After closing a $7.1-million financing last month, Soligenix (OTCQB:SNGX) is preparing to begin later this year Phase II clinical testing of its two lead product candidates to treat oral mucositis in head and neck cancer patients and pediatric Crohn's disease.
"These two programs are examples of our diverse pipeline," President and CEO Christopher J. Schaber says in an interview with BioTuesdays.com, pointing to nine potential value drivers in development that address high unmet medical needs in orphan and rare diseases.
Soligenix's multiple programs in biotherapeutics and vaccines for biodefense are targeting indications, each of which has a market potential of at least $200-million-plus, he adds.
Dr. Schaber says the company plans to begin a Phase II/III trial this year with a two-tablet proprietary formulation of immediate- and delayed-release oral BDP (beclomethasone 17, 21-dipropionate), referred to by its research name, SGX203, in pediatric Crohn's patients. "We anticipate that there will be no placebo group in the trial, so risk is manageable since we're not going up against any comparators."
He explains that the SGX203 drug candidate is designed to treat inflammation in the upper and lower GI tract. It is positioned as a corticosteroid option, with less toxicity than the current standard systemic steroid therapy, prednisone. Soligenix formulations of oral BDP have been tested in approximately 350 subjects to date, with no major or unanticipated side effects in the treatment of GI inflammation, Dr. Schaber notes.
BDP has been used for over 35 years via other methods of delivery, including inhaled forms for asthma, nasal forms for rhinitis and creams for severe inflammatory skin disorders. There are over 160,000 children and adolescents with Crohn's worldwide.
"We're looking at SGX203 as a first line treatment and expect to have primary endpoint data during the second half of 2014," he says. SGX203 has received orphan drug and fast track designation from the FDA.
Soligenix is using the same two-tablet, time-release formulation of oral BDP, referred to as SGX201, to block an inflammatory component of acute radiation enteritis in the GI tract of cancer patients receiving pelvic radiation therapy. Radiation enteritis affects over 200,000 cancer patients worldwide and there is currently no approved therapy for the condition. SGX201 has received fast track designation from the FDA.
A NIH grant supported a successful Phase I study, demonstrating safety and potential dose response for diarrhea, nausea and vomiting, and an assessment of enteritis, Dr. Schaber says. "We're hoping the NIH will support a Phase IIb study that we would like to begin in the first half of 2014."
In addition to pediatric Crohn's disease and acute radiation enteritis, Soligenix is developing its formulations of oral BDP for the treatment of chronic GI graft-versus-host disease (GVHD), a common complication after a bone marrow or stem cell transplant in which someone receives bone marrow tissue or cells from a donor. Data from a Phase II study are expected in the second half of 2014.
At the end of 2012, Soligenix acquired a novel drug technology, known as SGX94, to modulate the innate immune system in order to reduce inflammation, eliminate infection and enhance tissue healing by binding to the pivotal regulatory protein p62, also known as sequestosome-1.
Dr. Schaber says the technology is simultaneously anti-inflammatory and anti-infective. "It's not bacteria-specific but acts on the body to trigger the innate immune system to fight infection, tissue damage and inflammation."
He points out that Soligenix is developing the technology in both of its key business segments-specifically, cancer supportive care applications, such as oral mucositis in its biotherapeutics business segment, and infectious disease applications, such as melioidosis and GI acute radiation syndrome in its vaccines/biodefense business segment.
BioTherapeutics Business Segment
The lead compound in the program, SGX942, was the subject of a Phase I study in 84 healthy volunteers, which demonstrated safety and evidence of an anti-inflammatory response. SGX942 also has received fast track designation from the FDA.
With SGX942, Soligenix plans to start later this year a Phase II study in up to 75 head and neck cancer patients with oral mucositis and expects primary endpoint data in the second half of 2014. There is no drug approved for oral mucositis in head and neck cancer.
Earlier this month, Soligenix teamed up with SciClone Pharmaceuticals (SCLN) and gained access to SciClone's oral mucositis clinical and regulatory data library in exchange for commercialization rights in China, including Hong Kong and Macau.
SciClone completed two sequential Phase II clinical studies in 2010 and 2012, evaluating its drug, SCV-07, for the treatment of oral mucositis caused by chemo-radiation therapy in head and neck cancer patients, before terminating its program. As this is the same population that Soligenix is pursuing for its oral mucositis program, this information has the potential to increase the probability of success of its upcoming Phase II clinical study.
"Our collaboration with SciClone is an ideal match," Dr. Schaber contends. "SciClone has a significant commercial presence and expertise in China and their clinical and regulatory contribution to the SGX942 oral mucositis program has the potential to accelerate development while dramatically improving clinical response."
Oral mucositis affects over 180,000 head and neck cancer patients worldwide. It is a debilitating side effect of chemo- and radiation therapy that causes massive ulceration of the mouth, tongue, soft palate and oropharynx. In addition to severe pain and inability to eat, this condition often leads to reduced cancer treatment tolerance.
In May, Soligenix signed a collaboration deal with Intrexon, which is controlled by renowned biotech entrepreneur Randal (RJ) Kirk, to develop and commercialize human monoclonal antibody therapies for new biodefense and infectious disease applications for melioidosis, using Intrexon's advanced human antibody discovery and production technologies.
Dr. Schaber says the collaboration is unique because the goal is to develop a therapy that will treat both a deadly disease currently affecting millions of people as well as fight a potential biological weapon. There is no preventive vaccine or effective immunotherapy for melioidosis.
Melioidosis is caused by Burkholderia pseudomallei, a gram-negative bacterium that is highly resistant to antibiotic treatment regimens, with mortality rates as high as 40% in parts of Southeast Asia and Northern Australia. It is also considered a high-priority biodefense threat, with the potential for widespread release through an aerosol.
Investors in the company's recent $7.1-million financing included an affiliated fund of Third Security, a venture capital firm founded by Mr. Kirk. Soligenix intends to appoint a Third Security designee to its board. Dr. Schaber says the appointment will add investment banking expertise to the board for the first time.
In addition to biotherapeutics, Soligenix's biodefense business segment is funded entirely through government grants and contracts, totaling some $25-million to date.
Vaccine/BioDefense Business Segment
For example, the company's ThermoVax platform has achieved positive proof-of-concept data for stability and shelf-life of vaccines at temperatures exceeding 40 degrees Celsius, which avoids the need to refrigerate vaccines. According to the WHO, 50% of all vaccine doses globally are wasted because they lose their cold-chain temperature storage.
Dr. Schaber says that to date, the company has obtained six months of stability data, with no degradation, for its aluminum-adjuvant ricin toxin vaccine, RiVax.
RiVax has the potential to be the first approved ricin toxin vaccine and has received orphan drug status from the FDA. The company is currently evaluating additional adjuvants for more rapid onset of immunity for RiVax and hopes to begin Phase II studies in the first half of 2014, Dr. Schaber says.
The company is also continuing development of thermostable formulations for its anthrax vaccine, VeloThrax, under an NIH grant and is in the process of submitting applications for additional grants to support clinical development in 2014.
Soligenix's biodefense program also includes OrbeShield for GI acute radiation syndrome (ARS), involving its two-tablet immediate- and delayed-released formulation of oral BDP, which has been "repurposed" within the government's BARDA guidelines and also does not require refrigeration.
Dr. Schaber says the company has demonstrated statistically significant survival in post-radiation exposure versus controls in canine models of GI ARS. The company recently received a $600,000 NIH Small Business grant to continue work in canine models and is awaiting a decision on a contract proposal which was made to BARDA last February.
Significant WW Market Potential