Poseida Therapeutics(PSTX) - 2020 Q4 - Annual Report

CAR-T Product Development - The company is advancing a broad pipeline with plans to have up to six CAR-T product candidates in the clinic by 2022, targeting both hematological and solid tumor oncology indications[14]. - The most advanced product candidate, P-BCMA-101, is in a potentially registrational Phase 2 clinical trial for relapsed/refractory multiple myeloma, with outpatient dosing approved by the FDA[14][23]. - P-BCMA-101, an autologous CAR-T targeting BCMA, is currently in a potentially registrational Phase 2 clinical trial, with interim results showing favorable tolerability and low levels of CRS[35]. - P-PSMA-101, an autologous CAR-T for mCRPC, demonstrated complete tumor cell elimination in 100% of preclinical models, with plans to accelerate its allogeneic version, P-PSMA-ALLO1, if clinical efficacy is promising[35]. - The company is developing both autologous and allogeneic CAR-T therapies targeting hematological malignancies, with a focus on commercializing in community hospital settings and outpatient infusion sites[46]. - The company is advancing its first CAR-T targeting MUC1-C, P-MUC1C-ALLO1, with an IND filing and Phase 1 clinical trial expected by the end of 2021[47]. - P-PSMA-101 achieved complete elimination of tumor cells to undetectable levels in 100% of animals in a preclinical model of mCRPC[109]. - P-BCMA-ALLO1, a fully allogeneic CAR-T product candidate, is anticipated to enter Phase 1 clinical trials by the first half of 2021[151]. - P-PSMA-ALLO1 is an allogeneic CAR-T product candidate targeting PSMA for mCRPC, with an IND filing and Phase 1 trial anticipated after analyzing preliminary results from P-PSMA-101[191]. Gene Delivery Technologies - The proprietary non-viral piggyBac DNA Delivery System allows for stable gene insertion with a significantly larger genetic cargo capacity compared to viral methods, potentially greater than 20 times that of lentivirus[26]. - The proprietary PiggyBac DNA Delivery System allows for cargo delivery greater than 200 kb, enabling the incorporation of multiple therapeutic genes[58]. - The proprietary non-viral piggyBac DNA Delivery System enables the generation of CAR-T products with a high percentage of TSCM cells, potentially leading to more consistent and durable responses with lower toxicity[79]. - The manufacturing process using piggyBac is more efficient and cost-effective compared to viral-based methods, eliminating costly materials and reducing production timelines[92]. - The piggyBac DNA Delivery System allows the expression of up to four full-length CAR molecule genes, enhancing the potential for targeted therapy[114]. - The company aims to replace AAV technology with nanoparticle-based delivery for gene therapies, which is expected to improve tolerability and lower costs while addressing limitations of AAV[49]. - The company is exploring nanoparticle technologies to eliminate the need for AAV in gene therapies, potentially broadening application areas[72]. - The combination of piggyBac with AAV is expected to enable stable and high expression levels of therapeutic transgenes, even at low doses, mitigating toxicity risks associated with AAV[212]. Safety and Efficacy - The company is developing a proprietary safety switch that can rapidly eliminate genetically modified cells post-administration, enhancing patient safety[28]. - The use of a cellular safety switch in product candidates aims to manage adverse events by controlling CAR-T cell numbers during treatment[91]. - The Cas-CLOVER gene editing technology shows low to no off-target activity, providing a tolerability advantage over other gene editing systems[26]. - The Cas-CLOVER gene editing technology enables precise site-specific editing with minimal off-target activity, preserving TSCM characteristics in CAR-T cells[61]. - Clinical data indicates a strong correlation between the percentage of TSCM cells in CAR-T products and clinical response, with TSCM cells potentially enhancing persistence and efficacy[81]. - The company focuses on selecting targets for CAR-T therapies that are less likely to undergo antigen escape, enhancing the likelihood of sustained efficacy[103]. - The piggyBac technology reduces the risk of oncogenesis compared to viral methods, as it shows low integration into intragenic regions and does not contain harmful LTR sequences[90]. Manufacturing and Cost Efficiency - The engineering of proprietary booster molecules enables the generation of hundreds of doses from a single manufacturing run, significantly reducing costs to levels comparable to traditional biologic therapeutics[22]. - The use of booster molecules allows the company to produce hundreds of doses from a single healthy donor, significantly driving down manufacturing costs[77]. - The company aims to reduce CAR-T manufacturing costs to levels comparable to traditional biologic therapeutics, enabling off-the-shelf availability[77]. - The manufacturing process for P-BCMA-ALLO1 aims for a product that is essentially 100% CAR-positive, with significant advantages in cost and commercial reach[155]. - The use of proprietary booster molecules resulted in approximately five times greater expansion of allogeneic CAR-T cells during manufacturing compared to runs without the booster[176]. - The piggyBac manufacturing system uses only GMP DNA and RNA, eliminating the need for GMP virus, which significantly reduces production costs[124]. Clinical Trials and Regulatory Designations - The company anticipates an IND filing and initiation of a Phase 1 clinical trial for P-OTC-101, a liver-directed gene therapy for OTC deficiency, in 2022, following significant preclinical success[42]. - The Phase 2 clinical trial is expected to enroll 120 patients, aiming to demonstrate significant response rates to support a biologics license application (BLA) submission[139]. - P-BCMA-101 was granted FDA Regenerative Medicine Advanced Therapy Designation in November 2018 and Orphan Drug Designation in May 2019[150]. - The Phase 1 clinical trial for P-BCMA-ALLO1 is anticipated to enroll up to 40 patients and is expected to begin in the first half of 2021[179]. - The company plans to conduct additional Phase 2 and comparative Phase 3 clinical trials to support approval and label expansion into earlier lines of therapy[150]. Company Overview and Team - The management team consists of 206 employees, with 110 holding advanced degrees, including 54 with a Ph.D. and/or M.D. degree[52]. - The company has a deep pipeline of proprietary product candidates with composition of matter protection through at least 2037, focusing on CAR-T for oncology and liver-directed gene therapy programs for rare diseases[29].