Palladio bags $20 million Series B to topple a problematic kidney disease drug
Palladio Biosciences just took one step further in its quest to topple Otsuka’s Samsca with its own — it hopes safer — autosomal dominant polycystic kidney disease (ADPKD) drug.
The Pennsylvania-based biotech announced a $20 million Series B on Friday, which will fund a 10-person Phase III trial of its vasopressin V2 receptor agonist, lixivaptan. CEO Alex Martin expects to read out data in the first half of next year, then launch straight into a larger pivotal Phase III study with about 1,200 participants.
The smaller study is currently enrolling patients ages 18-65 who experienced liver chemistry abnormalities or signs of liver toxicity while on tolvaptan, the generic name of a brand primarly known as Samsca or Jynarque.
“The only approved treatment right now for patients with ADPKD is tolvaptan, and that is associated with significant liver toxicity. So if you had a drug that… had the same efficacy as tolvaptan, but didn’t have significant liver toxicity, that would be a safer and better alternative for patients,” Martin said. In 2013 the FDA updated the drug label on Samsca to limit its use for a maximum of 30 days because of serious liver injury potential.
The hormone vasopressin normally helps regulate water balance in the body. But in ADPKD patients, it also has a hand in cyst growth. The goal is to inhibit cyst growth and decrease fluid secretion into cysts by suppressing vasopressin at the V2 receptor, according to Palladio.
Just over a year ago, the company began a compassionate use study of lixivaptan in a patient who reacted negatively to tolvaptan.
Fourteen months later, the patient was “absolutely spotless,” Martin said. “No problems at all with her liver.” Now the question is — can this anecdotal result play out in a clinical trial?
In a Phase II study, dubbed ELiSA, patients treated with lixivaptan showed a mean urine osmolality (Uosm) decline of 80% in the hours after their first dose. And all patients with Stage 2 and 3 chronic kidney disease maintained a Uosm below 300 mOsm/kg over 24 hours, according to the results. One tolvaptan study showed that the drug achieved a Uosm below 300 mOsm/kg in 81% of patients.
“If you take lixivaptan for many years, you could theoretically delay your progression to dialysis for 5 to 10 years, or even push it off altogether so that you wouldn’t need it,” Martin said.
The Series B haul will fund the entire first Phase III trial, called ALERT, which will assess safety. Martin said he expects to begin dosing ADPKD patients for that study in Q4 of this year. The second, larger study will likely be a three-year-trial, he said.
The financing round was led by new investor Samsara BioCapital. Previous investors Medicxi and Osage University Partners jumped in, as well as another new investor, the RocheVenture Fund.
Palladio was founded in 2015 by Care Capital vet Lorenzo Pellegrini. The Palladio COO has co-founded several portfolio companies, including Waltham, Massachusetts-based Minerva Neurosciences. Martin was previously CEO at Realm Therapeutics, which was snatched up by ESSA last year. He was also COO at Intercept Pharmaceuticals, and CFO at BioXell, which was bought by Cosmo Pharmaceuticals for $41 million in 2009.