Shares of Celldex Therapeutics jumped nearly 17% on the news that the US Food and Drug Administration has granted breakthrough therapy designation to its brain cancer immunotherapy Rintega.

The designation for Rintega (rindopepimut) has been granted by the agency for patients with EGFRvIII-positive glioblastoma (GBM). It is based on data from Phase II trials and a 745-patient late-stage study for newly-diagnosed GBM completed enrollment in December.

Celldex chief executive Anthony Marucci noted that these patients “have extremely limited treatment options, with only three new drugs approved in more than twenty years”. Data suggests Rintega may offer an improvement over existing standard of care for patients with EGFRvIII, a gene mutation which is expressed in tumors in about 30% of GBM cases.

The criteria for BTD require preliminary evidence that demonstrates a drug may have substantial improvement on at least one clinically significant endpoint over available therapy.