ERYTECH Pharma (Nasdaq & Euronext: ERYP),a clinical-stage biopharmaceutical company developing innovative therapies by encapsulating therapeutic drug substances inside red blood cells, today announced its intention to move forward towards the submission of a BLA to the US Food and Drug Administration (FDA) for eryaspase in hypersensitive acute lymphoblastic leukemia (ALL) patientsfollowing feedback from the agency in a pre-BLA meeting.

The purpose for the meeting was to discuss clinical, non-clinical and quality content and expectations for the Company's potential BLA submission. Based on the discussion and the totality of the available information to the Company to date, ERYTECH believes its regulatory package can potentially support an approval of eryaspase in hypersensitive ALL patients. Pending successful completion of remaining steps, the Company anticipates submitting a BLA in the fourth quarter of 2021.

"We are encouraged by the interactive dialogue with the agency, and grateful for the feedback and guidance we received on a potential path to approval," said Gil Beyen, CEO of ERYTECH. "This is an important milestone for ERYTECH as it advancesour lead product candidate eryaspase asan alternative treatment for ALL patients with hypersensitivity to PEG-asparaginase, while our Phase 3 trial in second line pancreatic cancer is nearing completion. If all goes well, we could be in a position tomakethis product candidateavailable toALL and pancreatic cancer patients in the course of next year."

In December 2020, positive Phase 2 clinical results were presented by the Nordic Society of Pediatric Hematology and Oncology, at the 2020 American Society of Hematology annual meeting. Eryaspase, in combination with chemotherapy, administered every two weeks, provided a sustained asparaginase enzyme activity level, and was generally well tolerated with few hypersensitivity reactions.

About Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is a cancer of the blood and bone marrow that is the most common type of cancer in children in the US and Europe. More than 13,000 cases are diagnosed in the US and Europe each year with the majority of patients diagnosed before age 20. Asparaginase has been an integral component of ALL treatment for several years but is associated with treatment-limiting hypersensitivity in up to 30% of patients. Discontinuation of asparaginase therapy in ALL patients has been associated with inferior event free survival highlighting the need for additional asparaginase based treatment options.

About ERYTECH and eryaspase

ERYTECH is a clinical-stage biopharmaceutical company developing innovative red blood cell-based therapeutics for severe forms of cancer and orphan diseases. Leveraging its proprietary ERYCAPS? platform, which uses a novel technology to encapsulate drug substances inside red blood cells, ERYTECH is developing a pipeline of product candidates for patients with high unmet medical needs. ERYTECH's primary focus is on the development of product candidates that target the altered metabolism of cancer cells by depriving them of amino acids necessary for their growth and survival.

The Company's lead product candidate, eryaspase, which consists of L-asparaginase encapsulated inside donor-derived red blood cells, targets the cancer cells' altered asparagine and glutamine metabolism. Eryaspase is in Phase 3 clinical development for the treatment of second-line pancreatic cancer and in Phase 2 for the treatment of triple-negative breast cancer. An investigator sponsored Phase 2 trial (IST) in acute lymphoblastic leukemia recently reported positive results, and a Phase 1 IST in 1L advanced pancreatic cancer is ongoing.

Eryaspase received Fast Track designation from the U.S. Food and Drug Administration (FDA) for the treatment of advanced pancreatic cancer. The FDA and the European Medicines Agency have granted eryaspase orphan drug status for the treatment of pancreatic cancer and ALL.

ERYTECH produces its product candidates for treatment of patients in Europe at its GMP-approved manufacturing site in Lyon, France, and for patients in the United States at its GMP manufacturing site in Princeton, New Jersey, USA. Eryaspase is not an approved medicine.