# PBD dimer (SG3199 / tesirine)

Source: https://onco.cc/terms/pbd-sg3199/  
OnCo record `pbd-sg3199` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The PBD dimer SG3199 crosslinks DNA in the minor groove without distorting it, so cells fail to detect the damage; it kills at picomolar concentrations, so ADCs need only a low drug-to-antibody ratio. Fluid retention, skin reactions and light sensitivity stopped several programmes; loncastuximab tesirine in large B-cell lymphoma is the approved example.

## Summary

Pyrrolobenzodiazepine dimers bind in the minor groove and crosslink DNA without distorting it, so cells struggle to detect and repair the damage. Potency is picomolar, allowing low drug-to-antibody ratios. Fluid retention, skin reactions and light sensitivity are characteristic, and several PBD programmes were stopped for toxicity (for example vadastuximab talirine). Loncastuximab tesirine in large B-cell lymphoma is the successful case.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: pyrrolobenzodiazepine dimer; tesirine payload; SG3199

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Pyrrolobenzodiazepine
- Wikipedia: https://en.wikipedia.org/wiki/Pyrrolobenzodiazepine

## Connected records

- technologies: [Antibody-drug conjugate (ADC)](https://onco.cc/technologies/adc/)
- drugs: [Loncastuximab tesirine](https://onco.cc/drugs/zynlonta/)
- terms: [DNA crosslinker payloads (PBD dimers)](https://onco.cc/terms/pbd-dimer-payloads/), [Payload (ADC)](https://onco.cc/terms/payload/), [Val-Ala dipeptide](https://onco.cc/terms/val-ala/)

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JSON: https://onco.cc/api/v1/entities/pbd-sg3199.json