P1-17-05: Preliminary Results of a Randomized Phase 2 Study of PD 0332991, a Cyclin-Dependent Kinase (CDK) 4/6 Inhibitor, in Combination with Letrozole for First-Line Treatment of Patients (pts) with Post-Menopausal, ER+, HER2−Negative (HER2–) Advanced Breast Cancer

Background: PD 0332991 is an orally bioavailable selective inhibitor of CDK 4/6 and prevents cellular DNA synthesis by prohibiting progression of the cell cycle from G1 into the S phase. Preclinical evaluations suggest that reduction in CDKN2A (p16) expression and cyclin D1 (CCND1) overexpression confer susceptibility to PD 0332991 (Finn 2009). In addition, PD 0332991 was synergistic in combination with tamoxifen in vitro in ER+ human breast cancer cell lines. Based on these observations, a phase 1/2 study in combination with letrozole as first-line therapy for advanced ER+ post-menopausal breast cancer was initiated. The phase 1 part of the study (completed) determined the recommended phase 2 dose to be PD 0332991 125 mg QD on Schedule 3/1 (3 weeks on treatment followed by 1-week off treatment) in combination with letrozole 2.5 mg QD. The combination was generally well tolerated and encouraging antitumor activity was observed. We present preliminary data from the randomized Phase 2 portion comparing letrozole alone to letrozole plus PD 0332991.

Methods: The Phase 2 portion of the study is designed as a two-part study; we present data from Part 1. In both parts, eligible patients are randomized 1:1 to letrozole 2.5 mg QD alone (control) or PD 0332991 125 mg QD on schedule 3/1 and letrozole 2.5 mg QD (treatment, tx). Part 1enrolled post-menopausal women with ER+, HER2− cancer using only ER+, HER2−as a selection criteria. Part 2 is now enrolling post-menopausal women with ER+, HER2− breast cancer with CCND1 amplification and/or loss of p16 by FISH (target N=150). The primary endpoint is progression-free survival (PFS); secondary endpoints include overall survival, response rate, safety, and correlative studies. Pts are stratified for disease site and length from prior adjuvant therapy. Pts continue assigned study treatment until disease progression, unacceptable toxicity, or consent withdrawal and are followed every 2 months to assess disease status. Tumor tissue was required for participation.

Results: 66 patients have been randomized in Part 1. At the time of data cut-off (April 2011) median duration of treatment is 20 (range 4–64) wks for control and 27 (2-59) wks for tx. Dose reductions occurred in 9 pts on the tx arm and none on the control arm. There are no complete responses. The number of partial responses for pts with measurable disease are similar between arms (4/22 control vs 5/24 in tx). The number of pts with stable disease> 24 weeks was higher in the tx arm (5 vs 8). The number of pts with best response of progressive disease is lower in the treatment arm (2 vs 6). PFS data are immature. Twelve pts remain on control vs. 21 on tx. As in the Phase I portion of the study, the most common treatment-related AEs were neutropenia and leucopenia without febrile neutropenia. Biomarker studies for CCND1 amplification, p16 loss, RB status, and Ki67 are ongoing.

Conclusion: The combination of PD 0332991 and letrozole is well tolerated as first-line treatment of ER+, HER2− post-menopausal breast cancer. Updated efficacy data and biomarker data will be presented.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-17-05.

OT2-01-02: First-Line Bevacizumab in Combination with Capecitabine or Paclitaxel for HER2−Negative Locally Recurrent or Metastatic Breast Cancer (LR/MBC): A Randomized Phase III Trial

Background

A number of phase III studies have shown significant progression-free survival (PFS) benefits with the combination of bevacizumab (Bev) and either first-line capecitabine (X) or taxane therapy in LR/MBC. The ongoing open-label, randomized, phase III CECOG-sponsored TURANDOT study (CECOG/BC.1.3.005) is investigating the efficacy and safety of first-line Bev plus paclitaxel (P) versus Bev plus X in this setting.

