The Food and Drug Administration (FDA) has issued a second Complete Response Letter (CRL) to Avenue Therapeutics regarding the New Drug Application (NDA) for intravenous (IV) tramadol for the management of adults with moderate to moderately severe pain in a medically supervised healthcare setting.

In the CRL, the FDA stated that the “delayed and unpredictable onset of analgesia with IV tramadol does not support its benefit as a monotherapy to treat patients in acute pain.” The FDA also noted that there is insufficient information related to the efficacy and safety of IV tramadol in combination with other analgesics for the intended patient population. There were no issues in the letter pertaining to Chemistry, Manufacturing and Controls (CMC).

The NDA for IV tramadol was submitted in December 2019, which included data from two phase 3 clinical trials involving patients who were treated following bunionectomy or abdominoplasty, along with an open-label safety study and an epidemiology study. Findings from the phase 3 trials showed that IV tramadol met all of the primary and most of the secondary endpoints.

Despite the FDA’s issuance of a second CRL, the Company intends to pursue regulatory approval for IV tramadol.


Avenue Therapeutics receives Complete Response Letter from the FDA for IV tramadol. [press release]. New York, NY: Avenue Therapeutics, Inc.; June 14, 2021.