The European Commission has granted orphan drug designation to synthetic hypericin, the active pharmaceutical ingredient in SGX301, for the treatment of cutaneous T-cell lymphoma (CTCL).
SGX301 is a first-in-class, photodynamic therapy utilizing safe, visible light for activation. Synthetic hypericin is a potent photosensitizer that is topically applied to skin lesions and activated by visible fluorescent light 16 to 24 hours later.
This treatment approach is intended to prevent the secondary malignancies that may occur following chemotherapy or photodynamic therapies that are dependent on ultraviolet exposure.
Combined with photoactivation, hypericin has demonstrated significant antiproliferative effects on activated, normal human lymphoid cells and inhibited the growth of malignant T cells isolated from CTCL patients.
Topical hypericin has also proven safe in a phase 1 study of healthy volunteers.
In a phase 2 trial of patients with CTCL (mycosis fungoides only) or psoriasis, topical hypericin conferred a significant improvement over placebo. Among CTCL patients, the treatment prompted a response rate of 58.3%, compared to an 8.3% response rate for placebo (P≤0.04).
Topical hypericin was also well tolerated in this trial. There were no deaths or serious adverse events related to the treatment. However, there were reports of mild to moderate burning, itching, erythema, and pruritus at the application site.
Soligenix, Inc., the company developing SGX301, is currently working with CTCL centers, the National Organization for Rare Disorders, and the Cutaneous Lymphoma Foundation to begin a 120-subject phase 3 trial of SGX301.
About orphan designation
The European Commission grants orphan designation to medicines designed to treat a life-threatening or chronically debilitating condition that affects no more than 5 in 10,000 persons in the European Union and has no satisfactory treatment available.
In addition to a 10-year period of marketing exclusivity after product approval, orphan drug designation provides incentives for companies seeking protocol assistance from the European Medicines Agency during the product development phase, as well as direct access to the centralized authorization procedure.
SGX301 has both orphan designation and fast track designation from the US Food and Drug Administration for the first-line treatment of CTCL.
