Importance of Risk Factors for Febrile Neutropenia Among Patients Receiving Chemotherapy Regimens Not Classified as High-Risk in Guidelines for Myeloid Growth Factor Use

Evaluating the safety and effectiveness of PegaGen® (pegfilgrastim) for the prevention of chemotherapy-induced febrile neutropenia: a post-marketing surveillance study

PURPOSE

Phase IV clinical trials are required to evaluate the real-world safety and effectiveness of drugs. This study aimed to evaluate the safety and effectiveness of once-per-cycle administration of PegaGen^® (pegfilgrastim, CinnaGen, Iran) in cancer patients.

METHODS

In this open-label, multicenter, prospective, real-world, post-marketing surveillance study, patients with any type of cancer receiving chemotherapy regimens with a high risk of febrile neutropenia (FN) were included if they were prescribed pegfilgrastim for FN prophylaxis. The primary objective of this study was to assess the safety and the secondary objective was to assess the effectiveness of pegfilgrastim in the prevention of FN in cancer patients.

RESULTS

A total of 654 patients (51.73 ± 15.12 years of age) were enrolled and 3615 cycles of pegfilgrastim injections were recorded. The most common malignancies among the study patients were breast cancer (n = 192, 29.36%), lymphoma (n = 131, 20.03%), and gastric cancer (n = 65, 9.94%). The median (Q1, Q3) number of pegfilgrastim cycles per patient was 6 (4, 7). A single 6 mg dose was injected in 99.17% of the cycles. A total number of 816 adverse events (AEs) were reported in 246 patients (37.62%). Bone pain was recorded in 141 patients (21.56%) and in 440 cycles (12.17%). Among all patients, 45 patients (6.88%) experienced FN 51 times, and FN frequency was 1.4% among cycles. Moreover, 14 (2.14%) patients were hospitalized following FN. Antibiotics were administered to 24 patients (3.67%) for FN treatment.

CONCLUSION

The results from this post-marketing surveillance study support the safety and effectiveness of PegaGen^® used for the prevention of chemotherapy-induced FN in patients with various types of cancer and treatment regimens.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT04460079.

Biosimilar Versus Originator Pegfilgrastim for Preventing Chemotherapy-Induced Neutropenia: A Phase III Randomized, Multicenter, Evaluator-Blinded, Noninferiority Study

PURPOSE

This study evaluated the efficacy, safety, and immunogenicity of biosimilar pegfilgrastim (PegFilBS) and originator pegfilgrastim (PegFilOR) in patients with stage 2-4 breast cancer.

METHODS

This phase III randomized, multicenter, evaluator-blinded, noninferiority study recruited women with stage 2-4 breast cancer in Argentina who were scheduled to receive chemotherapy. Stratification was based on the breast cancer stage. The primary end point was the duration of severe neutropenia (DSN, noninferiority margin: 1 day) in the first chemotherapy cycle. Secondary end points assessed were incidence of severe neutropenia, grade 3 neutropenia, febrile neutropenia, infections, postchemotherapy hospitalization and duration, and the incidence of adverse drug reactions (ADRs).

RESULTS

A total of 120 patients were randomly assigned to receive PegFilBS (58 patients) or PegFilOR (62 patients). Severe neutropenia occurred in 52 of 283 cycles (18.4%) for 27 patients who received PegFilBS and in 48 of 297 cycles (16.2%) for 20 patients who received PegFilOR (P = .48). During the first cycle, severe neutropenia occurred in 16 patients who received PegFilBS (DSN: 0.78 ± 1.53 days) and in 11 patients who received PegFilOR (DSN: 0.53 ± 1.25 days; 95% CI, -0.26 to 0.76 days). In the intention-to-treat analysis, the mean DSN values were 0.90 ± 1.79 days for the PegFilBS group and 0.50 ± 1.21 for the PegFilOR group (95% CI, -0.15 to 0.95 days). No significant differences were observed for the secondary efficacy end points. Three patients experienced seven ADRs in the PegFilBS group while 10 patients experienced 31 ADRs in the PegFilOR group. The most common ADR was myalgia.

