Durvalumab Treatment Patterns for Patients with Unresectable Stage III Non-Small Cell Lung Cancer in the Veterans Health Administration (VHA): A Nationwide, Real-World Study

BACKGROUND

Durvalumab is approved for the treatment of adults with unresectable stage III non-small cell lung cancer (NSCLC) post-chemoradiotherapy (CRT). This real-world study describes patient characteristics and durvalumab treatment patterns (number of doses and therapy duration; treatment initiation delays, interruptions, discontinuations, and associated reasons) among VHA-treated patients.

METHODS

This was a retrospective cohort study of adults with unresectable stage III NSCLC receiving durvalumab at the VHA between 1 January 2017 and 30 June 2020. Patient characteristics and treatment patterns were presented descriptively.

RESULTS

A total of 935 patients were included (median age: 69 years; 95% males; 21% Blacks; 46% current smokers; 16% ECOG performance scores ≥ 2; 50% squamous histology). Durvalumab initiation was delayed in 39% of patients (n = 367). Among the 200 patients with recorded reasons, delays were mainly due to physician preference (20%) and CRT toxicity (11%). Overall, patients received a median (interquartile range) of 16 (7-24) doses of durvalumab over 9.0 (2.9-11.8) months. Treatment interruptions were experienced by 19% of patients (n = 180), with toxicity (7.8%) and social reasons (2.6%) being the most cited reasons. Early discontinuation occurred in 59% of patients (n = 551), largely due to disease progression (24.2%) and toxicity (18.2%).

CONCLUSIONS

These real-world analyses corroborate PACIFIC study results in terms of the main reasons for treatment discontinuation in a VHA population with worse prognostic factors, including older age, predominantly male sex, and poorer performance score. One of the main reasons for durvalumab initiation delays, treatment interruptions, or discontinuations was due to toxicities. Patients could benefit from improved strategies to prevent, identify, and manage CRT and durvalumab toxicities timely and effectively.

Health Equity in Patients Receiving Durvalumab for Unresectable Stage III Non-Small Cell Lung Cancer in the US Veterans Health Administration

BACKGROUND

Real-world evidence is limited regarding the relationship between race and use of durvalumab, an immunotherapy approved for use in adults with unresectable stage III non-small cell lung cancer (NSCLC) post-chemoradiotherapy (CRT). This study aimed to evaluate if durvalumab treatment patterns differed by race in patients with unresectable stage III NSCLC in a Veterans Health Administration (VHA) population.

MATERIALS AND METHODS

This was a retrospective analysis of White and Black adults with unresectable stage III NSCLC treated with durvalumab presenting to any VHA facility in the US from January 1, 2017, to June 30, 2020. Data captured included baseline characteristics and durvalumab treatment patterns, including treatment initiation delay (TID), interruption (TI), and discontinuation (TD); defined as CRT completion to durvalumab initiation greater than 42 days, greater than 28 days between durvalumab infusions, and more than 28 days from the last durvalumab dose with no new durvalumab restarts, respectively. The number of doses, duration of therapy, and adverse events were also collected.

RESULTS

A total of 924 patients were included in this study (White = 726; Black = 198). Race was not a significant factor in a multivariate logistic regression model for TID (OR, 1.39; 95% CI, 0.81-2.37), TI (OR, 1.58; 95% CI, 0.90-2.76), or TD (OR, 0.84; 95% CI, 0.50-1.38). There were also no significant differences in median (interquartile range [IQR]) number of doses (White: 15 [7-24], Black: 18 [7-25]; P = .25) or median (IQR) duration of therapy (White: 8.7 months [2.9-11.8], Black: 9.8 months [3.6-12.0]; P = .08), although Black patients were less likely to experience an immune-related adverse event (28% vs. 36%, P = .03) and less likely to experience pneumonitis (7% vs. 14%, P < .01).

CONCLUSION

Race was not found to be linked with TID, TI, or TD in this real-world study of patients with unresectable stage III NSCLC treated with durvalumab at the VHA.

Durvalumab real-world treatment patterns and outcomes in patients with stage III non-small-cell lung cancer treated in a US community setting

Background: For eligible patients with unresectable stage III non-small-cell lung cancer, durvalumab consolidation therapy following chemoradiotherapy is the standard of care. Methods: This was a retrospective study of durvalumab-treated patients diagnosed between 1 August 2017 and 29 February 2020. Electronic health record data were assessed descriptively, with Kaplan-Meier methods used for duration of treatment and overall survival (OS). Results: Among 528 patients (median age 70 years, 51.5% male), the median duration of treatment was 7.1 months (95% CI: 6.0-9.0). Estimated 1- and 2-year OS rates were 83.5 and 64.0%, respectively, with median OS not reached. Conclusion: This study confirmed an OS benefit with durvalumab after chemoradiotherapy in a real-world setting, consistent with the results from the PACIFIC phase III clinical trial.

Racial disparities in the clinical use of durvalumab for patients with stage III unresectable non–small cell lung cancer treated at Veterans Health Administration facilities

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Background: Evidence from the PACIFIC study and real-world data highlight the benefit of durvalumab in patients with stage III unresectable non-small cell lung cancer (UR-NSCLC). However, limited literature exists regarding disparities in durvalumab treatment patterns such as treatment initiation delays (TID), treatment interruptions (TI), number of doses, duration of therapy (DOT), adverse effects (AEs), and treatment discontinuation (TD) in minority populations. Methods: Patients with stage III UR-NSCLC and a self-reported racial identity of Black or White treated with durvalumab following chemoradiotherapy (CRT) at any Veterans Health Administration (VHA) facility from January 1, 2017 to June 30, 2020 were included. Patients were followed from their date of durvalumab initiation through the earliest of their last VHA visit, loss to follow up, death, or end of the study; therefore, all patients had the opportunity to be treated for 12 months. Patients were excluded if durvalumab therapy was ongoing at the end of the study. Patient charts were retrospectively reviewed for baseline characteristics and durvalumab treatment patterns including TID (>42 days from end of CRT to durvalumab start), TI (>28 days between doses), number of doses, DOT, AEs, and TD. Nominal variables were compared using chi-square/Fisher’s exact tests. Continuous variables were compared using Student’s t-tests/Wilcoxon Rank Sum tests. Results: Among 924 patients, Black patients were younger than White patients (median age 67 years [IQR, 63-71] vs. 70 years [IQR, 65-73]; p<0.01), more likely to be current smokers (54% vs. 45%; p=0.03), with more chronic liver disease (22% vs. 9%; p<0.01), but less COPD (63% vs. 72%; p=0.01). Black patients experienced more TI (25% vs. 18%; p=0.03) but TID, number of doses, DOT, and TD were similar between the groups. Black patients were less likely to have an immune-related AE (irAE) (28% vs. 36%; p=0.03) (and less pneumonitis (7% vs. 14%; p<0.01)). Toxicity was the reason for TD in 12% of Black patients vs. 20% of White patients (p=0.01), with no other significant (α < 0.05) differences in reported reasons for TID, TI, or TD between the groups. Conclusions: In this real-world study, Black patients experienced similar TID, number of doses, and DOT as White patients. Black patients were less likely to experience an irAE (including pneumonitis) but experienced more TI; TD were similar but more likely to be from toxicity for White patients. Future research is needed to validate these findings.[Table: see text]

Treatment interruptions and discontinuations among patients with stage III unresectable non–small cell lung cancer treated with durvalumab at the Veterans Health Administration

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Background: The PD-1/PD-L1 pathway is a mechanism of immune evasion and disruption of this pathway with immune checkpoint inhibitors (ICIs) has shown clinical benefit in multiple malignancies. Based on results from the PACIFIC trial, durvalumab is approved as consolidation therapy in patients (pts) with stage III unresectable non-small cell lung cancer (UR-NSCLC) without progression following concurrent chemoradiotherapy (cCRT). Durvalumab has been used extensively in Veterans Health Administration (VHA) facilities, providing an opportunity to evaluate durvalumab treatment interruptions (TI), treatment discontinuations (TD), and the reasons for these on a national scale. Methods: Patients with stage III UR-NSCLC receiving durvalumab consolidation immunotherapy at the VHA between January 1, 2017 and June 30, 2020 with a minimum follow up for 12 months were included using ICD-10, HCPCS, and J codes and followed from their durvalumab start date through the earliest of last VHA visit, loss to follow up, death, or end of study (excluded if durvalumab therapy was ongoing at the end of the study, because the full treatment course could not be determined). TI were defined as durvalumab infusions separated by >28 days. Reasons for TI and TD are presented descriptively. Durations are reported using medians and interquartile ranges (IQR). Results: 935 pts were included (median age = 69 years; 95% males; 96% current or former smokers; 70% with COPD; histologies [squamous (50%), non-squamous (43%), other/missing (7%)]; and 77% with carboplatin-paclitaxel as their platinum-based CRT). Durvalumab TI were experienced by 19% of pts (median [IQR] number of TI = 1 [1-1], median [IQR] TI duration = 53 days [39-90]). The main reasons for TI were toxicity (8%) and social reasons (3%) (Table). The median duration of treatment (DoT) with durvalumab (TI included) was 9.0 months (IQR 2.9-11.8). Durvalumab TD occurred in 59% of pts. Top reasons for discontinuation across all 935 pts included disease progression (24%) and toxicity (18%) (Table). Conclusions: In this real world analysis of national VHA data, durvalumab DoT was similar to PACIFIC despite having a patient population with worse prognostic factors (e.g. more males, squamous, COPD) with 8% of VHA pts experiencing TI and 18% TD due to toxicity. Patients could benefit from additional efforts to prevent, identify, and manage toxicities in the UR-NSCLC population [Table: see text]

