Precigen Announces Groundbreaking Pivotal Study Data for PRGN-2012 in Patients with Recurrent Respiratory Papillomatosis in Which More than Half of Patients Achieved Complete Response

TABLE 1: Clinical Efficacy Summary

Total Patients (N=35)

Phase 1

(N=12)

Phase 2

(N=23)

Phase 1/2 Total

(N=35)

Complete Response

No surgeries needed during 12 months post-treatment

50% (6/12)

52% (12/23)

51% (18/35)

Decrease in Rate of Surgery

12 months post-treatment compared to 12 months pre-treatment

83% (10/12)

87% (20/23)

86% (30/35)

TABLE 2: Treatment-related Adverse Events Occurring in More Than 1 Patient

Total Patients (N=38)

1 x 10¹¹ PU

(N = 3)

5 x 10¹¹ PU

(N=35)

Grade 1

Grade 2

Grade 1

Grade 2

(N, %)

(N, %)

(N, %)

(N, %)

Chills

-

-

25 (71 %)

-

Fatigue

-

-

28 (80 %)

2 (6 %)

Fever

-

-

24 (69 %)

-

Headache

2 (6 %)

Hyperhidrosis

-

-

2 (6 %)

-

Injection site reaction

3 (100 %)

-

34 (97 %)

-

Myalgia

-

-

9 (26 %)

2 (6 %)

Nausea

-

-

8 (23 %)

-

Vomiting

-

-

2 (6 %)

-

About RRP

RRP is a rare, difficult-to-treat and sometimes fatal neoplastic disease of the upper and lower respiratory tracts that is caused by infection with HPV 6 or HPV 11.^1-4 RRP is classified based on age of onset as juvenile or adult. Currently, there is no cure for RRP and the current standard-of-care is repeated endoscopic debulking with ablation or excision of papillomatous lesions.^3,4 Recurrence of papilloma after surgical removal is very common and repeated procedures are required to debulk and monitor the disease, which exposes patients to anesthetic and surgical risks, and emotional distress. RRP morbidity and mortality results from the effects of papilloma mass on the vocal cords, trachea, and lungs, which may cause voice changes, stridor, airway occlusion, loss of lung volume, and/or post-obstructive pneumonia.⁵ Although rare, one to three percent of RRP cases can transform into invasive squamous cell carcinoma.^6,7

AdenoVerse^®

Precigen's AdenoVerse platform utilizes a library of proprietary adenovectors for the efficient gene delivery of therapeutic effectors, immunomodulators, and vaccine antigens designed to modulate the immune system. Precigen's gorilla adenovectors, part of the AdenoVerse library, have potentially superior performance characteristics as compared to current competition. AdenoVerse gene therapies have been shown to generate high-level and durable antigen-specific T-cell immune responses as well as an ability to boost these responses via repeat administration. Superior performance characteristics and high yield manufacturing of AdenoVerse vectors leveraging UltraVector^® technology allows Precigen to engineer cutting-edge investigational gene therapies to treat complex diseases.

About PRGN-2012 AdenoVerse^® Gene Therapy

PRGN-2012 is an investigational off-the-shelf AdenoVerse gene therapy designed to elicit immune responses directed against cells infected with human papillomavirus (HPV) 6 or HPV 11 for the treatment of RRP. PRGN-2012 was the first to receive Breakthrough Therapy Designation and an accelerated approval pathway for RRP from the US Food and Drug Administration (FDA). PRGN-2012 received Orphan Drug Designation from the FDA and from the European Commission. Results from the Phase 1 portion of the Phase 1/2 study were published in the peer-reviewed journal, Science Translational Medicine, a leading publication from the American Association for the Advancement of Science (AAAS).

AdenoVerse^® Clinical Programs

Precigen's AdenoVerse platform is currently under clinical investigation in a Phase 1/2 study of PRGN-2009 alone or in combination with an anti-PDL1/TGF-Beta Trap in patients with HPV-associated cancers (NCT04432597), a Phase 2 study of PRGN-2009 in combination with pembrolizumab in newly diagnosed patients with HPV-associated oropharyngeal squamous cell carcinoma (OPSCC) (NCT05996523), a Phase 2 study of PRGN-2009 in combination with pembrolizumab in patients with recurrent or metastatic cervical cancer (NCT06157151), and a Phase 1/2 study of PRGN-2012 in patients with recurrent respiratory papillomatosis (RRP) (NCT04724980). PRGN-2012 has been granted Orphan Drug Designation and Breakthrough Therapy Designation in patients with RRP by the FDA and Orphan Drug Designation by the European Commission. 

Precigen: Advancing Medicine with Precision^™

Precigen (NASDAQ:PGEN) is a dedicated discovery and clinical stage biopharmaceutical company advancing the next generation of gene and cell therapies using precision technology to target the most urgent and intractable diseases in our core therapeutic areas of immuno-oncology, autoimmune disorders, and infectious diseases. Our technologies enable us to find innovative solutions for affordable biotherapeutics in a controlled manner. Precigen operates as an innovation engine progressing a preclinical and clinical pipeline of well-differentiated therapies toward clinical proof-of-concept and commercialization. For more information about Precigen, visit www.precigen.com or follow us on X @Precigen, LinkedIn or YouTube.

Trademarks

Precigen, AdenoVerse, UltraVector 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

Some of the statements made in this press release are forward-looking statements. These forward-looking statements are based upon the Company's current expectations and projections about future events and generally relate to plans, objectives, and expectations for the development of the Company's business, including the timing and progress of preclinical studies, clinical trials, discovery programs and related milestones, the promise of the Company's portfolio of therapies, and in particular its CAR-T and AdenoVerse therapies. Although management believes that the plans and objectives reflected in or suggested by these forward-looking statements are reasonable, all forward-looking statements involve risks and uncertainties and actual future results may be materially different from the plans, objectives and expectations expressed in this press release. 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

Vice President, Investor Relations

Tel: +1 (301) 556-9850

[email protected] 

Media Contacts:

Donelle M. Gregory

[email protected] 

Glenn Silver

Lazar-FINN Partners

[email protected] 

References

¹ Mounts, P et al. (1982). "Viral etiology of juvenile- and adult-onset squamous papilloma of the larynx." Proc Natl Acad Sci U S A 79(17): 5425-5429.

² Smith, E et al. (1993). "Human papillomavirus infection in papillomas and nondiseased respiratory sites of patients with recurrent respiratory papillomatosis using the polymerase chain reaction." Arch Otolaryngol Head Neck Surg 119(5): 554-557.

³ Derkay, CS et al. (2008). "Recurrent respiratory papillomatosis: a review." Laryngoscope 118(7): 1236-1247.

⁴ Derkay, CS et al. (2019). "Update on Recurrent Respiratory Papillomatosis." Otolaryngol Clin North Am 52(4): 669-679.

⁵ Seedat, RY (2020). "Juvenile-Onset Recurrent Respiratory Papillomatosis Diagnosis and Management - A Developing Country Review." Pediatric Health Med Ther 11: 39-46.

⁶ Dedo, HH et al. (2001). "CO(2) laser treatment in 244 patients with respiratory papillomas." Laryngoscope 111(9): 1639-1644.

⁷ Silver, RD et al. (2003). "Diagnosis and management of pulmonary metastasis from recurrent respiratory papillomatosis." Otolaryngol Head Neck Surg 129(6): 622-629.