Table 1.

Novel and repurposed treatments for EPP and XLP

Medication	Mechanism of action	Manufacturer	Development stage
Afamelanotide	α-MSH analog	Clinuvel	FDA approved
Dersimelagon	Selective melanocortin-1 receptor agonist	Mitsubishi Tanabe	Phase 3 clinical trial
Cimetidine	Inhibition of ALAS	Generic	Phase 2 clinical trial
Bitopertin	Selective glycine transport inhibitor	Disc Medicine	Phase 2 clinical trial
—	ABCG2 transporter inhibitor	—	Animal models
—	Antisense oligonucleotide therapy	—	Animal models

α-MSH, α-melanocyte stimulating hormone; FDA, US Food and Drug Administration.