In a previous video, investigator Jessica Allegretti, MD, of the Crohn's and Colitis Center at Brigham and Women's Hospital in Boston, discussed the results from the QUASAR phase III induction study presented at the American College of Gastroenterology (ACG) annual meeting, which demonstrated early symptom improvement with guselkumab (Tremfya) in ulcerative colitis (UC).
Here, Allegretti reports that more than half of the patients who were not in clinical response with the IV induction therapy at week 12 achieved clinical response at week 24 when they stayed on treatment.
Following is a transcript of her remarks:
Hi everyone. My name is Jessica Allegretti and I'm the medical director for the Crohn's and Colitis Center at the Brigham and Women's Hospital. And today I'm going to be reviewing an abstract that was presented at ACG 2023 entitled "Cumulative Response to Guselkumab through Week 24 of Induction in Patients with Moderate to Severely Active Ulcerative Colitis: Results from the Phase III QUASAR Induction Study."
For a little bit of background, the phase III QUASAR induction study evaluated efficacy and safety of guselkumab, which is an IL [interleukin]-23 p19 subunit antagonist in patients with moderate to severely active UC. At week 12, guselkumab 200 mg IV has been shown to be more effective than placebo in inducing clinical remission and clinical response. However, patients not found to be in clinical remission or have achieved clinical response at week 12, were able to receive guselkumab through week 24. And in this abstract, the authors present the cumulative guselkumab efficacy and safety data through week 24.
So in this study, patients with a modified Mayo score of 5 to 9 and a Mayo endoscopic subscore of 2 or greater were randomized in a 3:2 fashion to receive guselkumab 200 mg IV or placebo at weeks 0, 4, and 8. Patients not found to be in clinical response at week 12 were able to receive guselkumab at weeks 12, 16, and 20. Notably, those that had received guselkumab 200 mg IV in the induction portion then went to receive guselkumab 200 mg subcutaneously after week 12. Those in the placebo group were given 200 mg IV. There was matching IV and [subcutaneous] placebo to maintain the blinding of this study. Final safety assessments were conducted through week 32.
The primary analysis population of this study consisted of 701 patients, and the demographics between the two groups were very similar. Notably, about 50% had a history of inadequate response or intolerance to prior advanced therapies.
At week 12, clinical response was achieved by a higher percentage of those treated with guselkumab compared to placebo, 61.5% compared to 27.9%, respectively. Of the guselkumab-treated patients who were not in clinical response at week 12 and received additional guselkumab treatment, 55% achieved clinical response at week 24. This yields a cumulative clinical response at week 12 or week 24 of 77.2% of patients randomized to receive guselkumab at baseline.
Notably, patients with and without history of prior exposure to advanced therapies benefited from continuing treatment with guselkumab through week 24.
So in conclusion, among patients randomized to guselkumab IV who did not achieve clinical response at week 12, continued treatment with guselkumab subcutaneously allowed 55% to achieve clinical response at week 24. Overall, more than three-quarters of patients randomized to guselkumab IV achieved clinical response either at week 12 or at week 24. And no new safety signals from guselkumab were identified in this study. Thank you so much for your attention.