Theriva™ Biologics Announces Upcoming Presentation of Data from VCN-01 Retinoblastoma Phase 1 Clinical Trial at APAO 2026

Rhea-AI Summary

Theriva Biologics (NYSE: TOVX) will present Phase 1 clinical outcomes and safety data for VCN-01 in refractory retinoblastoma at APAO 2026 in Hong Kong on 07 February 2026.

The invited session includes intravitreal two-injection trial results (NCT03284268), preclinical data showing synergy with topotecan, presentation logistics, and note of Orphan Drug and Rare Pediatric Disease designations and ongoing pivotal trial planning.

Positive

• Invited presentation of Phase 1 safety and clinical outcomes
• Preclinical data showing VCN-01 + topotecan synergistic antitumor activity
• VCN-01 holds Orphan Drug and Rare Pediatric Disease designations
• Company refining a potential pivotal trial design for retinoblastoma

Negative

• Results are from an early Phase 1 study, not yet pivotal evidence
• No pivotal trial initiated; design remains under refinement with regulators

News Market Reaction

+3.37%

2 alerts

+3.37% News Effect

-2.6% Trough Tracked

+$214K Valuation Impact

$7M Market Cap

0.1x Rel. Volume

On the day this news was published, TOVX gained 3.37%, reflecting a moderate positive market reaction. Argus tracked a trough of -2.6% from its starting point during tracking. Our momentum scanner triggered 2 alerts that day, indicating moderate trading interest and price volatility. This price movement added approximately $214K to the company's valuation, bringing the market cap to $7M at that time.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

Trial phase: Phase 1 VCN-01 dosing: Two intravitreal injections Trial identifier: NCT03284268 +5 more

8 metrics

Trial phase Phase 1 VCN-01 study in refractory intraocular retinoblastoma

VCN-01 dosing Two intravitreal injections Investigator-sponsored Phase 1 trial design

Trial identifier NCT03284268 VCN-01 intravitreal trial in pediatric retinoblastoma

APAO Congress 41st meeting Asia-Pacific Academy of Ophthalmology Congress in Hong Kong

Congress dates 5–8 February 2026 APAO 2026 meeting window

Presentation time 4:46 PM HKT Retinoblastoma session on 07 February 2026

Regulatory designations Orphan Drug, Rare Pediatric Disease VCN-01 for treatment of retinoblastoma

Session number 0211 Retinoblastoma session at APAO 2026

Market Reality Check

Price: $0.1807 Vol: Volume 851,449 is well be...

low vol

$0.1807 Last Close

Volume Volume 851,449 is well below the 20-day average 2,512,377 (relative volume 0.34). low

Technical Price at 0.178 is trading below the 200-day MA of 0.44 and sits 89.83% under the 52-week high, but only 7.81% above the 52-week low.

Peers on Argus

TOVX was down 1.11% pre-news while peers were mixed: ENTO -5.68%, AZTR -2.2%, GL...

TOVX was down 1.11% pre-news while peers were mixed: ENTO -5.68%, AZTR -2.2%, GLTO +2.86%, QNRX +8.55%, and XRTX 0%, pointing to stock-specific drivers rather than a unified biotech move.

Previous Conferences,clinical trial Reports

1 past event · Latest: Apr 22 (Positive)

Same Type Pattern 1 events

Date	Event	Sentiment	Move	Catalyst
Apr 22	Conference data preview	Positive	-8.3%	Planned presentation of VCN-01 preclinical synergy data in pancreatic cancer.

Pattern Detected

For conference/clinical-trial presentations, the single prior tagged event saw a negative move despite showcasing VCN-01-related data, suggesting past market reactions did not consistently reward this news type.

Recent Company History

Recent history for Theriva around VCN-01 data and conferences shows one tagged event on Apr 22, 2024, when the company announced plans to present preclinical synergy data for VCN-01 with first-line pancreatic cancer chemotherapy at a major cell and gene therapy meeting. That event led to a -8.3% one-day move. Today’s APAO 2026 retinoblastoma Phase 1 and preclinical synergy update extends the pattern of leveraging conferences to highlight VCN-01’s potential across indications.