Materials and methods: Eligible patients (pts) are aged ≥18 years with HER2−negative, chemonaïve LR/MBC, an ECOG performance status of 0–2 and a life expectancy >12 weeks. Prior chemotherapy and concomitant hormonal therapy for LR/MBC are not permitted, but prior (neo)adjuvant chemotherapy is allowed if completed ≥6 months before randomization or ≥12 months if taxane based. Pts are randomized to receive Bev 10mg/kg days 1, 15 plus P 90mg/m2 days 1, 8, 15, q28d (Arm A) or Bev 15mg/kg day 1 plus X 1,000mg/m2 bid days 1–14, q21d (Arm B) until disease progression, unacceptable toxicity or withdrawal of consent. The primary objective is to demonstrate non-inferiority in overall survival (OS) with Bev plus P versus Bev plus X (upper limit ≤1.33 for the two-sided confidence interval for hazard ratio [HR]). Secondary objectives are: comparison of overall response rate (RECIST criteria); PFS; time to response; duration of response; time to treatment failure; safety (CTCAE version 3); and quality of life (EORTC QLQ-30). The recruitment target is 560 pts. A sample size of 490 pts in the per-protocol population will be required to provide 80% power to reject the null hypothesis of inferiority at a one-sided significance level of 0.025, assuming a 24-month median OS with Bev plus P and an alternative hypothesis of HR=1. Data cut-off for adverse event reports was 12 Apr 2010. Interim and final efficacy analyses will be triggered after 175 and 389 events, respectively.

Results: Recruitment to the study began in Sep 2008 and was completed in Aug 2010, with 561 pts randomized. Follow-up is ongoing.

Conclusions: TURANDOT is the first study to examine the efficacy and safety of Bev plus P versus Bev plus X as first-line treatment for pts with LR/MBC.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT2-01-02.

The effect of tumor response on quality of life (QoL) in patients with KRAS wild-type metastatic colorectal cancer (mCRC): Analysis from the CRYSTAL study

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Background: In the CRYSTAL study cetuximab (cet) added to first-line chemotherapy (CT) significantly improved tumor response compared with CT alone in patients (pts) with KRAS wild-type (wt) mCRC, confirming existing data in this setting. Response to CT has been reported to lead to a corresponding increase in QoL, and QoL scores to predict overall survival in mCRC. In this exploratory analysis tumor response and QoL was investigated in pts from the CRYSTAL study.

Methods: Pts were classified as responders (Rs) or nonresponders (NRs) according to best overall response. QoL was assessed using single-item symptoms questions from the EORTC QLQ-C30 (q8-10, q12-18). Pts at baseline were considered symptomatic if they answered “quite a bit” or “very much” and asymptomatic if they answered “not at all” or “a little” to either one of the symptoms questions. Analysis was performed in all treatment groups (gps) on the change in symptoms in pts considered symptomatic or asymptomatic at baseline.

Results: 471 of 627 KRAS wt pts assessed for QoL had baseline data showing they were symptomatic or asymptomatic. In pts asymptomatic at baseline (n=278) there were more Rs (58%) than NRs (42%). In pts symptomatic at baseline (n=193), there were less Rs (40%) than NRs (60%). At week 8 in all treatment gps, in pts symptomatic at baseline more Rs than NRs became asymptomatic (Table). In pts asymptomatic at baseline, in the CT + cet gp at week 8, 61% of Rs remained asymptomatic compared with 50% of NRs. Data from week 16 and 24 also showed trends in favor of Rs in symptomatic or asymptomatic pts at baseline and will be presented.

Conclusions: Rs who are symptomatic at baseline experience higher symptom relief than NRs. Furthermore Rs who are asymptomatic at baseline are more likely to remain asymptomatic post baseline than NRs. These findings are independent of treatment.

