Crinetics' PALSONIFY™ shows lasting benefits in long-term acromegaly trials

Crinetics Pharmaceuticals has presented new long-term data for its acromegaly treatment, PALSONIFYTM (paltusotine), at ENDO 2026. The results cover two open-label extension (OLE) trials, PATHFNDR-1 and PATHFNDR-2, showing sustained effectiveness and tolerability over extended treatment periods. In PATHFNDR-1, patients who switched from monthly injectable somatostatin receptor ligands (SRLs) to PALSONIFY maintained stable IGF-1 levels at 0.81 times the Upper Limit of Normal (ULN) after 96 weeks. Pituitary tumour volumes also remained unchanged from baseline at week 48. Acromegaly symptoms, tracked via the Acromegaly Symptom Diary (ASD), showed no worsening at assessed timepoints.

PATHFNDR-2 reported a reduction in IGF-1 levels from 1.64x ULN at baseline to 0.96x ULN after 72 weeks of treatment. Among 83 patients with MRI scans at OLE Week 24, seven experienced a pituitary tumour volume reduction of over 20%. ASD scores in this group also remained stable throughout the study.

Across the pooled OLE population of 167 patients, the most frequent side effects were diarrhoea (15.6%), joint pain (11.4%), headache (11.4%), and urinary tract infections (10.2%). Four patients (2.4%) left the studies due to adverse events. The data demonstrate that PALSONIFY maintained stable IGF-1 levels, symptom control, and tumour sizes in most patients over long-term use. Only a small percentage discontinued treatment due to side effects, reinforcing its overall tolerability.