Patterns of Treatment Sequences in Chemotherapy and Targeted Biologics for Metastatic Colorectal Cancer: Findings from a Large Community-Based Cohort of Elderly Patients

Real-World Evidence of FOLFIRI Combined with Anti-Angiogenesis Inhibitors or Anti-EGFR Antibodies for Patients with Early Recurrence Colorectal Cancer After Adjuvant FOLFOX/CAPOX Therapy: A Japanese Claims Database Study

BACKGROUND

Oxaliplatin-containing adjuvant regimens (folinic acid, fluorouracil, and oxaliplatin/capecitabine and oxaliplatin [FOLFOX/CAPOX]) are used after curative resection of colorectal cancer (CRC). However, real-world evidence regarding treatment sequences and outcomes in patients with early recurrence CRC after adjuvant chemotherapy is limited.

OBJECTIVE

We aimed to describe the patient characteristics, treatment sequence, and overall duration of second-line (2L) therapy in patients with early recurrence CRC who received adjuvant chemotherapy (FOLFOX/CAPOX) followed by folinic acid, fluorouracil, and irinotecan (FOLFIRI) + anti-angiogenesis drugs (AA) or FOLFIRI + anti-epidermal growth factor receptor (EGFR) antibodies.

METHODS

This retrospective study analyzed Japanese administrative data from November 2014 to March 2023 of adult patients who underwent CRC resection surgery, started FOLFOX/CAPOX ≤3 months (mo) after surgery, and had early CRC recurrence. Early recurrence was defined as initiation of FOLFIRI+AA or FOLFIRI+anti-EGFR antibodies as 2L therapy, ≤12 mo of discontinuing adjuvant chemotherapy. Patient characteristics, treatment sequence, median time to treatment discontinuation (mTTD), i.e., duration between the start and end dates of 2L therapy (Kaplan-Meier method), and factors associated with 2L time to treatment discontinuation constituted the study outcomes (Cox regression model). Subgroup analyses were performed for timing of early CRC recurrence (≤6 mo and 6-12 mo) and tumor sidedness.

RESULTS

Among the 832 selected patients (median age [minimum-maximum] 67 (24-86) years, 56.4% male), CAPOX (71.3%) was more commonly used than FOLFOX (28.7%) as adjuvant therapy. FOLFIRI+AA (72.5%) was used more commonly than FOLFIRI+anti-EGFR antibodies (27.5%) in 2L. AA and anti-EGFR antibodies groups had similar mTTD: 6.2 mo (95% confidence interval 5.8, 6.9) and 6.1 mo (95% confidence interval 5.2, 7.4). Age ≥70 years showed significant association with shorter 2L treatment duration (hazard ratio 1.2, 95% confidence interval 1.0, 1.4; p = 0.03). The AA cohort's mTTD was numerically shorter in the ≤6 mo recurrence subgroup compared with the 6-12 mo recurrence subgroup (6.1 mo vs 8.1 mo); the anti-EGFR antibodies cohort had similar mTTD (5.8 mo vs 6.2 mo). The AA and anti-EGFR antibodies cohorts also had similar mTTD in the left-sided CRC subgroup (6.5 mo vs 6.2 mo), but not in the right-sided subgroup (5.6 mo vs 3.9 mo).

CONCLUSIONS

This is the first administrative data-based real-world evidence on treatment sequence and outcomes for patients with early recurrence CRC treated with FOLFIRI+AAs or FOLFIRI+ anti-EGFR antibodies after adjuvant FOLFOX/CAPOX therapy in Japan. Both regimens had similar TTD, but relapse timing and tumor sidedness may influence their efficacy.

