Results from the phase II clinical trial of dersimelagon have been published in the New England Journal of Medicine.

The trial was conducted by Mitsubishi Tanabe Pharma and was a randomized, placebo-controlled, phase 2 trial to study how effective and safe dersimelagon is in patients with erythropoietic protoporphyria (EPP) or X-linked protoporphyria (XLP).

The study measured the amount of time before symptoms started with sunlight exposure and how severe the symptoms were.

Patients 18-75 years of age were randomly assigned to either placebo or study drug (at dose of 100mg or 300 mg once-a-day for 16 weeks). The study measured the change from baseline to week 16 in the time to the first signs (prodrome) of symptoms associated with sunlight exposure. Patients recorded
daily sunlight exposure and symptom data in an eDiary. Quality of life and safety were also assessed. 


  • 102 patients (93 EPP & 9 XLP)  
  • 90% completed the treatment period 
  • Time to first symptoms from sunlight exposure increased significantly with study drug 
  • Results also suggest that quality of life improved in patients receiving study as compared with placebo. 
  • Most common adverse events that occurred or worsened during treatment were nausea, freckles, headache, and skin hyperpigmentation. 

At both doses, the study drug (dersimelagon) significantly increased the length of symptom-free sunlight exposure in patients with EPP or XLP. 




3 new sites are now open:

  • BOSTON, MA - Amy Dickey, MD, Porphyria Expert
  • PHILADELPHIA, PA - Manish Thapar, MD, Porphyria Expert
  • SAN FRANCISCO, CA - Dr. Bruce Wang, MD, Porphyria Expert

There are now 9 sites across the US are enrolling participants with EPP in the Phase 2 clinical trial on Bitopertin.

This is a Randomized, Double-blind, Placebo-controlled Study to Evaluate the Safety, Tolerability, Efficacy, and Protoporphyrin IX (PPIX) Concentrations in Participants with EPP.

UPA is working with Disc Medicine to educate patients about the trial and refer to study sites. Email info@porphyria.org, call 1-800-868-1292 or fill out this interest form to be contacted!

The UPA Scientific Advisory Board contributed to a video series highlighting responses to questions regarding porphyria diagnosis, management, and treatment. Access videos HERE.


UP and Coming

You are not alone!

Connecting with others who understand what you're going through is a great way to build a support system and community. UPA is pleased to launch Connect Up small group meetings for patients and caregivers to connect and socialize with others in a safe and inclusive environment. Connect UP groups will be peer-led and offered regularly over Zoom. SIGN UP HERE.

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Resources for



Resources for



Types of Porphyria

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Acute Intermittent Porphyria (AIP)

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Hereditary Coproporphyria (HCP)

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Variegate Porphyria (VP)

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ALAD-Deficiency Porphyria (ADP)

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Porphyria Cutanea Tarda (PCT)

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Erythropoietic Protoporphyria (EPP) and X-Linked Porphyria (XLP)

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Congenital Erythropoietic Porphyria (CEP)

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Hepatoerythro­poietic Porphyria (HEP)

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Who we are

Our Mission

The United Porphyrias Association is committed to improving the quality of life of the porphyria patient community and is relentlessly focused on advancing disease awareness, research, and therapies in all the porphyrias.

Our Vision

A world where patients are free from the pain and challenges of porphyria.

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Member Highlight

Victor Mejias

Erythropoietic Protoporphyria (EPP)

"I was diagnosed at the age of 6 with EPP after my parents noticed that every time I was outside I was experiencing anguishing discomfort. I never fully comprehended my diagnosis until I was able to connect with others. With the help of the UPA, I want to be able to help others live more comfortably with EPP and support the vision of a world where patients are free from the pain and challenges of porphyria. "

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