Watch out, Gilead: TG Therapeutics wins FDA nod for potentially safer Zydelig rival

TG Therapeutics has won an accelerated FDA go-ahead for PI3K inhibitor Ukoniq to treat two types of non-Hodgkin lymphoma. (TG Therapeutics)

The PI3K cancer drug family just got a new member, and it’s a potentially safer option than existing players, including Gilead Sciences’ Zydelig.

Friday, TG Therapeutics said it had won an accelerated FDA go-ahead for Ukoniq (umbralisib) for two types of blood cancer. It’s now allowed to treat relapsed or refractory marginal zone lymphoma (MZL) after at least one prior anti-CD20-based regimen and follicular lymphoma (FL) in patients who have failed at least three previous treatments.

Both indications came ahead of schedule, and TG plans to roll out the new, once-daily oral med immediately next week at a wholesale acquisition cost of $15,900 for a 30-day supply, the company’s chief commercial officer, Adam Waldman, said on a conference call Monday.

The price is higher than those of several other PI3K inhibitors out there, including Zydelig, Verastem Oncology’s Copiktra and Bayer’s Aliqopa. But TG CEO Michael Weiss said his company views Ukoniq as part of a separate drug class; in addition to PI3K delta, the drug also targets casein kinase 1 epsilon, a regulator of oncoprotein translation that’s been implicated in cancer cell formation. So he pointed to other recently launched MZL and FL drugs, saying Ukoniq’s price came in at the lower end of the range.

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Ukoniq’s approval was backed by phase 2 data from the UNITY-NHL trial. The drug triggered a response in 49% of MZL patients and the median duration of response was not reached after more than 20 months of follow-up. In previously treated FL, the drug induced a response in 43% of patients, lasting for a median of 11.1 months.

TG touts Ukoniq as a safer option than other PI3K delta inhibitors. As Cantor Fitzgerald analyst Alethia Young noted in a Monday report, Ukoniq doesn’t bear a black box warning. By contrast, both Copiktra and Zydelig bear black box warnings for side effects including infections, diarrhea or colitis, cutaneous reactions and pneumonitis. It’s not that Ukoniq doesn’t have those problems, but the FDA only lays them out in the safety information section of the drug's label without specifically highlighting them in a dreaded boxed warning.

Waldman said the lack of a boxed warning didn’t change TG’s promotional strategy with Ukoniq, but he labeled it as a differentiator in the minds of physicians.

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Ukoniq marks TG’s first commercial product. The company has assembled a field team of about 70 professionals across sales, marketing, medical and access, Waldman said.

The drug’s long-lasting benefits, coupled with a favorable safety profile, also open up the possibility for combinations. The company already has several trials planned, including with its own anti-CD20 antibody, ublituximab, in the all-important chronic lymphocytic leukemia space. The pairing recently posted positive phase 3 outcomes when pitted against a combo of Roche’s CD20 drug Gazyva and chemotherapy chlorambucil in CLL.

For all three indications combined, Cantor's Young projected Ukoniq peak sales of $1.6 billion, though she acknowledged that figure is higher than what Wall Street’s expecting.

Ukoniq’s continued approval may be contingent upon a confirmatory trial, for which the company is working out details with the FDA, Weiss said.