Poseida Sinks 35% On Prostate Cancer Trial Halt Following Patient Death

Market Trading EssentialsAugust 18, 2020

2 minutes read

Shares in Poseida Therapeutics tanked 35% in the extended market session after a US regulator halted the trial of its prostate cancer treatment following the death of a patient.

PSTX) announced that the US Food and Drug Administration (FDA) halted the company’s Phase 1 clinical trial for P-PSMA-101 for the treatment of metastatic castrate resistant prostate cancer.” data-reactid=”13″>The stock plunged to $8.51 in Monday’s after-market trading. Poseida (PSTX) announced that the US Food and Drug Administration (FDA) halted the company’s Phase 1 clinical trial for P-PSMA-101 for the treatment of metastatic castrate resistant prostate cancer.

The cell and gene therapeutics company said that the trial was put on hold to investigate the death of a patient. The patient in question, who had metastatic castrate-resistant prostate cancer, had failed treatment with multiple anti-cancer agents and was treated with P-PSMA-101 in late July. Through the first 7 days post-treatment, the patient had normal lab results and no clinical symptoms indicating an adverse reaction. The patient missed both his day 10 and day 14 follow up visits, but during this time developed symptoms that subsequently led to hospitalization. He died of hepatic failure at day 19 post-treatment.

Poseida focuses on developing non-viral gene-engineered autologous and allogeneic CAR-T cell therapies for the treatment of cancer and differentiated nanoparticle-based gene therapies.

The Nasdaq-listed company added that although the direct cause of the hepatic failure has not yet been confirmed, the patient developed symptoms consistent with macrophage activation syndrome (MAS). MAS is a potentially fatal overactivation of the immune system which has been associated with CAR-T therapies, but can have other causes such as infection and autoimmune disease.

“The clinical investigator has assessed the SAE [serious adverse event] as possibly related to P-PSMA-101 pending further investigation,” Poseida wrote in a SEC filing. “The company is awaiting a formal response from the FDA and is preparing recommendations designed to allow resumption of the clinical trial.”

Once the FDA’s questions are answered and a plan is submitted, the FDA has 30 days to notify Poseida if the clinical study of P-PSMA-101 may be resumed.

price target of $25 implying 92% upside potential to current levels.” data-reactid=”23″>Poseida went public last month with the stock priced at $16 a share. Since then, the stock has been initiated with three Buy ratings and an average price target of $25 implying 92% upside potential to current levels.

Raju Prasad started coverage with a Buy rating, saying that the company’s robust pipeline of wholly owned CAR-T and gene therapy candidates and extensive platform optionality has the potential for “significant value creation”.” data-reactid=”24″>Earlier this month, William Blair analyst Raju Prasad started coverage with a Buy rating, saying that the company’s robust pipeline of wholly owned CAR-T and gene therapy candidates and extensive platform optionality has the potential for “significant value creation”.

See PSTX stock analysis on TipRanks)” data-reactid=”25″>“Poseida’s broad suite of platform technologies competitively positions it well in the cell therapy, gene therapy, and gene editing landscapes, while providing long-term optionality,” Prasad wrote in a note to investors. “We believe the bulk of the valuation for Poseida is in P-BCMA-101/P-BCMA-ALLO1 and P-PSMA-101, and that clinical data from these two programs will drive the stock price in the near term.” (See PSTX stock analysis on TipRanks)