Historical Comparison

+8.3% avg move · In the past, TOVX had one other ‘conferences,clinical trial’ event for VCN-01, on Apr 22, 2024, whic...

conferences,clinical trial

+8.3%

Average Historical Move conferences,clinical trial

In the past, TOVX had one other ‘conferences,clinical trial’ event for VCN-01, on Apr 22, 2024, which moved the stock by 8.3%. Today’s APAO 2026 retinoblastoma update fits this pattern of using conferences to showcase VCN-01 data.

The company has progressed from presenting VCN-01 preclinical synergy data in pancreatic cancer in 2024 to sharing Phase 1 clinical outcomes and new preclinical combination data in retinoblastoma at APAO 2026, illustrating broader development of the VCN-01 platform.

Regulatory & Risk Context

Active S-3 Shelf

Shelf Active

Active S-3 Shelf Registration 2025-11-07

An effective Form S-3 was filed on Nov 7, 2025 to register up to 16,184,560 shares for resale upon exercise of New Warrants. Theriva is not selling shares itself under this prospectus and receives no proceeds from resale, but may receive cash if holders exercise the warrants, which are subject to stockholder and NYSE American approval and a 4.99%/9.99% beneficial ownership cap.

Market Pulse Summary

This announcement centers on Phase 1 safety and clinical outcomes for VCN-01 in refractory retinobla...

Analysis

This announcement centers on Phase 1 safety and clinical outcomes for VCN-01 in refractory retinoblastoma and preclinical synergy data with topotecan, to be presented at APAO 2026. It builds on Theriva’s ongoing strategy of showcasing VCN-01 across indications at major meetings. Investors may track details of ocular safety, response durability, and the proposed pivotal design, alongside previously disclosed warrant-related share overhang and registration of up to 16,184,560 resale shares.

Key Terms

phase 1, oncolytic adenovirus, orphan drug, rare pediatric disease, +4 more

8 terms

phase 1 medical

"Safety and clinical outcomes of Phase 1 study of VCN-01..."

Phase 1 is the first stage of testing a new drug or medical treatment in people, focused primarily on safety, how the body handles the product, and finding a tolerated dose. Think of it as a short, tightly controlled experiment with a small group to check for dangerous side effects before wider testing; for investors it is an early milestone that reduces some uncertainty but still carries high risk and potential for both big value changes and setbacks.

oncolytic adenovirus medical

"Title: Update on Oncolytic Adenovirus VCN-01 Trial in Retinoblastoma"

An oncolytic adenovirus is a virus based on adenovirus that has been modified to preferentially infect and kill cancer cells and often to activate the immune system against tumors—imagine a guided missile that both destroys cancer cells and raises an alarm for the body's defenses. Investors should note these therapies can deliver large upside if clinical trials prove effective, but they carry substantial clinical, manufacturing and regulatory risks that can cause big valuation swings.

orphan drug regulatory

"VCN-01 has Orphan Drug and Rare Pediatric Disease designations..."

A drug designated for an orphan disease is a medicine developed to treat a rare condition that affects only a small number of people. Regulators often give these drugs special incentives—such as reduced costs, faster review, and temporary exclusive selling rights—to encourage development, which matters to investors because those incentives can make a small market financially viable and reduce competition, much like a temporary patent on a niche product.

rare pediatric disease regulatory

"Orphan Drug and Rare Pediatric Disease designations for the treatment of retinoblastoma"

A rare pediatric disease is a serious medical condition that primarily affects children and occurs so infrequently that only a small number of patients exist. Investors care because treatments for such conditions often get special regulatory incentives—think of government fast lanes and rewards for developers—making smaller markets potentially profitable due to pricing power, shorter development timelines, and reduced competition, much like a niche product that receives government-backed advantages.

intravitreal medical

"evaluating the safety and tolerability of two intravitreal injections of VCN-01..."

