Hospital infection immunotherapy developer Aridis files for $34.5M IPO

Immunotherapy developer Aridis Pharmaceuticals has filed for a $34.5 million IPO as it plans to move its fully human antibodies for hospital-related infections into late-phase clinical trials.

The San Jose, California-based company plans to list on the Nasdaq using the symbol ARDS. Pricing terms were not disclosed. Founded in 2003, Aridis acquired six anti-infective immunotherapies and its discovery platform from Switzerland-based Kenta Biotech in 2013.

Its lead candidate, AR-301, is being developed as an add-on to standard-of-care antibiotic treatments for hospital-acquired or ventilator-associated pneumonia infections, or HAP/VAP, caused by the Staphylococcus aureus bacteria, including MRSA strains.

The company is also aiming for the Chinese market through a joint venture with Shenzhen Hepalink Pharmaceutical Group established in February. The jointly owned subsidiary will conduct clinical trials in the country, with submissions planned for the China Food and Drug Administration.

“As in many countries across the world, antibiotic resistance is a rapidly growing problem in China because of overuse of broad-spectrum antibiotics,” Aridis Founder and CEO Vu Truong said at the time. “There is a strong need for new, innovative anti-infectives to stem the tide of resistance and expand treatment options in the sizable Chinese market.”

Aridis’ AR-301 works by targeting the toxins secreted by S. aureus—binding to them and preventing them from breaking down immune cells and lung tissue—to complement the bacteria-killing properties of conventional antibiotics.

It has received a Fast Track designation from the FDA, as well as orphan status in the European Union. Aridis has completed an end-of-phase 2 meeting with the FDA, and plans to launch a phase 3 trial of AR-301 before the end of the year, the company said in its prospectus filed with the SEC.

The unique mechanism of action may slow the progression of a pneumonia infection, and may be useful against S. aureus infections at surgical sites, in the bloodstream, diabetic ulcers, or in skin or other soft tissues, the company said. The monoclonal antibody was discovered by screening B-cell lymphocytes from a patient with an S. aureus infection.

While a recently completed phase 2a trial showed decreases in the time treated patients remained intubated, when it came to assessing whether a patient’s infection was cured, based on the sole judgment of the investigator, there was no statistically significant difference between the addition of AR-301 and standard-of-care alone, with a high overall cure rate.

However, the company said the results suggest AR-301 may help cure more infections faster, while reducing the patient’s time under mechanical ventilation and overall duration of hospital stay.

Aridis is also studying two other antibodies in Pseudomonas aeruginosa-based HAP/VAP infections: AR-105, fast-tracked by the FDA, is expected to produce phase 2 data in the first half of next year; while AR-101 has completed a phase 2a trial, and is slated for a phase 2/3 study launch by the end of 2019.

To gear up for the new trials, the company recently brought on BioMarin’s VP of clinical development, Wolfgang Dummer, to serve as its chief medical officer. Before Biomarin, Dummer spent 11 years at Genentech, helping to oversee the development of the immunotherapies Rituxan and Ocrevus. Aridis also hired Mitchell Rosner, senior director of analytical sciences and quality at Synthetic Genomics, to be its new VP of quality.

Editor's note: This story has been updated with a correction. AR-105 has been granted FDA Fast Track status, not AR-101.