Durvalumab treatment initiation delays in patients with unresectable stage III non–small cell lung cancer treated at Veterans Health Administration facilities

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Background: Durvalumab is an FDA-approved immunotherapy for the treatment of adults with UnResectable stage III non-small cell lung cancer (UR-NSCLC) without disease progression following concurrent chemoradiotherapy (CRT). There are limited real-world data regarding Durvalumab treatment initiation delays (TIDs) and reasons for them in the UR-NSCLC population. Methods: Patients with stage III UR-NSCLC receiving consolidation Durvalumab at the Veterans Health Administration (VHA) between January 1, 2017 and June 30, 2020 were selected from the VHA database using ICD-10, HCPCS, and J codes. All had the opportunity to be treated for 12 months and were followed from Durvalumab initiation through the earliest of their last VHA visit, loss to follow up, death, or the study’s end (and excluded if Durvalumab therapy was ongoing at the study’s end). Trained data abstractors determined the occurrence and reasons for TIDs (> 6 weeks from end of CRT to initiation of Durvalumab as in the PACIFIC trial) by chart review. Results: 935 patients were eligible for analysis (median age = 69 years; 95% males; 16% with ECOG performance status >1). TIDs occurred in 39% of the patients (Table). Durvalumab was initiated 61 days (median) from the end of CRT in TID patients vs. 31 days for those without TIDs. There were no significant (α<0.05) differences in age, race, smoking status, histology, or ECOG performance status and no comorbidity differences (except in patients with a history of cerebrovascular accident, for whom TIDs were more likely) between the TID/No-TID patients. Patients without timely post-CRT scans were more likely to have a TID. Of the 367 patients who experienced TIDs, 200 had documented reasons for the delay, consisting of other (not categorized) (28.5%), physician preference (20%), toxicity (11%), patient preference (10.5%), decline in performance status (10%), system issues (9.5%), social reasons (9%), and progression (0.5%). Conclusions: This is one of the largest retrospective cohort studies reporting real-world data in patients with UR-NSCLC receiving Durvalumab. TIDs were associated with increased time to post-CRT scans. This potential issue can be improved with care coordination and involvement of cancer navigators. Additional studies are needed to assess the impact of TIDs on survival outcomes.[Table: see text]

Patient and Caregiver Preferences for First-Line Treatments of Metastatic Non-Small Cell Lung Cancer: A Discrete Choice Experiment

PURPOSE

The approval of immune checkpoint inhibitors for metastatic non-small-cell lung carcinomas (mNSCLC) treatment has presented more care options. Therefore, it is important to identify the benefit-risk trade-offs patients and caregivers are willing to make among potential treatment options. This study quantified the preferences of patients and caregivers for attributes of mNSCLC treatment.

METHODS

Patients with mNSCLC and caregivers completed an online survey assessing preferences using a discrete choice experiment. Respondents chose between hypothetical treatment profiles, with varying levels for 7 attributes associated with first-line treatment, including overall survival (OS), progression-free survival, select adverse events (AEs), and regimen (caregivers). Hierarchical Bayesian modeling was used to estimate attribute-level preference weights.

RESULTS

Patients (n = 308) and caregivers (n = 166) most valued increasing OS from 11 to 30 months, followed by decreasing the risk of a serious AE (grade 3/4) that may lead to hospitalization from 70% to 18%. These attributes were over twice as important to both sets of respondents as the other attributes measured. Patients and caregivers would accept increases in the risks of a serious AE (grade 3/4) from 18% to 70% and all grades nausea from 10% to 69% if OS increased by 16.8 and 4.0 months, respectively. The least valued attributes were all grades of pneumonitis (patients) and all grades of skin rash (caregivers).

CONCLUSION

Patients and caregivers are willing to make trade-offs between efficacy and toxicity and may require up to 1.5 years of increased OS to accept a higher risk of AEs. These results can provide guidance to oncologists when engaging in shared-decision making discussions.

Update of Incidence, Prevalence, Survival, and Initial Treatment in Patients With Non-Small Cell Lung Cancer in the US

Importance

Updated estimates of non-small cell lung cancer (NSCLC) in the US are needed.

Objective

To calculate the most recent epidemiologic estimates of NSCLC in the US.

Design, Setting, and Participants

This cross-sectional epidemiological analysis used the most recently released data from US cancer registries. The population-based US Cancer Statistics (USCS) database (2010-2017), comprised of the Surveillance, Epidemiology, and End Results (SEER) program and the National Program of Cancer Registries (NPCR) (collectively, SEER-NPCR) provided the NSCLC incidence estimate. The SEER-18 database provided data for incidence, prevalence, survival, and initial treatment by NSCLC stage. Adults aged 18 years or older diagnosed with NSCLC identified by International Classification of Diseases for Oncology, Third Edition, morphology codes were included.

Main Outcomes and Measures

Annual age-adjusted NSCLC incidence per 100 000 persons; annual prevalence per 100 000 persons; survival rate; initial treatment. Due to database release delays, incidence data were available through 2017, and other parameters through 2016. The analysis was conducted from June 2020 to July 2020.

Results

There were 1.28 million new NSCLC cases recorded during 2010 to 2017 in the US (SEER-NPCR: 53% male; 67% ≥ 65 years). From 2010 to 2017, NSCLC incidence per 100 000 decreased from 46.4 to 40.9 overall (age <65 years: 15.5 to 13.5; age ≥65 years: 259.9 to 230.0); the incidence of stage II, IIIA, and IIIB NSCLC was stable, and stage IV decreased slightly from 21.7 to 19.6, whereas stage I incidence increased from 10.8 to 13.2. From 2010 to 2016, NSCLC prevalence per 100 000 increased from 175.3 to 198.3 (nationwide projection of SEER-18); prevalence increased among younger patients (77.5 to 87.9) but decreased among older patients (825.1 to 812.4). Period survival analysis found that 26.4% of patients survived 5 years, which is higher than previously reported. The proportion of stage I NSCLC treated with radiation as single initial treatment rose markedly from 14.7% in 2010 to 25.7% in 2016. Patients with stage IV NSCLC aged 65 years or older were most likely to be untreated (38.3%).

Conclusions and Relevance

The findings of this cross-sectional epidemiological analysis suggest that the increased incidence of stage I NSCLC at diagnosis likely reflected improved evaluation of incidental nodules. A smaller proportion of patients aged 65 years or older with stage IV NSCLC were treated. Earlier detection and availability of effective treatments may underlie increased overall NSCLC prevalence, and higher than previously reported survival.

Durvalumab consolidation therapy following chemoradiotherapy among patients with unresectable stage III non-small cell lung cancer (NSCLC) treated in a U.S. community oncology network

295

Background: While the introduction of durvalumab consolidation therapy shifted the treatment paradigm for unresectable stage III NSCLC, few studies have examined real-world use of durvalumab in this patient population. Methods: This was a retrospective study of adult patients diagnosed with unresectable Stage III NSCLC between 8/1/2017-2/29/2020 who received chemoradiotherapy (CRT) followed by durvalumab consolidation therapy in The US Oncology Network. Structured electronic health record (EHR) data was used to screen for potentially eligible patients who received durvalumab consolidation. Through a targeted chart review, patients’ eligibility was verified. Study variables on patient demographics, clinical characteristics, CRT and durvalumab treatment patterns were sourced from structured and unstructured EHR data. Results: Among 1,626 patients who received CRT during the study observation period and were screened through structured records, 851 (52.3%) of these patients received durvalumab. Through chart review, 528 patients were verified to be eligible for this analysis (median age 70 years, 51.5% male, 18% Eastern Cooperative Oncology Group performance status [ECOG PS] score of 0, 59% with an ECOG PS score of 1). Across the study population, 73.9% received a total radiation dose between 54 and 66 Gy, with the rest receiving higher doses (6.5%), lower doses (3.2%) or doses not documented (15.8%). The mean and median time from end of radiation to post-CRT scan were 41 and 36 days, respectively; the mean and median time from end of radiation to durvalumab initiation were 58 and 47 days, respectively, with 57% of patients initiating durvalumab > 42 days. At the end of study observation period (median follow-up duration of 46.9 weeks), 173 of 528 patients (32.7%) were still actively receiving durvalumab treatment, 98 (18.6%) had completed planned treatment and 257 (48.7%) had discontinued treatment due to progression (18.2%), adverse events (17.2%), death (5.3%) or other reasons (8%). Conclusions: These results provide insights into real-world use of the PACIFIC regimen in a community setting with an older and more fragile population. Radiation therapy doses administered during CRT were largely consistent with the PACIFIC trial. There were delays in time to post-CRT scan and durvalumab initiation, with more than half of patients starting durvalumab > 42 days after CRT. These findings highlight opportunities for quality improvement measures in this population.

Treatment Decision Drivers in Stage III Non-Small-Cell Lung Cancer: Outcomes of a Web-Based Survey of Oncologists in the United States

PURPOSE

We conducted a cross-sectional survey of practicing medical oncologists in the United States to obtain insight into physician and patient treatment decision making in stage III non-small-cell lung cancer (NSCLC).

METHODS

A convenience sample of 150 oncologists completed a 38-question Web-based survey in January 2019.

