News Release Details

- RP-L102 Continues to Demonstrate Increasing and Durable Engraftment (Peripheral Vector Copy Number) In Fanconi Anemia Patients for Up to Thirty Months with First-Generation Process –

NEW YORK--(BUSINESS WIRE)--Oct. 18, 2018-- Rocket Pharmaceuticals, Inc. (Nasdaq:RCKT) (“Rocket”), a leading U.S.-based multi-platform gene therapy company, presents updated long-term clinical data from its ongoing Phase 1/2 clinical trial of RP-L102 for Fanconi Anemia (FA) at the 2018 Annual Congress of the ESGCT in Lausanne, Switzerland.

Title: Gene Therapy Trial in Non-Conditioned Fanconi Anemia Patients
Session: Blood Disorders I
Presenter: Paula Rio, Ph.D., Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT)/ CIBER-Rare Diseases / IIS-Fundación Jiménez Díaz

Four patients have met the requisite 12-month follow-up time for long-term stem-cell engraftment analysis. As evidenced by progressively increasing vector copy number (VCN) in peripheral blood mononuclear cells, RP-L102 continues to demonstrate durable engraftment in all four patients, ranging from 18 to 30 months since gene therapy administration. Patients also demonstrated improved resistance of bone marrow CD34+ cells in the presence of mitomycin-C (MMC) and durable increases in peripheral T-lymphocyte chromosomal stability in the presence of diepoxybutane (DEB). MMC- and DEB-resistance are two key diagnostic measures of functional and phenotypic correction in FA. Trends for continued stabilization of previously-declining blood counts and the progressive increase of corrected versus non-corrected peripheral blood leukocytes continued for all patients. These patients were treated with “Process A”—the first one developed for RP-L102.

Of note, the first patient in this cohort (Patient 2002)—whose stem cells were collected at an early age and is representative of the target demographic—experienced improvements in peripheral VCN from 0 at month 0, to 0.43 at month 24, and to 0.55 at month 30. Patient 2002 also demonstrated improvements in bone marrow MMC-resistance from 0% to more than 70% at month 24, approaching the normal range.

“These data are very encouraging,” said Gaurav Shah, M.D., Chief Executive Officer and President of Rocket. “The improvements highlight the natural selective advantage that uniquely exists in FA for gene corrected stem cells over diseased stem cells and obviates the need for conditioning. Furthermore, the data reflect the potential of RP-L102 to restore the functionality of bone marrow hematopoietic stem cells.”

In the first half of 2019, Rocket plans to treat patients in the U.S.—under a Rocket-sponsored Investigational New Drug (IND) application—and in the EU with “Process B” RP-L102. This new optimized process incorporates higher cell doses, transduction enhancers, and commercial-grade vector.

Data from this presentation will be available in the Company’s corporate presentation at: www.rocketpharma.com/pipeline/.

About RP-L102 (LVV-based gene therapy for Fanconi Anemia)

RP-L102 is Rocket’s lentiviral vector (LVV)-based gene therapy in development for patients with FA with Rocket’s collaboration partners at Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) in Spain, CIBER-Rare Diseases and IIS-Fundación Jiménez Díaz. The International Fanconi Anemia Gene Therapy Working Group helped develop the structure of RP-L102, which begins with a HIV-1-derived, self-inactivating lentiviral vector. RP-L102’s lentiviral vector carries the FANC-A gene as part of the PGK-FANCA-WPRE expression cassette which includes a phosphoglycerate kinase (PKG) promoter and an optimized woodchuck hepatitis virus posttranscriptional regulatory element (WPRE). The ex vivo administration process begins with the removal and isolation of hematopoietic stem cells using a CD34+ selection process. Autologous genetically modified CD34+ enriched hematopoietic cells (fresh or cryopreserved) are infused back into patients to restore function. RP-L102 is currently being studied in a Phase 1/2 clinical trial in the European Union with an Investigational Medicinal Product Dossier (IMPD) in place with the Spanish Agency for Medicines and Health Products. RP-L102 has been granted Orphan Drug designation for the treatment of Fanconi Anemia type A in the United States and in Europe.

