INO-3107

INO-3107 is INOVIO's investigational DNA immunotherapy targeting HPV-6 and HPV-11, the viral strains that cause Recurrent Respiratory Papillomatosis (RRP), a rare disease where benign tumors regrow repeatedly in the airway and force patients into surgery every few months. The BLA is under FDA review with a PDUFA decision date (the FDA-mandated decision deadline) of October 30, 2026, built on Phase 1/2 data from a 32-patient open-label adult study showing 81.3% of patients had fewer surgeries the year after treatment, including 28.1% who had zero surgeries [1][2][3][4]. The BLA was filed under the accelerated approval pathway, and FDA has preliminarily flagged inadequate information to justify that pathway, a material wrinkle that INOVIO plans to resolve through a pre-decision meeting [4]. Approval would make INO-3107 the first drug therapy ever cleared for RRP, the first DNA vaccine cleared by FDA for any indication, and INOVIO's first commercial product after more than two decades. For a company that has burned through public money on COVID, Zika, MERS, and cervical-pre-cancer DNA vaccine programs without an approval, this is the binary that determines whether INOVIO survives as an independent entity [7].

Novel investigational therapy. The submission rests on Phase 1/2 data from NCT04398433 (n=32, completed), not a Phase 3 trial [3]. The BLA was filed under the accelerated approval pathway, and per INOVIO's December 2025 BLA-acceptance disclosure, FDA preliminarily found inadequate information to justify accelerated approval and has signaled a substantive review issue; INOVIO intends to request a meeting with the agency [4]. FDA has also stated it does not currently plan to convene an Advisory Committee for this BLA [4], which materially reframes the public risk signal between now and the October 30, 2026 PDUFA decision. RRP's rarity and the total absence of any approved drug therapy gave INOVIO the regulatory use to file a BLA directly off Phase 1/2 results, an unusual path the FDA reserves for serious diseases with no alternatives. INO-3107 holds FDA Breakthrough Therapy Designation and Orphan Drug Designation [5]. Patients with RRP currently have no option beyond repeated surgical debulking under general anesthesia, sometimes every six to eight weeks, with cumulative airway scarring as a long-term cost. Adjuvant therapies including cidofovir and bevacizumab are used off-label without controlled evidence of meaningful benefit. The BLA covers adults only; juvenile-onset RRP (JO-RRP), the more aggressive pediatric form, is not part of this filing. If approved, INO-3107 also becomes the first FDA commercial validation of INOVIO's CELLECTRA electroporation delivery platform, which has only ever held a Device Master File and a European CE mark, never a US approval [8]. The Nat Commun 2025 publication is the most current public dataset for the BLA package [1].

RRP is caused by chronic infection with HPV types 6 and 11, the same low-risk strains that cause genital warts. In the airway, these viruses turn normal epithelial cells into cauliflower-like papillomas that grow back faster than surgeons can cut them out. Adult patients average four to five surgeries per year, sometimes ten or more. The immune system fails to clear the virus on its own, because the HPV proteins driving the growth (called E6 and E7) are produced quietly inside infected cells where antibodies cannot reach them. INO-3107 is a piece of synthetic DNA encoding instructions to make HPV-6 and HPV-11 versions of E6 and E7. The DNA is injected into muscle, then electroporation, a brief electrical pulse from INOVIO's CELLECTRA device, pokes temporary holes in cell membranes so the DNA actually gets inside cells. Those cells then produce small amounts of E6 and E7, which trains killer T-cells to recognize and destroy HPV-infected papilloma cells wherever they find them, including in the airway [1]. The biological case is reasonable. HPV proteins are genuinely foreign, T-cell responses against E6/E7 have shown the ability to clear HPV lesions in cervical disease settings, and the Phase 1/2 data confirmed that vaccinated patients did generate measurable HPV-specific T-cell responses that correlated with clinical benefit on surgery reduction [1][2].

The registration dataset comes from NCT04398433, a Phase 1/2 open-label single-arm study in 32 adults with HPV-6 or HPV-11-driven RRP who required at least two (per the published efficacy population, with most patients having 3+) surgical interventions in the prior 12 months [3]. Four doses of INO-3107 at 1 mg by intramuscular electroporation at weeks 0, 3, 6, and 12. Primary endpoint was safety (treatment-emergent adverse events and serious TEAEs). The key secondary efficacy endpoint was change in number of surgical interventions during the 52 weeks after dosing versus the 52 weeks before [1][3]. Open-label, single-arm, n=32 is thin by oncology standards but standard for ultra-rare disease BLAs where each patient acts as their own historical control. The within-patient comparison (surgeries before vs after) is defensible because RRP recurrence is metronomic and patients know their own surgical cadence within a month or two. Limitations are real. No randomized control, no placebo group, and the published 52-week post-treatment window was the primary efficacy comparator (with a separate Laryngoscope 2025 long-term extension addressing durability) [2]. Hawthorne effects (patients enrolled in a clinical trial may behave differently than they would outside it, including delaying elective surgery decisions) cannot be fully excluded. From the Nat Commun 2025 paper: 81.3% (26/32) of patients had fewer surgeries in the year after dosing, the median was a decrease of 3 surgeries (95% CI -3, -2) from a pre-treatment median of 4 (range 2-8), and 28.1% (9/32) had a complete response of zero surgeries during or after the dosing window [1]. The Laryngoscope 2025 extension reported that the proportion of patients with a 50-100% surgery reduction rose from 72% in Year 1 to 86% in Year 2, and complete responses rose from 28% to 50% [2]. That effect size, with durability data now in hand, is large enough to survive most of the uncontrolled-design skepticism on the efficacy axis, though it does not resolve the accelerated-approval-pathway question FDA has raised.

