P-REALITY Overall Survival

Median OS (secondary endpoint) was not reached with PALBACE^® in combination with letrozole versus 43.1 months with letrozole alone.^1,* 

• Although median OS was reached in the LET alone group, significant censoring in the OS analysis highlights the need for subsequent evaluation with longer follow-up¹
• At 2 years’ follow-up, OS rate was 78.3% with IBRANCE + LET vs 68.0% with LET alone¹

• Although median OS was reached in the LET alone group, significant censoring in the OS analysis highlights the need for subsequent evaluation with longer follow-up¹
• At 2 years' follow-up, OS rate was 78.3% with PALBACE^® + LET versus 68.0% with LET alone¹

Adapted from DeMichele A, et al. 2021.¹

After sIPTW adjustment, median follow-up was 24.2 and 23.3 months for PALBACE^® in combination with letrozole and letrozole alone, respectively.

In an exploratory analysis, a consistent OS benefit with PALBACE^® in combination with letrozole versus letrozole alone was generally observed across examined subgroups, except race (after sIPTW) adjustments.^1,†

Small patient numbers can be a limitation of subgroup analyses. These analyses are considered exploratory. No adjustments were made for multiple testing in the subgroup analyses.

The PALOMA-2 randomised clinical trial (first-line trial of PALBACE^® in combination with letrozole vs. placebo + letrozole) began in February 2013 and includes OS as a secondary endpoint.⁴ The planned number of events required for a final OS analysis has not been reached. Patients will continue to be followed for the final analysis.

*OS was defined as the number of months from the start of treatment with PALBACE® in combination with letrozole or letrozole alone to death due to any cause as recorded by Flatiron in the data extract. The date of death was acquired from a recent mortality data set generated by combining multiple data sources and benchmarked against the National Death Index. Patients who did not die were censored at the study cut-off date (31 May 2019).

^†Race by cohort interaction and metastatic sites by cohort interaction were the only subgroup variable-by-treatment cohort interaction that were significant (P<0.0001 and P = 0.0050, respectively). However, race data were not present in the 'other/unknown' race group. Similar subgroup results were observed in the propensity score matching analysis.
^‡Bone-only disease was defined as metastatic disease in the bone only.
^§Visceral disease was defined as metastatic disease in the lung and/or liver; patients could have had other sites of metastases. No visceral disease was defined as no lung or liver metastases.

CI, confidence interval; Dx, diagnosis; ECOG PS, Eastern Cooperative Oncology Group performance status; HR, hazard ratio; LET, letrozole; N, total number of patients; ND, not determined; NE, not estimable; NR, not reached; OS, overall survival; sIPTW, stabilised inverse probability treatment weighting

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