Interim Results for Hybryte Study

Following 18 weeks of treatment, 75% of patients achieved "Treatment Success," reinforcing HyBryte as a potentially safe and fast-acting therapy for this chronic and underserved cancer.

The IIS is sponsored by Ellen Kim, MD, Director, Penn Cutaneous Lymphoma Program, Vice Chair of Clinical Operations, Dermatology Department, and Professor of Dermatology at the Hospital of the University of Pennsylvania who was a leading enroller in the Phase III FLASH (Fluorescent Light Activated Synthetic Hypericin) study and is the Principal Investigator for the confirmatory Phase III FLASH2 study for the treatment of early-stage CTCL. To date, nine patients have been enrolled and treated with HyBryte over a time period of up to 54 weeks in the IIS, with all data for the Week 18 timepoint now complete. Consistent with the Phase III trials, Treatment Success is predefined as a greater than or equal to 50% improvement in the cumulative mCAILS (modified Composite Assessment of Index Lesion Severity) score compared to Baseline. Of the eight patients who could be evaluated through Week 18, six (75%) had a Treatment Success. The 18-week treatment window is the same window that is being evaluated in the FLASH2 double-blind, placebo-controlled, randomized study that is currently enrolling patients. This rapid response is a distinct advantage of HyBryte™ therapy, with many other therapies used in CTCL taking up to six to 12 months to generate a clinically meaningful treatment response. Of these eight evaluable patients through Week 18, four have gone on to complete the 54-week treatment with an average maximum improvement in mCAILS score of 85%, three are still on treatment and one dropped out (due to logistical issues). HyBryte appears to be safe and well tolerated in all patients.

The complete response rates observed, including three patients achieving a complete response on this study to date, as well as the consistent treatment response and safety profile across multiple HyBryte clinical studies, has been exciting to see," noted Dr. Kim, Principal Investigator of the IIS. "In the first Phase III FLASH study, HyBryte was shown to be efficacious with a benign safety profile compared to the current therapies of steroids, chemotherapeutics and ultraviolet light in this chronic orphan disease. With limited treatment options, especially in the early stages of their disease, CTCL patients are often searching for alternative treatments. In our study funded by the FDA , initial results evaluating the expanded use of HyBryte in a "real world" treatment setting remain very promising, further supporting and extending results from the previous positive Phase II and III clinical trials. It also provides further confidence to the potential responses we can expect to see in the confirmatory Phase  III placebo-controlled FLASH2 study. We look forward to continuing to work with the FDA to complete the IIS while we participate in the confirmatory 18-week FLASH2 study."

"We are pleased with these recent study results, giving patients an opportunity to access the therapy in an open-label setting," stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix. "CTCL is an incredibly difficult to treat orphan disease and remains an area of unmet medical need with a very limited number of safe and effective therapies. Following the initial Phase III FLASH study, which demonstrated the safety and efficacy of shorter courses of HyBryte therapy, we are pleased to see that continuing treatment for longer time periods is resulting in the anticipated improved outcomes for patients. The majority of patients show a strong treatment response by Week 18, a noticeable advantage over other therapies that may take six to 12 months to show improvement. As the body of compelling data continues to grow in support of this novel therapy, we look forward to continuing to work with Dr. Kim on this important study as well as advancing enrollment in the 80-patient confirmatory Phase III FLASH2 replication study. We will plan to provide additional updates on the IIS as data becomes available."

The clinical study RW-HPN-MF-01, "Assessment of Treatment with Visible Light Activated Synthetic Hypericin Ointment in Mycosis Fungoides Patients" is designed as an open-label, multicenter clinical trial enrolling approximately 20 patients in the U.S. Patients have the potential to be treated for up to 54 weeks with twice a week dosing (visible light activation following ointment application by 24 ± 6 hours). The study also allows for potential transition to a "real-world" setting with home-use. The primary endpoint for the study is evaluating the number of treatment successes defined as ≥50% reduction in the cumulative mCAILS score from Baseline to end of the treatment. Study RW-HPN-MF-01 is supported by an FDA Orphan Products Development Grant of up to $2.6 million.