Shares of Tempest Therapeutics Inc ( TPST ) are trading lower on Thursday, with a session volume of 21 million as per data from Benzinga Pro.

The company announced new data from the ongoing Phase 1b/2 clinical study on amezalpat2 (TPST-1120).

The drug candidate delivered a six-month improvement in median overall survival advantage when combined with atezolizumab and bevacizumab compared to atezolizumab and bevacizumab alone in the first-line treatment of patients with unresectable or metastatic hepatocellular carcinoma (HCC), the most common type of primary liver cancer.

At the cutoff date of February 14, 2024, the new data from 40 patients randomized to the amezalpat arm and 30 patients randomized to the control arm show:

21-month median OS for the amezalpat arm versus 15 months for the control arm, a six-month survival advantage.

20/40 patients remain in survival follow-up in the amezalpat arm, compared to 9/30 patients in the control arm.

0.65 hazard ratio for OS, revealing a stable HR since the top-line analysis 10 months earlier when the HR was 0.59.

A manageable safety profile is consistent with Phase 1 data.

The earlier top-line data analysis, dated April 20, 2023, had a median follow-up of 9.2 and 9.9 months for the amezalpat and control arms, respectively and showed:

A confirmed objective response rate of 30% for the amezalpat arm versus 13.3% for the control arm.

Biomarker subpopulation findings were consistent with the mechanism of action of amezalpat. Patients with b-catenin activating mutations (21% in this study (n=7)) showed a cORR of 43% and a disease control rate (DCR) of 100% in the amezalpat arm.

The amezalpat arm was consistently active across both PD-L1 positive and PD-L1 negative tumors, with a cORR of 27% in the amezalpat arm compared to 7% for the control arm in PD-L1 negative tumors.

Amezalpat remains well tolerated, with safety data comparable between the two arms.

HCC is an aggressive cancer with rising mortality and is projected to become the third leading cause of cancer death by 2030. Every year, more than 900,000 people worldwide are diagnosed with HCC.

Price Action: TPST shares are down 16.5% at $2.38 before spiking as high as $4.82 during the premarket session at last check Thursday.

Image by PDPics from Pixabay