Abstract P3-15-02: Underreporting of Myelotoxicity with Emerging Breast Cancer Regimens

Background: Although many emerging regimens that incorporate targeted agents may produce increased myelosuppressive side-effects, clinical data guiding colony-stimulating factor (CSF) use with these regimens are not readily available. This review assessed the reporting diligence around febrile neutropenia and the related use of CSF and antibiotics in published clinical trials evaluating emerging regimens for breast cancer treatment.

Methods: We searched Medline, EMBASE, and Cochrane databases to identify randomized, controlled phase 3 breast cancer studies published between Jan 2005 and June 2009. After excluding trials of vaccines, hormonal therapy alone, and stem cell transplantation/mobilization, corresponding publications were retrieved and data extracted on the incidence of neutropenia and its complications and CSF/antibiotic use. We then calculated the percentage of these publications that reported each outcome.

Results: Of 463 trials identified from the search, only 73 met the inclusion criteria. Overall, 70% and 55% of trials reported the incidence of grade 3/4 neutropenia and febrile neutropenia, respectively (Table). Neutropenia-related hospitalizations were reported in 3% of trials. Prophylactic use of CSF and antibiotics was defined in the methods section of 59% and 23% of trials, respectively; and only reported in the results section of 22% and 5% of trials, respectively.

Conclusion: Clinically significant neutropenia and neutropenia-related events (including febrile neutropenia) were generally described in the studies evaluated; however, the reported use of CSF and/or antibiotics was infrequent and inconsistent in the published literature of emerging regimens. A standardized approach to reporting neutropenic outcomes as well as the use of supportive care measures can assist cliniciansto prospectively manage the relevant toxicities associated with these emerging regimens and thereby facilitate their safe and effective use in clinical practice.

Table: Reporting of myelotoxicity data in published phase 3 trials

CSF = colony-stimulating factor

Are comorbidities present in non-Hodgkin's lymphoma (NHL) patients (pts) enrolled in recent clinical trials different from those observed in previous clinical trials?

e19540

Introduction: Co-morbidities are often more prevalent in community practice than in clinical studies due to an increased mortality risk (Kuderer 2006; Noga 2007). As NHL treatments have changed and NHL rates in the US have increased 81% from 1973 to 1997 (Garber 2001), pt characteristics of NHL practice-changing studies may have changed to reflect the general NHL population. Here we summarize major co-morbid conditions present in pts from 4 key NHL trials published from 1976 to 2007. Methods: Intermediate/high-grade NHLs are sensitive to combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP; McKelvey 1974; Fisher 1993), especially when combined with rituximab (RCHOP; Coiffier 2002). Entry criteria and demographics were tabulated from 4 interventional NHL trials published from 1976 to 2007: McKelvey 1976, a randomized study of 420 pts comparing CHOP and HOP; Fisher 1993, a phase 3, randomized study of 899 pts comparing CHOP, m-BACOD, ProMACE-CytaBOM, and MACOP-B; Coiffier 2002, a randomized study of 399 pts comparing CHOP with RCHOP; Noga 2007, an open-label study that included 325 NHL pts in community practice. Results: More recent NHL trials enrolled older pts compared with earlier trials ( Table ). Further, in the community-practice study by Noga et al (2007), nearly 1/3 of treated pts had at least 1 major co-morbidity. Such co-morbidities may have been formally or informally excluded in earlier clinical trials. Conclusions: More recent clinical trials tend to enroll older pts compared with earlier trials and tend to include pts with the major co-morbidities often seen in the general NHL population. Physicians may be more aware that cancer pts often have a significant prevalence of co-morbid conditions and that supportive care may allow these pts to benefit from study treatment. Clinical practice may also be changing to allow more elderly pts with co-morbidities to receive aggressive chemotherapy.