Real-World Outcomes in Patients with Metastatic Colorectal Cancer in Spain: The RWD-ACROSS Study

The retrospective, observational RWD-ACROSS study analyzed disease characteristics, systemic treatment, and survival in patients with metastatic colorectal cancer (mCRC) in Spain. In total, 2002 patients were enrolled (mean age 65.3 years; 62.7% male). Overall median overall survival (OS) was 26.72 months, and was longer in patients with left-sided tumors (28.85 vs. 21.04 months (right-sided tumors); p < 0.0001) and in patients receiving first-line anti-epidermal growth factor receptor (EGFR) treatment (31.21 vs. 26.75 (anti-vascular endothelial growth factor (VEGF) treatment) and 24.45 months (chemotherapy); p = 0.002). Overall median progression-free survival (PFS) was 10.72 months and was longer in patients with left-sided tumors (11.24 vs. 9.31 months (right-sided tumors); p < 0.0001), and in patients receiving either first-line anti-EGFR or anti-VEGF (12.13 and 12.00 vs. 8.98 months (chemotherapy); p < 0.001). PFS was longer with anti-VEGF treatment in patients with right-sided tumors and wild-type RAS (11.24 vs. 8.78 (anti-EGFR) and 7.83 months (chemotherapy); p = 0.025). Both anti-EGFR and anti-VEGF produced longer PFS in patients with left-sided tumors and wild-type RAS than chemotherapy alone (12.39 and 13.14 vs. 9.83 months; p = 0.011). In patients with left-sided tumors and mutant RAS, anti-VEGF produced a longer PFS than chemotherapy alone (12.36 vs. 9.34 months; p = 0.001). In Spain, wild-type RAS or left-sided mCRC tumors are predictive of longer survival times.

Mimicking Clinical Trials Using Real-World Data: A Novel Method and Applications

INTRODUCTION

Simulating individual-level trial data when only summary data are available is often useful for meta-analysis, forming external control arms and calibrating trial results to real-world data (RWD). The joint distribution of baseline characteristics in a trial is usually simulated by combining its summary data with RWD's correlations. However, RWD correlations may not be a perfect proxy for the trial. A misspecified correlation structure could bias any analysis in which the outcomes generating models are nonlinear or include effect modifiers.

METHODS

We developed an iterative algorithm using copula and resampling, which was based on the estimated propensity score for the likelihood of enrollment in a trial given participants' characteristics. Validation was performed using Monte Carlo simulations under different scenarios in which the marginal and joint distributions of covariates differ between trial samples and RWD. Two applications were illustrated using an actual trial and the Surveillance, Epidemiology, and End Results-Medicare data. We calculated the standardized mean difference (SMD) to assess the generalizability of the trial and explored the feasibility of generating an external control by applying a parametric Weibull model trained in RWD to predict survival in the simulated trial cohort.

RESULTS

Across all scenarios, approximated correlations derived from the algorithm were closer to the true correlations than the RWD's correlations. The algorithm also successfully reproduced the joint distribution of characteristics for the actual trial. A similar SMD was observed using simulated data and individual-level trial data. The 95% confidence intervals were overlapped between adjusted survival estimates from the simulated trial and actual trial Kaplan-Meier estimates.

CONCLUSIONS

The algorithm could be a feasible way to simulate individual-level data when only summary data are available. Further research is needed to validate our approach with larger sample sizes.

HIGHLIGHTS

The correlation structure is crucial to building the joint distribution of patient characteristics, and a misspecified correlation structure could potentially influence predicted outcomes.An iterative algorithm was developed to approximate a trial's correlation structure using published summary trial data and real-world data.The algorithm could be a feasible way to simulate individual-level trial data when only trial summary data are available.

Real-world overall survival of patients receiving cetuximab in later lines of treatment for metastatic colorectal cancer

Aim: To examine characteristics of and treatment duration and real-world overall survival (rwOS) in patients receiving cetuximab as second-line (2L) or third-line (3L) treatment for metastatic colorectal cancer. Materials & methods: This was a retrospective study of 1096 and 684 patients in 2L and 3L cohorts, respectively. Results: The most common cetuximab-based regimens were cetuximab + folinic acid, fluorouracil and irinotecan (2L: 44%; 3L: 32%) and cetuximab + irinotecan (2L: 28%; 3L: 35%). Kaplan-Meier survival estimates and stepwise Cox regression model analysis demonstrated median treatment duration and rwOS of 3.7 and 14.4 months, respectively, in patients receiving treatment in the 2L cohort. In the 3L cohort, treatment duration was 3.3 months and rwOS was 12.0 months. Conclusion: This large real-world study provides evidence of rwOS in patients with metastatic colorectal cancer receiving cetuximab-based regimens as 2L or 3L treatment.

Continuing Cetuximab vs Bevacizumab plus chemotherapy after first progression in wild-type KRAS, NRAS and BRAF V600E metastatic colorectal cancer: a randomized phase II trial

To evaluate the clinical efficacy of continuing cetuximab vs bevacizumab plus chemotherapy crossover after first progression to cetuximab regimen in wild-type KRAS, NRAS and BRAF V600E mCRC, we conducted this prospective, open-label and randomized phase 2 trial in three cancer centers from Oct 1, 2016 to July 1, 2020. Eligibility criteria included documented progressive disease during or after first-line treatment with cetuximab regimen; second biopsy confirmed as KRAS, NRAS and BRAF V600E wild-type mCRC. Patients were randomized to arm A (cetuximab+chemo) or arm B (bevacizumab+chemo) with second-line chemotherapy crossover. The primary end point was progression free survival (PFS). Secondary end points included objective response rate (ORR), overall survival (OS) and toxicity. Tissue VEGFA, ERBB2 and MET mRNA were examined by real time RT-PCR. A total of 104 patients (53 in arm A and 51 in arm B) were enrolled. Median PFS was 7.7 months (95% CI: 6.5-8.9) for arm A and 6.3 months (95% CI: 4.5-8.1) for arm B (p=0.931). Median OS was 18.2 months (95% CI: 14.5-21.9) for arm A and 16.4 months (95% CI: 14.2-18.6) for arm B (p=0.339). The ORR was 28.3% and 19.6% in arm A and arm B (p=0.31), respectively. MET mRNA was highly expressed in the cetuximab-progressed tumors, but treatment responsiveness to cetuximab or bevacizumab in each arm was not correlated with the MET expression level. The results showed no significant difference in PFS, OS and ORR between the two arms, but a trend in favor of the cetuximab continuation plus chemotherapy crossover was examined in all end points. High expression of MET in cetuximab-progressed tumors may indicate an existence of MET-dependent tumor cell population.

Artificial Intelligence Can Cut Costs While Maintaining Accuracy in Colorectal Cancer Genotyping

Rising cancer care costs impose financial burdens on health systems. Applying artificial intelligence to diagnostic algorithms may reduce testing costs and avoid wasteful therapy-related expenditures. To evaluate the financial and clinical impact of incorporating artificial intelligence-based determination of mismatch repair/microsatellite instability status into the first-line metastatic colorectal carcinoma setting, we developed a deterministic model to compare eight testing strategies: A) next-generation sequencing alone, B) high-sensitivity polymerase chain reaction or immunohistochemistry panel alone, C) high-specificity panel alone, D) high-specificity artificial intelligence alone, E) high-sensitivity artificial intelligence followed by next generation sequencing, F) high-specificity artificial intelligence followed by next-generation sequencing, G) high-sensitivity artificial intelligence and high-sensitivity panel, and H) high-sensitivity artificial intelligence and high-specificity panel. We used a hypothetical, nationally representative, population-based sample of individuals receiving first-line treatment for de novo metastatic colorectal cancer (N = 32,549) in the United States. Model inputs were derived from secondary research (peer-reviewed literature and Medicare data). We estimated the population-level diagnostic costs and clinical implications for each testing strategy. The testing strategy that resulted in the greatest project cost savings (including testing and first-line drug cost) compared to next-generation sequencing alone in newly-diagnosed metastatic colorectal cancer was using high-sensitivity artificial intelligence followed by confirmatory high-specificity polymerase chain reaction or immunohistochemistry panel for patients testing negative by artificial intelligence ($400 million, 12.9%). The high-specificity artificial intelligence-only strategy resulted in the most favorable clinical impact, with 97% diagnostic accuracy in guiding genotype-directed treatment and average time to treatment initiation of less than one day. Artificial intelligence has the potential to reduce both time to treatment initiation and costs in the metastatic colorectal cancer setting without meaningfully sacrificing diagnostic accuracy. We expect the artificial intelligence value proposition to improve in coming years, with increasing diagnostic accuracy and decreasing costs of processing power. To extract maximal value from the technology, health systems should evaluate integrating diagnostic histopathologic artificial intelligence into institutional protocols, perhaps in place of other genotyping methodologies.

Systemic chemotherapy and short-course radiation in metastatic rectal cancers: A feasible paradigm in unresectable and potentially resectable cancers

Background:

The optimal use and sequencing of short-course radiotherapy (SCRT) in metastatic rectal cancers (mRCs) are not well established.

Materials and Methods:

We retrospectively reviewed the records of mRC patients receiving SCRT followed by palliative chemotherapy between January 1, 2013, and December 31, 2016, in Tata Memorial Hospital. Patients were classified as having “potentially resectable” disease (local and metastatic) or “unresectable” disease at baseline based on prespecified criteria.

Results:

A total of 105 consecutive patients were available for analysis. The median age of patients was 48 years (range: 16–62 years), and 57.1% were male patients. Signet ring histology was seen in 13.3% of patients. The most common site of metastases was liver limited (29.5%), nonloco-regional nodes (12.4%), and lung limited metastases (9.5%). Chemotherapeutic regimens administered were capecitabine-oxaliplatin (70.5%), modified 5 fluorouracil (5 FU)-leucovorin-irinotecan-oxaliplatin (10.5%), and modified 5 FU-leucovorin-irinotecan (8.6%). Targeted therapy accompanying chemotherapy was administered in 27.6% of patients. About 42.1% of patients with potentially resectable disease and 11.1% with the unresectable disease at baseline underwent curative-intent resection of the primary and address of metastatic sites. With a median follow-up 18.2 months, median overall survival (OS) was 15.7 months (95% confidence interval: 10.42–20.99). Patients classified as potentially resectable had a median OS of 32.62 months while patients initially classified as unresectable had a median OS of 13.04 months (P = 0.016). The presence of signet ring morphology predicted for inferior mOS (P = 0.021).

Conclusions:

SCRT followed by systemic therapy in mRC is a feasible, efficacious paradigm for maximizing palliation, and achieving objective responses. The classification of patients based on resectability was predictive of actual resection rates as well as outcomes. Signet ring mRC show inferior outcomes in this cohort of patients.

Modifying Adaptive Therapy to Enhance Competitive Suppression

Adaptive therapy is a promising new approach to cancer treatment. It is designed to leverage competition between drug-sensitive and drug-resistant cells in order to suppress resistance and maintain tumor control for longer. Prompted by encouraging results from a recent pilot clinical trial, we evaluate the design of this initial test of adaptive therapy and identify three simple modifications that should improve performance. These modifications are designed to increase competition and are easy to implement. Using the mathematical model that supported the recent adaptive therapy trial, we show that the suggested modifications further delay time to tumor progression and also increase the range of patients who can benefit from adaptive therapy.

Are there socio-economic inequalities in utilization of predictive biomarker tests and biological and precision therapies for cancer? A systematic review and meta-analysis

BACKGROUND

Novel biological and precision therapies and their associated predictive biomarker tests offer opportunities for increased tumor response, reduced adverse effects, and improved survival. This systematic review determined if there are socio-economic inequalities in utilization of predictive biomarker tests and/or biological and precision cancer therapies.

METHODS

MEDLINE, Embase, Scopus, CINAHL, Web of Science, PubMed, and PsycINFO were searched for peer-reviewed studies, published in English between January 1998 and December 2019. Observational studies reporting utilization data for predictive biomarker tests and/or cancer biological and precision therapies by a measure of socio-economic status (SES) were eligible. Data was extracted from eligible studies. A modified ISPOR checklist for retrospective database studies was used to assess study quality. Meta-analyses were undertaken using a random-effects model, with sub-group analyses by cancer site and drug class. Unadjusted odds ratios (ORs) and 95% confidence intervals (CIs) were computed for each study. Pooled utilization ORs for low versus high socio-economic groups were calculated for test and therapy receipt.

