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Fostemsavir

Phase 3

HIV Infections | Small molecule | Infectious Disease |GSK plc|Last Updated: Feb 6, 2026

Success Probability
Approval Probability 71%
TA Base Rate26%
Adjusted LOA41%
ML RiskLOW_RISK
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Market & Valuation
rNPV $3.2B
Market Size $9.4B
Revenue Basis $1.6B
Competitors 6
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Trial Design
RandomizedCONTROLLEDDMCBiomarker
Total Trials2
Total Enrollment215
FDA Designations
No designations recorded
Clinical Trials (2)
NCT IDTitlePhaseStatusEnrollmentVelocityDesignStartCompletionLast UpdatedSitesCountries
NCT07393659A Continued Access Study for Participants Transitioning From ViiV Healthcare-sponsored or ViiV Healthcare-collaborative Parent Studies for HIV TreatmentPHASE3 NOT YET_RECRUITING 183May 8, 2026Dec 30, 2030Feb 6, 2026 -
NCT04757974Low-dose Fostemsavir Extended Release Relative Bioavailability StudyPHASE1 COMPLETED 32Mar 5, 2021Jul 31, 2021Sep 22, 20211 United States
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Study Endpoints
Primary Endpoints
Number of participants who discontinue the study intervention and the reason for discontinuation
Throughout the study period (from rollover visit at Day 1 until the end of study/withdrawal visit)
Number of participants with serious adverse events (SAE)
Throughout the study period (from rollover visit at Day 1 until the end of study /withdrawal visit)

A SAE is defined as any untoward medical occurrence that, at any dose, results in results in death, is life- threatening, requires inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability/incapacity, is a congenital anomaly/birth defect in the offspring of a study participant, abnormal pregnancy outcomes or a suspected transmission of any infectious agent via an authorized medicinal product.

Number of participants with adverse events of special interest (AESI)
Throughout the study period (from rollover visit at Day 1 until the end of study /withdrawal visit)

An adverse event (AE) is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. An AESI is defined as an AE of a scientific and medical concern specific to the study intervention, which may require further investigation in order to characterize and understand it.

Part 1: Area under the plasma concentration-time curve (AUC) from time zero to the last quantifiable time point (AUC[0-t]) of temsavir
Predose (Day 1) until 72 hour post dose
Part 1: AUC from time zero extrapolated to infinite time (AUC[0-infinity]) of temsavir
Predose (Day 1) until 72 hour post dose
Part 1: Maximum observed plasma concentration (Cmax)
Predose (Day 1) until 72 hour post dose
Secondary Endpoints
Part 1: Time to Cmax (Tmax) of temsavir
Predose (Day 1) until 72 hour post dose
Part 1: Elimination half-life (T1/2) of temsavir
Predose (Day 1) until 72 hour post dose
Part 1: Concentration at 12 hours post-dose of temsavir
12 hours post-dose
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Study Design & Arms
AllocationNA
MaskingNONE
ModelSINGLE_GROUP
PurposeTREATMENT
Treatment Arms
ArmTypeDescription
Continued Access GroupEXPERIMENTALParticipants with HIV-1 who received the study intervention and completed the protocol-defined treatment period in ViiV Healthcare-sponsored or ViiV Healthcare-collaborative parent studies (2020-001029-30, 2020-001426-57), and who continue to receive the study intervention from their respective parent study.
Part 1: Treatment sequence ABCEXPERIMENTALParticipants will receive FTR 3×200 mg ER tablets (Treatment A) in Period 1 followed by FTR 3×200 mg ER tablets (Treatment B) in Period 2 followed by FTR 600 mg ER tablet (Treatment C, reference) in Period 3.
Part 1: Treatment sequence BCAEXPERIMENTALParticipants will receive FTR 3×200 mg ER tablets (Treatment B) in Period 1 followed by FTR 600 mg ER tablet (Treatment C, reference) in Period 2 followed by FTR 3×200 mg ER tablets (Treatment A) in Period 3.
Part 1: Treatment sequence CABEXPERIMENTALParticipants will receive FTR 600 mg ER tablet in Period 1 (Treatment C, reference) followed by FTR 3×200 mg ER tablets (Treatment A) in Period 2 followed by FTR 3×200 mg ER tablets (Treatment B) in Period 3.
Part 1: Treatment sequence ACBEXPERIMENTALParticipants will receive FTR 3×200 mg ER tablets (Treatment A) in Period 1 followed by FTR 600 mg ER tablet (Treatment C, reference) in Period 2 followed by FTR 3×200 mg ER tablets (Treatment B) in Period 3.
Part 1: Treatment sequence BACEXPERIMENTALParticipants will receive FTR 3×200 mg ER tablets (Treatment B) in Period 1 followed by FTR 3×200 mg ER tablets (Treatment A) in Period 2 followed by FTR 600 mg ER tablet (Treatment C, reference) in Period 3.
Part 1: Treatment sequence CBAEXPERIMENTALParticipants will receive FTR 600 mg ER tablet (Treatment C, reference) in Period 1 followed by FTR 3×200 mg ER tablets (Treatment B) in Period 2 followed by FTR 3×200 mg ER tablets (Treatment A) in Period 3.
Part 2: Treatment sequence DEEXPERIMENTALParticipants will receive the selected low-dose formulation of FTR 3 × 200 mg ER tablets in a fasted state (Treatment D) in Period 1 and following a high fat high calorie meal (Treatment E) in Period 2.
Part 2: Treatment sequence EDEXPERIMENTALParticipants will receive the selected low-dose formulation of FTR 3 × 200 mg ER tablets following a high fat high calorie meal (Treatment E) in Period 1 and in a fasted state (Treatment D) in Period 2.
Interventions
NameTypeDescription
FostemsavirDRUGParticipants receive oral tablets with the dosages depending on the weight of the participants.
Dolutegravir (DTG)/ Lamivudine (3TC)DRUGParticipants receive oral tablets with the dosages depending on the weight of the participants.
Fostemsavir 600 mgDRUGFostemsavir tablets will be administered via oral route.
Fostemsavir 200 mgDRUGFostemsavir tablets will be administered via oral route.
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Eligibility Criteria
Age Range18 Years — 50 Years
SexALL
Healthy VolunteersNo

Inclusion Criteria: Participants are eligible to be included in this study only if all the following criteria apply: * Investigator confirmation of the participant's continued clinical benefit from the parent study intervention and the participant's completion of the protocol-defined treatment per...

Countries:United States
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Recent Changes (Last 90 Days)
LOWMay 26, 2026NCT07393659primaryCompletionDate: changed
LOWMay 24, 2026NCT07393659studyFirstPostDate: changed