Last reviewed · How we verify

RTB101

Restorbio Inc. · Phase 2 active Small molecule ✓ Verified May 2026

RTB101 is a Small molecule drug developed by Restorbio Inc.. It is currently in Phase 2 development. Also known as: Dactolisib, BEZ235.

RTB101 is a small molecule inhibitor of the serine/threonine-protein kinase mTOR, which is being studied in a Phase 3 clinical trial to determine its effectiveness in preventing clinically symptomatic respiratory illness in the elderly. RTB101 is also being investigated for its potential to treat respiratory tract infections, COVID-19, and clinically symptomatic respiratory illness.

Likelihood of approval
15.3% 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).
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 nameRTB101
Also known asDactolisib, BEZ235
SponsorRestorbio Inc.
ModalitySmall molecule
PhasePhase 2

Approved indications

No approved indications tracked.

Common side effects

No common side effects on file.

Key clinical trials

Primary sources

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

SourceUsed for
ClinicalTrials.govTrial 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:

Frequently asked questions about RTB101

What is RTB101?

RTB101 is a Small molecule drug developed by Restorbio Inc..

Who makes RTB101?

RTB101 is developed by Restorbio Inc. (see full Restorbio Inc. pipeline at /company/restorbio-inc).

Is RTB101 also known as anything else?

RTB101 is also known as Dactolisib, BEZ235.

What development phase is RTB101 in?

RTB101 is in Phase 2.

Related

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing