Treatment-Free Interval: A Novel Approach to Assessing Real-World Treatment Effectiveness and Economic Impact Among Patients with Irritable Bowel Syndrome with Diarrhea

INTRODUCTION

Objective assessment of treatment effectiveness using real-world claims data is challenging. This study assessed treatment-free intervals (TFI) as a proxy for treatment effectiveness, and all-cause healthcare costs among adult patients with irritable bowel syndrome with diarrhea (IBS-D) treated with rifaximin or eluxadoline in the USA.

METHODS

Adult patients (18-64 years) with IBS-D and ≥ 1 rifaximin or eluxadoline prescription were identified in the IQVIA PharMetrics® Plus database (10/01/2015-12/31/2021) and classified into two mutually exclusive cohorts (i.e., rifaximin and eluxadoline). Index date was the date of rifaximin or eluxadoline initiation. Entropy-balanced baseline characteristics, TFI (periods of ≥ 30 consecutive days without IBS-D treatment), and healthcare costs were reported. Healthcare costs were compared between cohorts using mean cost differences.

RESULTS

There were 7094 and 2161 patients in the rifaximin and eluxadoline cohorts, respectively. After balancing, baseline characteristics (mean age 44.1 years; female 72.4%) were similar between cohorts. A higher proportion of patients treated with rifaximin achieved a TFI of ≥ 30 days (76.2% vs. 66.7%), ≥ 60 days (67.0% vs. 47.0%), ≥ 90 days (61.0% vs. 38.7%), ≥ 180 days (51.7% vs. 31.0%), and ≥ 240 days (47.7% vs. 27.9%) compared to eluxadoline. Among patients with a TFI ≥ 30 days, mean TFI durations were 8.3 and 6.0 months for the rifaximin and eluxadoline cohorts. Mean all-cause healthcare costs were lower for rifaximin vs. eluxadoline ($18,316 vs. $23,437; p = 0.008), primarily driven by pharmacy costs ($7348 vs. $10,250; p < 0.001). In a simulated health plan of one million commercially insured lives, initiating 50% of patients on rifaximin instead of eluxadoline resulted in total cost savings of $2.1 million per year or $0.18 per-member-per-month.

CONCLUSIONS

This real-world study suggests that TFI is a meaningful surrogate measure of treatment effectiveness in IBS-D. Patients treated with rifaximin had longer treatment-free periods and lower healthcare costs than patients treated with eluxadoline.

Considerations for selecting second-line treatment in patients with progressive small cell lung cancer and the use of Lurbinectedin in this setting

Small cell lung cancer (SCLC) is characterized by high initial responses to platinum-based chemotherapy plus immune checkpoint inhibitors; however, most patients quickly relapse and require subsequent treatment. Second-line treatment options in SCLC remain limited, and treatment algorithms are not completely consistent across the available guidelines in this setting. This review highlights key considerations regarding selection of second-line treatment for patients with relapsed SCLC. In particular, the role of lurbinectedin, which was first approved in 2020, representing the first significant addition to treatment algorithms in this setting for decades, is summarized. Future directions, including the identification of SCLC subtypes and the need for predictive biomarkers to guide patient selection and targeted therapy, are also discussed.

Treatment effect of palbociclib plus endocrine therapy by prognostic and intrinsic subtype and biomarker analysis in patients with bone-only disease: a joint analysis of PALOMA-2 and PALOMA-3 clinical trials

Purpose

This analysis evaluated the relationship between treatment-free interval (TFI, in PALOMA-2)/disease-free interval (DFI, in PALOMA-3) and progression-free survival (PFS) and overall survival (OS, in PALOMA-3), treatment effect in patients with bone-only disease, and whether intrinsic subtype affects PFS in patients receiving palbociclib.

Methods

Data were from phase 3, randomized PALOMA-2 and PALOMA-3 clinical studies of hormone receptor‒positive/human epidermal growth factor receptor 2‒negative (HR+ /HER2−) advanced breast cancer (ABC) patients receiving endocrine therapy plus palbociclib or placebo. Subpopulation treatment effect pattern plot (STEPP) analysis evaluated the association between DFI and PFS and OS. PFS by luminal subtype and cyclin-dependent kinase (CDK) 4/6 or endocrine pathway gene expression levels were evaluated in patients with bone-only disease; median PFS and OS were estimated by the Kaplan–Meier method.

