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Context, anatomy, and key evidence

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proteasome inhibitor

Bortezomib

Published evidence · coverage incomplete
Anatomical contextAnatomy connections are not mapped yet.

No body region is highlighted until this profile has a supported anatomical connection. This does not mean the peptide has no biological effects.

Read published mechanism findings ↓

At a glance

What is it—and why does it matter?

In the marketed product Velcade, bortezomib is present in the form of a mannitol boronic ester. Bortezomib acts as a reversible inhibitor of the chymotrypsin-like proteolytic activity within the 26S proteasome. At 6 months, 27% had hematologic complete response with bortezomib/dexamethasone (BD), compared with 57% with the daratumumab-based regimen. Following oral dosing (po) in CD1 mice at 4 mg/kg, systemic exposure relative to IV (oral bioavailability, F) is reported as 11.0%.

Sources for this introduction: [1] [2] [3] [4]

This published profile is a reference in progress. Findings retain their source context; missing topics are marked below.

What is it?

A molecule, not a product name.

Identity

In the marketed product Velcade, bortezomib is present in the form of a mannitol boronic ester.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    The marketed drug Velcade, contains bortezomib as the mannitol boronic ester.

    IUPHAR ligand commentary · Clinical use

    iuphar-comments:6391:e48dbe41dd3d:e48dbe41dd3d

How does it work?

Target, response, and disposition.

Mechanism

The LC-MS/MS detection used high-resolution multiple reaction monitoring (MRM) with positive-mode electrospray ionization and 4 min total acquisition time per run.

Reported result
4 min per run
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Bortezomib and its internal standard were detected using high-resolution MRM in positive-mode electrospray ionization, with a total acquisition time of 4 min per run.

    A fast method for the quantification of bortezomib in serum and rat nervous tissue by liquid chromatography tandem mass spectrometry. · Abstract

    pubmed:42526316:6cbc59cf7e3d:6cbc59cf7e3d

Mechanism

The validated analytical calibration range for bortezomib in rat serum was 0.920-100 ng/mL.

Reported result
0.920-100 ng/mL
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Calibration ranges were 0.920-100 ng/mL for serum

    A fast method for the quantification of bortezomib in serum and rat nervous tissue by liquid chromatography tandem mass spectrometry. · Abstract

    pubmed:42526316:6cbc59cf7e3d:6cbc59cf7e3d

Mechanism

This Ki value reflects binding/inhibition in an isolated protein assay and does not indicate in vivo selectivity or effect.

Reported result
Ki = 2300.0 nM
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Molecule: CHEMBL325041 Target: Neutrophil elastase (CHEMBL248) Assay: Inhibitory activity against human leukocyte elastase Assay format: single protein format Standard result: Ki = 2300.0 nM pChEMBL value: 5.64 Document: CHEMBL1130744

    ChEMBL activities for CHEMBL325041 · Activity 89209

    chembl-activities:chembl325041:7ec28ddb226b:7ec28ddb226b

Mechanism

In a single-protein assay, bortezomib inhibited human cathepsin G with Ki = 630.0 nM.

Reported result
Ki = 630.0 nM
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Molecule: CHEMBL325041 Target: Cathepsin G (CHEMBL4071) Assay: Inhibitory activity against human cathepsin G Assay format: single protein format Standard result: Ki = 630.0 nM pChEMBL value: 6.20 Document: CHEMBL1130744

    ChEMBL activities for CHEMBL325041 · Activity 89210

    chembl-activities:chembl325041:7ec28ddb226b:7ec28ddb226b

Mechanism

Bortezomib acts as a reversible inhibitor of the chymotrypsin-like proteolytic activity within the 26S proteasome.

Source records
2
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Bortezomib is a reversible inhibitor of the chymotrypsin-like activity of the 26S proteasome.

    IUPHAR ligand commentary · Mechanism of action

    iuphar-comments:6391:e48dbe41dd3d:e48dbe41dd3d
  2. supports · Source-backed record
    Bortezomib is a reversible inhibitor of the chymotrypsin-like activity of the 26S proteasome.

