Patient preferences for features of HER2-targeted treatment of advanced or metastatic breast cancer: a discrete-choice experiment study

BACKGROUND

We aimed to quantify patients' benefit-risk preferences for attributes associated with human epidermal growth factor receptor 2 (HER2)-targeted breast cancer treatments and estimate minimum acceptable benefits (MABs), denominated in additional months of progression-free survival (PFS), for given treatment-related adverse events (AEs).

METHODS

We conducted an online discrete-choice experiment (DCE) among patients with self-reported advanced/metastatic breast cancer in the United States, United Kingdom, and Japan (N = 302). In a series of nine DCE questions, respondents chose between two hypothetical treatment profiles created by an experimental design. Profiles were defined by six attributes with varying levels: PFS, nausea/vomiting, diarrhea, liver function problems, risk of heart failure, and risk of serious lung damage and infections. Data were analyzed using an error component random-parameters logit model.

RESULTS

Among the attributes, patients placed the most importance on a change in PFS from 5 to 26 months; change from no diarrhea to severe diarrhea was the least important. Avoiding a 15% risk of heart failure had the largest MAB (5.8 additional months of PFS), followed by avoiding a 15% risk of serious lung damage and infections (4.6 months), possible severe liver function problems (4.2 months), severe nausea/vomiting (3.7 months), and severe diarrhea (2.3 months) compared with having none of the AEs. The relative importance of 21 additional months of PFS (increasing from 5 to 26 months) increased for women with HER2-negative disease and those with children.

CONCLUSIONS

Patients valued PFS gain higher than the potential risk of AEs when deciding between hypothetical breast cancer treatments.

Health-related quality of life in women with breast cancer: a review of measures

BACKGROUND

To identify and describe the breast cancer-specific health-related quality of life (HRQoL) instruments with evidence of validation in the breast cancer population for potential use in patients treated for breast cancer (excluding surgery).

METHODS

We conducted a systematic literature review using PubMed, Embase, and PsycINFO databases to identify articles that contain psychometric properties of HRQoL instruments used in patients with breast cancer. Relevant literature from January 1, 2009, to August 19, 2019, was searched. Articles published in English that reported psychometric properties (reliability, validity) of HRQoL instruments were identified.

RESULTS

The database search yielded 613 unique records; 131 full-text articles were reviewed; 80 articles presented psychometric data for instruments used in breast cancer (including generic measures). This article reviews the 33 full articles describing psychometric properties of breast cancer-specific HRQoL instruments: EORTC QLQ-C30, EORTC QLQ-BR23, FACT-B, FBSI, NFBSI-16, YW-BCI36, BCSS, QuEST-Br, QLICP-BR, INA-BCHRQoL, and two newly developed unnamed measures, one by Deshpande and colleagues (for use in India) and one by Vanlemmens and colleagues (for use among young women and their partners). The articles that described the EORTC QLQ-C30, QLQ-BR23, and FACT-B centered on validating translations, providing additional support for content validity, and demonstrating acceptability of electronic patient-reported outcome administration. Psychometric properties of the measures were acceptable. Several new measures have been developed in Asia with an emphasis on development on cultural relevance/sensitivity. Others focused on specific populations (i.e., young women with breast cancer).

CONCLUSIONS

Historically, there have been limited options for validated measures to assess HRQoL of patients with breast cancer. A number of new measures have been developed and validated, offering promising options for assessing HRQoL in this patient population. This review supports the reliability and validity of the EORTC QLQ-C30 and FACT-B; new translations and electronic versions of these measures further support their use for this population.

Prognostic factors of brain metastasis and survival among HER2-positive metastatic breast cancer patients: a systematic literature review

BACKGROUND

Patients with breast cancer who overexpress the human epidermal growth factor receptor 2 (HER2) and subsequently develop brain metastasis (BM) typically experience poor quality of life and low survival. We conducted a comprehensive literature review to identify prognostic factors for BM and predictors of survival after developing BM, and the effects of therapies with different mechanisms of action among patients with HER2+ breast cancer (BC).

METHODS

A prespecified search strategy was used to identify research studies investigating BM in patients with HER2+ BC published in English during January 1, 2009-to June 25, 2021. Articles were screened using a two-phase process, and data from selected articles were extracted.

RESULTS

We identified 25 published articles including 4097 patients with HER2+ BC and BM. Prognostic factors associated with shorter time to BM diagnosis after initial BC diagnosis included younger age, hormone receptor negative status, larger tumor size or higher tumor grade, and lack of treatment with anti-HER2 therapy. Factors predictive of longer survival after BM included having fewer brain lesions (< 3 or a single lesion) and receipt of any treatment after BM, including radiosurgery, neurosurgery and/or systemic therapy. Patients receiving combination trastuzumab and lapatinib therapy or trastuzumab and pertuzumab therapy had the longest median survival compared with other therapies assessed in this review.

