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EXHIBIT 99.1 Cellectis Reports Financial Results for the Second Quarter 2026 Lasme - cel : Pivotal Phase 2 in r / r B - ALL ( BALLI - 01 ) • FDA RMAT designation received for lasme - cel • Full Phase 1 clinical data from the BALLI - 01 trial presented at EHA 2026 • Pivotal Phase 2 first interim analysis expected in Q4 2026 Eti - cel : Phase 1 in r / r NHL ( NATHALI - 01 ) • Translational data from the NATHALI - 01 trial highlighting key drivers of response presented at EHA 2026 • Full Phase 1 dataset expected in Q4 2026 Cash , cash equivalents and fixed - term deposits of $ 169 million as of June 30 , 2026¹ provide runway into Q4 2027 . NEW YORK , Aug. 06 , 2026 ( GLOBE NEWSWIRE ) -- Cellectis ( the “ Company ” ) ( Euronext Growth : ALCLS - NASDAQ : CLLS ) , a clinical - stage biotechnology company using its pioneering gene editing platform to develop life - saving cell and gene therapies , today provided financial results for the second quarter 2026 ending June 30 , 2026 . " The lasme - cel and eti - cel clinical results presented at EHA 2026 are promising for patients with relapsed or refractory B - cell malignancies . We are also pleased to have received RMAT designation from the FDA for lasme- cel , which recognizes its potential to address an unmet medical need in B - ALL . We remain focused on advancing new options for people whose disease has returned or stopped responding to available therapies , " said André Choulika , Ph.D. , Co - Founder and Chief Executive Officer at Cellectis . 1 Cash , cash equivalents and fixed - term deposits include restricted cash of $ 2.3 million as of June 30 , 2026 classified as current and non - current financial assets and fixed - term deposits of $ 131.1 million as of June 30 , 2026 , classified as current financial assets . Allogeneic CAR - T Pipeline Lasme - cel in relapsed or refractory B - cell acute lymphoblastic leukemia ( r / r B - ALL ) - BALLI - 01 The Pivotal Phase 2 BALLI - 01 trial is ongoing . • In June 2026 , Cellectis received FDA Regenerative Medicine Advanced Therapy ( RMAT ) designation for lasme - cel for treatment of r / r CD22 positive B - ALL . This designation was granted based on the BALLI - 01 clinical data , demonstrating promising efficacy and a manageable safety profile . It reflects the FDA's recognition of the potential of lasme - cel to address the unmet medical need faced by patients with r / r B - ALL . • In June 2026 , Cellectis presented full Phase 1 data from the BALLI - 01 trial at an oral presentation at the European Hematology Association ( EHA ) 2026 Annual Congress . 45 patients were treated in third line and beyond ( 3L + ) , including 15 at the recommended Phase 2 dose ( RP2D ) , and 7 in the target Phase 2 population . Heavily pretreated population : A median of 5 prior lines of therapy in the target Phase 2 population ( range 2–11 ) ; 82 % had received prior blinatumomab , 56 % a CD22 - directed antibody drug conjugate ( ADC ) , 53 % CD19 CAR - T , and 47 % a prior hematopoietic stem cell transplantation ( HSCT ) . Efficacy Data ( target Phase 2 population ) 。 100 % overall response rate ( ORR ) ( 7/7 )