Tuesday's Small-Cap Winners & Losers

Small-cap stocks strayed far behind the sliding major indices Tuesday, and one of the worst performers was Inovio Biomedical (INO Quote).

The San Diego-based company plummeted 36% to $2.20 after halting patient enrollment in both of its late-phase pivotal studies on an investigational therapy called selective electrochemical tumor ablation (SECTA). An independent data-monitoring committee noted, among other things, that the mortality rate among the head- and neck-cancer patients treated with SECTA was higher than among those who underwent surgery.

Shares of North American Scientific (NASI Quote), which likewise makes cancer-treatment products, slid 18% to $1.23 after the California-based company's second-quarter revenue fell 22.9% year over year to $6.2 million, even though per-share losses halved to 11 cents. ...