New Data Available on SGX301 for CTCL, Mycosis Fungoides

From April 23-25, 2021, the American Academy of Dermatology (AAD) held its Virtual Meeting Experience (AAD VMX 2021). During the event, over 75 meetings discussed various research and other insights within the field of dermatology. According to Dermatology Times, one session consisted of Professor Ellen Kim discussing results from the Phase 3 FLASH clinical trial. Results from the trial, which evaluated SGX301 (synthetic hypericin ointment 0.25%) for patients with cutaneous T-cell lymphoma (CTCL), and in particular, mycosis fungoides, are available below.


During the clinical trial, researchers evaluated the safety, efficacy, and tolerability of SGX301 for patients with plaque or patch phase CTCL. According to Solgenix, SGX301 is:

a photodynamic therapy using synthetically manufactured hypericin in an ointment combined with visible fluorescent light. Synthetic hypericin, the active ingredient in SGX301, tends to accumulate in T-cells [where] it can be activated by safe, visible fluorescent light.

Following activation, SGX301 produces oxygen radicals. As Solgenix continues to explain, these radicals:

subsequently cause cellular toxicity, killing the targeted T-cells.

While there are currently treatments available for patients with CTCL, these are not always effective. For example, the current standard of care could consist of phototherapy, chemotherapy, or topical corticosteroids. But many patients require multiple treatment options. Additionally, these treatments may have detrimental adverse reactions. Thus, finding a new and more effective treatment option is needed.

Within the study, 169 patients enrolled. Patients were at least 18+ and had stage 1A, 1B, or 11A CTCL. During the trial, patients had 3 lesions treated by either SGX301 or a placebo. After the treatment was administered, it remained covered for 18-24 hours. Next, the lesions were treated with photodynamic therapy 2x weekly. Some study findings include:

  • Following the first treatment cycle (6 weeks on, 2 weeks off), 16% of patients treated with SGX301 had some response according to the modified Composite Assessment Index Lesion Severity (mCAILS) score. In the second treatment cycle, response rate rose to 40%. Finally, after the third and final treatment cycle, 49% achieved response.
  • SGX301 was relatively safe and well-tolerated. Adverse reactions (mild-to-moderate) included:
    • Skin burning or irritation
    • Blistering
    • Contact dermatitis
    • Hyperpigmentation
    • Skin redness
    • Itchiness

Altogether, researchers believe additional research is needed to affirm the benefits of SGX301. That being said, researchers also believe SGX301 could provide an advantage to patients with CTCL, and mycosis fungoides, over current therapies.

Cutaneous T-Cell Lymphomas (CTCLs)

Cutaneous T-cell lymphomas (CTCLs) are a group of conditions characterized by abnormal T-cell accumulation in the skin. Normally, T-cells play a role in immune response. But when CTCL forms, T-cells become malignant and attack the skin, causing health issues. There are a variety of CTCLs, including mycosis fungoides, Sézary syndrome, and lymphomatoid papulosis, among others. Typically, mycosis fungoides is considered to be the most common form of CTCL. Symptoms vary depending on which form of CTCL a patient has. While most patients only develop skin-related symptoms, an estimated 10% experience severe complications. Symptoms of CTCL include:

  • Hair loss
  • Inflamed or enlarged lymph nodes
  • Intensely itchy red skin over the entire body
  • Thickened skin on the palms and soles
  • Round patches of itchy or scaly skin
  • Skin lumps that might break open and ulcerate

Mycosis Fungoides

Considered a form of CTCL, mycosis fungoides manifests in the skin. While the skin itself does not become cancerous, the T-cells found in skin lesions often are. An estimated 1 in every 100,000 to 350,000 people is diagnosed with mycosis fungoides each year. Most patients are over 50 years old. Altogether, this condition also impacts males 2x more than females.

Mycosis fungoides is chronic and develops in stages. First, the premycotic phase occurs. During this stage, patients develop a scaly, red rash. Typically, the rash develops in areas of the skin that are not often sun-exposed. While this rash may last for a while, there are usually no associated symptoms.

Next comes Stage I, or the patch stage. In this stage, patients experience:

  • Insomnia
  • Generalized itchiness
  • Itchy pink lesions that appear in patches on the skin
    • Note: This rash often appears on the thighs, butt, breasts, or lower abdominal area.

Then, Stage II is known as the plaque or infiltrating stage. During this stage, lymph nodes become inflamed. Additionally, the small, circular, raised, and purple plaques begin to grow. These plaques may be small bumps or hardened lesions. Either way, they grow and begin to fuse with each other. Next comes Stage III, the fungoid or tumor stage. Not all patients reach this point; some lesions “stabilize” and do not progress any further. But for those that due, bluish or reddish-brown tumors, which may resemble mushrooms, form on the skin. These may ulcerate and cause infections.

Finally, in the later stages, patients may also experience symptoms such as:

  • General malaise
  • Fatigue
  • Anemia (low red blood cell count)
  • Fever
  • Unintended weight loss
  • Difficulty swallowing
  • Chronic cough
  • Eye pain
  • Partial vision loss
  • Enlarged liver and/or spleen
  • Gastrointestinal distress

Learn more about mycosis fungoides.

Jessica Lynn

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.

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