Palbociclib-letrozole as first-line treatment for advanced breast cancer: Updated results from a Japanese phase 2 study

Palbociclib is a highly selective, reversible, oral inhibitor of cyclin‐dependent kinases 4 and 6 that is approved to treat hormone receptor‐positive/human epidermal growth factor receptor 2‐negative advanced breast cancer. An open‐label, single‐arm, Japanese phase 2 study was conducted to investigate the efficacy and safety of palbociclib plus letrozole as first‐line treatment in 42 postmenopausal patients with estrogen receptor‐positive/human epidermal growth factor receptor 2‐negative advanced breast cancer. The probability of progression‐free survival originally reported at 1 year was 75.0% (90% confidence interval, 61.3‐84.4), but median progression‐free survival was not attained at the primary analysis. In this report, updated efficacy and safety results with a longer follow‐up period are presented. The median duration of treatment in the updated analysis was 33.0 months (range, 1.8‐49.2). The probability of progression‐free survival at 1 year was 75.6% (90% confidence interval, 62.4‐84.7). Median progression‐free survival was 35.7 months (95% confidence interval, 21.7‐46.7). Objective response rate and disease control rate were 47.6% (95% confidence interval, 32.0‐63.6) and 85.7% (95% confidence interval, 71.5‐94.6), respectively. Common treatment‐related adverse events (all grades; grade 3/4) were neutropenia (100%; 93%), leukopenia (83%; 60%), and stomatitis (76%; 0%). Treatment‐related febrile neutropenia was reported in one patient. In general, no clinically meaningful deterioration in health‐related quality of life was observed. Palbociclib plus letrozole remained effective and tolerable in Japanese postmenopausal patients with estrogen receptor‐positive, human epidermal growth factor receptor 2‐negative advanced breast cancer in this updated analysis.

Efficacy and safety of sunitinib in Japanese patients with progressive, advanced/metastatic, well-differentiated, unresectable pancreatic neuroendocrine tumors: final analyses from a Phase II study

Background

In an interim analysis of a Phase II trial in Japanese patients with pancreatic neuroendocrine tumors (panNETs), sunitinib demonstrated antitumor activity with an objective response rate (ORR) of 50% (95% confidence interval [CI], 21–79) and a median progression-free survival (PFS) of 16.8 months (95% CI, 9.3–26.2). Here, we report the final analyses of efficacy and safety, as well as additional analyses, from this Phase II study.

Methods

This was a multicenter, open-label, Phase II trial (NCT01121562) of sunitinib in Japanese patients with panNETs. Patients received oral sunitinib 37.5 mg/day on a continuous daily dosing schedule. Dose modifications were permitted. The primary endpoint was clinical benefit rate (CBR). Secondary endpoints included ORR, PFS, overall survival (OS), safety and pharmacokinetics.

Results

Of 12 patients enrolled and treated, all discontinued treatment—the majority (n = 8) owing to disease progression. Most patients were male (n = 8), <65 years of age (n = 11) and had a non-functional tumor (n = 10). The median (range) number of days on drug was 323.5 (22–727). The CBR (95% CI) was 75.0% (42.8–94.5). ORR (95% CI) was 50.0% (21.1–78.9). Median (95% CI) PFS was 16.8 (9.3–26.2) months; however, median (95% CI) OS was not reached (22.0–not estimable). Most common adverse events (AEs; all-causality) were diarrhea (n = 10; 83.3%), hand-foot syndrome (n = 8; 66.7%) and hypertension (n = 8; 66.7%).

Conclusions

These results support the efficacy and safety of sunitinib in Japanese patients with panNETs. Appropriate AE management through dose reduction and interruption may prolong sunitinib treatment and maximize its efficacy.

Treatment status and safety of crizotinib in 2028 Japanese patients with ALK-positive NSCLC in clinical settings

Objective

Post-marketing surveillance (PMS) was performed in Japan to obtain information on the safety and efficacy of crizotinib.

