Maxim Pharmaceuticals said on Wednesday the U.S. Food and Drug Administration had allowed it to expand advanced testing of a drug for treating skin cancer.

The FDA ruling will enable more patients to use the drug Ceplene - in combination with the drug interleukin-2 - for treatment of advanced malignant melanoma, the Swedish-American drug firm said.

The decision allows it to “provide expanded access of Ceplene to patients in the United States while investigation of the drug continues in the company’s confirming phase III clinical trial,” Maxim said in a statement.

Phase III trials are the last stage of testing before a company submits all documents to the FDA and requests full approval of the drug for commercial release. The development is a further step toward the drug coming onto the market.

Maxim’s shares were up 4.5 percent at 69.50 crowns at 1015 GMT, after earlier rising as high as 71 crowns, in a Swedish market whose blue-chip OMX index was off 1.4 percent.

Analysts said there was more upside potential in the stock.

“We see the information concerning the FDA’s decision about the product Ceplene as being very positive,” said Swedish growth stock analysts Redeye. “We see today’s initial share price rise as being on the small side.”