UroGen’s UGN-101 clears 57% of tumors in pivotal trial

UroGen Pharma’s UGN-101 has triggered durable complete responses in 57% of the low-grade upper tract urothelial carcinoma (UTUC) patients enrolled in its phase 3 trial. The readout from the ongoing pivotal trial comes as UroGen performs a rolling NDA under the leadership of new CEO Liz Barrett.  

Barrett, the former CEO of Novartis Oncology, was unveiled as the leader of UroGen last week and has now started her reign with an update on UGN-101, a formulation of mitomycin that uses reverse thermal gel technology to increase the time the drug is in contact with the cancer. UroGen linked the drug to a 59% complete response rate in an interim readout in May and came close to matching that performance in the latest update.

UroGen now has primary endpoint data on 61 of the 71 patients enrolled in the pivotal trial. More than half of the patients experienced complete responses. Analysts at Jefferies think a 20% complete response rate could be clinically meaningful and sufficient for FDA approval. 

Surgery, the current standard of care, can also totally eliminate tumors, but it suffers from high rates of recurrence, poses risks to the older patients who make up the majority of the UTUC population and is only viable for some people. 

Close to half of the patients treated in the UroGen trial had unresectable tumors, leaving kidney removal as their only approved option. The ability of UGN-101 to tackle such tumors, coupled to its noninvasive nature, gives it a built-in advantage over surgery. If UroGen can also link UGN-101 to a lower rate of disease recurrence, it could establish the drug as the first-line standard of care. 

That effort is ongoing. When UroGen presented data in May, it said none of the tumors of patients who experienced complete responses had recurred. Back then, UroGen only had six months of data on four patients. 

Now, UroGen has six months of follow-up data on half of the patients who had complete responses. All these patients were disease free after six months. UroGen is encouraged by the data.

“The durability observed in the OLYMPUS study provides further evidence that the non-surgical treatment of LG UTUC with UGN-101 may result in clinically-meaningful, recurrence free survival,” UroGen CMO Mark Schoenberg said in a statement.

UroGen is set to take the data to the FDA. The Israeli-American company initiated a rolling NDA late last year and plans to seek approval for UGN-101 using data on the 71 patients enrolled in the phase 3 trial.

Shares in UroGen slipped 8% in early trading following the release of the data, which were widely expected to be positive. The stock gained more than 25% in the days preceding the readout on the back of the appointment of Barrett and in anticipation of the phase 3 readout.