Use of targeted therapies for advanced renal cell carcinoma in the Veterans Health Administration

Patterns of first-line targeted therapy utilization and adherence among older adults diagnosed with metastatic renal cell carcinoma

BACKGROUND

Despite the rapid approval of targeted therapies for metastatic renal cell carcinoma (mRCC) evidence on real world treatment patterns remains limited. This study evaluated patterns of first-line targeted therapy utilization and adherence in older adults, a population with a high burden of RCC.

METHODS

2093 patients aged ≥66 years with a primary diagnosis of mRCC were identified from United States (US)-based cancer registry and administrative claims data (2007-2015). We included only patients with de novo disease. We assessed the initiation of first-line targeted therapy within four months of diagnosis and persistence and adherence to targeted therapy, using the proportion of days covered (PDC). Multivariable logistic regression yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs) to describe characteristics associated with targeted therapy versus no targeted therapy initiation and for high (≥80% PDC) versus low adherence.

RESULTS

28.8% of patients received first-line targeted therapy within four months of diagnosis, with the proportion of patients receiving targeted therapy increasing over time. Older age (one-year increment OR:0.95 95%CI 0.93, 0.97), high comorbidity burden (OR:0.65 95%CI0.46, 0.93) and clear cell histology (OR:1.54 95%CI 1.19, 2.00) were associated with targeted therapy initiation. 48.2% of patients exhibited a high PDC to oral targeted therapy at 120 days, which was attenuated with inclusion of patients who died during the time period (34.2% PDC ≥80%).

CONCLUSION

Increasing age, high comorbidity burden and non-clear cell histology were associated with decreased targeted therapy initiation among patients with de novo mRCC. Our findings suggest adherence to oral therapies was low; future research exploring the mechanisms and impact of low adherence in this older patient population is warranted.

Practice Patterns and Outcomes of Novel Targeted Agents for the Treatment of ERBB2-Positive Metastatic Breast Cancer

Importance

Clinical trials have shown that the addition of pertuzumab to trastuzumab-based chemotherapy for first-line treatment of ERBB2-positive metastatic breast cancer is associated with considerable improvement in overall survival (OS). In the second-line setting, trastuzumab emtansine (T-DM1) improves OS compared with capecitabine/lapatinib in patients previously treated with trastuzumab-based chemotherapy. However, there are few data describing long-term real-world outcomes with these agents.

Objective

To describe practice patterns and outcomes associated with pertuzumab and T-DM1 in routine clinical practice.

Design, Setting, and Participants

This population-based retrospective cohort study used the Ontario Cancer Registry linked to electronic treatment databases to identify all patients treated with pertuzumab and T-DM1 following reimbursement approval in Ontario, Canada, which has a single-payer public health system. Participants included women with stage IV ERBB2-positive metastatic breast cancer receiving treatment with pertuzumab for first-line metastatic indication from December 2013 through December 2017, and those treated with T-DM1 from May 2014 through December 2017. Pertuzumab and T-DM1 cohorts were analyzed separately. Data were analyzed December 2019 to December 2020.

Exposures

Treatment with pertuzumab or T-DM1.

Main Outcomes and Measures

The primary outcome was OS, determined using the Kaplan-Meier method. Factors associated with OS were identified using a Cox proportional hazard model.

Results

The median (interquartile range [IQR]) age of the 795 women who received pertuzumab and 506 women who received T-DM1 was 57 (49-67) and 56 (48-66) years, respectively. Among the entire population, the median (IQR) OS and time on treatment was 43 (16.2-unavailable) and 14 (6.0-26.2) months, respectively. In the T-DM1 cohort, the proportion of pertuzumab-naive patients decreased over time from 68 of 91 [74.7%] in 2014 to 16 of 89 [18.0%] in 2017 (P < .001). The median (IQR) OS and time on treatment was 15 (6.7-27.7) and 4 (1.4-9.0) months, respectively. Median OS was shorter for patients with prior pertuzumab treatment than in the pertuzumab-naive subgroup (12 vs 19 months; adjusted hazard ratio, 0.70; 95% CI, 0.55-0.89; P = .004).

Conclusions and Relevance

In this population-based cohort study, the survival of patients treated with pertuzumab and T-DM1 in routine practice appeared inferior to results from pivotal clinical trials. Differences in outcome likely reflect differences in patient population and previous lines of therapy in routine practice. Further work is needed to understand the effectiveness of T-DM1 after pertuzumab exposure.

Use of targeted therapies for advanced renal cell carcinoma in the Veterans Health Administration

BACKGROUND

The objective of this study is to describe the use of targeted therapies for the treatment of advanced renal cell carcinoma (RCC) and overall survival (OS) among patients in clinical practice in the Veterans Health Administration (VHA).

METHODS

A retrospective cohort of 286 patients from 24 VHA Medical Centers diagnosed with advanced clear cell RCC between Fiscal Year (FY) 2010 and FY2014 was followed through September 30, 2016. Among patients who received targeted therapy, we described the medications taken, duration of therapy, and overall survival. We also assessed the effect of the first therapy received on overall survival using Cox Proportional Hazards models.

RESULTS

There were 66 patients who did not receive therapy for their advanced RCC. Of the 220 treated patients, the mean (sd) number of medications received was 1.9 (1.1). The medications most commonly used first were sunitinib (61.8%), pazopanib (17.3%), and temsirolimus (10.9%). The median duration of first-line therapy was 86 days (interquartile range [IQR] 42, 210). Median total duration of therapy was 159 days (IQR 58, 397). 62.3% of patients had ≥ 1 dose of therapy held or reduced, mainly due to an adverse drug event (ADE). Median survival from the start of treatment to death was 1.08 years (IQR 0.80, 1.31). Finally, receipt of temsirolimus vs sunitinib (HR 1.95 [95%CI 1.09,3.47]) as the first targeted therapy was independently associated with an increased hazard of death.

CONCLUSION

Our analysis of targeted therapies for advanced RCC in VHA suggests duration of treatment is shorter in a real-world setting than in clinical trials, and dose reductions and ADEs are more common.