An intravitreal treatment is one given by injecting medicine directly into the gel-like center of the eye, delivering drugs straight to the site of retinal disease rather than through pills or eye drops. Investors care because this delivery method affects development costs, regulatory review, clinical risk, manufacturing and distribution complexity, and reimbursement — all factors that influence a therapy’s commercial potential.

vitreous seeds medical

"may improve outcomes in refractory retinoblastoma patients with difficult-to-treat vitreous seeds"

Vitreous seeds are cancer cells or cell clumps that have broken off and are floating in the vitreous, the clear gel that fills the eye, similar to debris suspended in a bowl of jelly. For investors, their presence matters because they make cancers harder to treat, often requiring different drug delivery methods, additional procedures, or longer trials, which can affect clinical outcomes, regulatory decisions, and commercial prospects for therapies targeting intra‑ocular disease.

standard of care chemotherapy medical

"topotecan (a standard of care chemotherapy for retinoblastoma) is coadministered with VCN-01"

An established chemotherapy regimen that doctors commonly use as the accepted medical treatment for a particular cancer, based on evidence of safety and effectiveness. It serves as the default or “baseline” therapy against which new drugs or approaches are compared in clinical trials, so investors watch it because a new treatment’s ability to beat or replace this standard affects regulatory approval, patient adoption, pricing, and market size.

retinoblastoma medical

"in pediatric patients with intraocular retinoblastoma that was refractory..."

A rare childhood cancer that starts in the retina, the light-sensing layer at the back of the eye; it can destroy vision and, if untreated, spread beyond the eye. For investors, retinoblastoma matters because progress or setbacks in treatments, diagnostics, or surgery affect the commercial prospects, regulatory approvals, litigation risk, and reimbursement for companies working in pediatric oncology or ophthalmology—like a product defect that can trigger costly fixes and reshape market value.

AI-generated analysis. Not financial advice.

- Safety and clinical outcomes of Phase 1 study of VCN-01 (zabilugene almadenorepvec) in refractory retinoblastoma patients to be presented in an invited session at the 41^st Asia-Pacific Academy of Ophthalmology (APAO) Congress in Hong Kong on Saturday, 07 February 2026 –

- Preclinical data will highlight synergistic antitumor activity for the combination of topotecan and VCN-01 that may improve outcomes in refractory retinoblastoma patients with difficult-to-treat vitreous seeds -

ROCKVILLE, Md. and BARCELONA, Spain, Feb. 03, 2026 (GLOBE NEWSWIRE) -- Theriva™ Biologics (NYSE American: TOVX), (“Theriva” or the “Company”), a diversified clinical-stage company developing therapeutics designed to treat cancer and related diseases in areas of high unmet need, today announced an invited presentation of clinical outcomes and safety data from the investigator sponsored Phase 1 clinical study (NCT03284268) evaluating the safety and tolerability of two intravitreal injections of VCN-01 (zabilugene almadenorepvec) in pediatric patients with intraocular retinoblastoma that was refractory to systemic, intra-arterial, or intravitreal chemotherapy, and for whom enucleation was the only recommended treatment. Preclinical data describing the synergistic antitumor effects observed when topotecan (a standard of care chemotherapy for retinoblastoma) is coadministered with VCN-01 will also be presented. These data will be presented during a retinoblastoma focused session at the upcoming Asia-Pacific Academy of Ophthalmology (APAO) Congress (held in conjunction with the 37^th Annual Scientific Meeting Hong Kong Ophthalmological Symposium) taking place in Hong Kong, China, 5-8 February 2026.

Details of the presentation can be found online and below.

• Presenting Author: Dr. Jaume Català-Mora, Pediatric Ophthalmologist, Sant Joan de Déu-Barcelona Children’s Hospital
• Title: Update on Oncolytic Adenovirus VCN-01 Trial in Retinoblastoma
• Session: 0211 Retinoblastoma in Association With Asian Retinoblastoma Group
• Date & Time: Saturday 07 February, 2026, at 4:46 PM HKT (3:46 AM US EDT)
• Location: Rooms S224-225, Level 2, Hong Kong Convention and Exhibition Centre (HKCEC)
  

