Precigen Presents New Long-Term Durability Data for PAPZIMEOS, Recently Granted Seven-Year Market Exclusivity, Demonstrating Complete Responses Beyond 4 Years

Rhea-AI Summary

Precigen (Nasdaq:PGEN) reported new long-term durability data for PAPZIMEOS in adults with recurrent respiratory papillomatosis (RRP).

As of April 30, 2026, 15 of 18 complete responders (83%) maintained responses for at least 36 months, 5 beyond 4 years, with no new safety events. PAPZIMEOS has FDA full approval and seven-year orphan drug market exclusivity.

AI-generated analysis. Not financial advice.

Positive

• 15 of 18 complete responders (83%) maintain complete response for at least 36 months
• All complete responders have 36–51 months follow-up, mean follow-up of 40 months
• Five complete responders remain surgery-free with ongoing responses beyond 4 years
• No new adverse safety events observed during long-term follow-up
• PAPZIMEOS granted full FDA approval for adults with recurrent respiratory papillomatosis
• Seven-year US FDA orphan drug market exclusivity granted to PAPZIMEOS

Negative

• None.

Key Figures

Durable responders: 15 of 18 (83%) Minimum follow-up: 36 months Follow-up range: 36 to 51 months +5 more

8 metrics

Durable responders 15 of 18 (83%) Complete responders with ongoing complete responses at April 30, 2026 cutoff

Minimum follow-up 36 months All complete responders had at least this duration of follow-up

Follow-up range 36 to 51 months Range of follow-up for complete responders

Mean follow-up 40 months Mean follow-up duration for complete responders

Long-term responders 5 patients Complete responders with ongoing responses beyond 4 years

Market exclusivity 7 years US FDA orphan drug market exclusivity for PAPZIMEOS

Additional treatment 0 treatments No additional RRP treatments during follow-up for complete responders

New safety events None observed No new adverse safety events in long-term follow-up

Market Reality Check

Price: $4.34 Vol: Volume 5,529,870 vs 20-da...

normal vol

$4.34 Last Close

Volume Volume 5,529,870 vs 20-day average 3,919,745 (relative volume 1.41x) indicates elevated trading activity ahead of this update. normal

Technical Shares at $4.34, trading above the 200-day MA of $3.98, and about 20.59% below the 52-week high of $5.465 while well above the 52-week low of $1.28.

Peers on Argus

PGEN fell 3.77% while peers were mixed: ZYME -0.75%, GPCR -4.47%, but RCUS +3.64...

PGEN fell 3.77% while peers were mixed: ZYME -0.75%, GPCR -4.47%, but RCUS +3.64%, NTLA +2.7%, and TRML flat. This pattern points to stock-specific factors rather than a uniform biotech move.

Historical Context

5 past events · Latest: May 27 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
May 27	Orphan exclusivity update	Positive	+3.8%	FDA granted seven-year US orphan drug exclusivity for PAPZIMEOS.
May 26	Investor conferences	Positive	+0.0%	Company scheduled fireside chats with J.P. Morgan and Goldman Sachs.
May 13	Q1 2026 earnings	Positive	+10.8%	First PAPZIMEOS-driven quarter with $21.6M net product revenue and narrower loss.
May 07	Earnings call notice	Neutral	+1.4%	Announcement of timing for Q1 2026 results and business update call.
Apr 07	Commercial uptake update	Positive	-1.7%	Reported robust PAPZIMEOS uptake and Q1 2026 revenue expected above $18M.

Pattern Detected

Recent PAPZIMEOS and earnings news has generally seen positive or modestly negative moves, with one notable selloff on a positive commercial update.

Recent Company History

Over the past two months, Precigen has transitioned firmly into a commercial story around PAPZIMEOS. Q1 2026 results on May 13 showed revenue of $23.3M, driven by $21.6M from PAPZIMEOS, and the stock rose 10.84%. An early April update on ‘robust uptake’ and expected Q1 revenue above $18M saw a -1.67% reaction. More recently, the grant of US orphan exclusivity through August 14, 2032 produced a 3.77% gain. Today’s long-term durability data extends this same commercialization and differentiation narrative.

Regulatory & Risk Context

Active S-3 Shelf

Shelf Active

Active S-3 Shelf Registration 2025-08-19

An effective Form S-3 shelf registration filed on August 19, 2025 registers secondary sales by selling stockholders of up to 143,809,489 common shares and 79,000 preferred shares. The filing states Precigen will receive no proceeds from these sales, which may increase trading liquidity but do not directly fund the company.

Market Pulse Summary

This announcement highlights long-term durability and safety for PAPZIMEOS, with 83% of complete res...

