GSK4428859A

GlaxoSmithKline · Phase 2 active Small molecule Quality 0/100

GSK4428859A is a Small molecule drug developed by GlaxoSmithKline. It is currently in Phase 2 development. Also known as: belrestotug, EOS884448.

Likelihood of approval

18.3% vs 15.3% industry baseline

If approved by FDA: likely 2031–2034

Steps remaining: Phase 3 → NDA/BLA submission

Confidence: Medium

Why this estimate

• Baseline phase 2 → approval rate +15.3pp
  Industry-wide phase 2 drugs reach approval ~15.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas).
• Big-pharma sponsor +3.0pp
  GlaxoSmithKline is a top-20 pharma sponsor — historical approval rates run ~3pp above average due to scale, regulatory experience, and trial-design quality.

Predicted approval windows by jurisdiction (conditional on FDA approval)

Regulator	Country	Likely year	Lag vs FDA
FDA	US	2031–2034	—
EMA	EU	2032–2035	+0.7 yr
MHRA	GB	2032–2035	+0.7 yr
Health Canada	CA	2032–2036	+0.9 yr
TGA	AU	2032–2036	+1.2 yr
PMDA	JP	2032–2036	+1.5 yr
NMPA	CN	2033–2037	+2.3 yr
MFDS	KR	2032–2036	+1.4 yr
CDSCO	IN	2032–2037	+1.8 yr
ANVISA	BR	2033–2037	+2.3 yr

Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).

Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.

At a glance

Generic name	GSK4428859A
Also known as	belrestotug, EOS884448
Sponsor	GlaxoSmithKline
Modality	Small molecule
Phase	Phase 2

Approved indications

No approved indications tracked.

Common side effects

No common side effects on file.

Key clinical trials

• First-Time-in-Human Study of GSK4381562 in Participants With Advanced Solid Tumors (PHASE1)
• A Platform Study of Novel Immunotherapy Combinations in Participants With Previously Untreated, Advanced/Metastatic Non-Small-Cell Lung Cancer (PHASE2)
• Study of the Safety and Effectiveness of GSK6097608 in Participants With Advanced Solid Tumors (PHASE1)
• A Study of Belrestotug Plus Dostarlimab Compared With Placebo Plus Pembrolizumab in Previously Untreated Participants With Programmed Death Ligand 1 (PD-L1) High Non-small-cell Lung Cancer (NSCLC) (PHASE3)
• Platform Trial of Novel Regimens Versus Standard of Care (SoC) in Participants With Non-small Cell Lung Cancer (NSCLC) (PHASE2)
• Study of Novel Regimens in Relapsed or Refractory Multiple Myeloma (PHASE1)
• Study of EOS-448 With Standard of Care and/or Investigational Therapies in Participants With Advanced Solid Tumors (PHASE1, PHASE2)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Source	Used for
ClinicalTrials.gov	Trial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• GSK4428859A CI brief — competitive landscape report
• GSK4428859A updates RSS · CI watch RSS
• GlaxoSmithKline portfolio CI

Frequently asked questions about GSK4428859A

What is GSK4428859A?

GSK4428859A is a Small molecule drug developed by GlaxoSmithKline.

Who makes GSK4428859A?

GSK4428859A is developed by GlaxoSmithKline (see full GlaxoSmithKline pipeline at /company/gsk).

Is GSK4428859A also known as anything else?

GSK4428859A is also known as belrestotug, EOS884448.

What development phase is GSK4428859A in?

GSK4428859A is in Phase 2.

Related

• Manufacturer: GlaxoSmithKline — full pipeline
• Also known as: belrestotug, EOS884448