CONCLUSIONS

More research is needed to better understand risk factors for BM and survival after BM in the context of HER2+ BC, as well as the assessment of new anti-HER2 therapy regimens that may provide additional therapeutic options for BM in these patients.

Quality-adjusted time without symptoms or toxicity (Q-TWiST) of trastuzumab deruxtecan (T-DXd) versus chemotherapy in patients with advanced gastric cancer from the DESTINY-Gastric01 trial

4057

Background: DESTINY-Gastric01 (NCT03329690) is a randomized, phase 2 study evaluating trastuzumab deruxtecan (T-DXd) in patients with HER2-positive advanced gastric cancer who progressed after ≥2 regimens. T-DXd significantly improved objective response rate (51% vs. 14%; P < 0.001) and overall survival (median OS; 12.5 vs. 8.4 months; P = 0.01) relative to chemotherapy (irinotecan or paclitaxel), leading to regulatory approval in USA and Japan. This post hoc analysis evaluated the overall effect of treatment differences on the quality of survival after discounting for time spent with toxicities or disease progression by comparing the Q-TWiST for patients who received T-DXd versus those who received chemotherapy. Methods: Patients were randomized 2:1 to receive T-DXd or chemotherapy. For each treatment arm, OS, truncated at 10.1 months (the median OS for the entire analysis population, following Q-TWiST convention), was partitioned into three health states: time with grade ≥3 toxicities before disease progression (TOX), time before disease progression without symptoms of disease progression or toxicity (TWiST), and time following disease progression prior to death or censoring (PROG). Mean duration in each state was weighted by a utility score, determined first in a threshold analysis, using a range of hypothetical utility values to generate quality-adjusted states, and then based on observed EQ-5D-5L scores, for that state; the sum of the utility-weighted durations yielded the Q-TWiST value for the time until the end of 10.1 months’ follow-up. In both threshold and observed utility analyses, 95% confidence intervals (CIs) and two-sided P values were calculated using the bootstrap method. Results: Relative to patients receiving chemotherapy (n = 62), patients receiving T-DXd (n = 125) had significantly longer unweighted durations of TOX (3.0 vs. 1.6 months; P < 0.01) and TWiST (3.1 vs. 2.1 months; P < 0.05) and a shorter unweighted duration of PROG (2.4 vs. 3.7 months; P < 0.01). Using a matrix of 25 hypothetical utility-weight combinations, with a TWiST utility of 1 and TOX and PROG utilities ranging from 0 to 1, Q-TWiST differences between treatment arms ranged from −0.5 to 2.3 months, favoring T-DXd in 22 combinations, of which 15 were statistically significant. Using observed EQ-5D-5L utility values, Q-TWiST was 0.9 months (95% CI, 0.2-1.5) longer for T-DXd than for chemotherapy (6.6 vs. 5.7 months), significantly favoring T-DXd ( P < 0.05). Conclusions: Over a 10-month follow-up period, treatment with T-DXd was associated with a statistically significant gain in quality-adjusted OS versus chemotherapy among previously treated patients with gastric cancer. An analysis using observed EQ-5D-5L utility scores found a statistically significant advantage in Q-TWiST for T-DXd. Clinical trial information: NCT03329690.

Incidence of pneumonitis/interstitial lung disease induced by HER2-targeting therapy for HER2-positive metastatic breast cancer

Purpose

Anti-human epidermal growth factor receptor 2 (HER2) therapies are associated with interstitial lung disease (ILD), also referred to as pneumonitis. In this literature review, we describe the incidence of ILD among patients with HER2-positive metastatic breast cancer (MBC) receiving anti-HER2 therapies, and we describe existing recommendations for monitoring and managing drug-induced ILD among these patients.

Methods

We searched PubMed and Embase to identify clinical trials and postmarket observational studies that investigated anti-HER2 therapies for HER2-positive MBC, reported on ILD, and were published during January 1, 2009 to July 15, 2019. Articles were screened by two researchers; data were extracted from the full-text articles.

Results

The 18 articles selected for this review assessed 9,886 patients who received trastuzumab (8 articles), lapatinib (4 articles), trastuzumab emtansine (3 articles), trastuzumab deruxtecan (2 articles), or trastuzumab duocarmazine (1 article). The overall incidence of all-grade ILD was 2.4% (n = 234), with 66.7% (n = 156) occurring as grade 1–2 events, 0.5% grade 3–4 (n = 54; incidence), and 0.2% grade 5 (n = 16; incidence). The highest ILD incidence (21.4%) was among patients receiving trastuzumab combined with everolimus and paclitaxel. Ten studies indicated that ILD events were managed via dose interruption, dose reduction, or treatment discontinuation; two studies included detailed guidelines on managing drug-induced ILD.

