Concordance between the clinical trial assay (CTA) used to identify patients for recruitment to the Phase 2 clinical trial of BALVERSA (42756493-BLC2001) and the therascreen FGFR RGQ RT-PCR Kit (CDx) was evaluated in a bridging study (1).
Samples with valid results for both the therascreen FGFR RGQ RT-PCR Kit and CTA (292 samples) were analyzed to assess the positive percent agreement (PPA), negative percent agreement (NPA) and overall percent agreement (OPA), based on agreement between the two methods for overall FGFR gene alteration status (i.e., FGFR Alteration Detected or Alteration Not Detected). Results are shown in Table 1.
Table 1. therascreen FGFR RGQ RT-PCR Kit versus CTA (with CTA as reference method)
|Measure of agreement ||Percent agreement % (N) ||Two-sided 95% CI |
|Positive percent agreement (PPA) ||87.2% (82/94) ||79.0, 92.5 |
|Negative percent agreement (NPA) ||97.0% (192/198) ||93.5, 98.6 |
|Overall percent agreement (OPA) ||93.8% (274/292) ||90.5, 96.1 |
The primary objective of the 42756493-BLC2001 study was to evaluate the objective response rate (objective response rate [ORR] = complete response [CR] + partial response [PR]) by RECIST criteria as assessed by investigator assessment. The ORR by Blinded Independent Review Committee (BIRC) was also determined. The observed clinical benefit in the subset of patients that were FGFR Alteration Detected with the therascreen FGFR RGQ RT-PCR Kit (n = 81) was comparable to that observed in the full study population (n = 99).
The therascreen FGFR RGQ RT-PCR Kit is therefore indicated for use as an aid in identifying patients with cases of urothelial cancer that harbor these alterations and are therefore eligible for treatment with BALVERSA (erdafinitib).