[Table: see text]

[Table: see text]

Modulation of factor VIII-specific memory B cells

The development of inhibitory antibodies against factor VIII (FVIII) is the major complication in patients with haemophilia A who are treated with FVIII products. Memory B cells play an essential role in maintaining established antibody responses. Upon re-exposure to the same antigen, they are rapidly re-stimulated to proliferate and differentiate into antibody-secreting plasma cells (ASC) that secrete high-affinity antibodies. It is, therefore, reasonable to believe that memory B cells have to be eradicated or inactivated for immune tolerance induction therapy to be successful in patients with haemophilia A and FVIII inhibitors. The aim of our studies was the development of strategies to prevent FVIII-specific memory B cells from becoming re-stimulated. We established a 6-day in vitro culture system that enabled us to study the regulation of FVIII-specific murine memory-B-cell re-stimulation. We tested the impact of the blockade of co-stimulatory interactions, of different concentrations of FVIII and of ligands for toll-like receptors (TLR). The blockade of B7-CD28 and CD40-CD40 ligand interactions prevented FVIII-specific murine memory B cells from becoming re-stimulated by FVIII in vitro and in vivo. Furthermore, high concentrations of FVIII blocked re-stimulation of FVIII-specific murine memory B cells. Triggering of TLR7 amplified re-stimulation by low concentrations of FVIII and prevented blockade by high concentrations of FVIII. We conclude that we defined modulators that either amplify or inhibit the re-stimulation of FVIII-specific murine memory B cells. Currently, we are investigating whether the same modulators operate in patients with haemophilia A and FVIII inhibitors.

[Chronic thromboembolic pulmonary hypertension: recommendations of the Cologne Consensus Conference 2010]

In the 2009 European Guidelines on pulmonary hypertension one section covers aspects of pathophysiology, diagnosis and treatment of chronic thromboembolic pulmonary hypertension (CTEPH). The practical implementation of the guidelines for this disease is of crucial importance, because CTEPH is a form of pulmonary hypertension which can be surgically cured. It is, however, frequently diagnosed late in the course of disease and often treated not correctly. In the European Guidelines CTEPH is addressed relatively briefly, although it is a common form of PH which is often overlooked. Any patient with unexplained PH should be evaluated for the presence of CTEPH. A ventilation/perfusion lung scan is recommended as the first step to exclude CTEPH. If the ventilation/perfusion lung scan or multislice CT angiography reveals perfusions defects suggesting the diagnosis of CTEPH, the patient should be referred to a centre with expertise in the medical and surgical management of these patients. After diagnosis of CTEPH the case has to be reviewed by an experienced surgeon in a PEA centre for assessment of operability. The recommendations of the European guidelines are summarized in the current manuscript with additional comments regarding diagnosis and treatment according to most recent evidence.

Cetuximab plus FOLFIRI first line in patients (pts) with metastatic colorectal cancer (mCRC): A quality-of-life (QoL) analysis of the CRYSTAL trial

