Roche Holding (SIX:ROG) said on Monday that an experimental treatment strategy for advanced breast cancer failed to meet the primary goal in a late-stage clinical trial. The Swiss drugmaker reported that the combination of its investigational agent giredestrant with Pfizer's Ibrance did not achieve a statistically significant improvement in progression-free survival, the trial's designated primary endpoint.
According to Roche, the study did register a numerical improvement in progression-free survival for patients receiving the combination versus comparator, but that difference did not reach statistical significance. The company also said the combination was generally well tolerated, and that observed adverse events were in line with the established safety profiles of each individual therapy.
This trial represents the first of two late-stage studies evaluating giredestrant as a first-line treatment option for advanced breast cancer, Roche said. The company indicated that findings from the second Phase 3 study are expected to be published next year, with no additional timing or detail provided in the announcement.
The announcement highlights a mixed outcome: while there was some evidence of clinical activity in the form of a numerical progression-free survival benefit, the absence of statistical significance means the study did not meet its pre-specified primary objective. Roche framed the safety experience as consistent with what clinicians and patients already know about the individual drugs involved in the combination.
Roche did not provide further efficacy subgroup data or additional context on secondary endpoints in the initial release. The company also did not change its statement about the timing for results from the second late-stage study, which remains slated for publication next year.
Summary
Roche reported that the giredestrant plus Ibrance combination failed to show a statistically significant progression-free survival benefit in a late-stage study despite a numerical improvement and an acceptable tolerability profile. This was the first of two Phase 3 trials; the second study's results are expected next year.