34-10-9-30/h3-4,18,20,24,30H,5-17H2,1-2H3,(H2,23,25,31)/t18-,20+,39?/m0/s1
Chemical Name	2-[2-(2-hydroxyethoxy)ethoxy]ethyl 4-[[(2S,6R)-6-(4-amino-2-oxopyrimidin-1-yl)morpholin-2-yl]methoxy-(dimethylamino)phosphoryl]piperazine-1-carboxylate
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	In individuals with genetic mutations amenable to exon 45 skipping, the goal of the technique is to enable the creation of internally shortened dystrophin [2].
References	[1]. Shirley M. Casimersen: First Approval. Drugs. 2021;81(7):875-879. [2]. Casimersen. Am J Health Syst Pharm. 2021;78(13):1149-1150.
Additional Infomation	See also: Casimersen (annotation moved to).

Solubility Data

Solubility (In Vitro)	H2O : ~100 mg/mL (~13.19 mM)
Solubility (In Vivo)	Solubility in Formulation 1: 100 mg/mL (13.19 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.7314 mL	8.6570 mL	17.3139 mL
	5 mM	0.3463 mL	1.7314 mL	3.4628 mL
	10 mM	0.1731 mL	0.8657 mL	1.7314 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.