RESULTS

Surveyed oncologists (82% community based) had an average of 15 years of clinical experience and had treated an average of 20 patients newly diagnosed with stage III NSCLC in the previous 6 months. Oncologists reported presenting 55% of their patients with stage III NSCLC to tumor boards. For patients with new unresectable stage III NSCLC seen in the previous 6 months, concurrent chemoradiation therapy (cCRT) was reported as the initial treatment in an average of 48% of patients. The most frequent reason for delays in starting the initial chosen treatment was insurance preauthorization processes (reported by 65% of oncologists). A total of 55% of all patients with unresectable stage III NSCLC who received cCRT went on to receive consolidation immunotherapy; for patients who received consolidation chemotherapy after cCRT, the rate of immunotherapy was lower (42%). Biomarker test results were given as the reason for oncologists not recommending immunotherapy after cCRT in approximately a quarter of cases. The 112 oncologists with eligible patients who declined immunotherapy reported previous treatment fatigue as the reason in 34% of patients and insurance challenges in 19% of patients.

CONCLUSION

Oncologists reported notable deviations from treatment guidelines for stage III NSCLC. Our findings highlight important opportunities to improve decision making and the coordination of care in stage III NSCLC.

Oncologist decision drivers in stage III non-small cell lung cancer: Outcomes of a web-based survey

35

Background: Clinical guidelines seek to optimize patient care. We investigated how oncologists manage stage III non-small cell lung cancer (NSCLC) patients from diagnosis through treatment decision-making and drivers impacting guideline adherence. Methods: A sample of US medical oncologists (n=150) participated in a 38-question, 25-min web-based quantitative survey in January 2019. Participation required at least 3 yrs in practice and 3 stage III NSCLC patients treated in the prior 6-mo period. Results: Surveyed oncologists (82% community; 18% academic), on average, had 15 yrs of clinical experience and treated 20 stage III NSCLC patients in the prior 6 mos. Time from first treatment decision to initiation averaged >2–4 wks in 31% and >4 wks in 20% of patients, respectively. Oncologists recommend definitive concurrent chemoradiation therapy (cCRT) in 48% of unresectable stage III NSCLC patients. Reasons for not recommending cCRT include patient unlikely to tolerate cCRT (64% of oncologists), presence of a targetable mutation (41%), patient inability to travel consistently to receive treatment/inconvenient dosing (41%), and patient cost/affordability (34%). Eighteen percent of unresectable stage III NSCLC patients decline recommended cCRT. Fifty-five percent of patients who receive cCRT go on to receive consolidation immunotherapy (IO). Insurance challenges led to oncologists not recommending consolidation IO in 19% of patients. In the 85% of oncologists who conduct EGFR or PD-L1 testing, positive EGFR or negative PD-L1 tests are reasons for not recommending consolidation IO in 27% of patients (12% and 15%, respectively). Over half (55%) of unresectable stage III NSCLC patients who receive definitive cCRT also receive consolidation chemotherapy, which is no longer recommended in guidelines. Patients receiving consolidation CT were less likely to receive consolidation IO than the overall cohort of patients receiving cCRT (42% vs. 55%). Conclusions: Oncologists reported important variances in guidelines and standards of care related to the stage III NSCLC patient treatment journey. While some deviations from both are expected, there may be areas of focus for quality improvement initiatives.

Changing treatment patterns in patients with stage IV non-small cell lung cancer (NSCLC) from United States community-based oncology practices

13

Background: This study evaluated the shift in treatment patterns in Stage IV NSCLC following the approval of immune-oncology (IO) agents in the US. Methods: A retrospective cohort study was performed using structured data from a US community-based oncology electronic medical record (EMR) database for care received from Jan 2015-May 2018. The study sample included patients with Stage IV NSCLC, ≥18 years of age initiating first-line (1L) treatment with chemotherapy (chemo) or IO agents and classified into 3 groups: chemo alone, IO alone, or chemo+IO. Treatment patterns in 1L and treatment switch patterns in second-line (2L) are reported. A sub-group analysis of patients initiating 1L therapy during the last 6 months of the study period (Dec 2017-May 2018) was conducted to explore changes in 1L treatment patterns in the post-IO approval setting. Chart reviews were done for a subset of patients initiating 1L from Jan 2017-May 2018 to extract information on programmed cell death ligand 1 (PD-L1) testing and evaluate the association of PD-L1 expression levels with receipt of IO therapy. Results: Between Jan 2015-May 2018, 1,969 patients received 1L therapy with a chemo or IO agent. Mean age (SD) was 69.0 (10.1) years, with 44.7% female. The majority of patients (79%, n = 1570) initiated 1L therapy with chemo alone and 21% initiated IO (alone [14%, n = 271] or in combination with chemo [7%, n = 128]). Of 1L patients, 41% (n = 809) were treated with 2L therapy. Of the 1L chemo alone group, 37% (n = 580) received IO in 2L. The use of IO agents in 1L increased from 21% to 48% (n = 147) in the sub-group analysis of 305 patients initiating therapy Dec 2017-May 2018. In the subset of 62 patients whose charts were reviewed, 87% (n = 54) had their tumor tested for PD-L1, of which 37% (n = 20) had high (≥50%) expression values. The majority of high-PD-L1 patients were treated in 1L with IO alone (80%, n = 16), followed by chemo+IO (15%; n = 3), and only 5% (n = 1) received chemo alone. Conclusions: Initially, IO was used as 2L treatment for Stage IV NSCLC, but IO use shifted to 1L setting in the US by the end of 2017. The use of IO therapy alone or with chemotherapy in 1L was more likely in patients with ≥50% PD-L1 expression level.

