Solriamfetol at higher-than-approved doses—specifically doses of 300, 600, and 1,200mg, which are 2 to 4 times the maximum recommended dose—produces drug-liking responses, including elevated mood and feelings of relaxation, that are similar in degree to those of phentermine (a Schedule IVcontrolled substance).[1] Elevated mood occurred in 2.4% with placebo, 8 to 24% with solriamfetol, and 10 to 18% with phentermine, while feelings of relaxation occurred in 5% with placebo, 5 to 19% with solriamfetol, and 15 to 20% with phentermine.[1] As such, solriamfetol has significant misuse potential and is a controlled substance in the United States.[1] However, solriamfetol showed less misuse potential than Schedule II controlled stimulants like amphetamine and cocaine.[11] Consequently, the misuse potential of solriamfetol was rated as low and it was placed in the Schedule IV controlled substance category alongside phentermine.[11]
The oralbioavailability of solriamfetol is approximately 95%.[1] The median time to peak levels of solriamfetol is 2hours, with a range of 1.25 to 3.0hours.[1] A high-fat meal has minimal influence on the peak and total concentrations of solriamfetol, but does delay time to peak levels by approximately 1hour.[1] The apparent volume of distribution of solriamfetol is approximately 199L.[1] The plasma protein binding of solriamfetol is 13.3% to 19.4% over a concentration range of 0.059 to 10.1μg/mL.[1] Solriamfetol is minimally metabolized in humans.[1] It shows first-orderelimination with oral administration and has an elimination half-life of about 7.1hours.[1] The half-life of solriamfetol increases in the context of renal impairment.[1] Approximately 95% of a dose of solriamfetol is eliminated in urine as unchanged solriamfetol and 1% or less is eliminated as the minor inactive metaboliteN-acetylsolriamfetol.[1]
The drug was discovered by a subsidiary of SK Group, which licensed rights outside of eleven countries in Asia to Aerial Pharma in 2011.[8] Aerial ran two Phase II trials of the drug in narcolepsy[13] before selling the license to solriamfetol to Jazz in 2014; Jazz Pharmaceuticals paid Aerial $125 million up front and will pay Aerial and SK up to $272 million in milestone payments, and will pay double-digit royalties to SK.[8][14]
In 2019, solriamfetol was approved in the United States to improve wakefulness in adults with narcolepsy or obstructive sleep apnea (OSA).[15][16] It was granted orphan drug designation.[17]
The U.S. Food and Drug Administration (FDA) approved solriamfetol based primarily on evidence from five clinical trials (Trial 1/NCT02348593, Trial 2/NCT02348606, Trial 3/NCT02348619, Trial 4/NCT02348632, Trial 5 NCT01681121) of 622 patients with narcolepsy or obstructive sleep apnea (OSA).[15] The trials were conducted in Canada, Europe, and the United States.[15]
Solriamfetol was approved for medical use in the European Union in January 2020.[4]
In March 2022, it was announced that Axsome Therapeutics would be acquiring Solriamfetol, under the brand name Sunosi, from Jazz Pharmaceuticals, for an upfront sum of $53 million. Jazz will receive a high single-digit royalty on Axsome's U.S. net sales of Sunosi in the current indication, and a mid-single-digit royalty in the future indications. Axsome will also assume the commitments of Jazz to SK Biopharmaceuticals and Aerial Biopharma.[18]
Society and culture
Names
During development it has been called SKL-N05, ADX-N05, ARL-N05, and JZP-110.[9]
Legal status
In the United States, solriamfetol is a Schedule IV controlled substance,[1] meaning that it has an accepted medical use and a low potential for abuse, but that abuse may lead to physical or psychological dependence.[19] A prescription is required, and can only be refilled up to five times in a six-month period.[20] In countries of the European Union, a prescription is required.[4]
^ abPowell J, Piszczatoski C, Garland S (October 2020). "Solriamfetol for Excessive Sleepiness in Narcolepsy and Obstructive Sleep Apnea". Ann Pharmacother. 54 (10): 1016–1020. doi:10.1177/1060028020915537. PMID32270686. S2CID215605290.
^Abad VC, Guilleminault C (December 2018). "Solriamfetol for the treatment of daytime sleepiness in obstructive sleep apnea". Expert Rev Respir Med. 12 (12): 1007–1019. doi:10.1080/17476348.2018.1541742. PMID30365900. S2CID53106520.
^ abGursahani H, Jolas T, Martin M, Cotier S, Hughes S, Macfadden W, et al. (2023). "Preclinical Pharmacology of Solriamfetol: Potential Mechanisms for Wake Promotion". CNS Spectrums. 28 (2): 222. doi:10.1017/S1092852923001396. ISSN1092-8529. In vitro functional studies showed agonist activity of solriamfetol at human, mouse, and rat TAAR1 receptors. hTAAR1 EC50 values (10–16 μM) were within the clinically observed therapeutic solriamfetol plasma concentration range and overlapped with the observed DAT/NET inhibitory potencies of solriamfetol in vitro. TAAR1 agonist activity was unique to solriamfetol; neither the WPA modafinil nor the DAT/NET inhibitor bupropion had TAAR1 agonist activity.
^Pitre T, Mah J, Roberts S, Desai K, Gu Y, Ryan C, et al. (May 2023). "Comparative Efficacy and Safety of Wakefulness-Promoting Agents for Excessive Daytime Sleepiness in Patients With Obstructive Sleep Apnea : A Systematic Review and Network Meta-analysis". Ann Intern Med. 176 (5): 676–684. doi:10.7326/M22-3473. PMID37155992. S2CID258558603.
^Sullivan SS, Guilleminault C (2015). "Emerging drugs for common conditions of sleepiness: obstructive sleep apnea and narcolepsy". Expert Opinion on Emerging Drugs. 20 (4): 571–82. doi:10.1517/14728214.2015.1115480. PMID26558298. S2CID7951307.
^ abSurman CB, Walsh DM, Horick N, DiSalvo M, Vater CH, Kaufman D (October 2023). "Solriamfetol for Attention-Deficit/Hyperactivity Disorder in Adults: A Double-Blind Placebo-Controlled Pilot Study". J Clin Psychiatry. 84 (6). doi:10.4088/JCP.23m14934. PMID37819836. S2CID263715808.
† References for all endogenous human TAAR1 ligands are provided at List of trace amines
‡ References for synthetic TAAR1 agonists can be found at TAAR1 or in the associated compound articles. For TAAR2 and TAAR5 agonists and inverse agonists, see TAAR for references.