About Fanconi Anemia

Fanconi Anemia (FA) is a rare pediatric disease characterized by bone marrow failure, malformations and cancer predisposition. The primary cause of death among patients with FA is bone marrow failure, which typically occurs during the first decade of life. Allogeneic hematopoietic stem cell transplantation (HSCT), when available, corrects the hematologic component of FA, but requires myeloablative conditioning, which is highly toxic for the patient. HSCT is frequently complicated by graft versus host disease and also increases the risk of many solid organ malignancies. Approximately 60-70% of patients with FA have a FANC-A gene mutation, which encodes for a protein essential for DNA repair. Mutation in the FANC-A gene leads to chromosomal breakage and increased sensitivity to oxidative and environmental stress. Chromosome fragility induced by DNA-alkylating agents such as mitomycin-C (MMC) or diepoxybutane (DEB) is the ‘gold standard’ test for FA diagnosis. The DEB assay can further differentiate FA patients from somatic mosaic patients. Somatic mosaicism occurs when there is a spontaneous reversion mutation that can lead to a mixed chimerism of corrected and uncorrected bone marrow cells leading to stabilization or correction of an FA patient’s blood counts in the absence of any administered therapy. Somatic mosaicism provides strong rationale for the development of FA gene therapy and demonstrates the selective advantage of gene-corrected hematopoietic cells in FA¹.

¹Soulier, J.,et al. (2005) Detection of somatic mosaicism and classification of Fanconi anemia patients by analysis of the FA/BRCA pathway. Blood 105: 1329-1336

About Rocket Pharmaceuticals, Inc.

Rocket Pharmaceuticals, Inc. (Nasdaq:RCKT) (“Rocket”) is an emerging, clinical-stage biotechnology company focused on developing first-in-class gene therapy treatment options for rare, devastating diseases. Rocket’s multi-platform development approach applies the well-established lentiviral vector (LVV) and adeno-associated viral vector (AAV) gene therapy platforms. Rocket's lead clinical program is a LVV-based gene therapy for the treatment of Fanconi Anemia (FA), a difficult to treat genetic disease that leads to bone marrow failure and potentially cancer. Preclinical studies of additional bone marrow-derived disorders are ongoing and target Pyruvate Kinase Deficiency (PKD), Leukocyte Adhesion Deficiency-I (LAD-I) and Infantile Malignant Osteopetrosis (IMO). Rocket is also developing an AAV-based gene therapy program for an undisclosed rare pediatric disease. For more information about Rocket, please visit www.rocketpharma.com.

Cautionary Statement Regarding Forward-Looking Statements

Various statements in this release concerning Rocket's future expectations, plans and prospects, including without limitation, Rocket's expectations regarding the safety, effectiveness and timing of product candidates that Rocket may develop, including in collaboration with academic partners, to treat Fanconi Anemia (FA), Leukocyte Adhesion Deficiency-I (LAD-I), Pyruvate Kinase Deficiency (PKD) and Infantile Malignant Osteopetrosis (IMO), and the safety, effectiveness and timing of related pre-clinical studies and clinical trials, may constitute forward-looking statements for the purposes of the safe harbor provisions under the Private Securities Litigation Reform Act of 1995 and other federal securities laws and are subject to substantial risks, uncertainties and assumptions. You should not place reliance on these forward-looking statements, which often include words such as "believe", "expect", "anticipate", "intend", "plan", "will give", "estimate", "seek", "will", "may", "suggest" or similar terms, variations of such terms or the negative of those terms. Although Rocket believes that the expectations reflected in the forward-looking statements are reasonable, Rocket cannot guarantee such outcomes. Actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including, without limitation, Rocket's ability to successfully demonstrate the efficacy and safety of such products and pre-clinical studies and clinical trials, its gene therapy programs, the preclinical and clinical results for its product candidates, which may not support further development and marketing approval, Rocket's ability to commence a registrational study in FA within the projected time periods, the potential advantages of Rocket's product candidates, actions of regulatory agencies, which may affect the initiation, timing and progress of pre-clinical studies and clinical trials of its product candidates, Rocket's and its licensors ability to obtain, maintain and protect its and their respective intellectual property, the timing, cost or other aspects of a potential commercial launch of Rocket's product candidates, Rocket's ability to manage operating expenses, Rocket's ability to obtain additional funding to support its business activities and establish and maintain strategic business alliances and new business initiatives, Rocket's dependence on third parties for development, manufacture, marketing, sales and distribution of product candidates, the outcome of litigation, and unexpected expenditures, as well as those risks more fully discussed in the section entitled "Risk Factors" in Rocket's Annual Report on Form 10-K for the year ended December 31, 2017. Accordingly, you should not place undue reliance on these forward-looking statements. All such statements speak only as of the date made, and Rocket undertakes no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise.

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Source: Rocket Pharmaceuticals, Inc.

Claudine Prowse, Ph.D.
SVP, Corporate Strategy and IRO
Rocket Pharma, Inc.
The Empire State Building, Suite 7530
New York, NY 10118
cp@rocketpharma.com
www.rocketpharma.com
investors@rocketpharma.com