Conclusions

ILD is a well-described adverse drug reaction associated with several anti-HER2 drugs. Published ILD management guidelines are available for few anti-HER2 treatment regimens; however, guidance for monitoring for anti-HER2 drug-induced ILD is lacking.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05754-8) contains supplementary material, which is available to authorized users.

Patterns of Care in Patients with Metastatic Renal Cell Carcinoma Among a U.S. Payer Population with Commercial or Medicare Advantage Membership

BACKGROUND

Several systemic therapies are now approved for first- and second-line treatment of metastatic renal cell carcinoma (mRCC). Although the National Comprehensive Cancer Network (NCCN) guidelines offer physicians evidence-based recommendations for therapy, there are few real-world studies to help inform the utilization of these agents in clinical practice.

OBJECTIVES

To (a) describe the patterns of use associated with systemic therapies for mRCC among Humana members in the United States diagnosed with mRCC, (b) assess consistency with the NCCN guidelines for treatment, and (c) to describe the initial first-line therapy regimen by prescriber specialty and site of care.

METHODS

This was a retrospective study using Humana's claims database of commercially insured patients and patients insured by the Medicare Advantage Prescription Drug plan. The study period was from January 1, 2007, to December 31, 2013. Patients with mRCC were identified by ICD-9-CM codes 189.0/189.1 and 196.xx to 199.xx; all patients were between 18 and 89 years of age, had received systemic therapy for their disease, and were followed up for 180 days. Outcome measures included choice of initial systemic therapy, starting and ending doses, first-line treatment persistence and compliance, and choice of second-line therapy. Persistence was measured using time to discontinuation of first-line therapy and proportion of days covered (PDC; the ratio of [total days of drug available minus days of supply of last prescription] to [last prescription date minus first prescription date]). Compliance was measured using the medication possession ratio (MPR; the ratio of [total days supply minus days supply of last prescription] to [last prescription date minus first prescription date]).

RESULTS

A total of 649 patients met all inclusion criteria; 109 were insured by commercial plans and 540 were insured by Medicare. The mean ± SD age of patients was 68.6 ± 9.4 years, and 68.6% were male; Medicare patients were older than commercial patients (71.7 ± 7.4 vs. 56.6 ± 9.1 years, respectively; P < 0.001). The most common comorbidities among the patient population were hypertension, hyperlipidemia, diabetes, and heart disease. The majority of patients (68.6%) received an oral tyrosine kinase inhibitor (TKI) as their first line of therapy: 43.9% received sunitinib, 14.0% received sorafenib, 10.0% received pazopanib, and 0.6% received axitinib. Mean ± SD time to discontinuation of first-line TKI treatment was 169.1 ± 29.5 days with sunitinib, 160.3 ± 41.1 days with pazopanib, and 160.1 ± 41.4 days with sorafenib. Other first-line therapies included inhibitors of mammalian target of rapamycin (mTOR) (19.7%) and the antivascular endothelial growth factor agent bevacizumab (9.4%). Among patients receiving mTOR inhibitors, 14.8% were started on temsirolimus and 4.9% were started on everolimus. The median starting and ending doses were the same for each drug except for sunitinib. Mean ± SD times to discontinuation of temsirolimus, everolimus, and bevacizumab were 171.8 ± 26.2, 137.0 ± 62.2, and 150.8 ± 56.0 days, respectively. Persistence on first-line regimen as measured by PDC was high (PDC ≥ 80%) for 89% of oral therapies and 77% of injectable therapies; first-line compliance was high (MPR ≥ 80%) for 77% of oral therapies and 68% of injectables. Among patients who received second-line therapy, the most common regimen was everolimus (29.2%), followed by bevacizumab (19.8%), temsirolimus (15.6%), and sunitinib (13.6%). Specialty codes obtained from the database provider identified internal medicine specialists and oncologists as the most common prescribers of TKIs and mTOR inhibitors.

CONCLUSIONS

Patterns of use were similar for each of the prescribed systemic treatments for mRCC, and the majority of patients were highly persistent and compliant with first-line therapies. Time to treatment discontinuation was slightly longer with oral agents compared with injectable drugs.