Methods

Target patients included almost all patients with anaplastic lymphoma kinase-positive non-small cell lung cancer who were administered crizotinib. The observation period was 52 weeks. In the present study, we focused on the treatment status and safety of crizotinib therapy and analyzed the real-world data obtained by this PMS (ClinicalTrials.gov: NCT01597258).

Results

The safety analysis set included 2028 Japanese patients, and more than half of the patients (56.4%) were nonsmokers. The incidence of adverse drug reactions (ADRs) was 91.6%, and common ADRs (incidence ≥15%) were nausea (32.2%), diarrhea (24.3%), photopsia (18.9%), vomiting (17.5%) and dysgeusia (16.8%). Many patients (623 patients) discontinued treatment of crizotinib because of adverse events within 12 weeks after therapy initiation, which tended to frequently occur in the following cases: (1) elderly, (2) body weight <40 kg, (3) body surface area <1.2 m2 (4) ECOG PS 2–4, (5) higher Brinkman index and (6) history of occupational/environmental exposure such as asbestos/pneumoconiosis. The proportions of patients remaining on crizotinib therapy were 68.2% for 3 months, 55.2% for 6 months and 36.1% for 12 months, with a median duration of 7.9 months. Multivariate analysis with a Cox proportional hazard model identified 10 statistically significant patient background factors influencing the duration of crizotinib therapy.

Conclusions

No new safety concerns were observed in this PMS study. Our results provide useful information regarding the status of crizotinib therapy in the clinical setting.

Correction to: Phase II study of sunitinib in Japanese patients with unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumor

In the original publication of this article, the license subtype should be CC BY and not CC BY-NC.

Palbociclib in combination with letrozole as first-line treatment for advanced breast cancer: A Japanese phase II study

This single-arm, open-label, phase II study in 42 Japanese postmenopausal patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced breast cancer evaluated the efficacy, safety, and pharmacokinetics of first-line palbociclib (125 mg once daily, 3 weeks on/1 week off) coadministered with letrozole (2.5 mg once daily). Primary endpoint of investigator-assessed 1-year progression-free survival (PFS) probability was 75.0% (90% CI, 61.3%-84.4%), far surpassing the 40% lower limit of the 90% CI supporting efficacy. Median duration of treatment was 438 days. Among secondary efficacy measures, median PFS was not reached (95% CI, 16.7: not estimable), 17/42 patients (40.5%) had an objective response, 36/42 (85.7%) maintained disease control, and 27/42 (64.3%) remained in follow-up. Median overall survival was not reached, and 1-year survival probability was 92.9% (95% CI, 79.5%-97.6%). Results of intensive pharmacokinetics in a subset of 6 patients showed palbociclib steady-state mean area under the plasma concentration-time curve over the dosing interval [τ] and mean maximum plasma concentration were 1979 ng·h/mL and 124.7 ng/mL, respectively. For day 15 plasma samples from cycles 1 and 2, geometric mean of the within-patient mean trough concentration was 90.1 ng/mL. The most common treatment-related adverse events were neutropenia (100%) and stomatitis (73.8%). There was 1 case of treatment-related febrile neutropenia. Toxicities were generally tolerated and manageable by dose modifications and/or medical care. Efficacy and safety of first-line palbociclib plus letrozole therapy is supported in Japanese postmenopausal patients with treatment-naive ER+/HER2- advanced breast cancer.

Crizotinib versus Chemotherapy in Asian Patients with ALK-Positive Advanced Non-small Cell Lung Cancer

Purpose

Crizotinib has demonstrated superior progression-free survival (PFS) and objective response rates (ORRs) versus chemotherapy in previously treated and untreated patients with anaplastic lymphoma kinase (ALK)-positive advanced non-small cell lung cancer (NSCLC). We report the safety and efficacy of crizotinib in Asian subpopulations of two global phase III trials.

