Rhythm Pharmaceuticals wants an IPO to the tune of $115M

Rhythm Pharmaceuticals was a 2016 Fierce 15 winner.

Rhythm Pharmaceuticals, a 2016 Fierce 15 winner, is looking to get off a beefy $115 million IPO as the biotech public offering window appears to be staying open.

The rare disease biotech is working on pro-opiomelanocortin (POMC) deficiency obesity and Prader-Willi syndrome (PWS), conditions caused by rare genetic disorders that can make patients gain massive amounts of weight from a very young age, spurred on by an insatiable hunger, and lead to early deaths from obesity-related disorders.

Its FDA breakthrough-labeled drug, setmelanotide, goes after the MC4 pathway by working as a melanocortin 4 receptor (MC4R) agonist. This pathway has been studied by others for years, but this is the first attempt to go after POMC deficiency obesity.

The company is also working on trials for weight and eating behaviors in patients with Prader-Willi syndrome, another rare genetic disorder that causes life-threatening obesity.

Back in May, Rhythm started a phase 3 test of setmelanotide in POMC; last year, it posted midstage data from two POMC patients which showed it could cut weight down by 3.75 to 4.4 lbs per week, for 42 weeks, in two patients in their 20s who both weighed around 340 lbs before starting the study.

Although only two patients were in this trial, there are only 50 documented cases of the condition, so this still represents a relatively large portion of the patient population.

Back in February, Rhythm got off a $41 million mezzanine round of financing with existing investors including Deerfield Management, Ipsen, OrbiMed, MPM Capital, New Enterprise Associates, Pfizer Venture Investments and Third Rock Ventures. Two months later, it also hired former head of Sanofi Genzyme, David Meeker, as its new chair.

The Boston, MA-based company was founded in 2008 and plans to list on the Nasdaq under the symbol 'RYTM.'