Analysis

This announcement highlights long-term durability and safety for PAPZIMEOS, with 83% of complete responders maintaining benefit for at least 36 months and no new safety events. Together with the FDA’s 7-year orphan drug market exclusivity, it reinforces PAPZIMEOS as a differentiated therapy in recurrent respiratory papillomatosis. Investors may watch future updates on patient numbers, real-world outcomes, and ongoing follow-up to see whether durability remains consistent as experience broadens.

Key Terms

recurrent respiratory papillomatosis, non-replicating adenoviral vector-based immunotherapy, complete response, orphan drug, +4 more

8 terms

recurrent respiratory papillomatosis medical

"for the treatment of adults with recurrent respiratory papillomatosis (RRP)."

Recurrent respiratory papillomatosis is a rare condition in which benign but repeatedly returning growths form in the airways, especially the voice box and windpipe, causing hoarseness, breathing trouble and frequent need for medical procedures. For investors, it matters because the chronic, recurring nature of the disease drives ongoing demand for surgeries, drugs, and medical devices, and makes it a target for new therapies and regulatory reviews that can affect healthcare spending and company revenues.

non-replicating adenoviral vector-based immunotherapy medical

"a novel non-replicating adenoviral vector-based immunotherapy: Effects on complete"

A non-replicating adenoviral vector-based immunotherapy is a treatment that uses a harmless, disabled virus as a delivery truck to carry genetic instructions into the body’s cells so the immune system learns to recognize and attack a disease, such as a tumor or an infection. It matters to investors because this approach can offer targeted effects and a generally safer profile than live viruses, creating significant commercial and regulatory upside if clinical trials succeed, but also carrying typical biotech development and approval risks.

complete response medical

"demonstrated ongoing complete responses for at least 36 months without any"

A complete response is a positive outcome in which a company’s efforts to address issues or questions fully resolve the problem, often meaning that no further action or investigation is needed. For investors, it signals that concerns have been thoroughly addressed, which can boost confidence in the company's stability or decision-making. Think of it like a doctor fully treating an illness, leaving no remaining symptoms.

orphan drug regulatory

"US FDA granted seven-year period of orphan drug market exclusivity to PAPZIMEOS"

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.

market exclusivity regulatory

"US FDA granted seven-year period of orphan drug market exclusivity to PAPZIMEOS"

Market exclusivity is a limited legal protection that prevents rivals from selling the same drug or product for a set time, even if others could otherwise make a copy. It’s like a temporary shop window reserved for one seller, giving that company sole access to customers for that product. For investors, exclusivity can mean predictable sales and higher profit margins during the protected period, and the impending end of exclusivity is a key risk factor.

immunotherapy medical

"a novel non-replicating adenoviral vector-based immunotherapy: Effects on complete"

Treatment that uses or enhances the body’s immune system to detect and fight disease, most often cancers or chronic infections; think of it as training or arming the body’s own soldiers to find and destroy targets. It matters to investors because successful immunotherapies can lead to high-value drug approvals, recurring revenue from long-term treatments, and changes in competitive dynamics, while failures or safety issues in clinical trials can materially affect company valuations.

adenoviral vector medical

"a novel non-replicating adenoviral vector-based immunotherapy: Effects on complete"

Adenoviral vector is a harmless or modified virus used as a delivery vehicle to carry genetic instructions into human cells, similar to a delivery truck bringing a package to a house. It matters to investors because this delivery method underpins certain vaccines and gene therapies, affecting how well a treatment works, how safe it appears, how difficult it is to manufacture at scale, and how regulators and markets will value the underlying technology and intellectual property.

fda regulatory

"PAPZIMEOS was granted full approval by the United States Food and Drug Administration (FDA)"

The FDA is the U.S. federal agency that evaluates and approves medical drugs, devices, biological therapies and certain foods; think of it as the gatekeeper that decides whether a medical product is safe and effective for patients. For investors, FDA decisions determine whether a company can sell a product, affect expected revenue and introduce regulatory risk, so approvals, rejections or safety warnings can quickly move a company's valuation and stock price.

AI-generated analysis. Not financial advice.

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• 15 out of 18 complete responders, or 83%, demonstrated ongoing complete responses for at least 36 months without any additional treatment for RRP
• 5 complete responders have ongoing responses beyond 4 years
• Follow-up is ongoing; median duration of complete response has not yet been reached
• No new adverse safety events have been observed during long-term follow-up
• US FDA granted seven-year period of orphan drug market exclusivity to PAPZIMEOS

GERMANTOWN, Md., May 30, 2026 /PRNewswire/ -- Precigen, Inc. (Nasdaq: PGEN), a commercial-stage biopharmaceutical company specializing in the advancement of innovative precision medicines to improve the lives of patients, today announced updated long-term follow-up data from the pivotal study of PAPZIMEOS™ (zopapogene imadenovec-drba) for the treatment of adults with recurrent respiratory papillomatosis (RRP). Updated durability of response data were presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago in a presentation titled, "Zopapogene imadenovec-drba, a novel non-replicating adenoviral vector-based immunotherapy: Effects on complete and durable responses in recurrent respiratory papillomatosis pivotal trial."