CONCLUSION

Relative to PegFilOR, PegFilBS provided noninferior efficacy outcomes in Argentinian women with stage 2-4 breast cancer who were treated using myelosuppressive chemotherapy.

OUP accepted manuscript

Background

The FEbrile Neutropenia after ChEmotherapy (FENCE) score was developed to estimate the risk of febrile neutropenia (FN) at first cycle of chemotherapy but has not been externally validated. We aimed to validate the FENCE score based on its risk groups in patients treated at a comprehensive cancer center.

Methods

We conducted a retrospective study of treatment-naïve adult patients with solid tumors and diffuse large B-cell lymphoma who received first-cycle chemotherapy between January and November 2019. Patients were followed until the second cycle of chemotherapy to identify any FN events (neutrophil count <0.5 × 10⁹/L with fever ≥38.2°C). The FENCE score was determined and patients classified as low, intermediate, high, and very high risk. The discriminatory ability of classifying patients into FENCE risk groups was calculated as the area under the receiver operating characteristics curve and incidence rate ratios within each FENCE risk group.

Results

FN was documented during the first cycle of chemotherapy in 45 of the 918 patients included (5%). The area under the receiver operating characteristics curve was 0.66 (95% confidence interval [CI] = 0.58 to 0.73). Compared with the low-risk group (n = 285), the incidence rate ratio of developing FN was 1.58 (95% CI = 0.54 to 5.21), 3.16 (95% CI = 1.09 to 10.25), and 3.93 (95% CI = 1.46 to 12.27) in the intermediate (n = 293), high (n = 162), and very high (n = 178) risk groups, respectively.

Conclusions

In this study, classifying patients into FENCE risk groups demonstrated moderate discriminatory ability for predicting FN. Further validation in multicenter studies is necessary to determine its generalizability.

Primary Prophylaxis With Biosimilar Filgrastim for Patients at Intermediate Risk for Febrile Neutropenia: A Cost-Effectiveness Analysis

PURPOSE

Temporary COVID-19 guideline recommendations have recently been issued to expand the use of colony-stimulating factors in patients with cancer with intermediate to high risk for febrile neutropenia (FN). We evaluated the cost-effectiveness of primary prophylaxis (PP) with biosimilar filgrastim-sndz in patients with intermediate risk of FN compared with secondary prophylaxis (SP) over three different cancer types.

METHODS

A Markov decision analytic model was constructed from the US payer perspective over a lifetime horizon to evaluate PP versus SP in patients with breast cancer, non-small-cell lung cancer (NSCLC), and non-Hodgkin lymphoma (NHL). Cost-effectiveness was evaluated over a range of willingness-to-pay thresholds for incremental cost per FN avoided, life year gained, and quality-adjusted life year (QALY) gained. Sensitivity analyses evaluated uncertainty.

RESULTS

Compared with SP, PP provided an additional 0.102-0.144 LYs and 0.065-0.130 QALYs. The incremental cost-effectiveness ranged from $5,660 in US dollars (USD) to $20,806 USD per FN event avoided, $5,123 to $31,077 USD per life year gained, and $7,213 to $35,563 USD per QALY gained. Over 1,000 iterations, there were 73.6%, 99.4%, and 91.8% probabilities that PP was cost-effective at a willingness to pay of $50,000 USD per QALY gained for breast cancer, NSCLC, and NHL, respectively.

CONCLUSION

PP with a biosimilar filgrastim (specifically filgrastim-sndz) is cost-effective in patients with intermediate risk for FN receiving curative chemotherapy regimens for breast cancer, NSCLC, and NHL. Expanding the use of colony-stimulating factors for patients may be valuable in reducing unnecessary health care visits for patients with cancer at risk of complications because of COVID-19 and should be considered for the indefinite future.

The Impact of Baseline Risk Factors on the Incidence of Febrile Neutropenia in Breast Cancer Patients Receiving Chemotherapy with Pegfilgrastim Prophylaxis: A Real-World Data Analysis

Background: There are sparse data addressing whether standard risk factors for febrile neutropenia (FN) are relevant in patients receiving myelosuppressive chemotherapy and primary prophylaxis for FN, which would have implications for variables to consider during real-world comparative analyses of FN incidence. Objective: To assess the impact of baseline patient-specific risk factors and regimen risk on the incidence of FN in patients receiving pegfilgrastim primary prophylaxis. Methods: This was a retrospective observational study in patients with breast cancer (BC) who received myelosuppressive chemotherapy and prophylactic pegfilgrastim identified January 1, 2017-May 31, 2018 from MarketScan® research databases. The outcomes were defined as incidence of FN in the first cycle and among all cycles of chemotherapy using three different definitions for FN. Logistic regression and generalized estimating equations models were used to compare outcomes among patients with and without patient-specific risk factors and among those receiving regimens categorized as high-, intermediate-, or other-risk for FN (low-risk or undefinable by clinical practice guidelines). Results: A total of 4460 patients were identified. In the first cycle of therapy, patients receiving intermediate-risk regimens were at up to 2 times higher risk for FN across all definitions than those receiving high-risk regimens (P<0.01). The odds ratio for main FN among patients with ≥4 versus 0 risk factors was 15.8 (95% confidence interval [CI]: 1.5, 169.4; P<0.01). Patients with ≥3 FN risk factors had significantly greater risks for FN across all cycles of treatment than those with no risk factors; this was true for all FN definitions. Discussion: The choice of FN definition significantly changed the impact of risk factors on the FN outcomes in our study, demonstrating the importance of evaluating all proxies for true FN events in a database study. This is particularly important during real-world study planning where potential missteps may lead to bias or confounding effects that render a study meaningless. Conclusions: In patients with BC receiving chemotherapy with pegfilgrastim prophylaxis, patient-specific risk factors and regimen risk levels are determinants of FN risk. In real-world studies evaluating FN incidence, it is imperative to consider and control for these risk factors when conducting comparative analyses.

Supportive care in patients with cancer during the COVID-19 pandemic

Cancer care has been profoundly impacted by the global pandemic of severe acute respiratory syndrome coronavirus 2 disease (coronavirus disease 2019, COVID-19), resulting in unprecedented challenges. Supportive care is an essential component of cancer treatment, seeking to prevent and manage chemotherapy complications such as febrile neutropenia, anaemia, thrombocytopenia/bleeding, thromboembolic events and nausea/vomiting, all of which are common causes of hospitalisation. These adverse events are an essential consideration under routine patient management, but particularly so during a pandemic, a setting in which clinicians aim to minimise patients' risk of infection and need for hospital visits. Professional medical oncology societies have been providing updated guidelines to support health care professionals with the management, treatment and supportive care needs of their patients with cancer under the threat of COVID-19. This paper aims to review the recommendations made by the most prominent medical oncology societies for devising and modifying supportive care strategies during the pandemic.

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Cancer care has been profoundly impacted by the global pandemic of COVID-19, resulting in unprecedented challenges.

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Oncology societies have updated guidelines for the supportive care needs of patients with cancer under the threat of COVID-19.

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This paper reviews recommendations from prominent oncology societies for providing supportive care during the pandemic.

Use and effectiveness of pegfilgrastim prophylaxis in US clinical practice:a retrospective observational study

Background

Febrile neutropenia (FN) is a serious complication of myelosuppressive chemotherapy. Clinical practice guidelines recommend routine prophylactic coverage with granulocyte colony-stimulating factor (G-CSF)—such as pegfilgrastim—for most patients receiving chemotherapy with an intermediate to high risk for FN. Patterns of pegfilgrastim prophylaxis during the chemotherapy course and associated FN risks in US clinical practice have not been well characterized.