Quality-adjusted time without symptoms or toxicity analysis of pazopanib versus sunitinib in patients with renal cell carcinoma

BACKGROUND

In a phase 3, randomized, open-label trial (Pazopanib versus Sunitinib in the Treatment of Locally Advanced and/or Metastatic Renal Cell Carcinoma, COMPARZ; NCT00720941), pazopanib was found to be noninferior to sunitinib in terms of progression-free survival in patients with metastatic renal cell carcinoma with no prior therapy. Overall treatment differences were evaluated in a post hoc analysis with a quality-adjusted time without symptoms or toxicity (Q-TWiST) methodology.

METHODS

Each patient's overall survival was partitioned into 3 mutually exclusive health states: time with grade 3 or 4 toxicity (TOX), time without symptoms of disease or grade 3/4 toxicity of treatment, and time after tumor progression or relapse (REL). The time spent in each state was weighted by a health-state utility associated with that state and summed to calculate the Q-TWiST. A threshold utility analysis was used, and utilities were applied across the range of 0 (similar to death) to 1 (perfect health).

RESULTS

A total of 1110 patients were enrolled (557 on pazopanib and 553 on sunitinib). The mean TOX was 31 days (95% confidence interval, 13-48 days) longer for sunitinib versus pazopanib. In the threshold utility analysis, the difference in the Q-TWiST ranged from -11 days (utility for TOX, 1; utility for REL, 0) to 43 days (utility for TOX, 0; utility for REL, 1) in favor of pazopanib across most utility combinations. Differences were significant in less than half of the utility combinations examined, and this typically occurred when the utility for TOX was lower than the utility for REL.

CONCLUSIONS

Patients randomized to pazopanib had a slightly longer Q-TWiST in comparison with sunitinib patients, and this was primarily due to the reduced length of TOX.

Persistence and compliance among U.S. patients receiving pazopanib or sunitinib as first-line therapy for advanced renal cell carcinoma: a retrospective claims analysis

BACKGROUND

For first-line therapy options for advanced renal cell carcinoma (RCC), clinical trials have demonstrated similar efficacy for pazopanib and sunitinib as well as differing side-effect profiles, which may affect patient persistence in self-administration of these oral medications. However, the treatment patterns of each drug in real-world clinical practice, as opposed to the controlled environment of a trial, have not been directly compared.

OBJECTIVE

To compare persistence and compliance (adherence) with pazopanib versus sunitinib in a real-world setting.

METHODS

This was a retrospective claims analysis using 2 databases: Optum Research Database and Impact National Benchmark Database. Eligible patients included adult patients (aged ≥ 18 years) with ≥ 2 RCC diagnoses and evidence of first-line therapy with ≥ 1 subsequent pharmacy claim for pazopanib or sunitinib between October 2009 and July 2012. The date of the first pazopanib or sunitinib claim was defined as the index date. Additional requirements included continuous enrollment in the health plan for 2 months prior (baseline period) through 6 months after (follow-up period) the index date and no cancers other than those associated with RCC. Propensity score matching was used to minimize selection bias. Persistence with the index drug was compared using days to discontinuation, estimated level of persistence (ELPT) at 180 days, and proportion of days covered (PDC). PDC was defined by dividing the number of days covered with the index drug by the number of follow-up days. Compliance was estimated using medication possession ratio (MPR). For matched cohort pairs with > 1 fill, MPR was defined by dividing the number of days covered with the index drug by the number of days between the first and last index medication fill.

RESULTS

We identified 84 matched pairs among 97 patients prescribed pazopanib and 349 prescribed sunitinib. Among the matched population, mean comorbidity index score was 5.8 (95% CI = 1.8-6.0) for pazopanib, and 6.1 (95% CI =1.8-6.0) for sunitinib (P = 0.133). Evidence of any radiation therapy during the baseline period was significantly higher among the sunitinib cohort prior to matching (9% vs. 18%, P = 0.043), and evidence of surgery was higher in the pazopanib cohort after matching (12% vs. 7%, P = 0.046). Cohorts were balanced according to demographic and clinical characteristics with mean (SD) age of 63.0 (9.0) years and 77.4% male. During the 6-month period after drug initiation, there was no significant difference (P > 0.05) by drug cohort in the duration of index drug therapy or the percentage of patients who discontinued their index drugs. The mean (SD) time to discontinuation was 133.4 (62.8) days and 139.9 (55.6) days among the matched pazopanib and sunitinib cohorts, respectively (P = 0.445). In both cohorts, more than 40% of patients discontinued their index drugs (46.4% pazopanib and 44.1% sunitinib, P = 0.732). In addition, there was no significant difference by drug cohort in the ELPT at any time examined between 30 and 180 days after initiation of therapy. PDC with the index drug during the fixed 6-month follow-up was also examined. Although the mean PDC was significantly higher among the sunitinib cohort (0.77 vs. 0.68 for pazopanib, P = 0.037), there was no difference by cohort in the percentage of patients with high PDC (defined as ≥ 80%): 52.4% versus 56.0% for pazopanib and sunitinib, respectively (P = 0.622). Mean MPR among matched pairs with at least 2 fills for the index drug was significantly higher among the sunitinib cohort, although there was no difference by cohort in the percentage of patients with high MPR (defined as ≥ 80%): 81.4% versus 93.2% for pazopanib and sunitinib, respectively (P > 0.071).

