Refill gaps and dose reductions in patients treated with abiraterone acetate plus prednisone (AA+P) or enzalutamide (ENZ).

2017 ◽  
Vol 35 (6_suppl) ◽  
pp. e572-e572
Author(s):  
Dominic Pilon ◽  
Ajay S. Behl ◽  
Bruno Emond ◽  
Yongling Xiao ◽  
Patrick Lefebvre ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Index Date ◽  
Standard Dose ◽  
Package Insert ◽  
Dose Intensity ◽  
Treatment Interruption ◽  
Abiraterone Acetate ◽  
Castrate Resistant ◽  
Dose Reductions ◽  
Delivered Dose

e572 Background: Recently available treatmentssuch as AA+P or ENZ have improved survival and quality of life for patients with metastatic castrate resistant prostate cancer (mCRPC). However, drug-drug interactions, intolerance or toxicities can potentially lead to dose reductions or treatment interruption. This study assessed refill gaps and dose reduction events in patients treated with AA+P or ENZ. Methods: The MarketScan databases (03/2012-10/2015) were used to conduct a retrospective analysis. Patients initiated on AA+P or ENZ (index date) after 09/2012 with ≥ 6 months of continuous eligibility prior to index date and ≥ 1 diagnosis for prostate cancer were included. Inverse probability of treatment weighting (IPTW) was used to adjust for observed baseline confounders between groups. Weighted Kaplan-Meier (KM) rates and Cox proportional hazard models were used to compare the occurrence of refill gaps ( ≥ 14, ≥ 30, or ≥ 60 days) or dose reductions (i.e., relative dose intensity [RDI] ≤ 80%, and ≤ 85%) between groups. RDI was calculated as the ratio of the delivered dose intensity (total delivered dose divided by the period over which the total dose was measured) to the standard dose intensity as recommended in the package insert for AA+P or ENZ. Results: A total of 2,540 AA+P and 1,265 ENZ patients were identified. IPTW resulted in balanced baseline demographic, comorbidities, and disease characteristics. At 12 months post-index, patients initiated on ENZ were more likely to have an RDI ≤ 80% or ≤ 85% or to have a refill gap ≥ 30 or ≥ 60 days when compared to patients initiated on AA+P (Table). Conclusions: This study showed that mCRPC patients treated with ENZ were more likely to experience a refill gap and to reduce their treatment dose than patients treated with AA+P. [Table: see text]

G-CSF utilization during abiraterone acetate (AA) and cabazitaxel (C) therapy: A retrospective U.S. claims analysis.

2013 ◽  
Vol 31 (6_suppl) ◽  
pp. 205-205 ◽  
Author(s):  
Maneesha Mehra ◽  
Robert Stellhorn ◽  
Yvette Ng ◽  
Mary Beth Todd
Keyword(s):  
Prostate Cancer ◽  
Index Date ◽  
Median Number ◽  
Abiraterone Acetate ◽  
Claims Analysis ◽  
Docetaxel Treatment ◽  
Castrate Resistant Prostate Cancer ◽  
Nationally Representative ◽  
Concomitant Medications ◽  
Castrate Resistant

205 Background: AA and C are two recently approved therapies shown to extend survival in men with metastatic castrate-resistant prostate cancer (mCRPC) progressing after docetaxel treatment. The toxicity profiles of AA and C differ, and therefore it was hypothesized that the utilization of concomitant medications and supportive care measures, in particular G-CSF for the treatment of neutropenia, would differ as well. Methods: The Pharmetrics database (2008 to Jan 2012), a nationally representative, nonpayer-owned, integrated, commercial U.S. claims database, was used for this analysis. Eligible patients included those identified with a diagnosis of prostate cancer (ICD 9 code 185.X or 233.4) and a claim for either AA or C (identified by the appropriate NDC or J codes). Use of G-CSF was analyzed during treatment (defined as the period between the first claim to the last claim, full months inclusive) and also analyzed for the year prior to the first claim of either AA or C (index date). Results: 278 patients were identified with a claim for both cohorts. Median ages of patients in the two cohorts were similar (69 years in the AA cohort, 67.5 years in the C cohort). Docetaxel use in the year prior to the index date was 57% and 64% in the AA and C cohorts, respectively. The median duration of follow-up post-index date was 2.6 months in the AA cohort and 6.0 months in the C cohort. While the median number of prescriptions (3) was the same for the AA and C cohorts, the mean was slightly higher for C (4.4 vs 3.3). In the AA cohort, the use of G-CSF was as follows: 35% in the year before the index date and 3% during treatment. In the C cohort, the use of G-CSF was as follows: 42% in the year before the index date, and 67% during treatment. Conclusions: Based on this claims analysis, patients who received C were more likely to receive concomitant G-CSF vs patients who were receiving AA. This finding is consistent with the known risks/precautions relating to neutropenia as described in the TROPIC study for C. Prior to treatment, both cohorts had G-CSF use, which may be attributed to neutropenia during or following docetaxel therapy.

