SGX301 Demonstrates Positive Benefits for Cutaneous T-Cell Lymphoma

The Fluorescent Light Activated Synthetic Hypericin (FLASH) study examining SGX301 (synthetic hypericin) to treat patients with cutaneous t-cell lymphoma (CTCL) improved responses for patients and maintained a tolerable safety profile, according to Soligenix.

The data suggests that SGX301 remained tolerable for patients as the lack of hypericin circulation in the blood stream after topical application to lesions and the use of visible light benefited the patients.

"Along with SGX301's rapid response time and safety profile, the patch and plaque data from the study are extremely compelling," Brian Poligone, MD, PhD, lead enrolling investigator in the FLASH study, said in a press release. "Current treatments for CTCL are generally less effective against plaques and deeper lesions, very similar to the problem observed in psoriasis.”

Cycle 3 of the study found that SGX301 treatment further improved response rates, with 49% of patients receiving the treatment for 18 weeks showing a 50% or greater reduction in their combined Composite Assessment of Index Lesion Score (CAILS). This number is compared favorably to 40% of patients showing the same reduction after 12 weeks of treatment in cycle 2 of the study (P = 0.046).

More, continued analysis of cycles 1 and 2 of the study found that 12 weeks of treatment with SGX301 was equally effective on both patch ( 37%; P = 0.0009) and plaque (42%; P < .0001) lesions when compared to the cycle 1 placebo responses.

“The ability of SGX301 to target both patches and thicker plaques in CTCL is an important feature for this therapy and, if approved, will be of benefit to patients, regardless of their presentation,” said Poligone. “These results are consistent with the positive findings highlighted in a recently reported case study of folliculotropic mycosis fungoides, a hard to treat variant of CTCL where lesions are associated with the hair follicles deep in the skin and more resistant to phototherapy."

Cycle 3 of the study was specifically designed as a compassionate use, optional, cycle in which patents had the option to continue SGX301 treatment for 6 more weeks. Of the total study cohort of 169 patients, 66% chose to continue treatment. Similar to the previous cycles before it, the findings in cycle 3 were statistically significant in regard to the response of individual lesions.

More, there was no synthetic hypericin detected in the blood stream of patients, which helped to minimize concerns for drug effects outside of the tumor area. Overall, the researchers report that the safety profile is tolerable, which sits in contrast with existing second-line and off-label therapies for CTCL.

“These results continue to strengthen our long-standing belief that SGX301 has the potential to be a valuable and life-changing therapy for patients suffering from CTCL, which is an orphan disease and area of unmet medical need," Christopher J. Schaber, PhD, president and chief executive officer of Soligenix, said in a press release. "With the study now concluding, we continue to thoroughly assess commercialization and/or partnership of SGX301 while in parallel preparing for filing the New Drug Application with FDA.”

Reference:

Soligenix Announces Phase 3 FLASH Study Continues to Demonstrate Positive Benefits in Patients with Cutaneous T-Cell Lymphoma [news release]. Princeton, New Jersey. Published October 22, 2020. https://www.prnewswire.com/news-releases/soligenix-announces-phase-3-flash-study-continues-to-demonstrate-positive-benefits-in-patients-with-cutaneous-t-cell-lymphoma-301157831.html. Accessed October 22, 2020.