Soligenix, Inc. (Nasdaq: SNGX), a late-stage biopharmaceutical company dedicated to developing treatments for rare diseases, recently held a Type A Meeting with the United States Food and Drug Administration to discuss the refusal to file letter issued for the New Drug Application for HyBryte™ (synthetic hypericin sodium) for the treatment of early stage cutaneous T-cell lymphoma (CTCL).
The Phase 3 clinical trial (Study HPN-CTCL-01; also referred to as the FLASH study) demonstrated statistically significant results, making the potential approval of the drug a reality.
The FDA is requiring positive results from a second clinical study in order to accept an NDA filing for HyBryte™, beyond the Phase 3 FLASH study already conducted in this orphan indication. The Company has decided to work collaboratively with the FDA to discuss the protocol and evaluate the feasibility of conducting the additional clinical trial. An open dialogue has been established between the two parties to ensure that the proposed study meets the FDA’s requirements.
Soligenix and its clinical investigators are greatly disappointed by the delay in submitting the NDA for their HyBryte™ therapy to the FDA. Despite the setback, they remain committed to working with the FDA to bring the treatment to market for patients suffering from CTCL.
The Phase 3 FLASH trial was the largest double-blind, randomized, placebo-controlled clinical trial ever conducted in the CTCL population.
During the Type A meeting, the FDA and Soligenix discussed elements of protocol design for the additional confirmatory study, and they are eager to collaborate with the FDA to finalize the study design in order to meet the FDA’s requirements and bring HyBryte™ to the public.
HyBryte™ (SGX301) is a revolutionary photodynamic therapy that harnesses the power of visible light to treat skin lesions. Its active ingredient, synthetic hypericin sodium, is applied topically and taken up by malignant T-cells. What makes HyBryte™ unique is its use of visible light in the red-yellow spectrum, which penetrates deeper into the skin than ultraviolet light and thus treats deeper skin diseases and thicker plaques.
This approach eliminates the risk of secondary malignancies associated with other phototherapies and DNA-damaging drugs. In a clinical study, the effectiveness of hypericin was demonstrated, with patients experiencing a statistically significant (p=0.04) improvement. The FDA and EMA have granted HyBryte™ orphan drug and fast track designations, highlighting its groundbreaking potential.
The recently completed Phase 3 FLASH (Fluorescent Light Activated Synthetic Hypericin) study enrolled a total of 169 patients with Stage IA, IB, or IIA CTCL. The trial was conducted over three treatment cycles, twice weekly for the first six weeks and response was assessed at the end of the 8th week. In the double-blind first cycle, 116 patients were given HyBryte™ (0.25% synthetic hypericin) and 50 received placebo treatment.
The results showed an impressive 16% of those given HyBryte™ achieved at least a 50% reduction in lesions (measured using the CAILS score) compared to only 4% in the placebo group (p=0.04). The treatment was found to be safe and well-tolerated.
In the second open-label treatment cycle (Cycle 2), HyBryte™ proved to be a safe and effective treatment for the index lesions of cutaneous T-cell lymphoma. A comparison of the response rate between the 12-week and 6-week treatment groups revealed a statistically significant improvement (p<0.0001), indicating that continued treatment results in better outcomes.
Notably, HyBryte™ was also found to be equally effective in treating both plaque (response 42%, p<0.0001 relative to placebo treatment in Cycle 1) and patch (response 37%, p=0.0009 relative to placebo treatment in Cycle 1) lesions of CTCL, a significant finding given the difficulty in treating such lesions. In sum, the results of Cycle 2 showed that HyBryte™ treatment leads to a 40% response rate (p<0.0001 vs the placebo treatment rate in Cycle 1).
In Cycle 3, an optional compassionate use/safety cycle, 66% of patients elected to receive HyBryte™ treatment of all their lesions. Of this subset, an impressive 49% showed a positive treatment response (p<0.0001 vs. those who received placebo in Cycle 1).