Contemporary trends in abiraterone and enzalutamide prescription by provider specialty.

2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 366-366
Author(s):  
Daniel Pucheril ◽  
Ye Wang ◽  
Dimitar V. Zlatev ◽  
Paul L. Nguyen ◽  
Adam S. Kibel ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Abiraterone Acetate ◽  
Optimal Timing ◽  
Part D ◽  
Southern States ◽  
Radiation Oncologists ◽  
Medical Oncologists ◽  
Specific Outcome ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

366 Background: Androgen deprivation therapy (ADT) with LHRH-agonists and anti-androgens, is established in the management of prostate cancer and is administered by urologists, medical oncologists, and radiation oncologists. Newer agents for ADT, abiraterone acetate (ABI) and enzalutamide (ENZA) were approved by the FDA in 2011 and 2012, respectively, for the management of metastatic castrate resistant prostate cancer (mCRPC) after failing chemotherapy. We evaluated the contemporary economic burden of ABI and ENZA and their adoption by specialty. Methods: Because a majority of men with mCRPC are > 65 years of age, we utilized Medicare Part D data from 2013-15. The specific outcome variables of interest included the aggregate reimbursement and total number of prescriptions for ABI and ENZA, by specialty. Descriptive statistics and trend analysis were performed. Results: From 2013-15, the total number of prescription rose from 52457 to 81058 for ABI and from 17141 to 69181 for ENZA. Though medical oncologists prescribed more than 75% of ABI/ENZA prescriptions each year, the proportion of prescriptions written by urologists increased annually. The greatest increase in the percentage of prescriptions originating from urology occurred from 2013-2014 for ABI (3.96% to 8.62%) and from 2014-15 for ENZA (5.42% to 15.64%); meanwhile, prescriptions by radiation oncology were negligible throughout the study. Southern states accounted for greater than one third of ABI and ENZA prescriptions. By 2015, the aggregate reimbursement of Part D claims for ENZA and ABI was $790 million each. Among all medication claims, ENZA and ABI represent the 29th and 30th most expensive by aggregate cost. Conclusions: While medical oncologists account for the vast majority of ENZA and ABI prescriptions, the prescriptions by urologists is increasing while prescriptions by radiation oncologists remain negligible. Though approved for mCRPC patients, ENZA and ABI are already among the costliest medications covered by Medicare. As Level 1 indications for the use of these medications increase and now include castrate-sensitive patients, further study should be directed at determining optimal timing and indication for prescription.

Treatment duration and utilization patterns in metastatic castration-resistant prostate cancer patients receiving enzalutamide or abiraterone acetate.

2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 229-229
Author(s):  
Vahan Kassabian ◽  
Scott Flanders ◽  
Samuel Wilson ◽  
Bruce A. Brown ◽  
Yan Song ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Treatment Duration ◽  
Index Date ◽  
Abiraterone Acetate ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Kaplan Meier ◽  
Utilization Patterns ◽  
The Difference ◽  
Hormonal Therapies

229 Background: Enzalutamide (ENZA) and abiraterone acetate (ABI) are approved hormonal therapies for men with metastatic castration-resistant prostate cancer (mCRPC). This study assessed real-world treatment duration and utilization patterns in patients receiving ENZA or ABI. Methods: Adult mCRPC patients initiating ENZA or ABI before or after cytotoxic chemotherapy were identified from the Truven MarketScan® claims database (2012–2015). The index date was the first initiation of ENZA or ABI; continuous insurance enrollment for ≥6 months prior to and ≥3 months after the index date was required. Treatment discontinuation was defined as a prescription gap of ≥45 days. Median treatment duration was estimated using Kaplan–Meier method. Treatment switching was defined as starting a new mCRPC-related therapy within 30 days before to 45 days after the discontinuation date. Analyses were separately conducted for chemo-naïve and chemo-experienced patients. Results: The study included 3230 chemo-naive (ENZA 920; ABI 2310) and 692 chemo-experienced patients (ENZA 262; ABI 430). Among chemo-naive patients, ENZA cohort was older (mean age 74.5 vs 73.5; p = 0.013), with a higher proportion of comorbidities vs ABI cohort. Treatment duration was longer for ENZA cohort than ABI cohort (log-rank p = 0.008; median = ENZA 10.7 vs ABI 8.8 months). Within 1 year of initiation, 55.7% of ENZA and 60.8% of ABI cohort discontinued treatment and 22.5% and 34.7%, respectively, switched to other mCRPC therapies. Results were consistent among subgroups with specific comorbidities. Treatment duration was shorter among chemo-experienced patients than chemo-naïve; the difference between ENZA vs ABI among chemo-experienced patients was not statistically significant (log-rank p = 0.255; median = ENZA 7.5 vs ABI 7.1 months). Conclusions: Despite a more complex profile at baseline, chemo-naive mCRPC patients in the ENZA cohort had a longer treatment duration and lower proportion of switching to other prostate-cancer-directed therapies vs the ABI cohort. The difference of treatment duration between the two cohorts was not statistically significant for chemo-experienced patients.

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