PAPZIMEOS was granted full approval by the United States Food and Drug Administration (FDA) and was subsequently granted seven-year market exclusivity, further strengthening its position as the first and only approved therapy for the treatment of adults with RRP.

Key data highlights from the ASCO presentation include:

• 15 out of 18 complete responders, or 83%, demonstrated ongoing complete responses as of the April 30, 2026 data cutoff (see Figure 1);
• Patients did not receive any additional treatments for RRP, including surgery or off-label investigational treatments, during this follow-up period;
• All complete responders had at least 36 months of follow-up, with a median follow-up of 36 months (range: 36 to 51 months) and a mean follow-up of 40 months;
• 5 complete responders have ongoing responses beyond 4 years;
• Median duration of complete response has not yet been reached; and
• No new safety events were observed during long-term follow-up.

"The presentation at ASCO marks an important maturation of the PAPZIMEOS pivotal study data, with all complete responders now followed for at least 36 months, 83% with ongoing response, including 5 patients who are surgery-free beyond 4 years," said Helen Sabzevari, PhD, President and CEO of Precigen. "For adults living with RRP, durability matters. These results continue to show that PAPZIMEOS provides sustained complete responses, reinforcing its role as the new standard of care for a disease historically managed through repeated surgeries."

About RRP
RRP is a rare, debilitating, and potentially life-threatening disease of the upper and lower respiratory tract caused by chronic HPV 6 or HPV 11 infection. RRP can lead to severe voice disturbance, compromised airways, and recurrent post-obstructive pneumonia. Although rare, RRP has the potential for transformation to malignant cancer and can be fatal. Management of RRP has primarily consisted of repeated surgeries, which do not address the underlying cause of the disease and can be associated with significant morbidity as well as significant patient and health system burden. As the number of lifetime surgeries increases, the risk for irreversible iatrogenic laryngeal injury increases with each surgery, and patients may undergo hundreds of these surgeries over their lifetimes. RRP can impact patients' work and social lives, financial stability, and mental health. Patients with RRP can experience substantial impacts to daily living with decreased quality of life and high health care utilization. Based on an internal analysis of claims data and electronic health records, there are approximately 27,000 adult RRP patients in the US.

About PAPZIMEOS^™ (zopapogene imadenovec-drba), for subcutaneous injection only
PAPZIMEOS is the first and only FDA-approved therapy for the treatment of adults with RRP and the first and only approved therapy to address the root cause of RRP. PAPZIMEOS is a non-replicating adenoviral vector-based immunotherapy designed to express a fusion antigen comprising selected regions of human papillomavirus (HPV) types 6 and 11 proteins. PAPZIMEOS is designed to generate an immune response directed against HPV 6 and HPV 11 proteins in patients with RRP. Discovered and designed in Precigen's labs using Precigen's proprietary AdenoVerse therapeutic platform, PAPZIMEOS represents a new therapeutic paradigm for RRP.

Indication and Important Safety Information

What is PAPZIMEOS?
PAPZIMEOS is a type of immunotherapy used to treat a condition called recurrent respiratory papillomatosis (RRP) in adults.

What is the most important information I should know about PAPZIMEOS?
Some people may have a reaction to the shot. Signs and symptoms may include redness, pain, swelling, itching, or warmth where the shot was given. After your first treatment, your healthcare provider will watch you for at least 30 minutes to make sure you're feeling okay.

Please contact your doctor immediately if you develop an infection, the reaction to your shot worsens, or you experience any of the below symptoms, which may indicate a systemic allergic reaction:

• Difficulty breathing
• Widespread rash
• Facial swelling

Thrombotic events (blood clots that block your blood vessels) may occur after your PAPZIMEOS shot. Please notify your doctor immediately if you have the following symptoms:

• Shortness of breath
• Chest pain
• Leg swelling
• Persistent abdominal pain
• Severe or persistent headaches
• Blurred vision

What should I know before taking PAPZIMEOS?
Before taking PAPZIMEOS, tell your healthcare provider about all of your medical conditions, including:

• If you are pregnant or plan to become pregnant because it is not known if PAPZIMEOS will harm the unborn baby.
• If you are breastfeeding or plan to breastfeed. It is unknown if PAPZIMEOS is present in breast milk, or how it affects the breastfeeding child or milk production. Talk to your healthcare provider about the best way to feed your baby during treatment with PAPZIMEOS.

