Tofersen (BIIB067; Qalsody) is an antisense oligonucleotide that facilitates the degradation of superoxide dismutase 1 (SOD1) mRNA in an RNase H-dependent manner, thereby lowering the synthesis of SOD1 protein. Tofersen is employed in research pertaining to amyotrophic lateral sclerosis (ALS).Approved in 2023 by FDA for treating SOD1 amyotrophic lateral sclerosis.

Physicochemical Properties

CAS #	2088232-70-4
Appearance	Off-white to light yellow solid powder
Synonyms	BIIB067; BIIB 067; Qalsody; BIIB-067; ISIS SOD1Rx; ISIS-SOD1Rx; ISIS SOD1Rx; Tofersen
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	Tofersen targets the SOD1 mRNA by binding to it through Watson-Crick base pairing with antisense oligonucleotides (ASOs). In order to degrade the targeted RNA, tofersen activates RNase H1[2].
References	[1]. Phase 1-2 Trial of Antisense Oligonucleotide Tofersen for SOD1 ALS. N Engl J Med. 2020 Jul 9;383(2):109-119. [2]. Antisense oligonucleotides extend survival and reverse decrement in muscle response in ALS models. J Clin Invest. 2018 Aug 1;128(8):3558-3567.

Solubility Data

Solubility (In Vitro)	H2O : ~100 mg/mL (~14.0 mM)
Solubility (In Vivo)	Solubility in Formulation 1: 100 mg/mL (14.03 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.)