Table 2.
PFS of patients with BRCA-mutant tumors: BRCA1 or BRCA2 LOH versus no BRCA1 or BRCA2 LOH (tBRCA-mutant ITT population evaluable for BRCA zygosity).
| Median PFS,a mo | |||||||
|---|---|---|---|---|---|---|---|
| Group | Evaluable for BRCA zygosity, n | BRCA1 or BRCA2 LOH, n | No BRCA1 or BRCA2 LOH, n | BRCA1 or BRCA2 LOH | No BRCA1 or BRCA2 LOH | HR (95% CI) | P value |
| Talazoparib arm | |||||||
| ITT | 149 | 122 | 27 | 9.0 | 6.9 | 0.868 (0.512–1.470) | 0.597 |
| 1 prior line of chemotherapy | 56 | 40 | 16 | 6.9 | 5.8 | 0.879 (0.407–1.899) | 0.740 |
| HR+ BC | 89 | 66 | 23 | 13.0 | 8.5 | 0.542 (0.285–1.032) | 0.058 |
| Chemotherapy arm | |||||||
| ITT | 87 | 73 | 14 | 5.8 | 5.6 | 1.797 (0.751–4.298) | 0.179 |
| 1 prior line of chemotherapy | 26 | 23 | 3 | 3.6 | 5.6 | 0.809 (0.177–3.702) | 0.783 |
| HR+ BC | 54 | 45 | 9 | 6.7 | 5.6 | 0.696 (0.238–2.030) | 0.500 |
Note: Cox proportional hazards model with no BRCA1/2 LOH as the reference group was used to calculate HR and 95% CI. HR < 1 indicates better PFS in the BRCA1 or BRCA2 LOH group, whereas HR > 1 indicates better PFS in the no BRCA1 or BRCA2 LOH group. Log-rank two-sided test was performed to compare between the two groups. Evaluable ITT population includes all patients with tumor samples suitable for the genomic evaluation and analyzed using FoundationOne CDx who have known or likely pathogenic BRCAmut (BRCA CNAs excluded) and who are evaluable for BRCA zygosity. Subgroups shown are of the evaluable ITT population defined by previous line of chemotherapy or cancer subtype. PFS is per RECIST 1.1 by IRF assessment.
Abbreviations: HR+ BC, hormone receptor–positive breast cancer; mo, months.
aBased on Kaplan–Meier estimates.