    IUPHAR ligand commentary · Mechanism of action

    iuphar-comments:6391:e48dbe41dd3d:e48dbe41dd3d

Mechanism

The analytical calibration range for bortezomib in rat nervous tissue was 4.00-100 ng/g.

Reported result
4.00-100 ng/g
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    and 4.00-100 ng/g for nervous tissue.

    A fast method for the quantification of bortezomib in serum and rat nervous tissue by liquid chromatography tandem mass spectrometry. · Abstract

    pubmed:42526316:6cbc59cf7e3d:6cbc59cf7e3d

Mechanism

The study’s analytical objective was LC-MS/MS quantification of bortezomib in two rat matrices: serum and sciatic nervous tissue.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    The aim of this study was to develop and validate LC-MS/MS methods for the quantification of bortezomib in rat serum and rat sciatic nervous tissue.

    A fast method for the quantification of bortezomib in serum and rat nervous tissue by liquid chromatography tandem mass spectrometry. · Abstract

    pubmed:42526316:6cbc59cf7e3d:6cbc59cf7e3d

Mechanism

Detection used high-resolution MRM with positive-mode electrospray ionization and took 4 min per run.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Bortezomib and its internal standard were detected using high-resolution MRM in positive-mode electrospray ionization, with a total acquisition time of 4 min per run.

    A fast method for the quantification of bortezomib in serum and rat nervous tissue by liquid chromatography tandem mass spectrometry. · Abstract

    pubmed:42526316:6cbc59cf7e3d:6cbc59cf7e3d

Mechanism

The study aimed to create and validate LC‑MS/MS tests to measure bortezomib in rat serum and rat sciatic nerve tissue.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    The aim of this study was to develop and validate LC-MS/MS methods for the quantification of bortezomib in rat serum and rat sciatic nervous tissue.

    A fast method for the quantification of bortezomib in serum and rat nervous tissue by liquid chromatography tandem mass spectrometry. · Abstract

    pubmed:42526316:6cbc59cf7e3d:6cbc59cf7e3d

Pharmacokinetics

A cell-free plasma protein binding assay reports that bortezomib is 84.1% plasma-protein-bound (PPB) in human plasma.

Reported result
PPB = 84.1 %
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Molecule: CHEMBL325041 Target: Plasma (CHEMBL613652) Assay: Protein binding in human plasma Assay format: cell-free format Standard result: PPB = 84.1 % Document: CHEMBL1141651

    ChEMBL activities for CHEMBL325041 · Activity 2104943

    chembl-activities:chembl325041:7ec28ddb226b:7ec28ddb226b

Pharmacokinetics

Bortezomib undergoes primary oxidative metabolism through multiple CYP450 isoenzymes (3A4, 2D6, 2C19, 2C9, 1A2), and deboronation yields metabolites that are inactive as 26S proteasome inhibitors.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Bortezomib is primarily oxidatively metabolized via cytochrome P450 enzymes, 3A4, 2D6, 2C19, 2C9, and 1A2. Deboronated metabolites are inactive as 26S proteasome inhibitors.

    IUPHAR ligand commentary · Metabolism

    iuphar-comments:6391:e48dbe41dd3d:e48dbe41dd3d

Pharmacokinetics

In CD1 mouse given 0.8 mg/kg iv, bortezomib AUC (0 to infinity) was 927.0 ng.hr.mL-1.

Reported result
AUC = 927.0 ng.hr.mL-1
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Molecule: CHEMBL325041 Target: Mus musculus (CHEMBL375) Assay: AUC (0 to infinity) in CD1 mouse at 0.8 mg/kg, iv Assay format: organism-based format Standard result: AUC = 927.0 ng.hr.mL-1 Document: CHEMBL1141651

    ChEMBL activities for CHEMBL325041 · Activity 2104822

    chembl-activities:chembl325041:7ec28ddb226b:7ec28ddb226b

Pharmacokinetics

Following oral dosing (po) in CD1 mice at 4 mg/kg, systemic exposure relative to IV (oral bioavailability, F) is reported as 11.0%.

