Fostemsavir’s instruction manual and listing status

1. Name: fostemsavir, fostemsavir, RUKOBIA

2. Indications:

Fostemsavir can be used in combination with other antiretroviral drugs and is suitable for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adult patients with severe drug resistanceHIV-1 infection who have failed current antiretroviral treatment due to drug resistance, intolerance or safety considerations.

3. Usage and dosage:

The recommended dose of fostansavir is one tablet600 mg taken twice daily with or without food. Swallow slices whole. Do not chew, crush, or split tablets.

4. Adverse reactions:

In clinical studies of fostansavir, the most common adverse reactions include nausea, diarrhea, headache, abdominal pain, indigestion, fatigue, rash, sleep disorders, drowsiness, vomiting, etc., and the most serious adverse reactions include immune reconstitution inflammatory syndrome.

5. Supply and storage:

Folstansavir extended-release tablets,600 mg, beige, 60 tablets in a bottle, with child safety cap. May be stored at 20°C to 25°C (68°F to 77°F) ; tolerances are allowed between 15°C and 30°C (59°F and 86°F). Folstansavir extended-release tablets may have a slight vinegar-like odor.

6. Taboo:

Folstansavir is contraindicated in the following patients:

1. Previous allergyfostemsavir or any component of fostemsavir;

2. Concomitant use of strong cytochromeP450 (CYP) 3A inducers, because the plasma concentration of the active part fostemsavir may be significantly reduced, resulting in loss of virological response. These medications include, but are not limited to:

(1) Androgen receptor inhibitor: enzalutamide

(2) Anticonvulsants: carbamazepine, phenytoin

(3) Antimycobacteria: Rifampicin

(4) Anti-tumor drug: Mitotane

(5) Herbal products: St. John's wort (Hypericum perforatum)

7. Mechanism of action:

The gp120 subunit of HIV-1 gp 160 envelope glycoprotein is a new target for the treatment of HIV-1 infection. These subunits are responsible for promoting the first step in the viral life cycle, attachment, by mediating the interaction between the virus and the host cell CD4 receptor. After attachment, HIV-1 undergoes assembly, budding, and maturation within the host cell and then releases mature viral particles to continue the viral life cycle.

Active metabolite of fostansavirtemsavir is an HIV-1 attachment inhibitor. It binds directly to the gp120 subunit and inhibits the interaction of the virus with the host CD4 receptor, thereby preventing the initial attachment required for viral replication. It has also been shown to inhibit other gp120-dependent post-attachment steps required for viral entry.

8. Listing situation:

Forstansavir was approved by the U.S. National Medical Products Administration (FDA) on 2020-07-02 and was approved by the European Medicines Agency (EMA) for launch in the EU on 2021-02-04 under the trade name RUKOBIA. There is no news of listing in China and other regions.

Reference materials:https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a21006b7-6d6f-4f06-81b4-17978756452b