{"entity":{"id":"dm4","kind":"term","name":"DM4","aka":["ravtansine","soravtansine payload","ravtansine, soravtansine"],"tldr":"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.","asOf":"2026-09-09","wikipedia":"https://en.wikipedia.org/wiki/Ravtansine","links":[{"label":"Semisynthetic maytansine analogues incl. DM4 (Widdison et al., J Med Chem 2006)","url":"https://doi.org/10.1021/jm060319f"}],"tags":[],"related":["bystander-effect"],"cancers":[],"sections":[],"technologies":["adc"],"targets":[],"drugs":["mirvetuximab-soravtansine"],"companies":[],"institutions":[],"pathways":[],"terms":["payload","tubulin-inhibitor-payloads"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":["paper-widdison-j-med-chem"],"journals":[],"dependsOn":[],"notes":[],"category":"ADC chemistry"},"route":"/terms/dm4/","neighbours":{"term":[{"id":"bystander-effect","kind":"term","name":"Bystander effect (ADC)","route":"/terms/bystander-effect/"},{"id":"payload","kind":"term","name":"Payload (ADC)","route":"/terms/payload/"},{"id":"sulfo-spdb","kind":"term","name":"Sulfo-SPDB (disulfide)","route":"/terms/sulfo-spdb/"},{"id":"tubulin-inhibitor-payloads","kind":"term","name":"Tubulin inhibitor payloads","route":"/terms/tubulin-inhibitor-payloads/"}],"technology":[{"id":"adc","kind":"technology","name":"Antibody-drug conjugate (ADC)","route":"/technologies/adc/"}],"drug":[{"id":"mirvetuximab-soravtansine","kind":"drug","name":"Mirvetuximab soravtansine","route":"/drugs/mirvetuximab-soravtansine/"}],"paper":[{"id":"paper-widdison-j-med-chem","kind":"paper","name":"Semisynthetic maytansine analogues for the targeted treatment of cancer","route":"/key-papers/paper-widdison-j-med-chem/"}],"pathway":[{"id":"mitotic-spindle-checkpoint","kind":"pathway","name":"Mitosis & the spindle assembly checkpoint","route":"/pathways/mitotic-spindle-checkpoint/"}]}}