What are the most common side effects of PAPZIMEOS?
The most common side effects include:

• Pain, redness, or swelling where the shot was given
• Feeling tired
• Chills
• Fever
• Muscle aches
• Nausea (feeling sick)
• Headache
• Increased heart rate
• Diarrhea
• Vomiting
• Sweating a lot

These are not all of the possible side effects of PAPZIMEOS. Call your healthcare provider for medical advice about side effects. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088. You may also report side effects to Precigen, Inc. at 1-855-PGE-NRRP (1-855-743-6777).

Please see full Prescribing Information.

Precigen: Advancing Medicine with Precision^®
Precigen (Nasdaq: PGEN) is a commercial-stage biopharmaceutical company specializing in the advancement of innovative precision medicines to address difficult-to-treat diseases with high unmet patient need. Precigen is dedicated to advancing scientific breakthroughs from proof-of-concept through commercialization. With a strong commitment to innovation, Precigen is developing a robust pipeline of differentiated therapies across its core therapeutic areas of immuno-oncology, autoimmune disorders, and infectious diseases. For more information about Precigen, visit www.precigen.com or follow us on LinkedIn or YouTube.

Trademarks
Precigen, PAPZIMEOS, AdenoVerse, and Advancing Medicine with Precision are trademarks of Precigen and/or its affiliates. Other names may be trademarks of their respective owners.

Cautionary Statement Regarding Forward-Looking Statements
This press release contains "forward-looking" statements within the meaning of the safe harbor provisions of the US Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as: "anticipate," "intend," "plan," "goal," "seek," "believe," "project," "estimate," "expect," "strategy," "future," "likely," "may," "should," "will" and similar references to future periods. These statements are subject to numerous risks and uncertainties that could cause actual results to differ materially from what the Company expects. Examples of forward-looking statements include, among others, information relating to the Company's business and business plans, the success of efforts to commercialize PAPZIMEOS™ (zopapogene imadenovec-drba) for the treatment of recurrent respiratory papillomatosis (RRP) in adults including the revenue that the Company expects to realize from such efforts, the Company's ability to successfully obtain foreign regulatory approvals for PAPZIMEOS, expectations about the safety and efficacy of PAPZIMEOS, the ability of PAPZIMEOS to treat RRP, the Company's future financial and operational results including the Company's ability to reach cash flow break-even, and the Company's ability to commence clinical studies or complete ongoing clinical studies for the Company's clinical and pre-clinical stage candidates. The Company has no obligation to provide any updates to these forward-looking statements even if its expectations change. All forward-looking statements are expressly qualified in their entirety by this cautionary statement. For further information on potential risks and uncertainties, and other important factors, any of which could cause the Company's actual results to differ from those contained in the forward-looking statements, see the section entitled "Risk Factors" in the Company's most recent Annual Report on Form 10-K and subsequent reports filed with the Securities and Exchange Commission.

Investor Contact:
Steven M. Harasym
Tel: +1 (202) 365-2563
investors@precigen.com 

Media Contact:
Donelle M. Gregory
press@precigen.com

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SOURCE Precigen, Inc.

FAQ

What long-term durability results did Precigen (PGEN) report for PAPZIMEOS in May 2026?

Precigen reported that 15 of 18 complete responders (83%) maintained complete responses for at least 36 months. According to Precigen, follow-up ranged from 36 to 51 months, with a mean of 40 months and median duration of complete response not yet reached.

How many PAPZIMEOS patients remain surgery-free beyond 4 years in the PGEN RRP trial?

Five complete responders in the PAPZIMEOS pivotal trial have ongoing responses beyond 4 years. According to Precigen, these adults with recurrent respiratory papillomatosis required no additional RRP treatments, including surgery or off-label investigational therapies, during the long-term follow-up period.

Did Precigen (PGEN) report any new safety issues for PAPZIMEOS in long-term follow-up?

No new adverse safety events were observed during long-term PAPZIMEOS follow-up. According to Precigen, all complete responders were followed for at least 36 months, and durability data were updated as of the April 30, 2026 cutoff without additional safety concerns.

What regulatory status and market exclusivity does PAPZIMEOS have according to Precigen (PGEN)?

PAPZIMEOS has full FDA approval for adults with recurrent respiratory papillomatosis and seven-year orphan drug exclusivity. According to Precigen, this exclusivity period in the United States strengthens PAPZIMEOS’s position as the first and only approved RRP therapy for adults.

What was presented about PAPZIMEOS at the 2026 ASCO Meeting for Precigen (PGEN)?

Precigen presented updated durability and response data from the PAPZIMEOS pivotal RRP trial at ASCO 2026. According to Precigen, the presentation highlighted complete and durable responses, with 83% of complete responders still in response and no new long-term safety events reported.

Why are the new PAPZIMEOS data important for adults with RRP and PGEN investors?

The data show sustained complete responses over three to four-plus years without additional RRP treatment. According to Precigen, these durability and safety findings support PAPZIMEOS’s role as a new standard of care and align with its seven-year US orphan drug exclusivity.