CONCLUSIONS

In the first 6 months of treatment, persistence and compliance to pazopanib and sunitinib were similar. Future studies are needed, including those assessing larger cohorts and longer follow-up periods.

Cost-effectiveness of pazopanib versus sunitinib for renal cancer in the United States

BACKGROUND

Current first-line treatments for metastatic renal cell carcinoma (mRCC) include the multityrosine kinase inhibitors pazopanib and sunitinib. Both agents had similar progression-free survival (PFS) and overall survival (OS) in the COMPARZ trial (Comparing the Efficacy, Safety and Tolerability of Pazopanib versus Sunitinib); however, the adverse event profiles of the 2 agents are different. In the PISCES trial (Patient Preference Study of Pazopanib versus Sunitinib in Advanced or Metastatic Kidney Cancer), patients and physicians preferred pazopanib primarily because it offered better health-related quality of life (HRQoL) and caused less fatigue.

OBJECTIVE

To compare the cost-effectiveness of pazopanib versus sunitinib from a U.S. health care system perspective in the first-line treatment of patients with mRCC.

METHODS

A partitioned-survival analysis model with 3 health states (preprogression, postprogression, and dead), data from 2 randomized controlled trials of pazopanib versus sunitinib (COMPARZ and PISCES), and secondary sources were used to calculate the incremental cost per quality-adjusted life-year (QALY) gained for pazopanib versus sunitinib. A time horizon of 37.5 months was used in the base case, consistent with the duration of follow-up used in the COMPARZ trial. The proportion of patients in each health state over time was based on Kaplan-Meier survival distributions for PFS and OS from the COMPARZ trial. Utility values were obtained from the PISCES trial. Costs were based on medical resource utilization data from the COMPARZ trial and unit costs from secondary sources. Probabilistic sensitivity analyses and deterministic sensitivity analyses were conducted.

RESULTS

In the base case, pazopanib was estimated to provide more QALYs at a lower cost compared with sunitinib (pazopanib dominant). In probabilistic sensitivity analyses, pazopanib was projected to be dominant in 69% of the simulations. The probability that pazopanib was more cost-effective than sunitinib was ≥ 90% for threshold values of cost-effectiveness between the range of $10,000-$160,000 per QALY gained. In deterministic sensitivity analyses, pazopanib was dominant in all scenarios examined.

CONCLUSION

Results of this study suggest that pazopanib is cost-effective compared with sunitinib as the first-line treatment of patients with mRCC in the United States.

Health care costs among renal cancer patients using pazopanib and sunitinib

BACKGROUND

Pazopanib was noninferior to sunitinib in progression-free survival in a phase III, open-label, randomized clinical trial comparing the efficacy and safety of the 2 drugs for treatment of patients with advanced renal cell carcinoma (RCC). A secondary analysis of this trial conducted on patient-reported health care resource utilization (HCRU) endpoints revealed significantly fewer monthly telephone consultations and emergency department visits among patients treated with pazopanib over the first 6 months of treatment.

OBJECTIVES

To (a) compare total costs of HCRU and adverse events (AEs) in patients with advanced RCC receiving first-line pazopanib or sunitinib from the phase III clinical trial and (b) perform a post hoc economic analysis that applied direct medical care and pharmacy unit costs, obtained from the Truven Health MarketScan Databases, to HCRU and AE rates.

METHODS

Total HCRU costs included components for provider contacts, diagnostics, hospitalizations, procedures, and study/nonstudy drugs. Patients were stratified by the presence or absence of an AE in order to estimate costs attributable to AEs. Costs were adjusted to 2013 U.S. dollars. The highest 1% of cost outliers were equally excluded from each group. Univariate (t-test and Kaplan-Meier sample average [KMSA]) and multivariate (using treatment group and region as covariates) analyses were performed.

RESULTS

A total of 906 patients (pazopanib, n = 454; sunitinib, n = 452) reported HCRU; higher rates were observed for sunitinib. In unadjusted cost analyses, the mean total costs for pazopanib-treated patients were 8.0% lower than those treated with sunitinib ($80,464 vs. $86,886; P = 0.20). The difference in KMSA-estimated costs was significantly higher for sunitinib versus pazopanib ($156,128 vs. $143,585; P = 0.003). Adjusted cost differences between arms consistently suggested higher costs for sunitinib. Among patients who experienced greater than or equal to 1 AE, costs were $8,118 higher for pazopanib-treated patients and $14,343 for sunitinib-treated patients.

