Positive Treatment Response Reinforced With SGX301 in Cutaneous T-Cell Lymphoma

The novel photodynamic therapy for skin lesions, SGX301, improved responses compared with placebo when administered twice daily for 12 weeks in patients with early-stage cutaneous T-cell lymphoma (CTCL), according to results from the pivotal phase III FLASH study announced by Soligenix, Inc. The results are considered statistically significant and a confirmation that SGX301 benefits patients with CTCL.¹

The positive response rate was increased to 40% with SGX301 versus placebo ( P <.0001) in the study population.

"As anticipated, the data continues to become more compelling with extended SGX301 treatment," stated Ellen Kim, MD, director of the Dermatology Clinic, Perelman Center for Advanced Medicine and lead investigator of the FLASH study. "This treatment response is comparable to other, less safe, treatment alternatives, showing a statistically significant response at just 6 weeks, which continues to significantly increase with more treatment. The response rate at 12 weeks is similar to other therapies, some of which patients must take for more than a year. In addition to the efficacy demonstrated, SGX301 remains well tolerated with a unique mechanism of action that is not associated with DNA damage like other currently available therapies."

Topline results from the study were reported in March 2020 and showed statistically significant responses in patients who were treated with SGX301 versus placebo (P = .04) in the Composite Assessment of Index Lesion Score (CAILS) primary end point assessment at 8 weeks for cycle 1. At least a 50% improvement was observed for both cycles. The responses were twice as robust after 12 weeks of SGX301, according to the preliminary assessment of cycle 2. The treatment was also safe and well tolerated in patients. ^1,2

FLASH is a multicenter, randomized, double-blind, placebo-controlled study designed to determine the efficacy of topical SGX301 and fluorescent bulb0light irradiation in patients with CTCL. In the study, patients are randomized 2:1 and receive 0.25% SGX301, which is applied twice per week followed by fluorescent light therapy in cycle 1. Three indexed lesions are treated and then evaluated during cycle 2 and in cycle 3, and all patients have a chance to receive an open-label cycle of active SGX301 for all lesions.¹

Aside from treatment response, the FLASH study is investigating complete response, degree of improvement in 3 treated lesion, duration of response, time to relapse, and safety as secondary end points.

The developer of SGX301 accepts that the toxicity profile will show that it is a safe alternative to available therapies due to the fact that it is not associated with DNA damage. It is also expected that SGX301 will continue to show promise as a treatment for patients with CTCL in the FLASH study.

“We are extremely pleased with the study results, which demonstrate successful continued treatment with SGX301 and reinforces its potential to be a valuable and life-changing new therapy for patients suffering from early-stage CTCL, which is an orphan disease and area of unmet medical need,” said Christopher J. Schaber, PhD, president and chief executive officer of Soligenix.

FLASH is ongoing and has completed enrollment of the 169 patients needed per the trial protocol. To be eligible, patients were required to have a clinical diagnosis of CTCL stage IA, IB or IIA, a minimum of 3 evaluable and discrete lesions. The study excluded individuals who had a history of hypersensitivity to the sun, unhealed sunburn, as well as individuals who had received prior topical steroids for CTCL within 2 weeks, systemic steroids, and similar therapies within 3 weeks, a significant history of systemic immunosuppression due to therapy or infection, and other investigational drugs within 30 days of joining the study.

_References:

_{1. Soligenix announces positive phase 3 FLASH study demonstrates increased efficacy with continued treatment in patients with cutaneous t-cell lymphoma [news release]. Princeton, New Jersey: Soligenix, Inc; April 30, 2020. https://bit.ly/2We9LOb. Accessed April 30, 2020.}

_{2. Soligenix announces positive top-line results for its pivotal phase 3 FLASH trial evaluating sgx301 in treatment of cutaneous t-cell lymphoma [new release]. Princeton, New Jersey: Soligenix, Inc; March 19, 2020. https://bit.ly/2KNCqUZ. Accessed April 30, 2020.}