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Pegfilgrastim in colorectal cancer (CRC) patients (pts) receiving every-two-week (Q2W) chemotherapy (CT): Long-term results from a phase II, randomized, controlled study

4072

Background: Survival in advanced CRC is prolonged by adding oxaliplatin (Ox) and/or irinotecan (Iri) to Q2W 5-fluorouracil/leucovorin (5FU/LV). Combination therapy, however, has a higher incidence of febrile neutropenia (FN) and related toxicities. This study evaluated pegfilgrastim dosing on day 4 of Q2W regimens in CRC. Here we present long-term follow-up of these pts. Methods: Advanced CRC pts were randomized (1:1) to pegfilgrastim 6mg or placebo, which was stratified by CT regimen received: FOIL, FOLFOX, or FOLFIRI. We previously reported grade 3/4 neutropenia (primary endpoint) in 43% placebo and 13% pegfilgrastim pts in the 4-cycle treatment phase (odds ratio = 0.19, 95% CI: 0.10–0.37; p < 0.0001). After end of treatment, pts were followed long term for ≤ 2 years (inclusive of ≤ 8 additional cycles) for serious adverse events (SAEs), overall survival (OS), and progression-free survival (PFS). Median follow-up time was 519 days. Kaplan-Meier methods estimated OS and PFS from study day 1. The study was not powered to detect PFS or OS differences between treatment groups. Results: Of 241 pts analyzed (123 pegfilgrastim, 118 placebo), 49% received FOLFOX, 26% FOLFIRI, and 25% FOIL. In the treatment period, 8% placebo and 2% pegfilgrastim pts had grade 3/4 FN ( Table ). Pegfilgrastim was well tolerated with no dose delays attributed to leukocytosis. Pegfilgrastim and placebo had similar PFS and OS ( Table ). No SAEs related to study drug were reported in the follow-up period. Conclusions: In this randomized, placebo-controlled study, pegfilgrastim significantly lowered neutropenic risk. Bone pain incidence in this CRC population was lower than in breast cancer pts treated with a taxane (Vogel J Clin Oncol 2005); the incidence in pegfilgrastim pts was modestly increased over placebo. Leukocytosis was not a concern despite the 11-day dosing interval. Long-term results suggest similar PFS and OS in the pegfilgrastim and placebo pts in this CRC study.

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Exploratory analysis describing ultrasonic (US) evaluation of spleen size during peripheral blood progenitor cell (PBPC) mobilization by filgrastim in normal donors

7102

Background: Filgrastim is used to mobilize CD34+ cells into the peripheral blood that are collected by apheresis for allogeneic transplantation. We prospectively evaluated spleen size during PBPC mobilization Methods: Donors ≥18 yrs eligible to be PBPC donors per institutional guidelines enrolled. Splenic assessments were done before, during, and after PBPC mobilization. Filgrastim dose and schedule and leukapheresis (LK) procedures were per local practice. Spleen size by US was measured in 3 dimensions: longitudinal (craniocaudal), transverse, and diagonal (perpendicular to transverse). Splenic volume was estimated by taking the cross-product of 3 dimensions and multiplying by 0.52, approximating an ellipse volume. Stiff (ASH 2007) reported the primary endpoint, fold change from baseline in splenic volume during mobilization. Exploratory analyses, including a linear regression evaluating the effect of age and baseline spleen size on fold-change, were performed. Results: 309 enrolled, median age 44yrs, 56% male. Median fold volume change from baseline to first LK was 1.47, resolving to near baseline 1 week after last LK. No significant clinical sequelae, including splenic rupture, were reported. Older donors appeared to have the smallest baseline spleen volume and the largest fold change (table). Linear regression analyses indicated age was a significant predictor for both baseline spleen volume (p=0.0031) and spleen volume fold change from baseline at first LK (p=0.0499). Conclusions: During mobilization, spleen volume transiently increased from baseline to day of 1st LK and returned to near baseline 1 week after last LK. Older donors tended to have smaller baseline splenic volume and greater fold changes in spleen size. Preclinical models suggest decreasing hematopoietic stem cell homing after mobilization with aging (Morrison 1996; Wagers 2002), which could result in splenic accumulation of progenitor and stem cells.

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Darbepoetin alfa for treating anemia in low-risk myelodysplastic syndrome patients: Interim results after 27/28 weeks

6564

Background: Patients (pts) with myelodysplastic syndrome (MDS) disorders often develop anemia, resulting in increased transfusions and fatigue. Using the erythropoiesis-stimulating agent (ESA) epoetin alfa to treat anemia in low-risk MDS pts results in an average response rate of 30% (40% when used with G-CSF). Pilot studies suggest that 150 or 300 mcg/week (wk) darbepoetin alfa (DA) can raise hemoglobin (Hb) levels in anemic MDS pts. Methods: This fully enrolled (n = 209), phase 2, single-arm, 52-wk ongoing study is examining DA 500 mcg every 3 weeks (Q3W) for treating anemic pts (Hb ≤ 11 g/dL) with low- or intermediate-risk MDS (IPSS definition). The study’s primary endpoint is the proportion of pts achieving an erythroid response by 13 wks. Other endpoints include the proportion of pts achieving an erythroid response by 27/28 wks and change in both Hb levels and FACT-F scores. Results are stratified by whether pts received ESA therapy before enrollment: ESA-naïve (ESA-N) vs ESA-treated (ESA-T). Results: Previous interim data suggested that low-risk MDS pts can achieve a major erythroid response after 13 wks of DA 500 mcg Q3W. This is the first reported summary of results from a planned interim analysis after 27/28 wks of treatment (n = 129). Of 84 ESA-N pts, 51% were men, 86% were white, and the average (SD) age was 74.1 (9.7) years; the 45 ESA-T pts had similar demographics. During 27/28 wks of treatment, a majority of pts achieved a major erythroid response. ESA-N pts had a mean (SD) 1.2 (1.4) g/dL rise in Hb levels from BL and a clinically significant increase in FACT-F score from BL ( Table ). Of the 129 pts analyzed after 27/28 wks, 83% reported an adverse event (AE) and none reported serious treatment-related AEs or thrombotic events (of 189 pts analyzed after 13 wks, 1 pt reported a serious treatment-related AE). Conclusions: These interim results suggest that DA 500 mcg Q3W is well tolerated and can raise Hb levels in anemic, low-risk MDS pts. Final 27/28-wk data from all enrolled pts (n = 209) will be shown.

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Final results of a large, community-based, prospective study evaluating the impact of first and subsequent cycle pegfilgrastim on neutropenic events in patients receiving myelosuppressive chemotherapy

8569

Background: Neutropenia is the major dose-limiting complication of myelosuppressive chemotherapy (CT). The Awareness of Neutropenia in CT (ANC) Study Group has prospectively documented cycle 1 febrile neutropenia (FN) in 8% of patients (pts) receiving CT with or without growth factor support in community practice. Our study was conducted to assess the impact of first and subsequent cycle pegfilgrastim use on neutropenic events in pts receiving CT in community practice. Interim data were previously reported (Ozer ASCO 2005). Methods: Pts ≥18 years with cancers other than leukemia or MDS were eligible, including pts with major comorbidities. Key exclusion criteria of this open-label study were weekly CT or concurrent radiotherapy (RT). Pts were to receive pegfilgrastim 6 mg ∼24 hours after CT (min 4 cycles planned). Primary endpoints were neutropenic hospitalization and CT dose delays and reductions; additionally, FN (absolute neutrophil count <1×109/L with temperature ≥38.2oC) was measured. Results: 319 centers enrolled 2,249 pts (2,500 planned); 2,112 patients who received CT and pegfilgrastim after proper consent were included in final analyses. Most pts were women (75%). Major tumor types included: breast (46%), lung (16%), and ovarian (8%) cancers, and lymphoma (18%). 36% of pts were ≥65 years (mean age [SD]: 59 [12.8]), 55% had stage 3/4 or extensive disease, 23% received prior CT, 17% received prior RT, and 27% had a significant comorbidity. Neutropenic complications occurred infrequently (table). FN was experienced by 3.6% (95% CL: 2.8, 4.5) of pts in cycle 1 and in 6.3% (5.3, 7.5) in all cycles. Serious adverse events were consistent with toxicities observed in pts receiving CT. Conclusions: Pts treated in community practice receiving pegfilgrastim in every cycle of myelosuppressive CT experienced a low incidence of neutropenic complications and alterations in CT dose and schedule due to neutropenia.

[Table: see text]

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Darbepoetin alfa for treating anemia in patients with low-risk myelodysplastic syndromes: Exploratory analysis of baseline predictors of response

6579

Background: Patients (pts) with myelodysplastic syndromes (MDS) often develop anemia, resulting in fatigue and increased transfusions. The erythropoiesis-stimulating agents (ESAs) epoetin alfa and darbepoetin alfa (DA) can raise hemoglobin (Hb) levels in low-risk MDS pts. Baseline (BL) endogenous erythropoietin (eEPO) levels, transfusion history, and FAB sub-type can be predictive factors of response to ESAs (Hellström-Lindberg et al., 2003). Methods: This is an ongoing, fully enrolled (n = 209), phase 2, single-arm, 52-week (wk) study of DA 500 mcg every three weeks (Q3W) for treating anemia (Hb ≤ 11 g/dL) in low- or intermediate-risk MDS pts. A planned interim analysis was done after 13 wks (n = 189). The primary endpoint is the proportion of pts with an erythroid response by 13 wks. Other endpoints include change in Hb levels and in FACT-F score from BL. Results are stratified by whether pts received an ESA before enrollment: ESA-naïve (ESA-N) pts vs ESA-treated (ESA-T) pts. Exploratory analyses of the percentage of pts with an erythroid response adjusted by BL eEPO or FAB category were done. Results: Of 130 ESA-N pts, 52% were women, 86% were white, 58% had refractory anemia (RA), 34% had RA with ringed sideroblasts (RARS), 8% had RA with excess blasts (RAEB), and the mean (SD) age was 74.8 (10.1) years. The 59 ESA-T pts had similar demographics. A majority of ESA-N pts had an erythroid response, achieved a target Hb of 11 g/dL, and had a clinically significant rise in FACT-F score; ESA-N pts with lower BL eEPO levels were more likely to have a major erythroid response ( Table ). A major erythroid response was seen in 50% of pts with RA (n = 111), in 30% of pts with RARS (n = 64), and in 23% of pts with RAEB (n = 13). Of all 189 pts, 78% had an adverse event (AE), 1 had a serious treatment-related AE (hypertension), and none had thrombotic events. Conclusions: These interim results suggest that FAB sub-type and BL eEPO may affect response. Final 13-wk data from all enrolled pts (n = 209) will be shown.

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A randomized double-blind phase II study to evaluate same-day vs next-day administration of pegfilgrastim with carboplatin and docetaxel in patients with NSCLC

7110

Background: Combination therapy with carboplatin and docetaxel has demonstrated activity against non-small cell lung cancer (NSCLC), but is associated with at least a moderate risk of febrile neutropenia (FN). Though pegfilgrastim is given only once-per-cycle 24 hours after chemotherapy (CT), administering pegfilgrastim on the same day as CT would be convenient for patients (pts). Methods: Pts ≥18 years with previously untreated stage IIIB or IV NSCLC and ECOG ≤2 who were candidates for carboplatin AUC 6 and docetaxel 75 mg/m2 were randomized 1:1 to receive pegfilgrastim 6 mg within 4 hours or approximately 24 hours after CT. The primary endpoint was the duration of grade 4 neutropenia (DSN) in cycle 1. Same-day administration was considered noninferior to next-day if the upper 95% confidence interval (CI) limit for the difference in DSN between groups in cycle 1 was <2 days. Results: As planned, 90 pts were enrolled. 88 pts received blinded study drug. Pts in the same-day and next-day groups had comparable mean baseline ANC and similar proportions of pts completed the study (43% vs 45%). In cycle 1, only 5% of pts in both groups experienced grade 4 neutropenia; resulting in a mean DSN of 0 days. Similarly in cycle 4, 10% (lasting for 1 day only) and 0% of pts in the same-day and next-day groups experienced grade 4 neutropenia. No pts experienced FN during the study. 44% of pts in the same-day and 33% of pts in the next-day group experienced serious adverse events. Conclusions: In this study of lung cancer patients receiving carboplatin and docetaxel, use of pegfilgrastim from the first cycle was well-tolerated in both treatment groups. Although the incidence of grade 3/4 neutropenia was lower than previously reported for this regimen, DSN appeared to be similar for patients in the same-day and next-day groups. Additionally, few patients experienced reductions or delays in CT delivery.