Reported result
F = 11.0 %
Source records
2
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Molecule: CHEMBL325041 Target: Mus musculus (CHEMBL375) Assay: Oral bioavailability in CD1 mouse at 4 mg/kg Assay format: organism-based format Standard result: F = 11.0 % Document: CHEMBL1141651

    ChEMBL activities for CHEMBL325041 · Activity 2104829

    chembl-activities:chembl325041:7ec28ddb226b:7ec28ddb226b
  2. supports · Source-backed record
    Molecule: CHEMBL325041 Target: Mus musculus (CHEMBL375) Assay: Oral bioavailability in CD1 mouse at 4 mg/kg Assay format: organism-based format Standard result: F = 11.0 % Document: CHEMBL1141651

    ChEMBL activities for CHEMBL325041 · Activity 2104829

    chembl-activities:chembl325041:7ec28ddb226b:7ec28ddb226b

What has been studied?

What the evidence says.

Comparative evidence

A real-world comparative study evaluated outcomes in newly diagnosed AL amyloidosis by comparing a daratumumab-based regimen against the bortezomib/dexamethasone (BD) regimen.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    This real-world study compared the efficacy and safety of a frequency-adjusted, cyclophosphamide-free Dara-based regimen with bortezomib/dexamethasone (BD).

    Frequency-adjusted daratumumab-based regimen versus bortezomib/dexamethasone in newly diagnosed AL amyloidosis: a matched-cohort study. · BACKGROUND

    pubmed:41560662:5b6283e7767e:5b6283e7767e

Comparative evidence

The quote gives 12-month CR rates and a p-value in a propensity score–matched analysis; it does not provide absolute numbers of responders or adjustment beyond matching.

Reported result
27% (BD) vs 63% (Dara-based); p= 0.002
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    and 12 months (63% vs. 27%,p= 0.002)

    Frequency-adjusted daratumumab-based regimen versus bortezomib/dexamethasone in newly diagnosed AL amyloidosis: a matched-cohort study. · RESULTS

    pubmed:41560662:5b6283e7767e:5b6283e7767e

Comparative evidence

For multiple myeloma therapy, bortezomib is commonly used in combination regimens with other therapeutic agents.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Combinations of bortezomib (BTZ) with other therapeutic agents remain the mainstay of MM treatment.

    Triptonide enhances DNA damage by inhibiting TRIP13‑mediated DNA repair and synergizes with bortezomib to suppress multiple myeloma. · Abstract

    pubmed:42464653:49dd52e3aaad:49dd52e3aaad

Comparative evidence

Time-to-CR is reported as a median with a p-value in matched cohorts; the quote does not specify censoring rules for this endpoint.

Reported result
120 days (BD) vs 61 days (Dara-based); p= 0.010
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    with a markedly shorter median time to CR (61 vs. 120 days,p= 0.010).

    Frequency-adjusted daratumumab-based regimen versus bortezomib/dexamethasone in newly diagnosed AL amyloidosis: a matched-cohort study. · RESULTS

    pubmed:41560662:5b6283e7767e:5b6283e7767e

Comparative evidence

At 6 months, 27% had hematologic complete response with bortezomib/dexamethasone (BD), compared with 57% with the daratumumab-based regimen.

Reported result
27% (BD) vs 57% (Dara-based); p= 0.018
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    The Dara-based group achieved significantly higher hematologic complete response (CR) rates at 6 months (57% vs. 27%,p= 0.018)

    Frequency-adjusted daratumumab-based regimen versus bortezomib/dexamethasone in newly diagnosed AL amyloidosis: a matched-cohort study. · RESULTS

    pubmed:41560662:5b6283e7767e:5b6283e7767e

Study findings

In a single-protein enzyme assay, bortezomib produces 96.0% inhibition of human cathepsin G when tested at 10 uM.