Furthermore, HyBryte™ was found to not be systemically available, indicative of its general safety profile. Despite extended and increased use of the product, HyBryte™ remained well-tolerated at the end of Cycle 3. It is clear that HyBryte™ is a safe and effective treatment option for multiple lesions.
HyBryte™ is a revolutionary therapy for CTCL with a unique mechanism of action that eliminates the risk of DNA damage and other side effects associated with other treatments, such as melanoma, skin damage, and premature skin aging.
It is the safest available treatment for CTCL, offering a safe and efficacious alternative with very limited systemic absorption, a compound that is not mutagenic, and a light source that is not carcinogenic. With no reported safety issues after three treatment cycles and a 6-month follow-up period, HyBryte™ is the ideal front-line therapy for those seeking a safe and effective treatment option.
The National Cancer Institute and the FDA have both provided funding to support the clinical evaluation of HyBryte™, a potential treatment for early-stage Cutaneous T-Cell Lymphoma (CTCL). The NCI awarded a Phase II SBIR grant (#1R44CA210848-01A1) to Soligenix, Inc., while the FDA granted a $2.6 million Orphan Products Development grant to a leading enroller in the Phase 3 FLASH study. Together, these investments are helping to advance research on this potentially life-saving therapy.
About Cutaneous T-Cell Lymphoma (CTCL)
CTCL is an aggressive form of non-Hodgkin’s lymphoma, a cancer of the white blood cells essential for our body’s immune system. Unlike other NHLs, CTCL is caused by a malignant expansion of T-cell lymphocytes that migrate to the skin, creating a range of lesions from patches to raised plaques and tumors.
Unfortunately, there is no cure for CTCL and median survival ranges from 12 years in the early stages to only 2.5 years in advanced stages. Though treatment may bring remission, CTCL lesions often return either in the same area or in new locations, making it a challenging and relentless disease.
CTCL is a rare form of non-Hodgkin’s lymphoma, affecting around 25,000 people in the United States alone. It is estimated that of the 700,000 individuals living with the disease, about 4% have CTCL, with around 3,000 new cases seen each year. This makes it a serious and dangerous illness that should not be taken lightly.
About Soligenix, Inc.
Soligenix is a cutting-edge biopharmaceutical company on a mission to develop and commercialize innovative treatments for rare diseases with unmet medical needs. Our Specialized BioTherapeutics business segment is leading the way with the development of HyBryte™ (SGX301 or synthetic hypericin sodium), a revolutionary photodynamic therapy that utilizes safe visible light to treat cutaneous T-cell lymphoma.
After a successful Phase 3 trial, we are now working towards gaining regulatory approval and launching commercialization activities for the product candidate in the U.S. In addition to HyBryte™, our development programs include expanding synthetic hypericin sodium (SGX302) into psoriasis, an IDR technology (dusquetide or SGX942) for treating inflammatory diseases like oral mucositis in head and neck cancer, and proprietary treatments of oral beclomethasone 17,21-dipropionate (BDP) to prevent/treat severe GI inflammation, including pediatric Crohn’s disease (SGX203).
Our Public Health Solutions business segment is actively developing innovative solutions to tackle the most pressing issues of our time. We have developed RiVax®, a ricin toxin vaccine candidate, SGX943, a therapeutic candidate for antibiotic resistant and emerging infectious diseases, and vaccine programs targeting filoviruses, such as Marburg and Ebola, and CiVax™, a vaccine candidate for the prevention of COVID-19 (caused by SARS-CoV-2).
All of these solutions are backed by our proprietary heat stabilization platform technology – ThermoVax® – and have been funded by government grants and contracts from the National Institute of Allergy and Infectious Diseases (NIAID), the Defense Threat Reduction Agency (DTRA) and the Biomedical Advanced Research and Development Authority (BARDA).
We are proud to be at the forefront of the fight against these diseases and are dedicated to finding solutions that will save countless lives.