Forty Seven and Rocket Pharmaceuticals Announce Research Collaboration for Fanconi Anemia

MENLO PARK, Calif. and NEW YORK, March 11, 2020 (GLOBE NEWSWIRE) — Forty Seven, Inc. (Nasdaq: FTSV) and Rocket Pharmaceuticals, Inc. (Nasdaq: RCKT) announced today that they have entered into a research collaboration to pursue clinical proof-of-concept for Forty Seven’s novel antibody-based conditioning regimen, FSI-174 (anti-cKIT antibody) plus magrolimab (anti-CD47 antibody), with Rocket’s ex vivo lentiviral vector hematopoietic stem cell (LVV HSC) gene therapy, RP-L102. The initial collaboration will evaluate this treatment regimen in Fanconi Anemia (FA), a genetic disease that affects patients’ capacity to produce blood cells and is associated with an increased risk of leukemia and other neoplasms. RP-L102, Rocket’s gene therapy approach for FA, involves treatment with patients’ own gene-corrected blood forming stem cells (hematopoietic stem cells, or HSCs).

Gene therapies for monogenic blood disorders have broad potential. One concern associated with these treatments is the toxicity of pre-therapy conditioning regimens that utilize cytotoxic chemotherapy and/or radiation to destroy existing HSCs and facilitate engraftment of gene-corrected HSCs. Forty Seven’s all-antibody based conditioning regimen is designed to address the limitations of current pre-treatment conditioning therapies. These regimens are often associated with serious side effects, including severe infection, cognitive impairment, infertility, endocrine dysfunction, secondary malignancies and organ damage. These toxicities are especially difficult for pediatric patients and are particularly severe for patients with FA, who are more sensitive to the DNA-damaging effects of traditional conditioning agents. Preliminary data demonstrate that RP-L102 may confer efficacy without pre-treatment conditioning.  The combination of RP-L102 with Forty Seven’s all-antibody conditioning regimen may provide patients an alternate treatment option in situations where conditioning may be advantageous.

“We are pleased to enter into this collaboration with Forty Seven,” said Jonathan Schwartz, M.D., Chief Medical Officer and Senior Vice President of Rocket. “RP-L102 ‘Process B’ is currently being evaluated in a registrational trial without the use of conditioning. In parallel, we are assessing incorporation of a non-genotoxic conditioning regimen as a part of Rocket’s life-cycle management strategy. Forty Seven’s novel all-antibody conditioning regimen could also be applied to Rocket’s other lentiviral programs, in which conditioning is more integral to the gene therapy approach.”

“We are initiating our first in human healthy volunteer study of FSI-174 in the first quarter this year, and are excited to enter into a partnership with Rocket at this time. Rocket is at the forefront of developing gene therapies for high unmet-need diseases, and this collaboration will provide an opportunity to evaluate the benefit of Forty Seven’s novel conditioning regimen with Rocket’s RP-L102 to help FA patients,” says Jens-Peter Volkmer, VP of Research at Forty Seven.

“This collaboration is in line with our strategy to study our anti-cKIT and anti-CD47, all-antibody conditioning regimen in combination with several different gene therapies, and to establish clinical proof-of-concept in a broad range of transplant indications,” said Mukul Agarwal, VP of Corporate Development at Forty Seven.

Maria Grazia Roncarolo, M.D., Scientific Advisor to Forty Seven, commented, “The goal of my life’s work is to bring pediatric patients transformative therapies for currently incurable diseases. We believe Rocket Pharmaceuticals’ commitment to devastating diseases, such as FA, addresses a critical unmet need and Forty Seven’s antibody conditioning creates an alternative avenue to deliver this therapy to those patients. We look forward to seeing how this collaboration may help patients in need.”

Under the terms of the agreement, Rocket will provide its ex vivo LVV HSC gene therapy platform and Forty Seven will contribute its innovative antibody-based conditioning regimen for the collaboration.

About FSI-174 and Magrolimab
FSI-174 is a humanized monoclonal antibody targeting cKIT, which is a receptor that is highly expressed on hematopoietic stem cells. Magrolimab is a humanized monoclonal antibody targeting CD47, which is a “don’t eat me” signal to macrophages and is expressed on all cells. Magrolimab is currently being investigated in Phase 2 clinical trials to treat cancer and has established clinical efficacy in four indications, including myelodysplastic syndrome, acute myeloid leukemia, diffuse large B cell lymphoma and follicular lymphoma, with a favorable safety profile in over 400 patients treated, including some patients treated continuously for over two years. When combined, FSI-174 sends a positive signal to macrophages to target blood forming stem cells for removal and magrolimab disengages inhibitory signals that block phagocytosis. Combination of these antibodies has shown efficient removal of blood forming stem cells, allowing for transplantation in pre-clinical models.

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. Graft-versus-host disease, a known complication of allogeneic HSCT, is associated with an increased risk of solid tumors, mainly squamous cell carcinomas of the head and neck region. 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. Somatic mosaicism occurs when there is a spontaneous correction of the mutated gene that can lead to stabilization or correction of a FA patient’s blood counts in the absence of any administered therapy. Somatic mosaicism, often referred to as ‘natural gene therapy’ provides a strong rationale for the development of FA gene therapy because of the selective growth advantage of gene-corrected hematopoietic stem cells over FA cells1.

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 advancing an integrated and sustainable pipeline of genetic therapies that correct the root cause of complex and rare childhood disorders. The company’s platform-agnostic approach enables it to design the best therapy for each indication, creating potentially transformative options for patients contending with rare genetic diseases. Rocket’s clinical programs using lentiviral vector (LVV)-based gene therapy are for the treatment of Fanconi Anemia (FA), a difficult to treat genetic disease that leads to bone marrow failure and potentially cancer, Leukocyte Adhesion Deficiency-I (LAD-I), a severe pediatric genetic disorder that causes recurrent and life-threatening infections which are frequently fatal, and Pyruvate Kinase Deficiency (PKD) a rare, monogenic red blood cell disorder resulting in increased red cell destruction and mild to life-threatening anemia. Rocket’s first clinical program using adeno-associated virus (AAV)-based gene therapy is for Danon disease, a devastating, pediatric heart failure condition. Rocket’s pre-clinical pipeline program is for Infantile Malignant Osteopetrosis (IMO), a bone marrow-derived disorder. For more information about Rocket, please visit

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About Forty Seven, Inc.
Forty Seven, Inc. is a clinical-stage immuno-oncology company that is developing therapies targeting cancer immune evasion pathways based on technology licensed from Stanford University. Forty Seven’s lead program, magrolimab, is a monoclonal antibody against the CD47 receptor, a “don’t eat me” signal that cancer cells commandeer to avoid being ingested by macrophages. This antibody is currently being evaluated in multiple clinical studies in patients with myelodysplastic syndrome, acute myeloid leukemia, and non-Hodgkin’s lymphoma.

For more information, please visit or contact

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