“We are very pleased with the on-going international interest in the novel clinical and preclinical findings by our collaborators treating retinoblastoma patients at Sant Joan de Déu-Barcelona Children’s Hospital,” said Steven A. Shallcross, Chief Executive Officer of Theriva Biologics. “Effective treatment of refractory retinoblastoma with vitreous seeds remains a significant unmet medical need for pediatric patients with this condition worldwide. Based on our previously reported Phase 1 clinical data, and the emerging preclinical findings, we believe that the intravitreal combination of VCN-01 and topotecan provides an exciting new opportunity to address this challenge and help preserve the eyes and quality-of-life of children with this rare but devastating cancer. VCN-01 has Orphan Drug and Rare Pediatric Disease designations for the treatment of retinoblastoma, and we are currently refining a potential pivotal clinical trial design in this indication for discussion with regulatory agencies.”

About VCN-01

VCN-01 (zabilugene almadenorepvec) is a systemically administered oncolytic adenovirus designed to selectively and aggressively replicate within tumor cells and degrade the tumor stroma that serves as a significant physical and immunosuppressive barrier to cancer treatment. This unique mode-of-action enables VCN-01 to exert multiple antitumor effects by (i) selectively infecting and lysing tumor cells; (ii) enhancing the access and perfusion of co-administered chemotherapy products; and (iii) increasing tumor immunogenicity and exposing the tumor to the patient’s immune system and co-administered immunotherapy products. Systemic administration enables VCN-01 to exert its actions on both the primary tumor and metastases. VCN-01 has been administered to over 140 patients to date in clinical trials of different cancers, including PDAC (in combination with chemotherapy), head and neck squamous cell carcinoma (with an immune checkpoint inhibitor), ovarian cancer (with CAR-T cell therapy), colorectal cancer, and retinoblastoma (by intravitreal injection). More information on these clinical trials is available at Clinicaltrials.gov. VCN-01 has Orphan Drug designation from the EMA and both Orphan Drug designation and Fast Track designation from the FDA for the treatment of pancreatic cancer. VCN-01 also has Orphan Drug designation and Rare Pediatric Diseases designation from the FDA for the treatment of retinoblastoma.

About Retinoblastoma

Retinoblastoma is a tumor that originates in the retina and is the most common type of eye cancer in children. It occurs in approximately 1/14,000 - 1/18,000 live newborns and accounts for 15% of the tumors in the pediatric population < 1 year old. The average age of pediatric patients at diagnosis is 2, and it rarely occurs in children older than 6. In Europe, retinoblastoma has an estimated incidence rate of 1 per 13,844 live births (14.1 per million children under the age of 5) with approximately 300 children diagnosed per year (Stacey et al. 2021). Preserving life and preventing the loss of an eye, blindness, and other serious effects of treatment that reduce the patient’s life span or the quality of life remains a challenge. In addition, children with retinoblastoma have been more likely to lose their eye and die of metastatic disease in low-resource countries.

About Theriva™ Biologics, Inc.

Theriva™ Biologics (NYSE American: TOVX), is a diversified clinical-stage company developing therapeutics designed to treat cancer and related diseases in areas of high unmet need. The Company’s subsidiary Theriva Biologics, S.L. , has been developing a new oncolytic adenovirus platform designed for intravenous (IV), intravitreal and antitumoral delivery to trigger tumor cell death, improve access of co-administered cancer therapies to the tumor, and promote a robust and sustained anti-tumor response by the patient’s immune system. The Company’s lead clinical-stage candidates are: (1) VCN-01 (zabilugene almadenorepvec), an oncolytic adenovirus designed to replicate selectively and aggressively within tumor cells, and to degrade the tumor stroma barrier that serves as a significant physical and immunosuppressive barrier to cancer treatment; (2) SYN-004 (ribaxamase) which is designed to degrade certain commonly used IV beta-lactam antibiotics within the gastrointestinal (GI) tract to prevent microbiome damage, thereby limiting overgrowth of pathogenic organisms such as VRE (vancomycin resistant Enterococci) and reducing the incidence and severity of acute graft-versus-host-disease (aGVHD) in allogeneic hematopoietic cell transplant (HCT) recipients); and (3) SYN-020, a recombinant oral formulation of the enzyme intestinal alkaline phosphatase (IAP) produced under cGMP conditions and intended to treat both local GI and systemic diseases. For more information, please visit Theriva Biologics’ website at www.therivabio.com.

