Rare Daily Staff

The Pfizer rare disease spin-out SpringWorks Therapeutics raised $162 million through an initial public offering of 9 million shares at $18 a share.

Shares are trading on the Nasdaq Global Select Market under the symbol SWTX.

SpringWorks began life with $103 million two years ago to advance certain stalled drugs in development at Pfizer that could have promise for benefitting underserved patient populations with rare diseases.

In June, the biotech received Fast Track designation from the U.S. Food and Drug Administration for its experimental therapy for the treatment of patients 2 and older with neurofibromatosis type 1-associated inoperable plexiform neurofibromas (NF1-PN) that are progressing or causing significant morbidity.

NF1-PN is a rare genetic disorder characterized by mutations in the MAPK pathway, leading to the growth of peripheral nerve sheath tumors that cause significant pain, disfigurement, and morbidity. NF1-PNs are most often diagnosed in the first two decades of life and are characterized by aggressive tumor growth, which is typically more rapid during childhood. There are currently no therapies approved for the treatment of NF1-PN.

SpringWorks’ experimental drug, PD-0325901, is an oral small molecule inhibitor of MEK1 and MEK2 in development for NF1-PN. MEK proteins play a critical role in the MAPK pathway, a key signaling network that regulates cell growth and survival, and whose activity is highly relevant in multiple oncology and rare disease indications.

At the end of August, SpringWorks received the FDA’s Breakthrough Therapy designation for nirogacestat, its experimental drug for the treatment of adult patients with the rare and progressive cancer known as desmoid tumors.

Nirogacestat is an oral, selective, small molecule gamma-secretase inhibitor in phase 3 clinical development for the treatment of desmoid tumors. Gamma secretase cleaves multiple transmembrane protein complexes, including Notch, which is believed to play a role in activating pathways that contribute to desmoid tumor growth.

Desmoid tumors are rare and often debilitating and disfiguring soft-tissue tumors that can aggressively invade surrounding healthy tissues and cause significant morbidities, including severe pain, internal bleeding, incapacitating loss of range of motion, and, in rare cases, death. It is estimated that 1,000 to 1,500 new desmoid tumor patients are diagnosed each year in the United States. There are currently no therapies approved by the FDA for the treatment of desmoid tumors.

Shares are trading on the Nasdaq Global Select Market under the symbol SWTX.

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