A phase 1 study of efatutazone, an oral peroxisome proliferator-activated receptor gamma agonist, administered to patients with advanced malignancies

BACKGROUND

Efatutazone (CS-7017), a novel peroxisome proliferator-activated receptor gamma (PPARγ) agonist, exerts anticancer activity in preclinical models. The authors conducted a phase 1 study to determine the recommended phase 2 dose, safety, tolerability, and pharmacokinetics of efatutazone.

METHODS

Patients with advanced solid malignancies and no curative therapeutic options were enrolled to receive a given dose of efatutazone, administered orally (PO) twice daily for 6 weeks, in a 3 + 3 intercohort dose-escalation trial. After the third patient, patients with diabetes mellitus were excluded. Efatutazone dosing continued until disease progression or unacceptable toxicity, with measurement of efatutazone pharmacokinetics and plasma adiponectin levels.

RESULTS

Thirty-one patients received efatutazone at doses ranging from 0.10 to 1.15 mg PO twice daily. Dose escalation stopped when maximal impact on PPARγ-related biomarkers had been reached before any protocol-defined maximum-tolerated dose level. On the basis of a population pharmacokinetic/pharmacodynamic analysis, the recommended phase 2 dose was 0.5 mg PO twice daily. A majority of patients experienced peripheral edema (53.3%), often requiring diuretics. Three episodes of dose-limiting toxicities, related to fluid retention, were noted in the 0.10-, 0.25-, and 1.15-mg cohorts. Of 31 treated patients, 27 were evaluable for response. A sustained partial response (PR; 690 days on therapy) was observed in a patient with myxoid liposarcoma. Ten additional patients had stable disease (SD) for ≥60 days. Exposures were approximately dose proportional, and adiponectin levels increased after 4 weeks of treatment at all dose levels. Immunohistochemistry of archived specimens demonstrated that PPARγ and retinoid X receptor expression levels were significantly greater in patients with SD for ≥60 days or PR (P = .0079), suggesting a predictive biomarker.

CONCLUSIONS

Efatutazone demonstrates acceptable tolerability with evidence of disease control in patients with advanced malignancies.

Abstract A128: A phase I study of liposomal-encapsulated docetaxel (LE-DT) in patients with advanced solid tumor malignancies

Background: Docetaxel is a semi-synthetic microtubule disrupting antineoplastic drug indicated for the treatment of a wide variety of solid tumor malignancies. Past clinical trials have shown a dose-response correlation when used in the treatment of prostate and breast cancer. Common dose limiting toxicities are myelosuppression and neuropathy. Liposomes are versatile drug carriers that may increase drug solubility, serve as sustained release systems, provide protection from drug degradation and drug related toxicities, and help overcome multidrug resistance mediated by P-glycoprotein or similar resistant efflux mechanisms. The aims of this phase I study were to determine the maximum tolerated dose (MTD), dose limiting toxicities (DLTs), pharmacokinetics (pK), and clinical response of LE-DT in patients with advanced solid tumor malignancies.

Methods: LE-DT was administered using a standard 3+3 dose escalation schema with dose levels of 50, 65, 85, 110, and 132 mg/m2. Drug was infused over 1 hour. Premedication with dexamethasone was not required as it is with standard docetaxel therapy. In patients who experienced infusionrelated reactions pre-medication with steroids, antihistamines, and antipyretics were provided in subsequent cycles. Toxicities were recorded using NCI-CTCAE 3.0, and response was assessed using RECIST criteria. PK samples were drawn during C1 and analyzed using Win NonLin.

Results: Twenty-four patients were treated in total. The total number of cycles each patient received ranged from 1 to 21 (median = 4). Dose escalation proceeded until DLTs were experienced by 2 out of 2 patients at the 132mg/m2 dose level (both Grade 4 neutropenia). When additional patients were treated at the 110 mg/m2 dose, 2 patients experienced Grade 4 neutropenia. The dose level was reduced to 85mg/m2, with one patient experiencing Grade 4 neutropenia at this level. The protocol was amended to allow G-CSF growth factor support and dose re-escalation. An additional 4 patients were treated at 110mg/m2 and none of these patients experienced Grade 4 neutropenia. At this dose level, two patients experiencing Grade 3 fatigue. No patient experienced Grade 3/4 neuropathy, even in two patients treated for 10 and 21 cycles. Two patients experienced Grade 2 neuropathy. Additional toxicities included Grade 3 anemia in three patients. Drug pharmacokinetics followed a two-compartment elimination pattern. Cmax and AUCinf were proportional to dose through the 110mg/m2 dose level with a mean clearance of 28.5L/hr/m2. At the 132mg/m2 dose Cl was 45.4 L/hr/m2. Serum half-lives at the differing dose levels ranged from 15.1 to 22.4 hr. There was no correlation between pK measures and toxicity. One patient had a confirmed partial response (PR) and another had an unconfirmed PR (8%). Eight patients (33%) had prolonged stable disease lasting more than 3 months. One patient continues to have stable disease after 21 cycles.

