Last reviewed 2026-06-02 · How we verify

AT13387 and Imatinib

Astex Pharmaceuticals, Inc. · Phase 2 active Small molecule ✓ Verified Jun 2026

AT13387 and Imatinib is a tyrosine kinase inhibitor Small molecule drug developed by Astex Pharmaceuticals, Inc.. It is currently in Phase 2 development for Chronic myeloid leukemia (CML), Acute lymphoblastic leukemia (ALL), Gastrointestinal stromal tumors (GIST). Also known as: Gleevec.

AT13387 is a potent and selective inhibitor of the B-Raf V600E kinase, while Imatinib is a tyrosine kinase inhibitor targeting BCR-ABL, c-Kit, and PDGFR.

AT13387 is a medication being studied in combination with Imatinib for the treatment of Gastrointestinal Stromal Tumor (GIST). Imatinib is a medication used to treat GIST, and it is being used in combination with AT13387 in a clinical trial to investigate its safety and efficacy.

Likelihood of approval

13.3% 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).
Oncology Phase 2 attrition -2.0pp
Oncology drugs have higher Phase 2-to-Phase 3 attrition than average — many fail to show OS benefit in larger studies.

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	AT13387 and Imatinib
Also known as	Gleevec
Sponsor	Astex Pharmaceuticals, Inc.
Drug class	tyrosine kinase inhibitor
Target	B-Raf V600E kinase, BCR-ABL, c-Kit, PDGFR
Modality	Small molecule
Therapeutic area	Oncology
Phase	Phase 2

Mechanism of action

AT13387 works by selectively binding to the B-Raf V600E kinase, thereby inhibiting its activity and potentially leading to cancer cell death. Imatinib, on the other hand, targets multiple tyrosine kinases, including BCR-ABL, c-Kit, and PDGFR, which are involved in the proliferation and survival of cancer cells.

Approved indications

Chronic myeloid leukemia (CML), Acute lymphoblastic leukemia (ALL)
Gastrointestinal stromal tumors (GIST)

Common side effects

Myelosuppression
Nausea
Diarrhea
Rash

Key clinical trials

A Study to Investigate the Safety and Efficacy of AT13387, Alone or in Combination With Imatinib, in Patients With GIST (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:

AT13387 and Imatinib CI brief — competitive landscape report
AT13387 and Imatinib updates RSS · CI watch RSS
Astex Pharmaceuticals, Inc. portfolio CI

Frequently asked questions about AT13387 and Imatinib

What is AT13387 and Imatinib?

AT13387 and Imatinib is a tyrosine kinase inhibitor drug developed by Astex Pharmaceuticals, Inc., indicated for Chronic myeloid leukemia (CML), Acute lymphoblastic leukemia (ALL), Gastrointestinal stromal tumors (GIST).

How does AT13387 and Imatinib work?

AT13387 is a potent and selective inhibitor of the B-Raf V600E kinase, while Imatinib is a tyrosine kinase inhibitor targeting BCR-ABL, c-Kit, and PDGFR.

What is AT13387 and Imatinib used for?

AT13387 and Imatinib is indicated for Chronic myeloid leukemia (CML), Acute lymphoblastic leukemia (ALL), Gastrointestinal stromal tumors (GIST).

Who makes AT13387 and Imatinib?

AT13387 and Imatinib is developed by Astex Pharmaceuticals, Inc. (see full Astex Pharmaceuticals, Inc. pipeline at /company/astex-pharmaceuticals-inc).

Is AT13387 and Imatinib also known as anything else?

AT13387 and Imatinib is also known as Gleevec.

What drug class is AT13387 and Imatinib in?

AT13387 and Imatinib belongs to the tyrosine kinase inhibitor class. See all tyrosine kinase inhibitor drugs at /class/tyrosine-kinase-inhibitor.

What development phase is AT13387 and Imatinib in?

AT13387 and Imatinib is in Phase 2.

What are the side effects of AT13387 and Imatinib?

Common side effects of AT13387 and Imatinib include Myelosuppression, Nausea, Diarrhea, Rash.

What does AT13387 and Imatinib target?

AT13387 and Imatinib targets B-Raf V600E kinase, BCR-ABL, c-Kit, PDGFR and is a tyrosine kinase inhibitor.

Drug class: All tyrosine kinase inhibitor drugs
Target: All drugs targeting B-Raf V600E kinase, BCR-ABL, c-Kit, PDGFR
Manufacturer: Astex Pharmaceuticals, Inc. — full pipeline
Therapeutic area: All drugs in Oncology
Indication: Drugs for Chronic myeloid leukemia (CML), Acute lymphoblastic leukemia (ALL)
Indication: Drugs for Gastrointestinal stromal tumors (GIST)
Also known as: Gleevec

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