Aridis Shares Plummet After Pneumonia Drug Flunks Midstage Study

Shares of the thinly traded, micro-cap biotech Aridis Pharmaceuticals Inc ARDS were retreating to a one-week low Tuesday morning.

What Happened

San Jose, California-based Aridis announced ahead of the market open that its first-in patient Phase 2 study that evaluated its AR-105 did not meet the primary endpoint of demonstrating superiority in clinical cure rates on Day 21 compared to placebo.

The drug is a fully human IgG1 monoclonal antibody for ventilator-associated pneumonia, or VAP, caused by gram-negative Pseudomonas aeruginosa.

Additionally, the company said it noted a statistically significant imbalance in all-cause mortality, as well as serious adverse event, or SAE, rates between the treatment groups that favored placebo.

Aridis said it will no longer allocate further resources for the clinical development of AR-105.

"Our team is analyzing the full data set to better understand these top-line results and report the final analysis as soon as possible," Chief Medical Officer Wolfgang Dummer said in a statement. 

What's Next

Aridis said it will now refocus on the balance of its pipeline, including its lead candidate AR-301; and AR-501, both of which are in clinics.

AR-301, which targets gram-positive S. aureus alpha-toxin, is in a Phase 3 study for VAP.

The company expects to report interim data in the first half of 2020 as well as the subsequent top-line data in late 2020.

The company also said it is on track with its AR-501 program, which is evaluating an inhaled formulation of gallium citrate being developed as a non-antibiotic anti-infective to treat lung infections in cystic fibrosis patients,

Aridis expects to report top-line data from a Phase 1/2a trial in healthy subjects by the first quarter of 2020 and in cystic fibrosis patients in the second quarter of 2021.

Aridis shares were sliding by 25% to $8.76 at the time of publication Tuesday. 

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