Materials and Methods

This analysis evaluated previously treated and untreated patients in two randomized, open-label phase III trials of crizotinib versus chemotherapy in ALK-positive advanced NSCLC in second-line (PROFILE 1007) and first-line settings (PROFILE 1014). Efficacy and safety were analyzed by race in the intention-to-treat and “as-treated” populations for efficacy and safety endpoints, respectively.

Results

In previously treated (n=157) and untreated (n=157) Asian patients, PFS was statistically significantly longer with crizotinib versus chemotherapy (hazard ratio for PFS, 0.526; 95% confidence interval, 0.363 to 0.762; p < 0.001 and hazard ratio, 0.442; 95% confidence interval, 0.302 to 0.648; p < 0.001, respectively). Similar antitumor activity was seen in the non-Asian and overall populations. ORRs were statistically significantly higher with crizotinib versus chemotherapy in both Asian and non-Asian previously treated and untreated patients (p < 0.05). The most common treatment-emergent adverse events (any grade)with crizotinib were vision disorder, diarrhea, and nausea, which were observed at a comparable incidence across Asian and non-Asian populations, irrespective of previous treatment status. Most adverse events were mild to moderate in severity.

Conclusion

These data, currently the only analysis showing Asian and non-Asian populations in the same study, support the efficacy and safety of crizotinib in Asian patients with previously treated or untreated ALK-positive advanced NSCLC.

Phase I study of palbociclib, a cyclin-dependent kinase 4/6 inhibitor, in Japanese patients

This phase I study in Japanese patients evaluated the safety, pharmacokinetics, and preliminary efficacy of palbociclib, a highly selective and reversible oral cyclin‐dependent kinase 4/6 inhibitor, as monotherapy for solid tumors (part 1) and combined with letrozole as first‐line treatment of postmenopausal patients with estrogen receptor‐positive, human epidermal growth factor receptor 2‐negative advanced breast cancer (part 2). Part 1 evaluated palbociclib 100 and 125 mg once daily (3 weeks on/1 week off; n = 6 each group) to determine the maximum tolerated dose. Part 2 evaluated palbociclib maximum tolerated dose (125 mg) plus letrozole 2.5 mg (n = 6). The most common treatment‐related adverse event was neutropenia (all grades/grade 3/4): 100 mg, 83%/67%; 125 mg, 67%/33%; and palbociclib plus letrozole, 100%/83%. Heavier pretreatment with chemotherapy may have resulted in higher neutropenia rates observed with the 100‐mg dose. Palbociclib exposure was higher with 125 vs 100 mg (mean area under the plasma concentration–time curve over dosing interval [τ]: 1322 vs 547.5 ng·h/mL [single dose], 2838 vs 1276 ng·h/mL [multiple dose]; mean maximum plasma concentration: 104.1 vs 41.4 ng/mL [single dose], 185.5 vs 77.4 ng/mL [multiple dose]). Half‐life was 23–26 h. No drug–drug interactions between palbociclib and letrozole occurred. Four patients had stable disease (≥24 weeks in one patient with rectal cancer [100 mg] and one with esophageal cancer [125 mg]) in part 1; two patients had partial response and two had stable disease (both ≥24 weeks) in part 2. Palbociclib at the 125‐mg dose (schedule 3/1) was tolerated and is the recommended dose for monotherapy and letrozole combination therapy in Japanese patients. The trials are registered with www.ClinicalTrials.gov: A5481010 and NCT01684215.