RESULTS

Among 10,722 citations screened, 62 papers (58 studies; 8 test utilization studies, 37 therapy utilization studies, 3 studies on testing and therapy, 10 studies without denominator populations or which only reported mean socio-economic status) met the inclusion criteria. Studies reported on 7 cancers, 5 predictive biomarkers tests, and 11 biological and precision therapies. Thirty-eight studies (including 1,036,125 patients) were eligible for inclusion in meta-analyses. Low socio-economic status was associated with modestly lower predictive biomarker test utilization (OR 0.86, 95% CI 0.71-1.05; 10 studies) and significantly lower biological and precision therapy utilization (OR 0.83, 95% CI 0.75-0.91; 30 studies). Associations with therapy utilization were stronger in lung cancer (OR 0.71, 95% CI 0.51-1.00; 6 studies), than breast cancer (OR 0.93, 95% CI 0.78-1.10; 8 studies). The mean study quality score was 6.9/10.

CONCLUSIONS

These novel results indicate that there are socio-economic inequalities in predictive biomarker tests and biological and precision therapy utilization. This requires further investigation to prevent differences in outcomes due to inequalities in treatment with biological and precision therapies.

Validation of a Cyclic Algorithm to Proxy Number of Lines of Systemic Cancer Therapy Using Administrative Data

PURPOSE

Researchers are automating the process for identifying the number of lines of systemic cancer therapy received by patients. To date, algorithm development has involved manual modifications to predefined classification rules. In this study, we propose a supervised learning algorithm for determining the best-performing proxy for number of lines of therapy and validate this approach in four patient groups.

MATERIALS AND METHODS

We retrospectively analyzed BC Cancer pharmacy records from patients' cancer diagnosis until end of follow-up (cohort-specific, 2014/2015). We created and validated a cyclic algorithm in patients with advanced cancers of varying histologies, diffuse large B-cell lymphoma, follicular lymphoma, and chronic lymphocytic leukemia. To assess internal and external validity, we used a split-sample approach for all analyses and considered lines of therapy identified through manual review as our criterion standard. We measured agreement using correlation coefficients, mean squared error, nonparametric hypothesis testing, and quantile-quantile plots.

RESULTS

Cohorts comprised 91 patients with advanced cancers, 121 with chronic lymphocytic leukemia, 440 with follicular lymphoma, and 679 with diffuse large B-cell lymphoma. Number of lines of therapy received and patients' treatment period length varied substantially across cohorts. Despite these differences, our algorithm successfully identified a best-performing proxy for number of lines of therapy for each cohort, which was moderate to highly correlated with (within-sample: 0.73 ≤ Pearson correlation ≤ 0.84; out-of-sample: 0.52 ≤ Pearson correlation ≤ 0.76) and whose distribution did not significantly differ from the criterion standard within or out of sample (P > .10).

CONCLUSION

Supervised learning is an ideal tool for generating a best-performing proxy that recognizes prescription drug patterns and approximates number of lines of therapy. Our cyclic approach can be used in jurisdictions with access to administrative pharmacy data.

Efficacy and Safety of Bevacizumab Combined With First-Line Chemotherapy in Elderly (≥75 Years) Patients With Metastatic Colorectal Cancer: A Real-World Study

BACKGROUND

Although elderly patients are the first concerned by colorectal cancer (CRC), they are underrepresented in clinical trials. The real-world CASSIOPEE study was thus conducted in elderly patients treated for metastatic CRC (mCRC).

METHODS

This French prospective, multicenter, noninterventional study aimed to estimate 1-year progression-free survival (PFS) and overall survival (OS), and describe treatments, patient autonomy (Instrumental Activities of Daily Living; Balducci scale), and safety over 24 months, in patients older than 75 with mCRC, starting first-line bevacizumab plus chemotherapy (NCT01555762).

