The nation’s shortage of certain drugs is threatening to affect research trials being conducted by Eli Lilly and Co. and Endocyte Inc.

According to Dow Jones Newswires, the cancer drug Doxil is being used in more than 30 clinical trials of new cancer medicines, but its manufacturer, New Jersey-based Johnson & Johnson, has halted supplies to clinical trials in order to make sure current patients get the drug.

About 2,500 patients are on a waiting list to receive the drug, Johnson told Dow Jones. Johnson’s U.S. sales of Doxil fell 87 percent in the third quarter as a result of the shortage, which Johnson blamed on equipment failures at its supplier, Ben Venue Laboratories.

Amy Sousa, a spokeswoman for Indianapolis-based Lilly, said an early-stage study combining Doxil with Lilly's experimental drug tasisulam for the treatment of ovarian cancer isn't currently treating patients due to the shortage.

West Lafayette-based Endocyte has warned that if the Doxil shortage lasts an extended period of time, it could delay a clinical trial testing a combination of its lead experimental compound, EC145, and Doxil in ovarian cancer.

Endocyte spokeswoman Martina Schwarzkopf told Dow Jones the company was ahead of its enrollment plan when the shortage was announced, helping it avoid a hiccup so far.

Other trials being conducted for Calfironia-based Amgen Inc., New Jersey-based Celgene Corp., as well as some university-sponsored studies, also have been affected by the Doxil shortage.

At least 300 clinical trials funded by the National Cancer Institute include a drug that is in short supply, a Department of Health and Human Services official told a congressional committee last month. The shortages have many causes, including stricter price limits from the federal Medicare program, industry consolidation and manufacturing-quality problems.