#United States #Princeton #Soligenix #HyBryte #Cutaneous T-Cell Lymphoma

Soligenix Reports Disappointing Interim Findings from Phase 3 FLASH2 Trial

On April 28, 2026, Soligenix, Inc. (Nasdaq: SNGX), a biopharmaceutical firm dedicated to treating rare diseases, announced the interim results of its pivotal Phase 3 FLASH2 trial. The trial was conducted to assess the efficacy of HyBryte™ (Synthetic Hypericin) in treating cutaneous T-cell lymphoma (CTCL). Unfortunately, the Data Monitoring Committee recommended halting the study due to a lack of anticipated efficacy, which was unexpected given the promising results from previous studies.

Interim Efficacy Analysis Results

In the first FLASH clinical trial, HyBryte™ exhibited statistically significant reductions in CTCL lesions after six weeks. However, the interim analysis from FLASH2 reported a stark contrast after 18 weeks of treatment. Dr. Christopher J. Schaber, President and CEO of Soligenix, expressed disappointment over these findings, stating, "Despite previous evidence of efficacy, this trial did not yield the expected results. We will conduct a thorough analysis to understand the variance in efficacy and assess any particular patient subsets that may still benefit from HyBryte™ therapy."

The FLASH2 study enrolled 169 patients with different stages of CTCL. During treatment, it was noted that while 16% of patients in the earlier cycles on HyBryte™ had shown significant lesion reduction, the same was not replicated in later phases of the trial. Soligenix is now focusing on understanding the reasons behind these unexpected results.

Future Directions

Considering the trial's outcome, the company is evaluating its options for future development. This includes analyzing its cash reserves, which stand at approximately $5.9 million, to strategize the next steps. Plans may involve merger and acquisition opportunities or advancing other treatments in their clinical pipeline, such as dusquetide for Behçet's disease, which recently showcased promising efficacy in a prior Phase 2 trial.

About HyBryte™

HyBryte™ represents a novel photodynamic therapy that employs synthetic hypericin as its active ingredient. The therapy utilizes visible light activation, distinguished from other treatments that rely on ultraviolet light exposure, which can increase the risk of secondary cancers. This innovative approach has demonstrated considerable anti-proliferative effects on malignant T-cells. Focusing on safety, HyBryte™ aims to offer a more effective and less harmful treatment option for patients suffering from CTCL.

In the first FLASH trial, the results highlighted the potential of HyBryte™ to offer substantial improvements over existing treatments such as Valchlor®. However, the FDA and EMA have indicated the necessity for a second successful Phase 3 trial to secure marketing approval, which is now under scrutiny following the interim analysis outcome in FLASH2.

The Impact of CTCL

Cutaneous T-cell lymphoma is a rare form of non-Hodgkin lymphoma that manifests through skin lesions caused by malignant T-cells. The varying degrees of severity present challenges both in treatment options and patient outcomes, with current therapeutic alternatives often associated with severe adverse effects. The necessity for effective and safe treatments remains paramount, particularly as CTCL currently has no definitive cure.

Conclusion

In light of the findings from the Phase 3 FLASH2 trial, Soligenix is committed to delving deeper into the data to understand the implications fully and explore all possible avenues for advancing its pipeline. The company remains steadfast in its mission to address unmet medical needs in rare diseases and is poised to adapt to the insights gleaned from this recent trial experience.