Linnaeus Therapeutics announced the U.S. Food and Drug Administration (FDA) has granted orphan drug designation for LNS8801 for the treatment of patients with metastatic uveal melanoma (MUM).

The FDA's Office of Orphan Drug Products grants orphan drug status to support drug candidates in development for underserved patient populations or rare disorders that affect fewer than 200,000 people in the United States. Orphan drug designation provides certain benefits, including market exclusivity upon FDA approval, exemption of FDA application fees, and tax credits for qualified clinical trials.

"We are extremely pleased to have received orphan drug designation for MUM from the FDA. This is an important milestone that has emerged from the very promising data we have seen in patients with MUM during dose escalation," said Patrick Mooney, MD, CEO of Linnaeus. "We look forward to further exploring the preliminary results with LNS8801 alone and also in combination with pembrolizumab when we open additional cohorts soon."

Having completed dose escalation, Linnaeus is currently testing LNS8801 in its phase 1/2 adaptive-design clinical trial as a monotherapy and in combination with KEYTRUDA? (pembrolizumab) in patients who had previous clinical benefit from immune checkpoint inhibitors and then subsequently progressed. This marks the first time any company has dosed a patient in a clinical trial specifically targeting the G protein-coupled estrogen receptor (GPER) in combination with pembrolizumab. Linnaeus intends to open a LNS8801 monotherapy cohort in patients with MUM and also a combination therapy cohort testing LNS8801 and pembrolizumab in patients with MUM in the near term as well as other targeted indications.

LNS8801 is an orally bioavailable and highly specific and potent agonist of GPER whose activity is dependent on the expression of GPER. GPER activation by LNS8801 rapidly and durably depletes c-Myc protein levels. In preclinical cancer models, LNS8801 displays potent antitumor activities across a wide range of tumor types, rapidly shrinking tumors and inducing immune memory.

In the ongoing phase 1/2 study in humans, LNS8801 monotherapy has been safe and well tolerated. Additionally, LNS8801 has demonstrated target engagement, c-Myc protein depletion, and clinical benefit in patients with advanced cancer. Data from the phase 1/2 study are anticipated to be presented in a peer-reviewed setting in 2021.