RESULTS

From 2012 to 2014, 402 patients were included (safety population: n = 383, efficacy population: n = 358). Patient characteristics were as follows: mean age, 81 ± 4 years (<80 years, 46%; 80-85 years, 44%; >85 years, 10%); men, 52%; colon primary tumor, 80%; main metastatic site, liver 66%; Eastern Cooperative Oncology Group performance 0-1, 81%. Median PFS was 9.1 months (95% confidence interval [CI]: 8.3-10.2). It was superior for patients ≤85 years (<80 years: 9.3 months; 80-85 years: 9.5 months) compared with patients >85 years (8.3 months). Median OS was 19.0 months (95% CI, 16.5-21.5) and decreased in the 2 oldest groups (20.6, 17.8, and 13.0 months). Autonomy assessments decreased over time leading to nonconclusive results. Twenty-six percent of patients experienced serious adverse events (SAEs): 7% bevacizumab-related SAEs, and 6% bevacizumab-targeted SAEs. Two fatal bevacizumab-related adverse events were reported (hemorrhagic stroke and intestinal ischemia).

CONCLUSIONS

This large French real-world study showed that medically fit older patients with mCRC could have a benefit/risk balance similar to that of younger patients when treated with first-line bevacizumab plus chemotherapy. Improvements in geriatric assessments are needed to better define this population.

Disease characteristics and treatment patterns of Chinese patients with metastatic colorectal cancer: a retrospective study using medical records from China

Background

Colorectal cancer (CRC) is the third most prevalent cancer in China but few large-scale studies were conducted to understand CRC patients. The current study is aimed to gain a real-world perspectives of CRC patients in China.

Methods

Using electronic medical records of sampled patients between 2011 and 2016 from 12 hospitals in China, a retrospective cohort study was conducted to describe demographics and disease prognosis of CRC patients, and examine treatment sequences among metastatic CRC (mCRC) patients. Descriptive, comparative and survival analyses were conducted.

Results

Among mCRC patients (3878/8136, 48%), the fluorouracil, leucovorin, and oxaliplatin (FOLFOX) and other oxaliplatin-based regimens were the most widely-used first-line treatment (42%). Fluorouracil, leucovorin, irinotecan (FOLFIRI) and other irinotecan-based regimens dominated the second-line (40%). There was no a dominated regimen for the third-line. The proportion of patients receiving chemotherapy with targeted biologics increased from less than 20% for the first- and second- lines to 34% for the third-line (p < 0.001). The most common sequence from first- to second-line was from FOLFOX and other oxaliplatin-based regimens to FOLFIRI and other irinotecan-based regimens (286/1200, 24%).

Conclusions

Our findings reflected a lack of consensus on the choice of third-line therapy and limited available options in China. It is evident o continue promoting early CRC diagnosis and to increase the accessibility of treatment options for mCRC patients. As the only nationwide large-scale study among CRC and mCRC patients before more biologics became available in China, our results can also be used as the baseline to assess treatment pattern changes before and after more third-line treatment were approved and covered into the National Health Insurance Plan in China between 2017 and 2018.

Algorithm to Identify Systemic Cancer Therapy Treatment Using Structured Electronic Data

PURPOSE

With the shift in the majority of oncology clinical care in the United States from paper records to electronic health records, researchers need efficient and validated processes to obtain accurate data about the entire treatment history of patients diagnosed with cancer. The objective of this study was to develop and validate an algorithm that is agnostic to the source of data but that can identify specific regimens in the entire course of systemic therapy treatment for patients diagnosed with breast, colorectal, or lung cancer.

METHODS

A cohort of patients with incident breast, colorectal, and lung cancer were randomly distributed into six groups. The algorithm was iteratively modified, and the performance was assessed until no additional modifications could be identified in the first three groups. The performance of the algorithm was confirmed in the three groups that remained.

RESULTS

The final model produced ranges of sensitivity between 97.2% and 100% for first-course systemic therapy across all cancers, with a false-positive rate of 0%. The algorithm matched the exact number of courses and the exact regimens of systemic therapy agents as captured by infusion, pharmacy, and procedure electronic medical record data for all courses of therapy 88% to 100% of the time.

CONCLUSION

Use of our validated algorithm that characterizes entire courses of systemic therapy treatment in patients diagnosed with breast, colorectal, and lung cancer will allow researchers in a variety of settings to conduct comparative effectiveness studies related to the uptake, safety, outcomes, and costs associated with the use of both novel and standard regimens.

