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SHATTUCK LABS Shattuck Labs Reports First Quarter 2021 Financial Results and Recent Business Highlights May 10 , 2021 - Initial dose - escalation data from Phase 1 clinical trial for lead wholly owned CD47 checkpoint inhibitor , SL - 172154 ( SIRPα - Fc - CD40L ) , expected in the second half of 2021 - - IND filings for SL - 172154 in hematologic malignancies anticipated in the second half of 2021- -Dose - escalation data from Phase 1 clinical trial for lead partnered PD - 1 checkpoint inhibitor , SL - 279252 ( PD1 - Fc - OX40L ) , expected in the second half of 2021 - AUSTIN , TX and DURHAM , NC , May 10 , 2021 ( GLOBE NEWSWIRE ) -- Shattuck Labs , Inc. ( Shattuck ) ( NASDAQ : STTK ) , a clinical - stage biotechnology company pioneering the development of bi - functional fusion proteins as a new class of biologic medicine for the treatment of patients with cancer and autoimmune disease , today reported financial results for the first quarter ended March 31 , 2021 and provided recent business highlights . " We have made steady progress across the organization this quarter and remain on - track to present clinical data from both SL - 172154 and SL - 279252 in the second half of this year , " said Taylor Schreiber , M.D. , Ph.D. , Chief Executive Officer of Shattuck . " In addition , we accelerated our expansion of SL - 172154 into hematologic malignancies , and we plan to announce our strategy to bridge an immunologically active dose identified in our ovarian cancer study into multiple hematologic indications in the second half of 2021. " First Quarter 2021 Recent Business Highlights and Other Recent Developments • Continued Enrollment of SL - 172154 Phase 1 Clinical Trial in Ovarian Cancer : Shattuck continues to enroll patients in a Phase 1 clinical trial for its lead wholly owned asset SL - 172154 , a dual CD47 / SIRPa inhibitor and CD40 agonist . The Phase 1 trial is an open label , multi - center , dose - escalation study to evaluate the safety , tolerability , pharmacokinetics , anti - tumor activity , and pharmacodynamic effects of SL - 172154 administered intravenously in patients with ovarian cancer . Initial dose - escalation data from the trial are expected in the second half of 2021 . • Continued Enrollment of SL - 172154 Phase 1 Clinical Trial in Squamous Cell Carcinoma of the Head and Neck or Skin : Shattuck continues to enroll patients in a Phase 1 clinical trial for SL - 172154 , administered intratumorally . The Phase 1 trial will evaluate the safety , tolerability , pharmacokinetics , anti - tumor activity , and pharmacodynamic effects of SL - 172154 in patients with squamous cell carcinoma of the head and neck or skin . Initial dose - escalation data from the trial are expected in the first half of 2022 . • Continued Enrollment of SL - 279252 Phase 1 Clinical Trial : Shattuck continues to enroll patients in a Phase 1 clinical trial evaluating SL - 279252 , a dual PD - 1 / PD - L1 inhibitor and OX40 receptor agonist . The Phase 1 trial is an open label , multi - center , dose - escalation , and dose - expansion study to evaluate the safety , tolerability , pharmacokinetics , anti - tumor activity , and pharmacodynamic effects of SL - 279252 in patients with advanced solid tumors or lymphomas . SL - 279252 is currently being developed in collaboration with Takeda Pharmaceuticals . Dose - escalation data from the trial are expected in the second half of 2021 . • Presented Preclinical Data for SL - 9258 : Preclinical data for SL - 9258 ( TIGIT - Fc - LIGHT ) , a dual TIGIT inhibitor and HVEM / LTẞR agonist , was presented at the American Association for Cancer Research ( AACR ) annual meeting in April 2021. These data demonstrated that SL - 9258 ( TIGIT - Fc - LIGHT ) was highly active in a PD1 acquired resistance model and outperformed dual checkpoint blockade with anti - PD1 antibodies and anti - TIGIT antibodies . • Presented Continued Preclinical Development of GADLEN Platform : Preclinical proof of concept data on Shattuck's proprietary Gamma Delta T Cell Engager ( GADLEN ™ ) platform were presented at the AACR annual meeting in April 2021 . These data demonstrated a multi - layer analysis to uncover the gamma and delta TCR usage in tumors and the butyrophilin expression pattern guiding the design of GADLEN therapeutics , which are intended to target both hematologic malignancies and solid tumor indications . First Quarter 2021 Financial Results • Cash Position : As of March 31 , 2021 , cash and cash equivalents and short - term investments were $ 321.2 million , as compared to $ 335.4 million as of December 31 , 2020 . • Research and Development ( R & D ) Expenses : R & D expenses for the first quarter ended March 31 , 2021 were $ 10.3 million , as compared to $ 8.1 million for the first quarter ended March 31 , 2020. The increase was primarily driven by an increase in our personnel related costs , expanded clinical development , and laboratory capabilities . • General and Administrative ( G & A ) Expenses : G & A expenses for the first quarter ended March 31 , 2021 were $ 4.4 million , as compared to $ 1.6 million for the first quarter ended March 31 , 2020. The increase was primarily driven by an increase in personnel related costs to support our activities associated with being a public company and operational