ATC Group: L01XF Retinoids for cancer treatment

Alitretinoin is a naturally-occurring endogenous hormone related to vitamin A, binds to and activates all known intracellular retinoid receptor subtypes (RAR, RAR, RAR, RXR, RXR, RXR). The efficacy of alitretinoin in treating KS lesions may be related to the demonstrated ability of alitretinoin to inhibit the in vitro growth of KS cells.

Bexarotene is a synthetic compound that exerts its biological action through selective binding and activation of the three RXRs: α, β, and γ. Once activated, these receptors function as transcription factors that regulate processes such as cellular differentiation and proliferation, apoptosis, and insulin sensitisation. The exact mechanism of action of bexarotene in the treatment of cutaneous T-cell lymphoma (CTCL) is unknown.

Tretinoin decreases cohesiveness of follicular epithelial cells resulting in decreased microcomedone formation. Additionally, tretinoin stimulates mitotic activity and increased turnover of follicular epithelial cells, causing extrusion of the comedones.