CONCLUSIONS

The findings suggest that health care costs were lower among patients with advanced RCC treated first-line with pazopanib versus sunitinib.

First-Line and Sequential Use of Pazopanib Followed by Mammalian Target of Rapamycin Inhibitor Therapy Among Patients With Advanced Renal Cell Carcinoma in a US Community Oncology Setting

BACKGROUND

Clinical trials have demonstrated that pazopanib prolongs progression-free survival (PFS), with an acceptable safety profile, for patients with advanced renal cell carcinoma (aRCC). The efficacy of second-line mammalian target of rapamycin (mTOR) inhibitors in pazopanib-treated patients has also been evaluated in clinical trials; however, few studies have evaluated first-line pazopanib or second-line mTOR inhibitors in real-world settings. The present study evaluated the outcomes of first-line pazopanib, and pazopanib followed by mTOR inhibitors, in a community oncology setting.

PATIENTS AND METHODS

The present study was a retrospective analysis of eligible patients in US Oncology's iKnowMed electronic health records database who had been treated for aRCC from November 1, 2009 to August 31, 2012. The patients received first-line therapy with pazopanib (cohort 1), followed by second-line therapy with either everolimus or temsirolimus (cohort 2). The key outcomes included overall survival (OS), PFS, adverse events (AEs), treatment patterns, and healthcare resource use.

RESULTS

The median OS in cohort 1 (n = 177) was 22 months, and the median PFS was 8.5 months. The most common AEs were fatigue (56%), diarrhea (52%), vomiting (44%), and nausea (40%). The median persistence was 151 days with pazopanib. The median OS in cohort 2 (n = 35) was 16 months; the median PFS was 5.7 months. The most common AEs were fatigue (51%) and nausea (34%). The median persistence was 93 days with everolimus and 49 days with temsirolimus.

CONCLUSION

The outcomes for the patients treated with first-line pazopanib in the community setting were consistent with those reported by previous prospective and retrospective studies. Although the second-line cohort was small, the results of mTOR inhibitors after pazopanib were also consistent with those of previous observations.

Persistence and compliance with pazopanib in patients with advanced renal cell carcinoma within a U.S. administrative claims database

BACKGROUND

Pazopanib is an oral tyrosine kinase inhibitor with demonstrated efficacy and tolerability in patients with advanced renal cell carcinoma (RCC).

OBJECTIVE

To examine pazopanib persistence and compliance (adherence) and other drug utilization patterns in both treatment-naïve (first-line) patients and those previously treated with RCC therapy in the real-world setting. Key factors affecting persistence and compliance were also explored.

METHODS

This was a retrospective claims analysis using the Truven Health MarketScan Databases to cover claims activity from October 2007 through March 2012. Patients with advanced RCC aged ≥ 18 years who had received pazopanib with 180 days of follow-up were included. Bivariate comparisons of results from first-line and previously treated patients with RCC were conducted. Pazopanib persistence was measured using (a) estimated level of persistence with therapy (ELPT; i.e., the percentage of patients remaining on therapy at 30, 60, and 90 days [patients were censored at 180 days]); (b) time to discontinuation (i.e., duration of therapy); and (c) proportion of days covered (PDC; i.e., the ratio of [total days drug available minus days' supply of last prescription] to [last prescription date minus first prescription date]). Compliance was measured by medication possession ratio (MPR; i.e., the ratio of [total days' supply minus days' supply of last prescription] to [last prescription date minus first prescription date]). Other drug utilization measures included days' supply, time to initiation, time to switching, and dose-related measures. Random forest models were used to explore key factors of pazopanib persistence and compliance.