Conclusion: LE-DT was tolerable with expected toxicities of neutropenia, anemia, and fatigue, but without water retention (edema). Importantly, in this heavily pretreated population no patient experienced clinically significant neuropathy. Clinical benefit (SD+PR) was observed in 41% of the patients. The recommended phase II dose of LE-DT is 110mg/m2 with growth factor support. Phase II studies of LE-DT in prostate and pancreatic cancers are planned.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A128.

A phase I trial of GMX1777, an inhibitor of nicotinamide phosphoribosyl transferase (NAMPRT), given as a 24-hour infusion

3581

Background: GMX1777 is a pro-drug which converts to GMX1778, a potent and specific small molecule inhibitor of NAMPRT, the rate-limiting enzyme in NAD+ synthesis. NAMPRT activity is increased in tumor cells dependent on the glycolytic pathway. The aims of this first-in-man study were to define a dose of GMX1777 administered by 24-hr infusion with acceptable safety for phase II studies, and to determine the pharmacokinetic (PK) parameters of both GMX1777 and GMX1778. Methods: GMX1777 was administered at ascending doses as a 24 hour IV infusion q21 days to successive cohorts of patients with advanced malignancies. Single patient cohorts were utilized until a toxicity >Grade (Gr) 1 was observed during cycle (C) 1; then a standard 3+3 dose escalation schema was used. PK samples were drawn during C1. Results: 19 patients (11 males; median age 57) received doses of 60, 120, 160, 200 or 140 mg/m2 over 24 hours. 49 doses were administered. There were no toxicities >Gr 1 during C1 at 60 mg/m2; however Gr 2 toxicities were observed at 120 mg/m2 and the cohort was expanded to 3 patients. Gr 4 GI hemorrhage and Gr 4 thrombocytopenia occurred at 200 mg/m2, leading to expansion of the 160 mg/m2 cohort. 3/6 patients at 160 mg/m2 had erythematous symmetrical Gr 3 rash occur during C2–5. Six patients enrolled at 140 mg/m2 had no Gr 3 rash and 140 mg/m2 was determined to be the MTD. Preliminary data indicate that the most common (>30%) adverse events of all grades were nausea (89%), diarrhea (79%), fatigue (68%), vomiting (58%), anorexia (42%), pruritis (42%), thrombocytopenia (42%), rash (37%), anemia (32%), constipation (32%), dyspnea (32%), and insomnia (32%). Lab findings include lymphopenia. Two patients had stable disease for > 4 cycles (6 & 4 mos), and 3 additional patients had SD for ≥ 3 mos. Preliminary PK data document rapid conversion of GMX1777 to GMX1778 at all dose levels. Conclusions: The MTD for GMX1777 administered as a 24 hour infusion q21 days is 140 mg/m2. Thrombocytopenia, GI hemorrhage, and skin rash (the last occurring after multiple cycles) were encountered at higher doses. Single-agent GMX1777 exhibited moderate clinical activity, suggesting that inhibition of NAMPRT should be explored in other schedules or in combination with other agents.

[Table: see text]

Comparison of mouse mammary gland imaging techniques and applications: reflectance confocal microscopy, GFP imaging, and ultrasound

Background

Genetically engineered mouse models of mammary gland cancer enable the in vivo study of molecular mechanisms and signaling during development and cancer pathophysiology. However, traditional whole mount and histological imaging modalities are only applicable to non-viable tissue.

Methods

We evaluated three techniques that can be quickly applied to living tissue for imaging normal and cancerous mammary gland: reflectance confocal microscopy, green fluorescent protein imaging, and ultrasound imaging.

Results

In the current study, reflectance confocal imaging offered the highest resolution and was used to optically section mammary ductal structures in the whole mammary gland. Glands remained viable in mammary gland whole organ culture when 1% acetic acid was used as a contrast agent. Our application of using green fluorescent protein expressing transgenic mice in our study allowed for whole mammary gland ductal structures imaging and enabled straightforward serial imaging of mammary gland ducts in whole organ culture to visualize the growth and differentiation process. Ultrasound imaging showed the lowest resolution. However, ultrasound was able to detect mammary preneoplastic lesions 0.2 mm in size and was used to follow cancer growth with serial imaging in living mice.

Conclusion

In conclusion, each technique enabled serial imaging of living mammary tissue and visualization of growth and development, quickly and with minimal tissue preparation. The use of the higher resolution reflectance confocal and green fluorescent protein imaging techniques and lower resolution ultrasound were complementary.

