This morning, Merrimack Pharmaceuticals, Inc. announced that orphan drug designation was granted to MM-121 (seribantumab) by the U.S. Food and Drug Administration (FDA).
MM-121 is an investigational drug candidate intended for the treatment of heregulin positive non-small cell lung cancer (NSCLC). The candidate is currently being evaluated in the SHERLOC trial with the first patient expected to be dosed by the end of 2017.
According to the American Cancer Society
, approximately 80-85% of all lung cancers are NSCLCs, and while NSCLCs are not uncommon, there are numerous subtypes that are considered rare. Among them, NSCLC testing positive for heregulin.
Heregulin is a soluble secreted growth factor that activates HER3 and HER4 transmembrane receptor tyrosine kinases. The growth factor is associated with cell proliferation, invasion, and survival, and heregulin positive cancer cells are characterized by their ability to evade the effects of targeted, cytotoxic and anti-endocrine therapies. Heregulin is also frequently responsible for contributing to the rapid clinical progression of NSCLC.
is a monoclonal antibody that targets the HER3 receptor and the hope is that, seribantumab, when used in a combination setting, can block the heregilin/HER3 signaling axis to make tumor cells more sensitive to the effects of the therapy.
"This is an important regulatory step forward for the clinical development of MM-121 in non-small cell lung cancer and we are pleased to have access to additional support from the FDA in this indication," said Sergio Santillana, M.D., MSc, Chief Medical Officer in a press release
. "Merrimack is dedicated to designing and developing novel precision therapeutics that shape treatment strategies for patients, and our randomized Phase 2 clinical trial of MM-121 in heregulin positive non-small cell lung cancer is well underway. We look forward to expanding the development of MM-121 to a biomarker-selected population of breast cancer patients later this year."
The SHERLOC study is a global randomized Phase 2, double-blind, placebo-controlled clinical study that is designed to assess the progression-free survival (PFS) of MM-121 in combination with docetaxel versus docetaxel alone. Patients enrolled have heregulin positive non-small cell adenocarcinoma of the lung, have progressed after a platinum-containing regimen, and may have received anti PD-1 or anti-PD-L1 therapy. Top line data is anticipated in the second half of 2018.
Additionally, Merrimack is conducting the SHERBOC trial to evaluate MM-121 in combination with the standard of care in patients with heregulin positive, hormone receptor positive, HER2 negative metastatic breast cancer. The first patient in that study is excepted to be enrolled by the end of 2017.
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