Forward-Looking Statement

This release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. In some cases forward-looking statements can be identified by terminology such as “may,” “should,” “potential,” “continue,” “expects,” “anticipates,” “intends,” “plans,” “believes,” “estimates,” and similar expressions, and include statements regarding preclinical data highlighting synergistic antitumor activity for the combination of topotecan and VCN-01 that may improve outcomes in refractory retinoblastoma patients with difficult-to-treat vitreous seeds; the intravitreal combination of VCN-01 and topotecan providing an exciting new opportunity to address the challenge of effective treatment of refractory retinoblastoma with vitreous seeds retinoblastoma and a potential pivotal clinical trial design in retinoblastoma These forward-looking statements are based on management’s expectations and assumptions as of the date of this press release and are subject to a number of risks and uncertainties, many of which are difficult to predict that could cause actual results to differ materially from current expectations and assumptions from those set forth or implied by any forward-looking statements. Important factors that could cause actual results to differ materially from current expectations include, among others, the ability to design a pivotal clinical trial in retinoblastoma for discussion with the FDA; VCN-01’s ability to have positive results in future trials for the treatment of retinoblastoma and other therapeutic benefits; the Company’s ability to reach clinical milestones when anticipated including enrolling the expected number of patients in each trial; the Company’s product candidates, including VCN-01, demonstrating safety and effectiveness, as well as results that are consistent with prior results; the ability to complete clinical trials on time and achieve the desired results and benefits, continuing clinical trial enrollment as expected; the ability to obtain regulatory approval for commercialization of product candidates or to comply with ongoing regulatory requirements, regulatory limitations relating to the Company’s ability to promote or commercialize their product candidates for the specific indications, acceptance of product candidates in the marketplace and the successful development, marketing or sale of the Company’s products, developments by competitors that render such products obsolete or non-competitive, the Company’s ability to maintain license agreements, the continued maintenance and growth of the Company’s and VCN’s patent estate, the ability to continue to remain well financed, and other factors described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 and its other filings with the SEC, including subsequent periodic reports on Forms 10-Q and current reports on Form 8-K. The information in this release is provided only as of the date of this release, and Theriva Biologics undertakes no obligation to update any forward-looking statements contained in this release on account of new information, future events, or otherwise, except as required by law.

For further information, please contact:

Investor Relations:
Kevin Gardner
LifeSci Advisors, LLC
kgardner@lifesciadvisors.com

Source: Theriva Biologics, Inc.

FAQ

What will Theriva Biologics (TOVX) present about VCN-01 at APAO 2026?

Theriva will present Phase 1 clinical safety and outcomes for intravitreal VCN-01 in refractory retinoblastoma. According to the company, the invited talk also includes preclinical synergy data with topotecan and presentation logistics for 07 February 2026.

What does the Phase 1 VCN-01 study (NCT03284268) involve for TOVX?

The Phase 1 trial evaluated two intravitreal injections of VCN-01 in pediatric refractory retinoblastoma patients. According to the company, it targeted patients facing enucleation after failing systemic, intra-arterial, or intravitreal chemotherapy.

How might combining VCN-01 and topotecan affect retinoblastoma treatment (TOVX)?

Preclinical data indicate synergistic antitumor activity when VCN-01 is coadministered with topotecan. According to the company, this combination may improve outcomes for patients with difficult-to-treat vitreous seeds in refractory retinoblastoma.

Does VCN-01 have regulatory designations relevant to retinoblastoma (TOVX)?

Yes. VCN-01 has Orphan Drug and Rare Pediatric Disease designations for retinoblastoma. According to the company, these designations support development and regulatory discussion toward a potential pivotal trial.

When and where is the VCN-01 retinoblastoma presentation at APAO 2026 for TOVX?

The presentation is scheduled for Saturday, 07 February 2026 at 4:46 PM HKT in Rooms S224-225 at HKCEC. According to the company, Dr. Jaume Català-Mora will present during the retinoblastoma-focused session.