Understanding breast cancer risk -- where do we stand in 2005?

Breast cancer is the most frequent cancer in women and represents the second leading cause of cancer death among women (after lung cancer). The etiology of breast cancer is still poorly understood with known breast cancer risk factors explaining only a small proportion of cases. Risk factors that modulate the development of breast cancer discussed in this review include: age, geographic location (country of origin) and socioeconomic status, reproductive events, exogenous hormones, lifestyle risk factors (alcohol, diet, obesity and physical activity), familial history of breast cancer, mammographic density, history of benign breast disease, ionizing radiation, bone density, height, IGF- 1 and prolactin levels, chemopreventive agents. Additionally, we summarized breast cancer risk associated with the following genetic factors: breast cancer susceptibility high-penetrance genes (BRCA1, BRCA2, p53, PTEN, ATM, NBS1 or LKB1) and low-penetrance genes such as cytochrome P450 genes (CYP1A1, CYP2D6, CYP19), glutathione S-transferase family (GSTM1, GSTP1), alcohol and one-carbon metabolism genes (ADH1C and MTHFR), DNA repair genes (XRCC1, XRCC3, ERCC4/XPF) and genes encoding cell signaling molecules (PR, ER, TNFalpha or HSP70). All these factors contribute to a better understanding of breast cancer risk. Nonetheless, in order to evaluate more accurately the overall risk of breast tumorigenesis, novel genetic and phenotypic traits need to be identified.

Stat5a is tyrosine phosphorylated and nuclear localized in a high proportion of human breast cancers

Signal transducers and activators of transcription (STATs) are latent cytoplasmic transcription factors that are activated and translocated into the nucleus after phosphorylation at a conserved tyrosine residue. Mouse model studies have demonstrated that activated Stat5a acts as a critical survival factor for normal, preneoplastic and malignant mammary epithelial cells. Very limited information is available, however, on the expression, tyrosine phosphorylation status and nuclear localization of Stat5a in human breast cancers. In our study, the pattern of Stat5a cellular localization was analyzed by immunohistochemistry in a series of 83 randomly selected primary human breast adenocarcinomas. Immunoprecipitation/Western blotting and immunohistochemistry assays employing different phospho-specific antibodies verified Stat5a tyrosine phosphorylation status. Stat5a was nuclear localized and tyrosine phosphorylated in 59 of 78 (76%) breast cancers examined; 38 of 78 (49%) demonstrated Stat5a nuclear localization in more than 25% of the breast cancer cells within the adenocarcinomas. Nuclear localized Stat5a was associated positively with increased levels of histologic differentiation (p = 0.03). A statistically significant positive association with p27 nuclear localization also was identified (p = 0.05). No relationship was found between nuclear localized Stat5a and menopausal status, tumor size, ploidy, percentage of cells in S-phase, lymph node metastases, ER, ErbB2, nuclear localized p21 or nuclear localized Stat5b/Stat3. As its role in human breast cancer progression and response to therapy is defined, Stat5a could become a new molecular target for breast cancer therapy.

Conditional over-expression of estrogen receptor alpha in a transgenic mouse model

Attempts to delineate the mechanisms of estrogen action have promoted the creation of several estrogen receptor alpha (ERalpha) mouse models in the past decade. These traditional models are limited by the fact that the receptors are either absent or present throughout all stages of development. The purpose of this work was to develop a conditional transgenic model that would provide an in vivo method of controlling the spatial and temporal regulation of ERalpha expression. The tetracycline responsive system was utilized. Three lines of transgenic mice carrying a transgene composed of the coding sequence for murine ERalpha placed under the regulatory control of a tet operator promoter (tet-op) were generated. These three lines of tet-op-mERa mice were each mated to an established line of transgenic mice expressing a tetracycline-dependent transactivator protein (tTA) from the mouse mammary tumor virus-long terminal repeat (MMTV-LTR). Double transgenic MMTV-tTA/tet-op-mERalpha mice were produced. All three lines demonstrated dominant gain of ERalpha shown by RT-PCR, immunoprecipitation, and immunohistochemistry. Transgene-specific ERalpha was expressed in numerous tissues including the mammary gland, salivary gland, testis, seminal vesicle, and epididymis. Expression was silenced by administration of doxycycline in the drinking water. This model can be utilized to evaluate the consequences of ERalpha dominant gain in targeted tissues at specific times during development. In this study dominant gain of ERalpha was associated with a reduction in epididymal/vas deferens and seminal vesicle weights consistent with the proposed action of ERalpha on fluid transport in the male reproductive tract. Combining this model with other dominant gain and gene knockout mouse models will be useful for testing effects of ERalpha action in combination with specific gene products and to evaluate if developmental and stage-specific expression of ERalpha can rescue identified phenotypes in gene knockout mice.