RESULTS

A total of 143 patients met all inclusion criteria; 43.3% were treated with pazopanib first line (first-line cohort), and 56.6% had ≥ 1 prior lines of therapy (previously treated cohort). The mean (± standard deviation [SD]) age of patients was 62.9 (± 10.3) years, and 71.3% of them were males. Continuous pazopanib therapy for up to 90 days was observed in greater than 50% of patients in both cohorts. In the first-line cohort, ELPT at 30, 60, and 90 days was 98.39%, 70.97%, and 56.45%, respectively; the mean (± SD) number of days to discontinuation was 112.2 (± 62.8); the mean (± SD) PDC was 84.7% (± 16.7%); and the mean (± SD) MPR was 85.2% (± 16.9%). Similar results were observed in the previously treated population: ELPT at 30, 60, and 90 days was 98.77%, 75.31%, and 58.02%, respectively; the mean (± SD) number of days to discontinuation was 118.7 (± 61.4); the mean (± SD) PDC was 87.8% (± 13.5%); and the mean (± SD) MPR was 90.1% (± 13.9%). Differences between the 2 cohorts were not statistically significant. More than 90% of patients in both cohorts had at least a 30-day supply of therapy (91.9% of first-line versus 90.2% of previously treated; P = 0.153). The mean (± SD) time from metastatic diagnosis to start of pazopanib therapy was 104.7 (± 199.3) days in the first-line cohort and 360.9 (± 187.0) days in previously treated patients (P = 0.001). Forty-six patients switched to another therapy: 17 patients in the first-line cohort and 29 patients in the previously treated cohort; the mean (± SD) time to switching therapy from each cohort was 94.7 (± 41.4) days and 87.8 (± 49.6) days (P = 0.146), respectively. Statistically significant differences were observed for the starting and ending doses between the 2 cohorts. The average daily dosage of pazopanib was greater than 700 mg in both cohorts (P = 0.055), with a maximum dose of 800 mg. Random forest models demonstrated that younger age and higher comorbidity predicted both higher persistence and compliance.

CONCLUSIONS

In this observational study, greater than 50% of patients with advanced RCC were on pazopanib for almost 4 months, with the majority of both cohorts achieving high persistence and high compliance. Additionally, younger age and higher comorbidity index were the strongest predictors of both greater persistence and compliance. Further studies with larger cohorts and longer follow-up are needed to validate these findings.

Epidemiology, treatment patterns, and outcomes of metastatic soft tissue sarcoma in a community-based oncology network

Purpose. To assess epidemiology, treatment patterns, and outcomes of metastatic soft tissue sarcoma (mSTS) patients in USA community oncology practices. Methods. This retrospective, descriptive study used US Oncology's iKnowMed electronic health records database. Adults (≥18 years) with mSTS and at least two visits between July 2007 and June 2010 were included. Key outcomes were practice patterns, overall survival (OS), and progression-free survival (PFS). Results. 363 mSTS patients (174 treated and 189 untreated) met the prespecified exclusion/inclusion criteria. The most common subtypes were leiomyosarcoma (n = 104; 29%), liposarcoma (n = 40; 11%), and synovial sarcoma (n = 12; 3%); the remainder (n = 207; 57%) comprised 27 histologic subtypes. Treated patients were younger and had lower ECOG scores; 75% and 25% received first-line combination or monotherapy, respectively. Median OS of treated and untreated patients was 22 and 17 months, respectively, and 29 months in patients with the three most common subtypes. Before controlling for effects of covariates, younger age and lower ECOG scores were associated with better OS and PFS. Conclusion. This study provides insights into mSTS epidemiology, treatment patterns, and outcomes in a large community-based oncology network. These results warrant further studies with larger cohorts.

Economic burden of selected adverse events in patients aged ≥65 years with metastatic renal cell carcinoma

OBJECTIVE

To estimate the costs of adverse events (AEs) in patients aged ≥65 years with metastatic renal cell carcinoma (mRCC).

METHODS

Retrospective study using the linked Surveillance, Epidemiology and End Results (SEER) Medicare database. Study subjects consisted of persons in SEER-Medicare, aged ≥65 years, with evidence of newly diagnosed mRCC between January 1, 2007 and December 31, 2007. Adverse events of interest consisted of Grade 3 or 4 toxicities that have been reported with frequency ≥5% in randomized controlled trials of sunitinib, sorafenib, bevacizumab, and pazopanib (i.e., targeted therapies for mRCC), and included abdominal pain, back pain, diarrhea, dyspnea, extremity pain, fatigue/asthenia, hand-foot syndrome, hypertension, lymphopenia, nausea/vomiting, neutropenia, proteinuria, and thrombocytopenia. Patients in SEER-Medicare with these events were identified based on ICD-9-CM diagnosis codes on Medicare claims. For each AE of interest, costs were tallied among evented patients over 30 days, beginning with the date of each patient's first mention of the AE, and were compared with those of non-evented patients over a similar 30-day period beginning with an identical 'shadow' index date. Total costs were compared on an unadjusted basis and with adjustment for differences in baseline characteristics using a generalized linear model.