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Background: Assessing QoL is important to evaluate the impact of treatment on pts with mCRC. The phase III CRYSTAL trial compared cetuximab plus FOLFIRI with FOLFIRI alone in the first-line treatment of patients with EGFR-expressing mCRC. Primary endpoint was progression-free survival (PFS); QoL was a secondary endpoint. Methods: Pts were randomised 1:1 to cetuximab (400 mg/m2 initial dose then 250 mg/m2/wk) plus FOLFIRI q2w (irinotecan 180 mg/m2, folinic acid 400 mg/m2, 5-FU bolus 400 mg/m2, 5-FU infusion 2400 mg/m2 over 46 h) (Group A, n=599) or FOLFIRI alone (Group B, n=599). QoL was assessed with the EORTC QLQ-C30 (v3.0) questionnaire. Pts were to complete the questionnaire at baseline, every 4 cycles, and at final tumor assessment. The primary QoL analysis focused on Global Health Status and Social Functioning scales and employed a pattern-mixture model that included the drop-out pattern. Descriptive statistics were provided for each multi-item scale considering QoL changes over time. Results: Risk of disease progression was significantly reduced by 15% (HR=0.85) in favor of Group A (p=0.0479); pts with KRAS wild-type (wt) tumors in Group A had a 32% (HR=0.68) reduced risk of progressing. Questionnaire completion compliance rates were similar between treatment groups. Pattern-mixture analyses showed no statistically significant differences between the two treatment groups for changes from baseline on the Global Health Status (p=0.29) and Social Functioning (p=0.39) scales. Comparing treatment groups in terms of QoL scores over time resulted in no statistically significant differences, apart from nausea/vomiting in favor of the cetuximab group at week 16 (10.2 vs 13.3; p=0.0129), week 32 (9.3 vs 12.5; p=0.0488) and week 40 (7.6 vs 12.5; p=0.0194). Conclusions: In pts with mCRC, cetuximab plus FOLFIRI first-line significantly prolongs PFS compared with FOLFIRI alone while preserving QoL. The PFS benefit is even more pronounced for pts with KRAS wt tumors. The EORTC QLQ-C30 Social Functioning scale was expected to reflect skin reactions related to cetuximab, but there was neither a clinically meaningful nor statistically significant difference between groups.

[Table: see text]

Multicenter phase III comparison of cisplatin/S-1 (CS) with cisplatin/5-FU (CF) as first-line therapy in patients with advanced gastric cancer (FLAGS): Secondary and subset analyses

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Background: The primary analysis of FLAGS (ASCO-GI-2009) showed that CS and CF had similar overall survival (OS) but CS had a significantly superior safety profile. Methods: 1,053 (1,029 treated; CS=521/CF=508) patients with untreated, advanced gastric/gastroesophageal adenocarcinoma were randomized to either S-1 (25 mg/m2 bid, d 1–21)/cisplatin (75 mg/m2 d 1) q 28 d or 5-FU (1,000 mg/m2/d 5-d infusion)/cisplatin (100 mg/m2 d 1) q 28 d. OS analyses for non-inferiority (NI), by pre-specified stratifications, and by the largest histologic subset (diffuse type histology) were performed. Results: OS for NI: OS from CS compared to CF had a HR=0.92 (two-sided 95% CI, 0.80–1.05). HR=1.05 being much lower than HR=1.22 derived from the literature. Using a stringent HR non-inferiority margin of 1.10, CS remains statistically significantly non-inferior (p=0.0068) to CF. The 74% preserved control effect by CS is well above the suggested 50% by Rothmann et al. (Statist-Med2003;22:239–264). OS by stratifications: Of 12 stratification sub-categories, CS produced OS HR=<1.0 in 9 and HR=>1.0 in 3. Subset analysis: OS analysis for diffuse type histology (n=590) showed that CS (median survival=9.0 months) resulted in a superior OS (Log rank p=0.0413; HR, 0.83 [95% CI, 0.70 to 0.99]) than CF (median survival=7.1 months). Conclusions: CS is statistically non-inferior to CF while proving much safer for the patients. CS resulted in a HR=<1.0 in the majority of pre-specified stratifications and CS produced statistically superior OS for patients with diffuse type histology (needs prospective studies). CS is an optimum substitute for CF. Supported by Taiho Pharma, USA.

No significant financial relationships to disclose.

IFPA meeting 2008 workshops report

Workshops are an important part of the IFPA annual meeting. At the IFPA meeting 2008 diverse topics were discussed in 12 themed workshops. Topics covered included: immunology of placentation; galectins and trophoblast invasion; signaling in implantation and invasion; markers to identify trophoblast subpopulations; placental pathology; placental toxicology; stereology; placental transport of fatty acids; placental mesenchymal stem cells; comparative placentation; trophoblast and neoplasia; trophoblast differentiation. This report is a summary of the various topics covered.