Efficacy and safety of monotherapy by pegvisomant, a growth hormone receptor antagonist, in Japanese patients with acromegaly

Pegvisomant is a GH receptor antagonist and strong inhibitor of insulin-like growth factor I (IGF-I) production. The treatment goal for acromegaly is to normalize serum IGF-I levels and attenuate associated symptoms. The efficacy and safety of pegvisomant as treatment for acromegaly have been reported in Caucasians, but not in Japanese. Here we report the clinical experience of using pegvisomant in Japanese patients with acromegaly. The efficacy and safety data for pegvisomant from two open-labeled clinical studies in Japan, conducted from 2004 to 2007, were re-analyzed using the new Japanese age- and sex-matched normative ranges for IGF-I. Eighteen patients with active acromegaly were enrolled in an initial pivotal study, and 16 of them were moved to a long-term (max 168 weeks) extension study. The dose of pegvisomant in the extension study was adjusted to 10-30 mg per day according to IGF-I levels. IGF-I normalization was observed in 81.3% (13/16 patients) during the extension study. The mean percentage decrease from baseline in serum IGF-I level was 64.7% at the time of last observation. The clinical symptoms and overall health status were improved, and the ring size was reduced over time until Week 12 and maintained. For safety, no clinically significant changes were observed both in the pituitary tumor size and the anti-GH antibody level. Three subjects were withdrawn from the studies due to an abnormal elevation of liver enzymes which resolved after discontinuation. Pegvisomant demonstrated excellent clinical efficacy and was well tolerated in Japanese patients with acromegaly.

How Should a Globalized CTD Be Created? An Introduction to the Japanese 3-Layer Approach

This article is based on the consensus of a task force of the Data Science Expert Committee, Japan Pharmaceutical Manufacturers Association. Common Technical Documents (CTDs) need to be harmonized in all of the ICH regions to enhance the scientific value and efficiency of these documents. Region-specific CTDs often require modifications for submission in different countries-an urgent issue not only for Japan but also for the countries where participation in the ICH framework will expand. CTDs themselves should be globalized, which means they should use not only a common format but also common contents, by incorporation of a 3-layer approach. In layer 1 of this approach, efficacy and safety of a study drug are evaluated through the overall study results; layer 2 entails evaluation of whether there is inconsistency in efficacy and/or safety of the study drug for a specific subgroup with overall results; and in layer 3, the results of layers 1 and 2 are used to evaluate benefits and risks in each applying country. The 3-layer approach can be used to create a globally common model using data collected in all countries in the study. This global evaluation allows benefits and risks to be evaluated in all countries and should allow globalized CTDs to be developed. Alignment between research and development sites by pharmaceutical companies and success of regulatory conventions can reduce the total amount of review time. Ultimately, these changes would lead to faster approval of new drugs.

Phase I study of sunitinib plus S-1 and cisplatin in Japanese patients with advanced or metastatic gastric cancer

BACKGROUND

This phase I, dose-finding study evaluated the maximum tolerated dose (MTD), safety, pharmacokinetics, and antitumor activity of sunitinib plus S-1/cisplatin in Japanese patients with advanced/metastatic gastric cancer.

PATIENTS AND METHODS

Patients received oral sunitinib on a continuous daily dosing (CDD) or 2-weeks-on/2-weeks-off schedule (Schedule 2/2; 25 mg/day or 37.5 mg/day), plus S-1 (80-120 mg/day)/cisplatin 60 mg/m(2).

RESULTS

Twenty-seven patients received treatment, including 26 patients treated per protocol (sunitinib 25 mg/day CDD schedule, n = 4; sunitinib 25 mg/day Schedule 2/2, n = 16 [dose-limiting toxicity (DLT) cohort, n = 6 plus expansion cohort, n = 10]; sunitinib 37.5 mg/day Schedule 2/2, n = 6). One patient erroneously self-administered sunitinib 12.5 mg/day and was excluded from the analyses. The MTD was sunitinib 25 mg/day on Schedule 2/2. DLTs were reported for: 2/4 patients given sunitinib 25 mg/day on the CDD schedule; 1/6 patients administered sunitinib 25 mg/day on Schedule 2/2 (grade [G] 3 neutropenic infection, G4 thrombocytopenia, and S-1 dose interruption ≥5 days), and 3/6 patients given sunitinib 37.5 mg/day on Schedule 2/2. Results below are for the overall MTD cohort (n = 16). The most frequently reported G3/4 adverse events were neutropenia (93.8 %) and leukopenia (75.0 %). The objective response rate was 37.5 %; six additional patients experienced no disease progression for ≥24 weeks. Median progression-free survival was 12.5 months. No pharmacokinetic drug-drug interactions were observed between sunitinib/S-1/cisplatin and S-1/cisplatin.

CONCLUSIONS

The MTD of sunitinib was 25 mg/day on Schedule 2/2 combined with cisplatin/S-1 in patients with advanced/metastatic gastric cancer. This regimen had a manageable safety profile and preliminary antitumor activity.

Phase II study of sunitinib in Japanese patients with unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumor

Background. Pancreatic neuroendocrine tumors (NETs) are rare but are frequently diagnosed at advanced stages and require systemic therapy. Patients and methods. This multicenter, open-label, phase II study evaluated sunitinib in Japanese patients with well-differentiated pancreatic NET. Patients received sunitinib 37.5 mg/day on a continuous daily dosing (CDD) schedule. The primary endpoint was clinical benefit rate (CBR; percentage of complete responses [CRs] plus partial responses [PRs] plus stable disease [SD] ≥24 weeks). Secondary endpoints included objective response rate (ORR), tumor shrinkage, progression-free survival (PFS) probability, safety, pharmacokinetics, and biomarkers. Results. Twelve patients received treatment. The CBR was 75 % (95 % confidence interval [CI], 43–94) and included 6 patients with a PR and 3 with SD. The ORR was 50 % (95 % CI, 21–79). PFS probability was 91 % (95 % CI, 54–99) at 6 months and 71 % (95 % CI, 34–90) at 12 months. Commonly reported treatment-emergent (all-causality), any-grade adverse events included diarrhea (n = 10), hand–foot syndrome and hypertension (both n = 8), fatigue and headache (both n = 7), and neutropenia (n = 6). No deaths on study were reported; one death due to disease progression occurred >28 days after end of treatment. Sunitinib on a CDD schedule resulted in sustained drug concentrations without accumulation across cycles. Tumor responses in all 12 patients did not appear to correlate with decreases in chromogranin A levels. Conclusions. Sunitinib 37.5 mg/day on a CDD schedule demonstrated antitumor activity in Japanese patients with unresectable, well-differentiated pancreatic NET. Commonly reported adverse events were consistent with the known safety profile of sunitinib.

First-line sunitinib plus FOLFIRI in Japanese patients with unresectable/metastatic colorectal cancer: a phase II study

This phase II, open-label, single-arm study investigated sunitinib + FOLFIRI in Japanese patients with treatment-naïve unresectable/metastatic colorectal cancer. Patients received i.v. FOLFIRI (levo-leucovorin 200 mg/m(2) + irinotecan 180 mg/m(2), followed by 5-fluorouracil 400 mg/m(2) bolus then 2400 mg/m(2) 46-h infusion) every 2 weeks, and oral sunitinib 37.5 mg/day on Schedule 4/2 (4 weeks on, 2 weeks off), until disease progression or treatment withdrawal. Progression-free survival (PFS) was the primary endpoint, with a target median of 10.8 months (35% improvement over FOLFIRI alone). Seventy-one patients started a median of 3 (range 1-11) sunitinib cycles (median relative dose intensity, <60%). The median PFS was 6.7 months (95% confidence interval, 4.7-9.2) by independent review, 7.2 months (95% confidence interval, 5.4-9.5) by investigator assessment. Objective response rate (complete responses + partial responses) was 36.6% (independent review) and 42.3% (investigator assessment). Clinical benefit rate (complete responses + partial responses + stable disease) was 83.1% (independent review) and 88.7% (investigator assessment). Common all-causality, any-grade, adverse events were: neutropenia and leukopenia (both 97.2%); thrombocytopenia (84.5%); diarrhea and nausea (both 78.9%); decreased appetite (74.6%); and fatigue (66.2%). Neutropenia (96%) was the most frequent grade 3/4 adverse event. This study was closed early due to findings from a concurrent phase III study of sunitinib + FOLFIRI in non-Japanese patients with metastatic colorectal cancer. In conclusion, the median PFS for sunitinib + FOLFIRI in Japanese patients was shorter than the 10.8 month target, indicating that sunitinib did not add to the antitumor activity of FOLFIRI. This study was registered with www.ClinicalTrials.gov (NCT00668863).

Phase I study of sunitinib plus modified FOLFOX6 in Japanese patients with treatment-naive colorectal cancer

AIM

This phase I study evaluated sunitinib plus modified FOLFOX6 (mFOLFOX6: 5-fluorouracil, leucovorin and oxaliplatin) in Japanese patients with treatment-naïve metastatic colorectal cancer.

PATIENTS AND METHODS

Sunitinib was administered orally (37.5 mg/day, 4 weeks on, 2 weeks off [Schedule 4/2; arm A] or 50 mg/day, 2 weeks on, 2 weeks off [Schedule 2/2; arm B]) with mFOLFOX6.

RESULTS

In arms A/B, respectively (n=6 each): median relative dose intensity was 50.4%/89.1% for sunitinib and 39.2-69.8%/73.0-80.5% for mFOLFOX6 components. Most adverse events were grade 1/2. The most frequent grade 3/4 adverse events were neutropenia, thrombocytopenia, and leukopenia. No significant drug-drug interactions were detected. Four patients had objective responses in each arm.

CONCLUSION

Sunitinib plus mFOLFOX6 had acceptable tolerability, with the Schedule 2/2 combination being generally more manageable than the Schedule 4/2. Based on two global trials and the present study, sunitinib on Schedule 2/2 combined with chemotherapy may be considered, if further first-line trials are planned.

Phase II study of sunitinib (SU) in Japanese patients with unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumor (NET)

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Background: SU is an oral, multitargeted, antiangiogenic, tyrosine kinase inhibitor effective in patients (pts) with unresectable, well-differentiated pancreatic NET. This open-label, phase II study examined whether SU is also effective in Japanese pts with this disease.

Methods: Japanese pts received SU 37.5 mg/day on a continuous daily dosing (CDD) schedule (28-day cycle). The primary endpoint was clinical benefit rate (CBR; complete response [CR] + partial response [PR] + stable disease [SD] ≥24 weeks). Secondary endpoints included: objective response rate (ORR; CR + PR), 6-mos progression-free survival (PFS) probability, safety and pharmacokinetics. Tumor assessments were performed at baseline and 8-wk intervals by CT or MRI (RECIST).

Results: Twelve patients were enrolled and received treatment (tx; median age 54 yrs, range 34–79); 9 were ongoing at data cut-off (July 1, 2011). CBR was 75.0% (95% CI 42.8, 94.5), comprising 5 PRs and 4 pts with SD ≥24 weeks. ORR was 41.7% (95% CI 15.2, 72.3). 6-mos PFS probability was 91.7% (95% CI 53.9, 98.8). One PR occurred in a pt with gastrinoma, in whom gastrin levels decreased by 93% and tumor bulk decreased by 45%. All-causality, any-grade (G) AEs included diarrhea (n=9, 75%), HFS and hypertension (both n=8, 67%). Neutropenia was the most common G3 AE (n=5, 42%, all tx-related). Three pts (25%) experienced G4 AEs (herpes encephalitis, convulsion, loss of consciousness [n=1] and lipase increased [n=2], all tx-related).Two pts (17%) experienced serious AEs: convulsion and loss of consciousness (n=1, tx-related), and acute cholecystitis (n=1, unrelated to tx). There were no deaths on study; one death due to disease progression occurred 3 mos after study withdrawal. On day 15 (cycle 1), mean trough plasma concentrations (n=10) for SU, its metabolite, and SU + metabolite were 53.9, 23.7 and 77.5 ng/mL, respectively. SU on a CDD schedule resulted in sustained drug concentrations without accumulation across cycles.