Utilisation of systemic therapy options in routine treatment of metastatic colorectal cancer in Australia

BACKGROUND

In the treatment of metastatic colorectal cancer (mCRC), exposure to all three active cytotoxic agents, 5-fluorouracil/capecitabine, irinotecan and oxaliplatin, improves overall survival. The addition of biologic agents (bevacizumab and cetuximab/panitumumab) further improves survival. The uptake of available systemic agents for mCRC in routine practice in Australia is poorly described.

METHODS

The ACCORD database was interrogated to determine demographics, treatments and outcomes for patients diagnosed with mCRC between 1 January 2011 and 1 January 2016 at six Melbourne centres.

RESULTS

About 1130 mCRC patients were identified: median age was 69 years (range 26-105); 61% had synchronous disease. KRAS status was known in 62%, of whom 49% were KRAS wild-type. At the time of analysis, 67% of all patients had commenced systemic treatment, 50% had received two or more lines of therapy and 19% of KRAS wild-type patients had received all five active drugs. Of KRAS-mutated patients, 35% had received all four Pharmaceutical Benefits Scheme-reimbursed active drugs. Patients who had not received chemotherapy included 72 patients who underwent metastasectomy alone. At a median follow up of 34 months, median overall survival was 25 months for all patients and 69 months for those who underwent metastasectomy.

CONCLUSION

In this community-based cohort, 33% of patients had not received any systemic therapy for mCRC, and few patients had received all available active systemic agents. As many patients remain alive, these figures will likely increase over time. The overall survival of patients with mCRC in this community-based cohort was 25 months and not dissimilar to that achieved in recent clinical trials.

A within-trial cost-effectiveness analysis of panitumumab compared with bevacizumab in the first-line treatment of patients with wild-type RAS metastatic colorectal cancer in the US

AIMS

This analysis investigated the cost-effectiveness of panitumumab plus mFOLFOX6 (oxaliplatin, 5-fluorouracil, and leucovorin) compared with bevacizumab plus mFOLFOX6 in the first-line treatment of patients with wild-type RAS metastatic colorectal cancer (mCRC).

MATERIALS AND METHODS

The cost-effectiveness analysis was developed from a third-party payer perspective in the US and was implemented using a partitioned survival model with health states for first-line treatment (progression-free), disease progression with and without subsequent active treatment, and death. Survival analyses of patients with wild-type RAS mCRC from the PEAK head-to-head clinical trial of panitumumab vs bevacizumab were performed to estimate time in the model health states. Additional data from PEAK informed the amount of each drug consumed, duration of therapy, subsequent therapy use, and toxicities related to mCRC treatment. Literature and US public data sources were used to estimate unit costs associated with treatment and duration of subsequent active therapies. Utility weights were calculated from patient-level data from panitumumab trials in the first-, second-, and third-line settings. A life-time perspective was taken with future costs and outcomes discounted at 3% per annum. Scenario, one-way, and probabilistic sensitivity analyses were performed.

RESULTS

Compared with bevacizumab, the use of panitumumab resulted in an incremental cost of US $60,286, and an incremental quality-adjusted life-year (QALY) of 0.445, translating into a cost per QALY gained of US $135,391 in favor of panitumumab. Results were sensitive to wastage and dose rounding assumptions modeled.

LIMITATIONS

Progression-free and overall survival were extrapolated beyond the follow-up of the primary analysis using fitted parametric curves. Costs and quality of life were estimated from multiple and different data sources.

CONCLUSIONS

The efficacy of panitumumab in extending progression-free and overall survival and improving quality of life makes it a cost-effective option for first-line treatment of patients with wild-type RAS mCRC compared with bevacizumab.