RESULTS

A total of 881 patients with mRCC met study entry criteria; 60% of these patients had Medicare claims with mention of one or more AEs of interest. Events occurring with frequency >20% included abdominal pain, dyspnea, and fatigue/asthenia; 10-20% of study subjects had encounters for back pain, extremity pain, and nausea/vomiting. Mean (standard deviation) total cost of care over 30 days was substantially higher among patients with AEs ($13,944 [$14,529]) compared with those without mention of these events ($1878 [$5264]). Adjusting for differences in baseline characteristics, the mean (95% confidence interval) difference in costs between evented and non-evented patients was $12,410 ($9217-$16,522). Study limitations include problems in event ascertainment due to inaccuracies in ICD-9-CM coding on Medicare claims data, and restriction of the study population to patients with metastatic involvement at initial diagnosis of RCC.

CONCLUSIONS

Costs of care are substantially higher in patients aged ≥65 years with mRCC who experience AEs commonly associated with sunitinib, sorafenib, bevacizumab, and pazopanib. Efforts to prevent and/or better manage these events potentially can reduce healthcare costs.

Pazopanib versus sunitinib in metastatic renal-cell carcinoma

BACKGROUND

Pazopanib and sunitinib provided a progression-free survival benefit, as compared with placebo or interferon, in previous phase 3 studies involving patients with metastatic renal-cell carcinoma. This phase 3, randomized trial compared the efficacy and safety of pazopanib and sunitinib as first-line therapy.

METHODS

We randomly assigned 1110 patients with clear-cell, metastatic renal-cell carcinoma, in a 1:1 ratio, to receive a continuous dose of pazopanib (800 mg once daily; 557 patients) or sunitinib in 6-week cycles (50 mg once daily for 4 weeks, followed by 2 weeks without treatment; 553 patients). The primary end point was progression-free survival as assessed by independent review, and the study was powered to show the noninferiority of pazopanib versus sunitinib. Secondary end points included overall survival, safety, and quality of life.

RESULTS

Pazopanib was noninferior to sunitinib with respect to progression-free survival (hazard ratio for progression of disease or death from any cause, 1.05; 95% confidence interval [CI], 0.90 to 1.22), meeting the predefined noninferiority margin (upper bound of the 95% confidence interval, <1.25). Overall survival was similar (hazard ratio for death with pazopanib, 0.91; 95% CI, 0.76 to 1.08). Patients treated with sunitinib, as compared with those treated with pazopanib, had a higher incidence of fatigue (63% vs. 55%), the hand-foot syndrome (50% vs. 29%), and thrombocytopenia (78% vs. 41%); patients treated with pazopanib had a higher incidence of increased levels of alanine aminotransferase (60%, vs. 43% with sunitinib). The mean change from baseline in 11 of 14 health-related quality-of-life domains, particularly those related to fatigue or soreness in the mouth, throat, hands, or feet, during the first 6 months of treatment favored pazopanib (P<0.05 for all 11 comparisons).

CONCLUSIONS

Pazopanib and sunitinib have similar efficacy, but the safety and quality-of-life profiles favor pazopanib. (Funded by GlaxoSmithKline Pharmaceuticals; COMPARZ ClinicalTrials.gov number, NCT00720941.).

Retrospective US database analysis of drug utilization patterns, health care resource use, and costs associated with adjuvant interferon alfa-2b therapy for treatment of malignant melanoma following surgery

Background

The purpose of this study was to identify a real-world US population having undergone surgery for malignant melanoma and describe treatment patterns, health care resource utilization, and costs for patients who subsequently received interferon alfa-2b (IFN) therapy or other standard of care chemotherapies.

Methods

A retrospective cohort study was conducted using administrative claims from MarketScan^® databases among melanoma patients diagnosed between 2004 and 2008 who had surgery and were subsequently treated with IFN or other chemotherapies. Health care resource utilization and costs of services (converted to 2009 dollars) were evaluated. Cost refers to the amount paid to providers associated with the health service.

Results

Of 18,075 subjects with melanoma surgery claims, 1525 (8.4%) were treated with IFN and 1194 (6.6%) with other chemotherapies. Median duration (days) and number of doses of IFN therapy were 29 and 20, respectively. Approximately half of patients who received IFN discontinued therapy within or after the one-month induction phase. For IFN therapy patients, average total cost per patient for the last melanoma-related surgery prior to start of therapy, including costs of the surgery itself, pathology, anesthesia, and hospital care, was $2219. The average total cost per patient related to IFN therapy was $1188; this included costs for drug, office visits, blood work, and infusions. Other chemotherapy costs ranged from $146 to $2678.

Conclusion

There is an unmet treatment need, considering that this study observed that melanoma patients on IFN therapy post-surgery do not complete the recommended one-year course of treatment which may compromise its full therapeutic benefits. Further study to investigate reasons for discontinuation may be warranted. In addition, costs associated with adjuvant IFN therapy in post-surgical treatment of disease are likely acceptable.