Methods

A retrospective cohort design and data from two commercial healthcare claims repositories (01/2010–03/2016) and Medicare Claims Research Identifiable Files (01/2007–09/2015) were employed. Study population included patients who had non-metastatic breast cancer or non-Hodgkin’s lymphoma and received intermediate/high-risk regimens. Pegfilgrastim prophylaxis use and FN incidence were ascertained in each chemotherapy cycle, and all cycles were pooled for analyses. Adjusted odds ratios for FN were estimated for patients who did versus did not receive pegfilgrastim prophylaxis in that cycle.

Results

Study population included 50,778 commercial patients who received 190,622 cycles of chemotherapy and 71,037 Medicare patients who received 271,944 cycles. In cycle 1, 33% of commercial patients and 28% of Medicare patients did not receive pegfilgrastim prophylaxis, and adjusted odds of FN were 2.6 (95% CI 2.3–2.8) and 1.6 (1.5–1.7), respectively, versus those who received pegfilgrastim prophylaxis. In cycle 2, 28% (commercial) and 26% (Medicare) did not receive pegfilgrastim prophylaxis; corresponding adjusted FN odds were comparably elevated (1.9 [1.6–2.2] and 1.6 [1.5–1.8]). Results in subsequent cycles were similar. Across all cycles, 15% of commercial patients and 23% of Medicare patients did not receive pegfilgrastim prophylaxis despite having FN in a prior cycle, and prior FN increased odds of subsequent FN by 2.1–2.4 times.

Conclusions

Notwithstanding clinical practice guidelines, a large minority of patients did not receive G-CSF prophylaxis, and FN incidence was substantially higher among this subset of the population. Appropriate use of pegfilgrastim prophylaxis may reduce patient exposure to this potentially fatal but largely preventable complication of myelosuppressive chemotherapy.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-6010-9) contains supplementary material, which is available to authorized users.

Development and validation of a cycle-specific risk score for febrile neutropenia during chemotherapy cycles 2-6 in patients with solid cancers: The CSR FENCE score

The absolute risk reduction by prophylaxis in chemotherapy-induced febrile neutropenia (FN) is largest in patients at highest underlying risk. Therefore, reliable predictive models are needed. Here, we develop and validate such a model for risk of FN during chemotherapy cycles 2-6. A prediction score for risk of FN during the first cycle has recently been published. Patients with solid cancers initiating first-line chemotherapy in 2010-2016 were included. Cycle-specific risk factors were assessed by Poisson regression using generalized estimating equations and random split sampling. The derivation cohort included 4,590 patients treated with 15,419 cycles, wherein 326 (2.1%) FN events occurred. Predictors of FN in multivariable analyses were: higher predicted risk of FN in the first cycle, platinum- or taxane-containing therapies, concurrent radiotherapy, treatment in cycle 2 compared to later cycles, previous FN or neutropenia and not receiving granulocyte colony-stimulating factors. Each predictor added between -2 and 8 points to each patient's score (median score 4; interquartile range, 1-6). The incidence rate ratios for developing FN in the intermediate (score 1-4), high (score 5-6) and very high risk groups (score ≥7) were 7.8 (95% CI, 2.4-24.9), 18.6 (95% CI, 5.9-58.8) and 51.7 (95% CI, 16.5-162.3) compared to the low risk group (score ≤0), respectively. The score had good discriminatory ability with a Harrell's C-statistic of 0.78 (95% CI, 0.76-0.80) in the derivation and 0.75 (95% CI, 0.72-0.78) in the validation cohort (patient n = 2,295, cycle n = 7,670). The Cycle-Specific Risk of FEbrile Neutropenia after ChEmotherapy score is the first published method to estimate cycle-specific risk of FN.