Continuum of care strategy in metastatic colorectal cancer: a review

Treatment of human metastatic colorectal cancer (mCRC) has changed remarkably in the past two decades. The use of novel therapies and more complex treatment strategies have contributed to progressively increase the median life expectancy of patients up to approximately 30 months. Although traditional cytotoxic chemotherapy and newer targeted therapy are now available for use in treating patients with mCRC, the optimal treatment strategy remains unknown. In recent years, there has been a treatment paradigm shift for mCRC patients with the emergence of the concept of ‘continuum of care’ as the optimal palliative therapy strategy. It is based on the concept whereby patients are exposed throughout the course of their disease to different active drugs; the therapy is personalized according to the need for rapid response, the burden of disease and molecular subtype status, such as RAS, BRAF, MMR and HER2. Drugs are often reintroduced if they demonstrated activity in a previous line of therapy, and most importantly, maintenance chemotherapy and/or intermittent therapy are considered. This review details available data for the use of the continuum of care strategy in mCRC, in which the strategy has provided significant clinical benefit in clinical studies. As our understanding advances, optimal treatment strategy for the patients with mCRC should still be individualized.

Cost-Effectiveness of Treatment Sequences of Chemotherapies and Targeted Biologics for Elderly Metastatic Colorectal Cancer Patients

BACKGROUND

Treatment patterns for metastatic colorectal cancer (mCRC) patients have changed considerably over the last decade with the introduction of new chemotherapies and targeted biologics. These treatments are often administered in various sequences with limited evidence regarding their cost-effectiveness.

OBJECTIVE

To conduct a pharmacoeconomic evaluation of commonly administered treatment sequences among elderly mCRC patients.

METHODS

A probabilistic discrete event simulation model assuming Weibull distribution was developed to evaluate the cost-effectiveness of the following common treatment sequences: (a) first-line oxaliplatin/irinotecan followed by second-line oxaliplatin/irinotecan + bevacizumab (OI-OIB); (b) first-line oxaliplatin/irinotecan + bevacizumab followed by second-line oxaliplatin/irinotecan + bevacizumab (OIB-OIB); (c) OI-OIB followed by a third-line targeted biologic (OI-OIB-TB); and (d) OIB-OIB followed by a third-line targeted biologic (OIB-OIB-TB). Input parameters for the model were primarily obtained from the Surveillance, Epidemiology, and End Results-Medicare linked dataset for incident mCRC patients aged 65 years and older diagnosed from January 2004 through December 2009. A probabilistic sensitivity analysis was performed to account for parameter uncertainty. Costs (2014 U.S. dollars) and effectiveness were discounted at an annual rate of 3%.

RESULTS

In the base case analyses, at the willingness-to-pay (WTP) threshold of $100,000/quality-adjusted life-year (QALY) gained, the treatment sequence OIB-OIB (vs. OI-OIB) was not cost-effective with an incremental cost-effectiveness ratio (ICER) per patient of $119,007/QALY; OI-OIB-TB (vs. OIB-OIB) was dominated; and OIB-OIB-TB (vs. OIB-OIB) was not cost-effective with an ICER of $405,857/QALY. Results similar to the base case analysis were obtained assuming log-normal distribution. Cost-effectiveness acceptability curves derived from a probabilistic sensitivity analysis showed that at a WTP of $100,000/QALY gained, sequence OI-OIB was 34% cost-effective, followed by OIB-OIB (31%), OI-OIB-TB (20%), and OIB-OIB-TB (15%).

CONCLUSIONS

Overall, survival increases marginally with the addition of targeted biologics, such as bevacizumab, at first line and third line at substantial costs. Treatment sequences with bevacizumab at first line and targeted biologics at third line may not be cost-effective at the commonly used threshold of $100,000/QALY gained, but a marginal decrease in the cost of bevacizumab may make treatment sequences with first-line bevacizumab cost-effective. Future economic evaluations should validate the study results using parameters from ongoing clinical trials.

DISCLOSURES

This study was supported in part by a grant from the Agency for Healthcare Research and Quality (R01-HS018956) and in part by a grant from the Cancer Prevention and Research Institute of Texas (RP130051), which were obtained by Du. The authors report no conflicts of interest. Study concept and design were primarily contributed by Parikh, along with the other authors. All authors participated in data collection, and Parikh took the lead in data interpretation and analysis, along with Lairson and Morgan, with assistance from Du. The manuscript was written primarily by Parikh, along with Lairson, Morgan, and Du, and revised by Parikh.