Gubra opens Phase 1/2a of GUB-UCN2, its own non-incretin obesity peptide

Danish biotech Gubra has started a Phase 1/2a clinical trial of GUB-UCN2, an internally developed peptide meant to shrink fat while protecting or even building muscle, the company said in its interim report for the first half of 2026 ^[1]. The trial, listed on ClinicalTrials.gov as NCT07702890, began enrolling on July 27, 2026 ^[2].

GUB-UCN2 is a urocortin-2 analog, a type of molecule that does not work through the GLP-1 pathway used by Ozempic, Wegovy, Mounjaro, Zepbound, or Foundayo. Gubra says the drug is designed to reduce fat mass while preserving or increasing skeletal muscle, a property the company is testing both on its own and layered on top of standard incretin-based therapy ^[1]. The three-part study will enroll healthy volunteers, people with obesity, and people with obesity and type 2 diabetes, with treatment lasting up to 16 weeks in some groups, and it will look closely at muscle volume and muscle function, not just body weight ^[2].

Gubra's CEO, Markus Rohrwild, called GUB-UCN2 the company's "next potential mega program," putting it alongside two partnered assets already advancing: Boehringer Ingelheim's BI 3034701, a GLP-1/GIP/NPY2 receptor agonist that entered Phase 2 and triggered a €10 million milestone payment to Gubra, and AbbVie's ABBV-295, a long-acting amylin analog that posted encouraging 12- to 13-week Phase 1 results ahead of a planned Phase 2 start in the third quarter of 2026 ^[1]. Gubra reported group revenue of DKK 126 million and an operating loss of DKK 123 million for the first half of 2026, with full-year guidance unchanged ^[1]. First data from the single ascending dose portion of the GUB-UCN2 trial are expected in the first half of 2027 ^[1].

Gubra's trial start predates a rival deal in the same mechanism. On August 24, 2026, Roche's Genentech unit agreed to pay $190 million upfront, with total payments of up to roughly $2.5 billion, for rights outside South Korea to HM17321, a competing urocortin-2 analog developed by Hanmi Pharmaceutical ^[2]. Roche executives said they were drawn to preclinical data suggesting the mechanism can reduce weight while preserving lean muscle, a decades-old observation about urocortin-2 signaling that both companies are now trying to turn into a marketed drug ^[2].

Why it matters for patients

Most approved obesity drugs today, including semaglutide and tirzepatide products, cause some loss of lean muscle mass along with fat, a side effect that researchers and patients have raised concerns about, especially for older adults. GUB-UCN2 and HM17321 represent an early attempt by two different companies to build a treatment aimed specifically at sparing muscle while cutting fat, using a mechanism unrelated to GLP-1. That could eventually offer an option distinct from, or used alongside, current incretin drugs.

But none of this changes what is available now. GUB-UCN2 has only just entered human testing, with no efficacy or safety data yet released, and the company's own timeline puts the first readout more than a year away, in the first half of 2027 ^[1]. HM17321 is further along only in the sense that Roche has licensed it, not that it has proven results in obesity patients ^[2]. Patients and clinicians should not expect any near-term change in treatment options because of this news.

What happens next

Gubra expects to release data from GUB-UCN2's single ascending dose study in the first half of 2027, with additional clinical data to follow on a rolling basis ^[1]. AbbVie's ABBV-295 is expected to begin Phase 2 testing in the third quarter of 2026 ^[1]. Gubra also plans an investor R&D event on October 27, 2026, where it says it will lay out its strategy through 2030 ^[1].