Pharmacodynamic assessments
The effect of dersimelagon treatment on pigmentation was assessed in all participants in Part A by measuring melanin density on three skin segments (lower back, forehead, and cheek) by spectrophotometry (Konica Minolta Spectrophotometry) prior to dersimelagon administration and at days 3, 5, and 15 following a single oral dose of dersimelagon. In Part E, melanin density was measured prior to dersimelagon administration and at days 3, 5, 7, 10, 15, 22, 29, and 57 by spectrophotometry on the lower back, forehead, cheek, neck, inner upper arm, and outer forearm. The melanin density was calculated according to the following formula: