Steven Shallcross
Analyst · Alliance Global Partners
Thanks, Chris, and good morning. I appreciate everyone taking the time to join us today. I'd like to begin by reiterating our deep commitment to advancing our organization and addressing unmet needs for difficult-to-treat cancers. In the first few months of 2023, we continue to make steady progress across our oncology-focused portfolio and remain on track to reach multiple value-enhancing milestones. With cash runway into the third quarter of 2024, we believe we're well positioned to execute on our corporate objectives.
As a reminder, our lead clinical candidate, VCN-01, is a systemically administered oncolytic adenovirus, designed to selectively replicate within the tumor, degrade the tumor matrix and increase tumor immunogenicity. We believe these features position VCN-01 for use in multiple indications in combination with multiple different types of therapies, providing multiple mechanisms of tumor killing.
Building on strong Phase I clinical data, we are advancing VIRAGE, our Phase IIb trial for patients with newly diagnosed metastatic pancreatic ductal adenocarcinoma, or PDAC, and we are pleased with the progress to date.
Enrollment and dosing are also underway for the Phase I trial of VCN-01 in patients with brain tumors, and we're preparing to engage with regulatory agencies to discuss the development and potential registration pathway for VCN-01 as an adjunct to chemotherapy in pediatric patients with advanced retinal blastoma.
As part of our oncology-focused portfolio, in addition to exploring the potential clinical benefits of VCN-01 in different solid tumor indications, we continue to screen patients and enroll them in the second cohort of the Phase Ib/IIa clinical trial of SYN-004, which we expect to complete in the first quarter of 2024.
As a reminder, SYN-004 is designed to prevent potentially fatal outcomes in patients who undergo allogeneic hematopoietic cell transplant, HCT, to treat hematologic cancers.
In parallel, we've taken important steps to identify new candidates through our OV discovery platform, which is designed to protect systemically administered oncolytic viruses from the host immune system and may facilitate repeated administration of oncolytic virus therapies, thus, increasing their efficacy and potentially allowing our pipeline programs to be used in standardized treatment cycles that are well established in cancer chemotherapy and immunotherapy.
With this brief introduction, I will now provide an update on recent activities and share details on how these programs continue to position Theriva at the forefront of oncolytic virus development, starting with our lead program, VCN-01.
It is well known that PDAC has 1 of the lowest survival rates among all cancers, and despite the growing incidence, efforts to improve upon the standard of care chemotherapy treatments have largely stalled. We believe VCN-01 has the potential to address the urgent need for new treatment options for patients with PDAC.
Enrollment and dosing are underway in VIRAGE, the multinational Phase IIb clinical study, evaluating intravenous VCN-01 in newly diagnosed PDAC patients treated with first-line standard of care chemotherapy, gemcitabine and nab-paclitaxel.
The trial is expected to enroll up to 92 adults at up to 25 sites across the U.S. and Europe. We are encouraged by the enrollment to date, which is a testament to both the engagement of our clinical trial sites and the intense commitment of our experienced clinical team.
In both the control arm and treatment arm, patients will receive gemcitabine and nab-paclitaxel standard of care chemotherapy in 28-day cycles. In the treatment arm only, patients will also receive systemically administered VCN-01 7 days prior to the first and fourth cycles of gemcitabine and nab-paclitaxel treatment.
Primary endpoints for the trial include overall survival and VCN-01 safety and tolerability. Additional endpoints include progression-free survival, objective response rate and measures of biodistribution, VCN-01 replication and immune response.
Since this is an open-label trial, progress will be monitored very closely, and steps to accelerate the clinical program may be implemented if supported by emerging data.
In addition to initiating the VIRAGE PDAC trial, we continue to work closely with key opinion leaders to refine our clinical strategy in retinoblastoma. We believe intravitreal VCN-01 has the potential to treat vitreous seeds in children with retinoblastoma, and we also look forward to leveraging our orphan drug designation in this indication to facilitate protocol discussions with the FDA and other regulatory agencies.
Since current clinical practice varies, and there is no regulatory guidance specific to retinoblastoma drug development, we are working with our key opinion leaders in the U.S., Europe, in Central and South America, to develop new potential treatment options for this difficult-to-treat cancer.
In parallel, with company-sponsored studies, the potential utility of VCN-01 is being explored in a number of investigator-sponsored studies that are underway at leading oncology research institutions around the world. In collaboration with the University of Leeds, we are evaluating intravenous VCN-01 in patients with high-grade brain tumors who are scheduled for surgical resection.
This Phase I trial is designed to evaluate the ability of VCN-01 to enter brain tumors following systemic administration. The leaky vasculature of many brain tumors may provide an excellent opportunity for systemically administered VCN-01 to enter the tumor where it may replicate and initiate tumor cell killing, destroy tumor stroma and stimulate an antitumor immune response.
Successful systemic delivery of VCN-01 to brain tumors could provide a less invasive intervention and potentially transform the way these cancers are treated. The Leeds investigators have initiated dosing and are exploring protocol refinements that may expand enrollment.
Additionally, enrollment in the Phase I clinical study in collaboration with Hospital Sant Joan de Déu in Barcelona, Spain, has been extended to additional patients. The study is designed to evaluate the safety and tolerability of VCN-01 in patients with intraocular retinoblastoma refractory to systemic intraarterial or intravitreal chemotherapy or radiotherapy.
We plan to hold the meeting with the FDA in the second half of 2023 to discuss the clinical development and potential registration pathway for VCN-01 as an adjunct to chemotherapy in pediatric patients with advanced retinoblastoma.
A separate investigator-sponsored study is exploring the therapeutic potential of VCN-01 in combination with durvalumab for patients with recurrent metastatic squamous cell carcinoma of the head and neck. We are encouraged by the data generated to date, highlighted by the acceptable safety profile seen with sequential dosing of VCN-01 and durvalumab as well as biological activity observed in head and neck cancer patients who failed multiple previous lines of therapy, including treatment with anti-PD-1 and PD-L1 agents.
We are planning to present additional efficacy and survival data from the study in the second half of 2023, and we will continue to explore collaboration and partnering opportunities to advance VCN-01 in this indication. The potential to enable the use of immune checkpoint inhibitors in refractory or in insensitive cancer patients is particularly compelling goal of VCN-01 that may have valuable utility in a range of cancer indications.
Turning to our ongoing Phase Ib/IIa clinical trial SYN-004, ribaxamase, to prevent acute graft versus host disease, or aGVHD, in patients undergoing allogeneic HCT treatment for hematologic cancers.
SYN-004 is intended to address key limitations of broad-spectrum antibiotics or IV beta-lactam antibiotics and potentially improve treatment outcomes with this important and widely used class of therapeutics. The Phase Ib/IIa study is designed to assess the feasibility of using SYN-004 in this specific patient population and to provide key information requested by the FDA regarding the safety and tolerability of SYN-004 in patients with impaired intestinal barrier function.
As a reminder, the study consists of 3 sequential cohorts designed to compare different IV beta-lactam antibiotics to treat fever following conditioning therapy. In each cohort, 8 patients will receive SYN-004 and 4 will receive placebo. Data from the first cohort was recently presented in April at the 33rd European Congress of Clinical Microbiology & Infectious Disease. While the data remain blinded, interim analysis suggests that SYN-004 is well tolerated and was not observed in the blood samples of the majority of the evaluable patients.
Building on these results, our second cohort is underway and is designed to evaluate SYN-004 in combination with piperacillin and tazobactam. This cohort will provide important additional safety information, in particular, whether oral SYN-004 has the potential to alter IV antibiotic levels in this patient population.
With our collaborators at Washington University, we continue to explore the potential of SYN-004 to reduce potentially fatal adverse events related to IV antibiotic use in allogeneic HCT recipients, including aGVHD and overgrowth and infection by pathological organisms such as C. difficile and vancomycin-resistant enterococci.
We are pleased with the progress of our clinical programs, and in parallel, continue to identify new candidates through our OV platform. Our proprietary technologies have tremendous potential for our pipeline, and we look forward to building upon our foundation of compelling proof of mechanism data generated with VCN-01 and VCN-11 to develop new Albumin Shield candidates incorporating additional therapeutic payloads.
Overall, I'm confident that the company's strong cash position and upcoming catalysts will provide a solid foundation for execution and value creation.
We remain focused on driving our clinical programs forward and exploring opportunities to expand our pipeline through our OV discovery platform.
We remain on track to complete enrollment for VIRAGE by early 2024, hold the pre-IND meeting with the FDA in the second half of 2023 to discuss the clinical development and potential registration pathway for VCN-01 as an adjunct to chemotherapy in pediatric patients with advanced retinoblastoma, present additional data from the study of VCN-01 in combination with durvalumab in patients with recurrent metastatic squamous cell carcinoma of the head and neck in the second half of 2023, and complete the second cohort of our Phase Ib/IIa clinical study of SYN-004 for the prevention of acute graft versus host disease in bone marrow transplant patients in the first quarter of 2024.
Now I'd like to briefly turn to our financial results for the first quarter ended March 31, 2023.
General and administrative expenses increased to $2.2 million for the 3 months ended March 31, 2023, from $1.7 million for the 3 months ended March 31, 2022. This increase of 29% is primarily comprised of increased expense related to the fair value of the contingent consideration, additional salary and benefits related to new headcount, audit fees, consulting fees, travel and VCN administrative expenses not included in the prior year, offset by a decrease in consulting and legal costs related to the VCN acquisition.
The charge related to stock-based compensation expense was $87,000 for the 3 months ended March 31, 2023, compared to $85,000 for the 3 months ended March 31, 2022.
Research and development expenses increased to $3 million for the 3 months ended March 31, 2023, from approximately $2.6 million for the 3 months ended March 31, 2022. This increase of 15% is primarily the result of increased clinical trial expenses related to VCN-01 not incurred in the prior year, offset by lower expenses related to our Phase Ib/IIa clinical trial of SYN-004 in allogeneic HCT recipients and decreased manufacturing expenses related to our Phase Ia clinical trial of SYN-020. We anticipate research and development expense to increase as we continue enrollment in our VIRAGE Phase II clinical trial of VCN-01 in PDAC, and our ongoing Phase I clinical trial in retinoblastoma, expand GMP manufacturing activities for VCN-01, and continue supporting our VCN-11 and other preclinical and discovery initiatives.
The charge related to stock-based compensation expense was $39,000 for the 3 months ended March 31, 2023, compared to $28,000 related to stock-based compensation expense for the 3 months ended March 31, 2022.
Other income was $370,000 for the 3 months ended March 31, 2023, compared to other expense of $21,000 for the 3 months ended March 31, 2022. Other income for the 3 months ended March 31, 2023, is primarily comprised of interest income of $364,000 and an exchange gain of $6,000. Other expense for the 3 months ended March 31, 2022, is primarily comprised of an exchange loss of $23,000, offset by interest income of $2,000.
Cash and cash equivalents totaled $36.1 million as of March 31, 2023, compared to $41.8 million as of December 31, 2022.
We remain deeply committed to improving patient outcomes for these very hard-to-treat cancers. And before we conclude today's call, I want to extend my sincere appreciation and gratitude for the foundational work that has brought us closer to delivering on our mission. I'd also like to thank the entire Theriva team, our investors and the many people, who have been supportive along the way, including our patients and their families.
With that, we're happy to take some questions.