Reported result
Inhibition = 96.0 %
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Molecule: CHEMBL325041 Target: Cathepsin G (CHEMBL4071) Assay: Inhibition of human cathepsin G at 10 uM Assay format: single protein format Standard result: Inhibition = 96.0 % Document: CHEMBL1141651

    ChEMBL activities for CHEMBL325041 · Activity 2104880

    chembl-activities:chembl325041:7ec28ddb226b:7ec28ddb226b

Study findings

Cell-line cytotoxicity (IC50) does not directly predict efficacy or safety in humans.

Reported result
IC50 = 1.7 nM
Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Molecule: CHEMBL325041 Target: A2780 (CHEMBL614004) Assay: Cytotoxicity against human A2780 cells Assay format: cell-based format Standard result: IC50 = 1.7 nM pChEMBL value: 8.77 Document: CHEMBL1141651

    ChEMBL activities for CHEMBL325041 · Activity 2104801

    chembl-activities:chembl325041:7ec28ddb226b:7ec28ddb226b

Study findings

Bortezomib has demonstrated inhibition of the chymotrypsin-like (β5) proteolytic activity within the human 26S proteasome.

Source records
1
Independent studies
1

Evidence boundary: Applies only to the source-defined population, formulation, dose, and assessment period.

Exact passages, locators, and provenance
  1. supports · Source-backed record
    Bortezomib has been shown to inhibit the chymotrypsin-like ( aka β5) activity of the human 26S proteasome [Reference 22349].

    IUPHAR ligand commentary · Bioactivity

    iuphar-comments:6391:e48dbe41dd3d:e48dbe41dd3d

Risks and interactions

Risks, organized for scanning.

This profile does not yet contain a published summary for this topic. This is a coverage gap, not evidence that no research exists.

Products and regulatory status

Same ingredient. Different records.

This profile does not yet contain a published summary for this topic. This is a coverage gap, not evidence that no research exists.

Administration context

The practical clinical context.

This profile does not yet contain a published summary for this topic. This is a coverage gap, not evidence that no research exists.

Research status + gaps

What still needs better answers?

  • No publishable claim yet for: administration, contraindication, interaction, regulatory, safety
  • 163 compiled claim(s) withheld by automated assurance: assurance_score_below_0.58 (104), assurance_score_below_0.72 (54), current_regulatory_source_required (33), extraction_ambiguity (105), extraction_confidence_not_high (1), high_risk_requires_regulatory_or_two_independent_sources (54), no_direct_support (156), proposal_not_staged (3)

These are the limits of this profile, not an exhaustive list of scientific uncertainties.

References + discovery

Open the records yourself.

  1. ChEMBL activities for CHEMBL325041

    chembl-activities · published 2026-08-25 · retrieved 2026-08-25T22:58:23Z

  2. IUPHAR ligand commentary

    iuphar-comments · published 2026-08-25 · retrieved 2026-08-25T22:58:23Z

  3. Frequency-adjusted daratumumab-based regimen versus bortezomib/dexamethasone in newly diagnosed AL amyloidosis: a matched-cohort study.

    pubmed · published 2026-12-01 · retrieved 2026-08-25T22:58:23Z

  4. Triptonide enhances DNA damage by inhibiting TRIP13‑mediated DNA repair and synergizes with bortezomib to suppress multiple myeloma.

    pubmed · published 2026-09-01 · retrieved 2026-08-25T22:58:23Z

  5. A fast method for the quantification of bortezomib in serum and rat nervous tissue by liquid chromatography tandem mass spectrometry.

    pubmed · published 2026-12-15 · retrieved 2026-08-25T22:58:23Z

Publication history and provenance

Version 5 · Automated assessment · 2026-08-26T08:42:26Z

273d27382bb4cb85c7634a0f8aae85acaf75b00d20a963cf0739d48172505d53