By Sam Boughedda
Investing.com — Bolt Biotherapeutics (NASDAQ:BOLT) shares tumbled after mediocre interim data from its early trial of a drug that is the company's lead immune-stimulating antibody conjugate.
The data, on a drug called BDC-1001, was shared at the European Society for Medical Oncology Immuno-Oncology (ESMO I-O) Congress.
Bolt shares are down over 50.6% in afternoon trading.
The company reported data from 57 subjects in the study across 16 different types of HER2-expressing solid tumors. Her-2 is described by cancer.org as a "protein that helps breast cancer cells grow quickly."
According to the company, BDC-1001 demonstrated favorable safety and tolerability and showed early signs of clinical activity. Furthermore, early signs of clinical activity were seen in 13 of 40 tumor evaluable subjects.
In June, the company reported preliminary data from the first 20 patients of the Phase 1/2 clinical trial, stating that there was one patient with a confirmed partial response. In today's update, Bolt said there is one durable partial response maintained through 52 weeks.
“Bolt Biotherapeutics is committed to agile clinical development based on data. In this Phase 1/2 study of BDC-1001, we have gained tremendous insight into the ability of this novel candidate to mobilize the patient’s immune system in targeting the tumor and its microenvironment," said Edith Perez, Chief Medical Officer of Bolt.