This drug is under FDA review (NDA/BLA), with a PDUFA decision date of 2026-10-30. Our estimate of 84% is the historical filing-approval rate for its area, adjusted for its rejection history (no prior Complete Response Letters). At this stage the early-trial design model no longer applies - what matters is that it reached the FDA and whether it has been rejected before.

Accelerated-approval pathway. FDA's December 2025 BLA acceptance notice flagged a preliminary finding of inadequate information to justify accelerated approval [4]. INOVIO plans to request a meeting to resolve this. A Complete Response Letter (CRL) at the October 30, 2026 decision date that asks for additional confirmatory evidence is the single most likely path to a non-approval outcome. CMC (Chemistry, Manufacturing, and Controls). INOVIO's prior BLA-stage work has been dogged by manufacturing concerns, most visibly when the FDA's clinical hold on the COVID program in 2020 forced the company off-track [7]. The CELLECTRA device has never been FDA-approved (it sits on a Device Master File from 2009 and carries an EU CE mark only) [8], adding device-side combination-product review on top of biologic-side review. Efficacy interpretation. The within-patient comparison is convincing to trialists, but a single-arm design is exposed to regression-to-mean and placebo arguments. The Year 2 durability data partially blunts this objection [2]. Safety. The reported tolerability profile is mild (mostly injection-site reactions and transient flu-like symptoms) [1][2]. DNA vaccines as a class have not produced serious safety signals in hundreds of trials over twenty years. Commercial. Adult RRP US prevalence is roughly 1 to 2 per 100,000 adults; JO-RRP (juvenile-onset, typically diagnosed before age 12) is a separate and more aggressive disease that is not in this BLA but represents a future label expansion target. At a $150,000 per course price (defensible for a one-time treatment that prevents repeat anesthesia events), peak US sales for the adult indication likely land in the $200 to $400 million range, not blockbuster territory. Class precedent. The closest INOVIO comparator is VGX-3100 in cervical high-grade squamous intraepithelial lesions (HSIL); REVEAL 1 reported positive primary and secondary endpoint results in March 2021 [9], and ApolloBio's separately-run Phase 3 in China announced positive topline results in May 2026 [10]. VGX-3100 has not yet reached FDA approval, but it is not a Phase 3 failure, so the historical narrative of a DNA-vaccine class graveyard does not hold. INO-3107 should be read as the lead candidate of a class that has now produced two positive Phase 3 datasets in adjacent HPV indications, not the last hope of a failed class.

Worth watching closely. October 30, 2026 PDUFA is a true binary catalyst for INOVIO (NASDAQ: INO). INOVIO reported $37.7 million in cash and short-term investments as of March 31, 2026, raised $16 million in net proceeds in April 2026, and guided to an approximately $18 million Q2 2026 operational cash burn, projecting runway into Q1 2027 - past the PDUFA date but with very little cushion if the decision is a CRL requiring a follow-up trial [11]. Approval likely multiplies the equity several times. A CRL likely halves it and forces a dilutive raise from a much weaker negotiating position. The key signal change versus the prior reading of this catalyst: FDA has stated it does not currently plan to hold an Advisory Committee meeting [4], so an AdComm announcement is no longer the expected pre-PDUFA risk tell. The real tells now are (a) any 8-K disclosing the outcome of INOVIO's planned meeting with FDA on the accelerated-approval pathway question and (b) any further FDA information requests during the review cycle. Both will land in the next 3 to 4 months. The failure mode in the event of a CRL matters more than the CRL itself. A CMC CRL is fixable on a 6 to 12 month timeline. A CRL asking for additional confirmatory clinical evidence on accelerated-approval criteria would push approval out by years and likely require new financing INOVIO is poorly positioned to raise on workable terms. Beyond INOVIO, the read-through extends to the DNA vaccine class as a whole and to any company using electroporation delivery (Geneos, ICVAX, others). First FDA approval would change risk perception across the category, and the class is in a stronger position than it appeared two years ago, with positive Phase 3 readouts on VGX-3100 in both the INOVIO REVEAL 1 trial [9] and the ApolloBio China Phase 3 [10]. That class-validation effect is the part most likely to be under-priced by the market today.

Outcome of INOVIO's requested FDA meeting on the accelerated-approval pathway question (next ~60 days) [4]. PDUFA decision on October 30, 2026. Any FDA information request issued during the review cycle (8-K disclosure required). INOVIO quarterly cash position and any pre-approval financing terms [11]. Long-term follow-up beyond Year 2 from NCT04398433. Reactions from RRP patient advocacy groups (RRPF) and pediatric ENT surgeons, who will determine real-world uptake if approved and will inform any future JO-RRP label expansion. Read-across to other electroporation-DNA assets following VGX-3100 REVEAL 1 [9] and ApolloBio Phase 3 [10] positive datasets.