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May 7 , 2021 SUTRO BIOPHARMA Sutro Biopharma Reports First Quarter 2021 Financial Results , Business Highlights and 2021 Anticipated Milestones - Additional follow - up data on STRO - 002 from the Phase 1 dose- escalation will be presented at ASCO 2021 ; enrollment for the dose- expansion is ongoing - Merck initiated IND - enabling toxicology studies for the first program under the cytokine derivatives collaboration resulting in a $ 15 million milestone payment earned in April 2021 - EMD Serono began a Phase 1 study for the bispecific MUC1 - EGFR ADC , M1231 , during the first quarter of 2021 - Financial position remains strong with cash , cash equivalents and marketable securities of $ 294.9 million as of March 31 , 2021 and projected runway into the second half of 2023 SOUTH SAN FRANCISCO , Calif . , May 7 , 2021 / PRNewswire / -- Sutro Biopharma , Inc. ( NASDAQ : STRO ) , a clinical - stage drug discovery , development and manufacturing company focused on the application of precise protein engineering and rational design to create next - generation cancer and autoimmune therapeutics , today reported its financial results for the quarter ended March 31 , 2021 , its recent business highlights , and provided a preview of anticipated selected milestones in 2021 . " We are enthusiastic about the meaningful clinical benefit of STRO - 002 , our FolRa - targeting Antibody - Drug Conjugate ( ADC ) , for women with advanced ovarian cancer , as demonstrated by the Phase 1 dose - escalation data , and look forward to providing follow - up data at ASCO , " said Bill Newell , Sutro's Chief Executive Officer . " We continue to enroll patients for the dose- expansion portion of the Phase 1 study and we have activated additional clinical sites . STRO - 002 is one of the four product candidates in the clinic that were discovered , developed , and are manufactured using our proprietary and integrated cell - free protein synthesis platform . We intend to continue creating value by leveraging our platform to deliver on therapeutics that are precise , rationally designed , and homogenous , for a broad set of patients with unmet medical needs . " Recent Business Highlights and Expected 2021 Milestones