Apixaban 5 and 2.5 mg twice-daily versus warfarin for stroke prevention in nonvalvular atrial fibrillation patients: Comparative effectiveness and safety evaluated using a propensity-score-matched approach

Prior real-world studies have shown that apixaban is associated with a reduced risk of stroke/systemic embolism (stroke/SE) and major bleeding versus warfarin. However, few studies evaluated the effectiveness and safety of apixaban according to its dosage, and most studies contained limited numbers of patients prescribed 2.5 mg twice-daily (BID) apixaban. Using pooled data from 4 American claims database sources, baseline characteristics and outcomes for patients prescribed 5 mg BID and 2.5 mg BID apixaban versus warfarin were compared. After 1:1 propensity-score matching, 31,827 5 mg BID apixaban-matched warfarin patients and 6600 2.5 mg BID apixaban-matched warfarin patients were identified. Patients prescribed 2.5 mg BID apixaban were older, had clinically more severe comorbidities, and were more likely to have a history of stroke and bleeding compared with 5 mg BID apixaban patients. Compared with warfarin, 5 mg BID apixaban was associated with a lower risk of stroke/SE (hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.60–0.81) and major bleeding (HR: 0.59, 95% CI: 0.53–0.66). Compared with warfarin, 2.5 mg BID apixaban was also associated with a lower risk of stroke/SE (HR: 0.63, 95% CI: 0.49–0.81) and major bleeding (HR: 0.59, 95% CI: 0.49–0.71). In this real-world study, both apixaban doses were assessed in 2 patient groups differing in age and clinical characteristics. Each apixaban dose was associated with a lower risk of stroke/SE and major bleeding compared with warfarin in the distinct population for which it is being prescribed in United States clinical practice.

Trial registration: Clinicaltrials.Gov Identifier: NCT03087487.

Effectiveness and safety of apixaban versus warfarin in non-valvular atrial fibrillation patients in "real-world" clinical practice. A propensity-matched analysis of 76,940 patients

The ARISTOTLE trial showed a risk reduction of stroke/systemic embolism (SE) and major bleeding in non-valvular atrial fibrillation (NVAF) patients treated with apixaban compared to warfarin. This retrospective study used four large US claims databases (MarketScan, PharMetrics, Optum, and Humana) of NVAF patients newly initiating apixaban or warfarin from January 1, 2013 to September 30, 2015. After 1:1 warfarin-apixaban propensity score matching (PSM) within each database, the resulting patient records were pooled. Kaplan-Meier curves and Cox proportional hazards models were used to estimate the cumulative incidence and hazard ratios (HRs) of stroke/SE and major bleeding (identified using the first listed diagnosis of inpatient claims) within one year of therapy initiation. The study included a total of 76,940 (38,470 warfarin and 38,470 apixaban) patients. Among the 38,470 matched pairs, 14,563 were from MarketScan, 7,683 were from PharMetrics, 7,894 were from Optum, and 8,330 were from Humana. Baseline characteristics were balanced between the two cohorts with a mean (standard deviation [SD]) age of 71 (12) years and a mean (SD) CHA ₂ DS ₂ -VASc score of 3.2 (1.7). Apixaban initiators had a significantly lower risk of stroke/SE (HR: 0.67, 95 % CI: 0.59–0.76) and major bleeding (HR: 0.60, 95 % CI: 0.54–0.65) than warfarin initiators. Different types of stroke/SE and major bleeding – including ischaemic stroke, haemorrhagic stroke, SE, intracranial haemorrhage, gastrointestinal bleeding, and other major bleeding – were all significantly lower for apixaban compared to warfarin treatment. Subgroup analyses (apixaban dosage, age strata, CHA ₂ DS ₂ -VASc or HAS-BLED score strata, or dataset source) all show consistently lower risks of stroke/SE and major bleeding associated with apixaban as compared to warfarin treatment. This is the largest “real-world” study on apixaban effectiveness and safety to date, showing that apixaban initiation was associated with significant risk reductions in stroke/SE and major bleeding compared to warfarin initiation after PSM. These benefits were consistent across various high-risk subgroups and both the standard-and low-dose apixaban dose regimens.