Conclusions: SU 37.5 mg/day on a CDD schedule demonstrated antitumor activity in Japanese pts with unresectable, well-differentiated pancreatic NET. Common AEs were consistent with the known safety profile of SU.

P1-16-01: A Randomized, Double-Blinded, Controlled Study of Exemestane vs. Anastrozole for the First-Line Treatment of Postmenopausal Japanese Women with Hormone Receptor Positive Advanced Breast Cancer

Background The steroidal irreversible aromatase inhibitor (AI) exemestane (E), the non-steroidal reversible AI anastrozole (A) and tamoxifen (T) are approved for the first-line treatment of the postmenopausal women with hormone receptor (HR) positive advanced breast cancer (ABC) in Japan. Although there are some studies which compare the efficacy and safety of AIs and T in the first-line disease setting, the number of studies that compare efficacy and safety of AIs is limited. We conducted this multicenter, randomized, double-blinded non-inferiority study, to evaluate the time to progression (TTP) in HR positive ABC randomized to therapy with E or A.

Methods Patients (pts) who were ≥20 years [yrs], postmenopausal, ECOG PS ≤1 and had HR positive ABC that recurred after the adjuvant therapy or metastatic disease settings were eligible and randomized (1:1) to 25 mg/day of E or to 1 mg/day of A. Data were evaluated for non-inferiority of E compared to A defined as the upper limit of a two-sided 95% confidence interval (CI) of the hazard ratio (HR) of TTP being less than or equal to 1.25. The primary endpoint was TTP assessed by the independent radiological images review committee (RIRC). Secondary endpoints included TTP by investigator, time to treatment failure, overall survival (OS), objective response rate (ORR), clinical benefit rate, and safety.

Results A total of 298 pts from 58 sites were randomized to E (n=149; mean age: 63.4 yrs) or A (n=149; mean age: 64.0 yrs). The mean BMI for the E and A arms were 23.0 kg/m2 and 23.6 kg/m2, respectively. Six pts (2 pts in E arm, 4 pts in A arm) were excluded from the full analysis set due to lack of evaluation for anti-tumor response after study medication started.

Median TTP (as per RIRC) was 13.8 months (M) vs. 11.1 M for E vs. A, respectively (HR 1.007; 95% CI: 0.771−1.317). Median TTP (Investigator) was 13.8 M vs. 13.7 M for E vs. A, respectively (HR 1.059; 95% CI: 0.816−1.374). The median OS for A treated pts was 60.1 M, OS for E was not reached (as of data cut-off: December 8, 2010). ORR for E was 43.9% (95% CI: 35.3−52.8) and 39.1% (95% CI: 30.6−18.1) for A. Other analyses, including sub-population analyses are ongoing.

The incidence of treatment related adverse events (AEs) in E arm was 71.1% (n=106) and in A arm 59.7% (n=89); the AEs were mostly grade 1 and 2 in 61.7% (n=92) and 53.7% (n=80) of pts respectively. They were expected and manageable. Treatment related SAEs were similar in both groups: 6 (4.0%) in E arm and 5 (3.4%) in A arm. The most common AEs for E were hot flushes (22.1%), arthralgias (16.8%), musculoskeletal stiffness (11.4%) and γ-GTP increased (10.1%); in A arm, hot flushes (14.8%) and arthralgia (16.8%) were observed in &gt;10% pts.

Conclusions Although median TTP (RIRC) of E is slightly improved compared with that of A, the result of TTP did not meet the non-inferiority criteria. There were no significant differences found between E and A in ORR. Although AEs in E were numerically higher, the observed AE profiles were similar to those previously reported for E and A. This study shows that E is comparable to A in efficacy and safety.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-16-01.