Results

Median durations of TFI were 37.1 and 30.9 months (PALOMA-2) and DFI were 49.2 and 52.0 months (PALOMA-3) in the palbociclib and placebo groups, respectively. Among the PALOMA-2 biomarker population (n = 454), 23% had bone-only disease; median PFS was longer with palbociclib versus placebo (31.3 vs 11.2 months; hazard ratio, 0.41; 95% CI 0.25‒0.69). The interaction effect of bone-only versus visceral disease subgroups on median PFS with palbociclib was not significant (P = 0.262). Among the PALOMA-3 biomarker population (n = 302), 27% had bone-only disease. STEPP analyses showed that palbociclib PFS benefit was not affected by DFI, and that palbociclib OS effect may be smaller in patients with short DFIs. Among patients who provided metastatic tumor tissues (n = 142), regardless of luminal A (hazard ratio, 0.23; 95% CI 0.11‒0.47; P = 0.0000158) or luminal B (hazard ratio, 0.26; 95% CI 0.12‒0.56; P = 0.000269) subtype, palbociclib improved PFS versus placebo.

Conclusions

These findings support palbociclib plus endocrine therapy as standard of care for HR+ /HER2− ABC patients, regardless of baseline TFI/DFI or intrinsic molecular subtype, including patients with bone-only disease.

Trial registration

Pfizer (clinicaltrials.gov:NCT01740427, NCT01942135).

Treatment Outcome of Second-Line Chemotherapy for Gynecologic Carcinosarcoma

INTRODUCTION

Carcinosarcoma is a rare cancer, and its prognosis is poor. There are few reports on the prognostic factors of patients with carcinosarcoma who receive second-line chemotherapy.

OBJECTIVE

To investigate the outcome and prognostic factors of patients who received second-line chemotherapy for gynecologic carcinosarcoma.

METHODS

We retrospectively investigated patients with ovarian or uterine carcinosarcoma, who were treated at two institutions from July 2006 to March 2018. All patients who had received second-line chemotherapy for advanced or recurrent disease were eligible. The efficacy of second-line chemotherapy and prognostic factors were evaluated.

RESULTS

Forty-six patients were eligible. Combination chemotherapy was used in approximately half (52.2%) of the patients. The response rate and disease control rate of second-line chemotherapy were 32.6 and 60.9%, respectively. The median follow-up period was 11.0 (range, 8.8-107.5) months. The median progression-free survival and overall survival were 6.3 (95% CI, 3.2-7.5) months and 12.9 (95% CI, 7.8-16.0) months, respectively. In the multivariate analysis of overall survival, a treatment-free interval >180 days was a significant good prognostic factor. The median overall survival was 7.8 (95% CI, 5.1-10.5) months in the <180 days group and 16.4 (95% CI, 13.1-130.6) months in the >180 days group (p = 0.0052; hazard ratio, 0.26; 95% CI, 0.10-0.66), respectively.

CONCLUSION

The outcome of gynecologic carcinosarcoma in the second-line setting is poor, especially in patients with a short treatment-free interval.

A phase II trial of intermittent nivolumab in patients with metastatic renal cell carcinoma (mRCC) who have received prior anti-angiogenic therapy

Background

Nivolumab is approved for mRCC patients who have received prior anti-angiogenic therapy but the duration of therapy required for sustained clinical benefit is unknown. A phase II clinical trial to investigate the feasibility of intermittent nivolumab dosing was conducted.

Methods

Patients ≥18 years of age with mRCC who were previously treated with at least one antiangiogenic therapy were eligible. Patients were treated with nivolumab for twelve weeks. Patients who had RECIST PD were removed from the trial. Patients who did not initially achieve ≥10% reduction in tumor burden (TB) continued nivolumab per standard of care. Patients with ≥10% TB reduction entered a treatment-free observation phase with re-imaging every 12 weeks. Nivolumab was restarted in patients with a ≥ 10% TB increase and again held with TB reduction ≥10%. This intermittent nivolumab dosing continued until RECIST PD while on nivolumab. The primary objective was feasibility of intermittent nivolumab, defined as the proportion of patients eligible for intermittent therapy who elect to receive intermittent nivolumab. Intermittent nivolumab would be considered “feasible” if the acceptance rate was ≥80%. Forty patients provides > 95% power with 0.05 type I error, assuming a null acceptance rate of 50%. With the approval of the combination of ipilimumab/nivolumab (April 2018) in front-line mRCC, this cohort was closed prior to completed pre-planned approval.

