Efficacy and safety of weekly nab-paclitaxel plus gemcitabine in Chinese patients with metastatic adenocarcinoma of the pancreas: a phase II study

BACKGROUND

This phase II bridging study assessed the safety and efficacy of nab-paclitaxel/gemcitabine (Metastatic Pancreatic Adenocarcinoma Clinical Trial [MPACT] regimen) in Chinese patients with metastatic pancreatic cancer (MPC).

METHODS

This 3-part sequential study evaluated nab-paclitaxel 125 mg/m2 plus gemcitabine 1000 mg/m2 on days 1, 8, and 15 every 4 weeks. Part 1 evaluated safety. Part 2 evaluated efficacy using Simon's optimal 2-stage design: if >2 responses were observed in Stage 1 (n = 28), 54 additional patients would be enrolled in Stage 2. If >9 responses were observed, the study was complete. Otherwise, nab-paclitaxel/gemcitabine would be compared with gemcitabine alone in Part 3. The primary endpoint was overall response rate (ORR). Secondary endpoints included duration of response (DOR), overall survival (OS), and safety.

RESULTS

Eighty-three patients were treated. The prespecified primary endpoint was met: the independently assessed ORR in Stages 1 + 2 was 35% (95% CI, 24.8-46.2); therefore, Part 3 was not initiated. The median DOR was 8.9 months (95% CI, 6.01-8.94). The median OS and progression-free survival were 9.2 (95% CI, 7.6-11.1) and 5.5 (95% CI, 5.29-7.16) months, respectively. The 12-month OS rate was 30%. In an updated analysis, the median OS was 9.3 months and the 12-month OS rate was 32%. Longer OS was observed in patients with baseline neutrophil-to-lymphocyte ratio ≤ 5 vs > 5. The most common grade ≥ 3 adverse events were leukopenia (35%), neutropenia (34%), anemia (15%), thrombocytopenia (10%), and fatigue (13%). Grade 3 peripheral neuropathy occurred in 7% of patients (no grade 4 reported).

CONCLUSIONS

The MPACT regimen of nab-paclitaxel/gemcitabine is efficacious in Chinese patients with MPC. No new safety signals were observed.

TRIAL REGISTRATION

NCT02135822 , May 8, 2014.

nab-Paclitaxel plus gemcitabine for metastatic pancreatic cancer: a subgroup analysis of the Western European cohort of the MPACT trial

Purpose

The global Phase III MPACT trial demonstrated superior efficacy of nab-paclitaxel plus gemcitabine over gemcitabine alone as first-line treatment for metastatic pancreatic cancer. Region was a randomization stratification factor in the MPACT trial. This subgroup analysis of MPACT examined efficacy and safety of patients treated in Western Europe.

Patients and methods

Patients received nab-paclitaxel plus gemcitabine or gemcitabine alone as first-line treatment for metastatic pancreatic cancer as previously described. A total of 76 patients were included in this analysis (n=38 for each arm).

Results

Differences between the overall Western European cohort and the intention-to-treat population included lower percentages of male patients (46% and 58%, respectively) and patients with biliary stents (8% and 17%), and higher percentages of patients with Karnofsky performance status of 90–100 (78% and 60%) and primary tumors in the body of the pancreas (48% and 31%). The median overall survival was 10.7 months with nab-paclitaxel plus gemcitabine vs 6.9 months with gemcitabine alone (hazard ratio [HR]: 0.82 [95% confidence interval (CI): 0.48–1.40]; P=0.471). Median progression-free survival was 5.3 vs 3.7 months, respectively (HR: 0.70 [95% CI: 0.37–1.33]; P=0.277). The independently assessed overall response rate was 18% vs 5% (response rate ratio, 3.50 [95% CI: 0.78–15.78]; P=0.076). The most common grade ≥3 adverse events with nab-paclitaxel plus gemcitabine and gemcitabine alone were neutropenia (46% vs 33%, respectively), leukopenia (35% vs 19%), anemia (22% vs 0%), asthenia (21% vs 6%), thrombocytopenia (14% vs 3%), and peripheral neuropathy (13% vs 3%).

Conclusion

Although a statistically significant difference between the treatment arms was not reached for efficacy endpoints, this study does report treatment benefit and a manageable safety profile associated with nab-paclitaxel plus gemcitabine in patients treated in Western Europe with metastatic pancreatic cancer.

nab-Paclitaxel Plus Gemcitabine Versus Gemcitabine in Patients with Metastatic Pancreatic Adenocarcinoma: Canadian Subgroup Analysis of the Phase 3 MPACT Trial

INTRODUCTION

The phase III MPACT trial in patients with metastatic pancreatic cancer (MPC) demonstrated superior efficacy of nab-paclitaxel (nab-P) plus gemcitabine (Gem) compared with Gem monotherapy, including the primary endpoint of overall survival (OS; median 8.7 vs. 6.6 months; hazard ratio [HR] 0.72; P < 0.001). A significant treatment difference favoring nab-P + Gem over Gem was observed for OS in patients treated in North America. The majority of patients were from the US (88%) with only 12% from Canada. Healthcare systems and treatment patterns are different between the 2 countries, and there is limited published information on outcomes of Canadian patients treated with first-line nab-P + Gem. This analysis evaluated efficacy and safety outcomes in Canadian patients in the MPACT trial.

METHODS

Treatment-naive patients with MPC (N = 861) received either nab-P 125 mg/m(2) + Gem 1000 mg/m(2) on days 1, 8, and 15 every 4 weeks or Gem 1000 mg/m(2) weekly for the first 7 of 8 weeks (cycle 1) and then on days 1, 8, and 15 every 4 weeks (cycle ≥2).

RESULTS

The MPACT trial enrolled 63 patients in Canada. Baseline characteristics were well balanced and comparable with those of the intent-to-treat population. Both OS (median 11.9 vs. 7.1 months; HR 0.76; P = 0.373) and progression-free survival (median 7.2 vs. 5.2 months; HR 0.65; P = 0.224) were numerically longer and overall response rate (27% vs. 17%; P = 0.312) was numerically higher with nab-P + Gem vs. Gem. The most common grade ≥3 adverse events with nab-P + Gem vs. Gem were neutropenia (22% vs. 10%), fatigue (34% vs. 33%), and neuropathy (25% vs. 0%).

CONCLUSION

This subanalysis confirmed that nab-P + Gem is an efficacious treatment option and has a manageable safety profile in patients with MPC treated in Canada.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT00844649.

FUNDING

Celgene Corporation, Summit, NJ, USA.

Optimizing initial chemotherapy for metastatic pancreatic cancer

The two combination chemotherapy regimens FOLFIRINOX and gemcitabine plus nab-paclitaxel represent major breakthroughs in the management of metastatic pancreatic cancer. Both regimens showed unprecedented survival advantage in the setting of front-line therapy. However, their application for treatment of patients in the community is challenging because of significant toxicities, thus limiting potential benefits to a narrow population of patients. Modifications to the dose intensity or schedule of those regimens improve their tolerability, while likely retaining survival advantage over single-agent chemotherapy. Newer strategies to optimize these two active regimens in advanced pancreatic cancer are being explored that can help personalize treatment to individual patients.

CA19-9 decrease at 8 weeks as a predictor of overall survival in a randomized phase III trial (MPACT) of weekly nab-paclitaxel plus gemcitabine versus gemcitabine alone in patients with metastatic pancreatic cancer

Any CA19-9 decline at week 8 and radiologic response by week 8 each predicted longer OS in both treatment arms. In the nab-P + Gem arm, the higher proportion of patients with week 8 CA19-9 decrease [82% (206/252); median OS 13.2 months] than a RECIST-defined response [16% (40/252); median OS 13.7 months] suggests that CA19-9 decline is a predictor of OS applicable to a larger population.

Background

A phase I/II study and subsequent phase III study (MPACT) reported significant correlations between CA19-9 decreases and prolonged overall survival (OS) with nab-paclitaxel plus gemcitabine (nab-P + Gem) treatment for metastatic pancreatic cancer (MPC). CA19-9 changes at week 8 and potential associations with efficacy were investigated as part of an exploratory analysis in the MPACT trial.

Patients and methods

Untreated patients with MPC (N = 861) received nab-P + Gem or Gem alone. CA19-9 was evaluated at baseline and every 8 weeks.

Results

Patients with baseline and week-8 CA19-9 measurements were analyzed (nab-P + Gem: 252; Gem: 202). In an analysis pooling the treatments, patients with any CA19-9 decline (80%) versus those without (20%) had improved OS (median 11.1 versus 8.0 months; P = 0.005). In the nab-P + Gem arm, patients with (n = 206) versus without (n = 46) any CA19-9 decrease at week 8 had a confirmed overall response rate (ORR) of 40% versus 13%, and a median OS of 13.2 versus 8.3 months (P = 0.001), respectively. In the Gem-alone arm, patients with (n = 159) versus without (n = 43) CA19-9 decrease at week 8 had a confirmed ORR of 15% versus 5%, and a median OS of 9.4 versus 7.1 months (P = 0.404), respectively. In the nab-P + Gem and Gem-alone arms, by week 8, 16% (40/252) and 6% (13/202) of patients, respectively, had an unconfirmed radiologic response (median OS 13.7 and 14.7 months, respectively), and 79% and 84% of patients, respectively, had stable disease (SD) (median OS 11.1 and 9 months, respectively). Patients with SD and any CA19-9 decrease (158/199 and 133/170) had a median OS of 13.2 and 9.4 months, respectively.

Conclusion

This analysis demonstrated that, in patients with MPC, any CA19-9 decrease at week 8 can be an early marker for chemotherapy efficacy, including in those patients with SD. CA19-9 decrease identified more patients with survival benefit than radiologic response by week 8.

GeneMed: An Informatics Hub for the Coordination of Next-Generation Sequencing Studies that Support Precision Oncology Clinical Trials

We have developed an informatics system, GeneMed, for the National Cancer Institute (NCI) molecular profiling-based assignment of cancer therapy (MPACT) clinical trial (NCT01827384) being conducted in the National Institutes of Health (NIH) Clinical Center. This trial is one of the first to use a randomized design to examine whether assigning treatment based on genomic tumor screening can improve the rate and duration of response in patients with advanced solid tumors. An analytically validated next-generation sequencing (NGS) assay is applied to DNA from patients’ tumors to identify mutations in a panel of genes that are thought likely to affect the utility of targeted therapies available for use in the clinical trial. The patients are randomized to a treatment selected to target a somatic mutation in the tumor or with a control treatment. The GeneMed system streamlines the workflow of the clinical trial and serves as a communications hub among the sequencing lab, the treatment selection team, and clinical personnel. It automates the annotation of the genomic variants identified by sequencing, predicts the functional impact of mutations, identifies the actionable mutations, and facilitates quality control by the molecular characterization lab in the review of variants. The GeneMed system collects baseline information about the patients from the clinic team to determine eligibility for the panel of drugs available. The system performs randomized treatment assignments under the oversight of a supervising treatment selection team and generates a patient report containing detected genomic alterations. NCI is planning to expand the MPACT trial to multiple cancer centers soon. In summary, the GeneMed system has been proven to be an efficient and successful informatics hub for coordinating the reliable application of NGS to precision medicine studies.