Page 1

PRESS RELEASE GRACELL Gracell Biotechnologies Reports First Quarter 2021 Unaudited Financial Results and Provides Corporate Update Reported updated long - term follow - up data for TruUCAR - enabled CD7 - targeted CAR - T product candidate GC027 for the treatment of T - ALL at AACR 2021 Annual Meeting Signed agreement with Lonza to manufacture FasTCAR - enabled product candidates in the U.S. Completed initial public offering of ADSS for net proceeds of US $ 220 million ; US $ 331.1 million in cash as of March 31 , 2021 SUZHOU , China and PALO ALTO , Calif . , May 17 , 2021 ( GLOBE NEWSWIRE ) Gracell Biotechnologies Inc. ( NASDAQ : GRCL ) ( " Gracell " ) , a global clinical - stage biopharmaceutical company dedicated to discovering and developing highly efficacious and affordable cell therapies for the treatment of cancer , today reported its unaudited financial results for the first quarter and recent business highlights . " We are thrilled to have ushered in the new year as a public company following a successful initial public offering that was supported by top - tier institutional investors , " commented Dr. William ( Wei ) Cao , founder , Chairman , and CEO of Gracell . " We have made significant advancements uring the first quarter regarding our pipe of innovative autologous and allogeneic CAR - T cell therapies . Recently , we announced dosing the first patient in the Phase 1/2 registrational study of GC007g , an allogeneic CAR - T cell therapy derived from HLA - matched donors for the treatment of r / r B - ALL . At the AACR 2021 Annual Meeting last month , we presented follow - up data on our off - the - shelf stand - alone allogeneic CAR - T cell therapy GC027 for the treatment of r / r T - ALL . With a patient maintaining minimal residual disease negative complete remission ( MRD- CR ) through 16.8 months , we are very encouraged by the potential of GC027 in this hard - to - treat indication . " Dr. Cao continued , " We are pleased to announce that we are expanding our leadership team with Jenny ( Yajin ) Ni , Ph.D. , M.D. , as Chief Technology Officer . Dr. Ni brings extensive experience in developing CAR - T cell therapies , including having successfully lead process development at both Pfizer and Allogene Therapeutics . We look forward to her contributions , including leading our technical operations teams including Chemistry , Manufacturing and Control ( CMC ) and manufacturing to ensure a smooth technology transfer to Lonza for our FasTCAR - enabled product candidate GC012F . " " We plan to build on the momentum achieved during the first quarter with several near - term catalysts expected during 2021. As we continue to ramp up clinical development efforts , we continue to expand our team in the U.S. and preparing to expand our GMP manufacturing facility in China . We also look forward to providing updates at the ASCO and EHA 2021 annual meetings on the FasTCAR - enabled BCMA / CD19 dual - targeting candidate GC012F for the treatment of r / r multiple myeloma , which has demonstrated fast , deep , and durable responses in a predominantly high - risk multiple myeloma patient population . We are excited to begin collaborating with Lonza to manufacture our FasTCAR - enabled product candidate GC012F as we work towards the U.S. IND filing in the first half of 2022. We believe the potential of our proprietary FasTCAR and TruUCAR platforms is vast , and we are working expeditiously to bring new product candidates into clinical development , " Dr. Cao concluded . First Quarter 2021 and Subsequent Highlights GC027 for the treatment of adult relapsed / refractory T cell acute lymphoblastic leukemia ( r / r T - ALL ) : GC027 is a TruUCAR - enabled CD7 - targeted allogeneic CAR - T cell therapy being studied in an ongoing Phase 1 IIT in China for the treatment of adult r / r T - ALL . GC027 is manufactured from T cells of non - HLA ( human leukocyte antigen ) -matched healthy donors . Updated long - term follow - up data ( data cut - off as of February 4 , 2021 ) for GC027 was presented at the 2021 American Association for Cancer Research ( AACR ) Annual Meeting ( Press Release April 2021 ) o Patients had received a median of six prior lines of therapy and received a single infusion of TruUCAR GC027 in one of three dose levels with the highest dose level at 1.5x107 cells / kg . Six patients ( 100 % ) treated achieved a complete remission with or without complete blood count recovery ( CR / CRI ) and five of the six patients ( 83 % ) achieved MRD- CR . At 6 months post treatment , three out of five patients ( 60 % ) had maintained MRD- CR . After 18.5 months of follow up for the initial patients treated , one patient continued to be MRD- CR at 16.8 months . One patient maintained MRD- CR until 9 months and one patient with primary refractory disease ( no response to VDP ) maintained his MRD- CR status until month 7. One additional patient treated presented initially with a high tumor burden and extensive extramedullary ( EM ) disease . After treatment with GC 027 and as confirmed by PET CT scan , all EM lesions resolved . The patient achieved MRD- CR at day 28. All six patients tolerated a single infusion of TruUCAR GC027 . No events of neurotoxicity ( ICANS ) or acute