Name: Dersimelagon (MT-7117) in Erythropoietic protoporphyria or X-linked protoporphyria: Heterogeneity of treatment effect
Published: 2026-09-21T21:42:40-04:00

Product information and disease description Place of product in therapy Approaches to treatment

Heterogeneity of treatment effect

5 evidence topics · 5 sources

Protoporphyrin concentration as a marker of disease severity

“Higher ePPIX levels were associated with earlier age of symptom onset (median ePPIX levels for those who developed symptoms before vs after 1 year of age, 1744 vs 1567 µg/dL; P = .02), less sun tolerance (median ePPIX levels for those reporting symptoms before vs after 10 minutes of sun exposure, 2233 vs 1524 µg/dL; P ≤ .001), and increased risk of liver dysfunction (median ePPIX levels for those with liver dysfunction vs normal liver function, 2016 vs 1510 µg/dL; P = .003).” (opens the source at this quote in a new tab)
“Male patients with XLP had significantly higher ePPIX levels, on average, than did patients with EPP (3574 vs 1669 µg/dL; P < .001). Marked clinical variability was seen in female patients with XLP owing to random X-chromosomal inactivation.” (opens the source at this quote in a new tab)

Greater effect in participants with higher baseline protoporphyrin in the phase 2 trial

“The post-hoc subgroup analysis evaluating the effects of baseline ePPIX levels in subjects grouped based on the baseline median ePPIX level of 1981 µg/dL. There was a statistically significant increase in average daily time to first prodromal symptom in the subgroup with ePPIX levels ≥1981 µg/dL receiving 100 mg (p=0.020) and 300 mg (p=0.003) compared to placebo. A trend to beneficial effect was also observed for the subgroup of subjects with ePPIX levels <1981 µg/dL receiving 100 mg (p=0.180) and 300 mg (p=0.216) compared to placebo.” (opens the source at this quote in a new tab)

Variability of severity in females with X-linked protoporphyria

“Because of the possibility of skewed X-inactivation, disease severity in females can vary from mild to as severe as XLP males.” (opens the source at this quote in a new tab)

Limits of protoporphyrin concentration for stratification

“blood PPIX concentrations also cannot be used to stratify EPP trial populations regarding disease severity and, vice versa, do not demonstrate a representative inclusion of trial participants.” (opens the source at this quote in a new tab)

Variability in response to the approved comparator

“Individual PBPF increased 1.8- to 180-fold (full range, median 15).” (opens the source at this quote in a new tab)