What happened

Shares of Idera Pharmaceuticals, Inc. (NASDAQ:IDRA), a clinical-stage biotech advancing novel therapies for skin-related diseases, are getting a bump after the company presented trial results at the annual European Society for Medical Oncology conference on Sunday. The stock is up about 16.9% as of 12:05 p.m. EDT on Monday.

So what 

On Sunday, Idera Pharmaceuticals presented final results from the dose-selection stage of a phase 1/2 trial investigating its melanoma candidate IMO-2125 in combination with Yervoy from Bristol-Myers Squibb. All but one of 18 patients enrolled in the exploratory trial experienced disease progression after treatment with increasingly popular PD-1 inhibitors Opdivo or Keytruda, and nine were treated with the dosage that will be used in the phase 2 stage of the trial.

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The published response rate among melanoma patients that progress after treatment with PD-1 inhibitors is between 10% and 13%. This is why investors were pleased to see that adding IMO-2125 to Yervoy shrank tumors in six of nine patients treated with the 8 mg dosage that will be used in the next part of the trial.

Now what

While a 66.7% response rate for the combo certainly looks great against the historical backdrop, there are a couple reasons today's bump wasn't a lot bigger. First, nine patients isn't a big enough group to draw conclusions from. Plus, historical trends for existing treatments that point to impressive efficacy rates for experimental drugs have a nasty tendency to evaporate during trials designed to confirm clinical benefits. 

The findings are impressive enough to warrant a larger phase 3 study with PD-1 refractory melanoma patients. Idera intends to begin enrolling patients for a trial that could support a new drug application for IMO-2125 early next year. If this candidate or Idera's dermatomyositis hopeful, IMO-8400, can repeat previous results in a timely fashion, this stock could soar.

Cory Renauer has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.