TG Therapeutics’ leukemia combo hits marks, guns for speedy FDA review

TG Therapeutics’ experimental med ublituximab used alongside AbbVie’s marketed Imbruvica (ibrutinib) has hit its primary endpoint in a phase 3 study in chronic lymphocytic leukemia (CLL) patients, as the company eyes an accelerated FDA approval later this year.

The top-line data posted this morning from the so-called Genuine study saw ublituximab and Imbruvica meet the test’s primary endpoint of hitting a statistically significant improvement in overall response rate (ORR), increasing ORR by more than 70% when compared to Imbruvica alone.

This test was focused on patients with previously treated, high-risk CLL, namely those positive for 17p deletion, 11q deletion or p53 mutation.

The absolute difference between the arms was around 30% (with a p-value of 0.001). In previous trials, Imbruvica’s response rates ranged from 43% to 58% in patients with previously treated CLL, while the Genuine study saw 47% ORR for Janssen’s med “fitting well within historical experience.”  

TG said that “advantages were seen for the combination in a number of secondary and other efficacy measures, including radiographic complete response rate, progression free survival and time to response,” but these data were not shared in its release.

More details will come later this year, but TG said based on these results, it is seeking a meeting with the FDA in the second half of 2017 “to discuss the results and filing for accelerated approval.”

TG’s candidate is a next-gen glycoengineered anti-CD20 mAb, while Imbruvica, which last year gained a first-line nod from the FDA in CLL, works as a Bruton's tyrosine kinase (BTK) inhibitor.

Its shares soared on the news, up by nearly a staggering 83% as investors welcome the positive data and planned near-term talks with the FDA. 

“We believe the results observed in the combination arm are extremely compelling and the regimen has the potential to become the standard of care for treating patients with high risk CLL that have progressed from other therapies,” said Michael Weiss, CEO and executive chair of TG Therapeutics.

“We believe that using combination therapy to accelerate and deepen response in poor prognosis high risk CLL is critically important for patient outcomes and we look forward to sharing these data with the FDA in the coming months to discuss filing for accelerated approval.”