Shares of Siga Technologies Inc. climbed Tuesday after the company said it qualified for about $79 million in payments after delivering more doses of its smallpox drug to the government.

Siga said it has delivered about 590,000 courses of its drug Arestvyr to the government in the last five months. Arestvyr has not been approved by the Food and Drug Administration, but the government is stockpiling it and another drugs in case of a terrorist attack, biological attack, or a natural outbreak.

Shares of Siga rose 21 cents, or 6.5 percent, to $3.46 in morning trading. Over the past 52 weeks, shares have traded between $2.33 and $4.60.