# Synthetic hypericin

Source: https://onco.cc/drugs/hypericin-sgx301/  
OnCo record `hypericin-sgx301` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

HyBryte is an ointment containing synthetic hypericin, the active pigment of St John's wort. Rubbed on patches of cutaneous T-cell lymphoma and switched on with ordinary visible light, it kills the lymphoma cells in the skin without ultraviolet light.

## Summary

Synthetic hypericin (SGX301, HyBryte) is Soligenix's photodynamic therapy for early-stage cutaneous T-cell lymphoma (mycosis fungoides). The ointment is applied to lesions and, after a delay, the area is exposed to visible fluorescent light twice a week. Because activation uses visible rather than ultraviolet light, the treatment avoids the skin-cancer and ageing risks of long-term PUVA and narrow-band UVB.

The phase 3 FLASH trial reported in 2020 that significantly more patients had a treatment response after the first 6-week cycle than with placebo ointment, and responses increased with longer treatment. The FDA asked for a second confirmatory study before approval, and the confirmatory FLASH2 trial is under way. The cutaneous T-cell lymphoma page names it as the skin-directed treatment closest to approval.

## Fields

- Kind: Treatment
- Status: phase-3
- Last checked: 2026-09-17
- Also known as: Hypericin; SGX301; Hypericin ointment
- Tags: subtype-drugs-wave
- Brand: HyBryte
- Code: SGX301
- Modality: Topical photosensitiser activated by visible light
- Mechanism: Hypericin, the pigment of St John's wort made synthetically, is applied to skin lesions and taken up by malignant T cells; visible light then activates it to generate reactive oxygen that kills the cells, without the ultraviolet exposure of PUVA.

## Sources

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

## Connected records

- cancers: [Cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome)](https://onco.cc/cancers/cutaneous-t-cell-lymphoma/)
- technologies: [Photodynamic therapy lasers and light sources](https://onco.cc/technologies/photodynamic-therapy-lasers/)
- companies: [Soligenix](https://onco.cc/companies/soligenix/)

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