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Papzimeos

Pronunciation: Pap-zim-e-os
Generic name: zopapogene imadenovec-drba
Dosage form: suspension for subcutaneous injection (5 x 10¹¹ PU/1 mL)

Medically reviewed by Carmen Pope, BPharm. Last updated on Aug 21, 2025.

What is Papzimeos?

Papzimeos is used to treat recurrent respiratory papillomatosis (RRP) in adults. This gene therapy is the first non-replicating adenoviral vector-based immunotherapy approved for RRP treatment. Papzimeos is given by subcutaneous injection 4 times over a 12-week interval.

RRP is a rare, life-threatening infection caused by human papillomavirus (HPV) types 6 and 11, resulting in voice problems, airway obstruction, and pneumonia.

Papzimeos (zopapogene imadenovec-drba) gained FDA approval on August 14, 2025.

Approval was supported by the PRGN-2012-201 clinical trial (NCT04724980), which demonstrated that 51% (18/35) of study participants achieved a complete response, with no surgeries needed for 12 months; 15 maintained response at 24 months.

How does Papzimeos work?

Mechanism

Papzimeos works in RRP by using selected parts of HPV 6 and HPV 11 proteins as a fusion antigen, training the immune system to recognize and attack cells infected with these viruses.

Side effects

Common side effects

The most common side effects of Papzimeos are:

Serious side effects and warnings

Papzimeos may cause the following serious side effects:

Injection site reactions. These have occurred after an injection of Papzimeos, and some may be severe. Signs and symptoms may include redness, pain, swelling, itching, or warmth at the injection site. Your healthcare provider will monitor you for these for at least 30 minutes after the initial treatment. Manage symptoms with a cold compress, over-the-counter pain relievers, or antihistamines if needed. Seek urgent medical attention if symptoms worsen or are accompanied by signs of a systemic allergic reaction (such as difficulty breathing, widespread rash, or facial swelling) or an infection

Thrombotic events. These may occur after a Papzimeos injection and symptoms may include shortness of breath, chest pain, leg swelling, persistent abdominal pain, or neurological symptoms (including severe or persistent headaches or blurred vision). Seek urgent medical attention if you develop any of these symptoms.

These are not all the side effects of Papzimeos. See the Papzimeos Prescribing Information for a list of side effects. To report suspected adverse reactions, contact Precigen Inc. at 855-743-6777, and medinfo@precigen.com or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

How is Papzimeos administered?

Papzimeos is administered by a health professional by subcutaneous (under the skin) injection, into the outer, upper arm or outer, upper thigh.

You and your healthcare provider should treat any material associated with the Papzimeos injection as contaminated.

Dosing information

Dose of Papzimeos for Recurrent Respiratory Papillomatosis (RRP) in Adults

Storage

Papzimeos requires storage at -60°C (-76°F) or less.

When ready to administer, remove Papzimeos from the freezer and thaw immediately in a 37°C (98.6°F) water bath or dry bead bath until there are no visible ice crystals in the vial, for a time of less than or equal to 5 minutes.

Treat any Papzimeos spills with a virucidal agent (eg, sodium hypochlorite with 0.5% active chlorine or 6% hydrogen peroxide) for 15 minutes.

Dispose of any unused product or waste materials as per facility biohazard waste disposal procedure.

Ingredients

Active ingredient: zopapogene imadenovec-drba 5 x 1011 PU/1 mL

Excipients: Tris base (10 mM), sodium chloride (75 mM), magnesium chloride hexahydrate (1 mM), polysorbate 80 (0.019 mM), and trehalose dihydrate (146 mM).

Supplied as a sterile, frozen suspension that has been aseptically filled into single-dose vials fitted with a rubber stopper and aluminum flip-cap seal.

Manufacturer

Papzimeos is manufactured by Precigen Inc., 20358 Senecca Meadows Parkway, Germantown, MD 20876 USA. U.S. Licence No. 2364.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.