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Randomized, double-blind, phase 2, study evaluating same-day vs next-day administration of pegfilgrastim with R-CHOP in non-Hodgkin’s lymphoma patients

7570

Background: R-CHOP is associated with a high risk of febrile neutropenia (FN). Pegfilgrastim is indicated to lower infection incidence, manifested by FN, when administered once-per-cycle 24 hrs after chemotherapy (CT). However, eliminating an office visit the day after CT is desirable. Methods: Pts ≥ 18 years with previously untreated non-Hodgkin’s lymphoma (NHL) who received R-CHOP (rituximab 375 mg/m2, C 750 mg/m2, H 50 mg/m2, O 1.4 mg/m2, prednisone 100 mg; for 6 cycles Q21D) were randomized 1:1 to pegfilgrastim 6mg within 4 hours or ∼24hrs after CT. The primary endpoint was the duration of severe (grade 4) neutropenia (DSN) in cycle 1. Same-day administration was considered noninferior to next-day if the upper limit of the 2-sided 95% CI for the difference in mean cycle 1 DSN (same day - next day) was <2 days. Results: 77 pts (8 mantle-cell, 69 diffuse large B-cell) were enrolled of 90 planned (due to slow accrual). 75 pts (36 same-day, 39 next-day) received CT and pegfilgrastim. Most pts had stage 3/4 disease (69% same-day, 74% next-day), no bone marrow involvement (75% same-day, 69% next-day) and ECOG status 0 or 1 (94% same-day, 97% next-day). Difference in mean cycle 1 DSN was 0.9 days (95% CI: 0.3–1.4) longer in the same-day than the next-day group (mean [SD]: 2.1 [1.22] vs 1.2 [1.20] days; grade 4 neutropenia incidence: 86% vs 64%). In cycle 1, more pts had a DSN ≥ 3 days in the same-day (36%) than the next-day group (15%). In cycle 4, mean DSN was longer in the same-day than the next-day group (mean [SD] 1.4 [1.40] vs 0.7 [0.94] days; grade 4 neutropenia incidence: 57% vs 42%). Pts in the 2 groups had similar occurrence of FN (17% vs 15%) and serious adverse events (33% vs 36%) across the study. Full dose on schedule, and the incidence of IV anti-infective use or hospitalization due to FN were also similar between groups. Conclusions: In cycles 1 and 4, the mean DSN was nearly 1 day longer for pts in the same-day group compared with the next-day group. Although the protocol-specified 2-day non-inferiority margin for DSN was met, for pts with NHL receiving R-CHOP, we recommend administering pegfilgrastim 24 hours after CT per labeling guidelines.

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Local delivery for gene therapy

Patients with head and neck cancers are excellent candidates for gene therapy. With few effective alternatives for patients with recurrent or locally metastatic disease, gene therapy offers a new approach for local control and the possibility to enhance other treatment modalities as well. Different therapeutic genes, including tumor suppressor genes, prodrug or suicide genes, and genes whose products enhance immunocompetence, can be delivered using specifically designed vectors with little toxicity or threat of undesirable viral spread. Two of these gene therapy agents, RPR/INGN 201 and HLA-B7 + beta2 microglobulin, have shown clinical activity, according to reports from phase I trials.