Roche Pursues FDA Approval for Eye Disease Drug Despite Mixed Phase 3 Results

Pharmaceutical giant Roche is moving forward with plans to seek regulatory approval for its eye disease drug candidate, vamikibart, despite mixed results from two phase 3 clinical trials. The Swiss drugmaker's decision highlights the complexities of drug development and the challenges faced by companies in interpreting clinical data.

MEERKAT and SANDCAT Trials Yield Conflicting Outcomes

Roche conducted two identical phase 3 studies, MEERKAT and SANDCAT, to evaluate the efficacy of vamikibart, an IL-6 inhibitor, in patients with uveitic macular edema (UME). The trials compared two doses of vamikibart to a sham control, with the primary endpoint focused on vision improvement.

While the MEERKAT study met its primary endpoint, the SANDCAT trial fell short of statistical significance. In MEERKAT, 36.9% of patients on the high dose of vamikibart achieved the primary endpoint of gaining at least 15 letters on the BCVA vision chart at Week 16. However, in SANDCAT, only 10.9% of high-dose patients met this criterion.

The low-dose results were more consistent between the two trials, with 19.9% and 20.7% of patients achieving the primary endpoint in MEERKAT and SANDCAT, respectively.

Roche Cites Secondary Endpoints and Overall Data in Decision to Pursue Approval

Despite the mixed primary endpoint results, Roche is emphasizing the positive outcomes observed in key secondary endpoints. The company reported rapid and clinically meaningful improvements in average change from baseline in BCVA and a measure of retinal thickness.

Dr. Levi Garraway, Roche's Chief Medical Officer, stated that the "totality of data" from the studies represents an important step for UME treatment. The company believes that the overall dataset, including secondary endpoint achievements, supports discussions with regulatory agencies.

Roche has suggested that underlying variability in the BCVA endpoint, along with differences in patient baseline characteristics and concomitant medications, may have contributed to the disparate outcomes between the two trials.

Implications for Vamikibart's Future and Market Positioning

The mixed results raise questions about vamikibart's chances of approval and its potential market position. If approved, the drug would enter a market currently dominated by systemic, local, and topical steroids for UME treatment.

Roche has already paused plans to develop vamikibart for diabetic macular edema, choosing instead to prioritize a VEGFxIL6 candidate for that indication. This decision leaves UME as the primary focus for vamikibart's potential commercialization.

Industry analysts have expressed relatively low expectations for vamikibart's commercial prospects. In a consensus estimate compiled by Roche, the drug was ranked at the bottom of a list of phase 3 programs expected to contribute significantly to the company's growth through 2029.

As Roche prepares to engage with regulatory agencies, the pharmaceutical industry will be watching closely to see how authorities interpret the mixed dataset and whether vamikibart can secure approval based on its overall clinical profile.