(Reuters) – The U.S. Food and Drug Administration declined to approve Blueprint Medicines Corp’s therapy for previously treated patients with a type of cancer that affects the stomach and small intestine, the drugmaker said on Friday.

Shares of the company fell 3.5% to $62.02 in premarket trading.

The regulator in its so-called complete response letter said that Blueprint’s application could not be approved in the current form.

The company was looking to win approval for the therapy, Ayvakit, in patients with gastrointestinal stromal tumor (GIST), who have exhausted all other treatment options.

Every year about 5,000 Americans are diagnosed with GIST and patients are at risk of the cancer recurring even after a successful surgery to remove the tumor.

Ayvakit was previously approved as the first treatment for a small subset of patients with a mutation of GIST. (https://reut.rs/3fTrmnN)

Last month, Ayvakit failed a late-stage study testing previously treated patients with GIST, prompting the company to discontinue further development of the therapy in patients without a specific mutation of the cancer.

(Reporting by Saumya Sibi Joseph and Vishwadha Chander in Bengaluru; Editing by Amy Caren Daniel)