Results

Of the 14 patients enrolled, 13 (93%) were male with a median age 65. All had a prior nephrectomy and 12 (86%) were intermediate-risk by IMDC criteria. Five patients (36%) met the criteria for the intermittent phase of the trial (median TB decrease 46%) and all agreed to intermittent therapy. With a median follow-up of 48 weeks, only one patient restarted therapy. The four remaining patients have a sustained response for a median of 34 weeks (range, 16–53) off therapy. No patients developed RECIST PD while off therapy.

Conclusions

This prospective experience of intermittent nivolumab dosing in mRCC supports further investigation of intermittent immunotherapy dosing strategies in RCC.

Trial registration

NCT03126331 (Intermittent Nivolumab in Metastatic Renal Cell Carcinoma Patients; Date of registration 4/27/2017; https://clinicaltrials.gov/ct2/show/NCT03126331).

Prognostic factors modifying the treatment-free interval in recurrent ovarian cancer

OBJECTIVES

While primary treatment for high-grade serous ovarian cancer tends to be uniform - maximal debulking and platinum/taxane adjuvant chemotherapy - there is little standardization of treatment in the recurrent setting beyond the exhaustive use of platinum therapies. Using secondary data from multiple centers participating in the Cancer Genome Atlas study (TCGA), we seek to characterize clinical features, timing and serial response data to provide empirical evidence for treatment expectations in the recurrent setting.

METHODS

We conducted a retrospective survival analysis of TCGA study primary and secondary patient chemotherapy regimens by characterizing the dynamics of 1119 lines of therapy comprising the treatment of 461 high-grade serous ovarian cancer patients. All patients with post-surgical drug therapy information from the TCGA database were included in this study.

RESULTS

A complete response to adjuvant therapy led to longer overall survival, but did not affect treatment free intervals (TFIs) after relapse of disease. A strong predictor of the TFI on the next treatment regimen was the previous TFI with a decaying effect. The number of previous treatments, of platinum treatments, and the length of time from surgery all have an exponentially decreasing effect on TFI. Re-treatment times appear to cluster at predictable times following surgery.

CONCLUSIONS

While patients experience a consistent reduction in TFI with increasing re-treatment, the initial adjuvant interval is unrelated to later interval lengths. Platinum re-treatment remained an effective option in patients typically thought to be platinum resistant and the timing of monitoring visits may drive overall re-treatment patterns.

Prognostic significance of the treatment-free interval in patients with recurrent endometrial cancer

OBJECTIVE

To identify prognostic factors of recurrent endometrial cancer, and clarify whether the treatment-free interval (TFI) predicts outcome in a wide spectrum of patients.

STUDY DESIGN

The clinical data of 60 patients treated for recurrent stage I-IV endometrial cancer between 1997 and 2012 were reviewed retrospectively. The Kaplan-Meier method and Cox regression analysis were used to estimate overall survival (OS) following recurrence and determine the factors influencing outcomes.

RESULTS

The median age at initial treatment was 59 (range 38-80) years and the median post-recurrence overall survival time was 40.0 (range 1.8-156.7) months. Multivariate analysis showed lymph node metastasis (hazard ratio (HR) 2.80; 95% confidence interval (95%CI) 1.29-6.09; p=0.009), TFI (HR 0.33; 95% CI 0.15-0.76; p=0.008), and symptomatic recurrence (HR 2.31, 95% CI 1.11-4.83, p=0.0025) were independent prognostic factors. Patients whose tumors recurred after a TFI≥12 months had better response rates than did those with a TFI<12 months (p<0.001).

CONCLUSION

TFI is a significant prognostic factor in recurrent endometrial cancer. Furthermore, the effect of chemotherapy on recurrent endometrial cancer is probably influenced by the duration of TFI.