Note: The review process for this manuscript was fully handled by Christian Weber, Editor in Chief.

Supplementary Material to this article is available online at www.thrombosis-online.com .

Issues on the Use of White Blood Cell Growth Factors in Oncology Practice

Appropriate use of myeloid growth factors may reduce the risk of neutropenic complications including febrile neutropenia (FN) in patients receiving cancer chemotherapy. The recently updated American Society of Clinical Oncology (ASCO) Guidelines on the Use of the White Blood Cell Growth Factors recommends routine prophylaxis with these agents starting in the first cycle when the risk of FN is 20% or greater. However, the risks for neutropenic complications and the risk of serious adverse consequences from FN vary considerably with different chemotherapy regimens as well as other disease-, treatment-, and patient-specific risk factors. Considerably more information is now available on the major risk factors for FN. Multivariable risk models combining factors look promising but require further validation. Most clinical studies of myeloid growth factor prophylaxis assessed relative risk (RR) of FN but were not powered to evaluate the effect of prophylaxis on disease-free or overall survival. Accumulating evidence suggests, however, that the appropriate use of these agents in selected patients may improve both short-term and long-term survival by reducing the immediate risk of mortality accompanying patients with high-risk disease developing FN as well as improving disease-free and overall survival by enabling the delivery of full dose intensity chemotherapy and reducing the risk of disease recurrence in patients treated with curative intent. Further studies to evaluate risk factors and models for FN are needed to guide clinical and shared decision making for the optimal personalized use of these agents and offer patients at increased risk the best chance of long-term disease control.

Risk of Neutropenia-Related Hospitalization in Patients Who Received Colony-Stimulating Factors With Chemotherapy for Breast Cancer

Purpose

To describe outcomes after granulocyte colony-stimulating factor (G-CSF) prophylaxis in patients with breast cancer who received chemotherapy regimens with low-to-intermediate risk of induction of neutropenia-related hospitalization.

Patients and Methods

We identified 8,745 patients age ≥ 18 years from a medical and pharmacy claims database for 14 commercial US health plans. This retrospective analysis included patients with breast cancer who began first-cycle chemotherapy from 2008 to 2013 using docetaxel and cyclophosphamide (TC); docetaxel, carboplatin, and trastuzumab (TCH); or doxorubicin and cyclophosphamide (conventional-dose AC) regimens. Primary prophylaxis (PP) was defined as G-CSF administration within 5 days of beginning chemotherapy. Outcome was neutropenia, fever, or infection-related hospitalization within 21 days of initiating chemotherapy. Multivariable regressions and number-needed-to-treat analyses were used.

Results

A total of 4,815 patients received TC (2,849 PP; 1,966 no PP); 2,292 patients received TCH (1,444 PP; 848 no PP); and 1,638 patients received AC (857 PP; 781 no PP) regimen. PP was associated with reduced risk of neutropenia-related hospitalization for TC (2.0% PP; 7.1% no PP; adjusted odds ratio [AOR], 0.29; 95% CI, 0.22 to 0.39) and TCH (1.3% PP; 7.1% no PP; AOR, 0.19; 95% CI, 0.12 to 0.30), but not AC (4.7% PP; 3.8% no PP; AOR, 1.21; 95% CI, 0.75 to 1.93) regimens. For the TC regimen, 20 patients (95% CI, 16 to 26) would have to be treated for 21 days to avoid one neutropenia-related hospitalization; with the TCH regimen, 18 patients (95% CI, 13 to 25) would have to be treated.

Conclusion

Primary G-CSF prophylaxis was associated with low-to-modest benefit in lowering neutropenia-related hospitalization in patients with breast cancer who received TC and TCH regimens. Further evaluation is needed to better understand which patients benefit most from G-CSF prophylaxis in this setting.