# DM4

Source: https://onco.cc/terms/dm4/  
OnCo record `dm4` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

DM4 is a maytansinoid payload released in a form that can cross membranes, giving mirvetuximab soravtansine a bystander effect that DM1 lacks.

## Summary

DM4 (ravtansine or soravtansine) is attached through a hindered disulfide linker (sulfo-SPDB). After cleavage the payload is S-methylated inside the cell into a neutral, permeable form, so it can diffuse into neighbouring cells. Ocular toxicity (keratopathy, blurred vision) is the dose-limiting effect and is managed with steroid eye drops.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: ravtansine; soravtansine payload; ravtansine, soravtansine

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Ravtansine
- Semisynthetic maytansine analogues incl. DM4 (Widdison et al., J Med Chem 2006): https://doi.org/10.1021/jm060319f

## Connected records

- terms: [Bystander effect (ADC)](https://onco.cc/terms/bystander-effect/), [Payload (ADC)](https://onco.cc/terms/payload/), [Sulfo-SPDB (disulfide)](https://onco.cc/terms/sulfo-spdb/), [Tubulin inhibitor payloads](https://onco.cc/terms/tubulin-inhibitor-payloads/)
- technologies: [Antibody-drug conjugate (ADC)](https://onco.cc/technologies/adc/)
- drugs: [Mirvetuximab soravtansine](https://onco.cc/drugs/mirvetuximab-soravtansine/)
- key papers: [Semisynthetic maytansine analogues for the targeted treatment of cancer](https://onco.cc/key-papers/paper-widdison-j-med-chem/)
- pathways: [Mitosis & the spindle assembly checkpoint](https://onco.cc/pathways/mitotic-spindle-checkpoint/)

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JSON: https://onco.cc/api/v1/entities/dm4.json