Clinically meaningful responses to sequential gemcitabine-based chemotherapy regimens in a patient with metastatic pancreatic cancer

National Cancer Institute's Precision Medicine Initiatives for the new National Clinical Trials Network

The promise of precision medicine will only be fully realized if the research community can adapt its clinical trials methodology to study molecularly characterized tumors instead of the traditional histologic classification. Such trials will depend on adequate tissue collection, availability of quality controlled, high throughput molecular assays, and the ability to screen large numbers of tumors to find those with the desired molecular alterations. The National Cancer Institute's (NCI) new National Clinical Trials Network (NCTN) is well positioned to conduct such trials. The NCTN has the ability to seamlessly perform ethics review, register patients, manage data, and deliver investigational drugs across its many sites including both in cities and rural communities, academic centers, and private practices. The initial set of trials will focus on different questions: (1) Exceptional Responders Initiative-why do a minority of patients with solid tumors or lymphoma respond very well to some drugs even if the majority do not?; (2) NCI MATCH trial-can molecular markers predict response to targeted therapies in patients with advanced cancer resistant to standard treatment?; (3) ALCHEMIST trial-will targeted epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) inhibitors improve survival for adenocarcinoma of the lung in the adjuvant setting?; and (4) Lung Cancer Master Protocol trial for advanced squamous cell lung cancer-is there an advantage to developing drugs for small subsets of molecularly characterized tumors in a single, multiarm trial design? These studies will hopefully spawn a new era of treatment trials that will carefully select the tumors that may respond best to investigational therapy.

Recent innovations in the USA National Cancer Institute-sponsored investigator initiated Phase I and II anticancer drug development

Exciting recent advancements in deep-sequencing technology have enabled a rapid and cost-effective molecular characterization of patient-derived tumor samples. Incorporating these innovative diagnostic technologies into early clinical trials could significantly propel implementation of precision medicine by identifying genetic markers predictive of sensitivity to agents. It may also markedly accelerate drug development and subsequent regulatory approval of novel agents. Particularly noteworthy, a high-response rate in a Phase II trial involving a biomarker-enriched patient cohort could result in a regulatory treatment approval in rare histologies, which otherwise would not be a candidate for a large randomized clinical trial. Furthermore, even if a trial does not meet its statistical endpoint, tumors from a few responders should be molecularly characterized as part of the new biomarker-mining processes. In order to accommodate patient screening and accelerate the accrual process, institutions conducting early clinical trials need to be a part of a multi-institution clinical trials network. Future clinical trial design will incorporate new biomarkers discovered by a 'phenotype-to-genotype' effort with an appropriate statistical design. To help advance such changes, the National Cancer Institute has recently reformed the existing early phase clinical trials network. A new clinical trial network, the Experimental Therapeutics Clinical Trials Network (ET-CTN), was begun and, in addition to its pre-existing infrastructure, an up-to-date clinical trial registration system, clinical trial monitoring system including electronic database and a central Institutional Review Board were formed. Ultimately, these reforms support identifying the most appropriate therapy for each tumor type by incorporating state-of-the-art molecular diagnostic tools into early clinical trials.

A Near-Complete Response to Treatment with Gemcitabine plus nab (®)-Paclitaxel in a Patient with Metastatic Pancreatic Cancer and Poor Performance Status: A Case Report

Patients with metastatic pancreatic adenocarcinoma and poor performance status (PS) are typically excluded from clinical trials of new systemic treatments. Due to concerns that such patients cannot tolerate the greater toxicity sometimes associated with combination chemotherapy regimens, the recommended treatment for pancreatic cancer patients with poor PS is gemcitabine monotherapy. We report the case of a 79-year-old female with pancreatic adenocarcinoma metastatic to the lungs, with multiple comorbidities and an Eastern Cooperative Oncology Group PS of 3, who achieved a rapid and prolonged objective response to gemcitabine plus nab^®-paclitaxel. The patient received a total of 11 cycles of treatment. Although her disease was well controlled with gemcitabine plus nab-paclitaxel, she died just over 11 months after diagnosis as a result of her comorbid conditions compounded by treatment-related hematologic toxicity. This case suggests that patients with metastatic pancreatic adenocarcinoma and poor PS may benefit from first-line combination therapy with gemcitabine plus nab-paclitaxel. Further study of this regimen in such patients is warranted.

A phase I study of an agonist CD40 monoclonal antibody (CP-870,893) in combination with gemcitabine in patients with advanced pancreatic ductal adenocarcinoma

PURPOSE

This phase I study investigated the maximum-tolerated dose (MTD), safety, pharmacodynamics, immunologic correlatives, and antitumor activity of CP-870,893, an agonist CD40 antibody, when administered in combination with gemcitabine in patients with advanced pancreatic ductal adenocarcinoma (PDA).

EXPERIMENTAL DESIGN

Twenty-two patients with chemotherapy-naïve advanced PDA were treated with 1,000 mg/m(2) gemcitabine once weekly for three weeks with infusion of CP-870,893 at 0.1 or 0.2 mg/kg on day three of each 28-day cycle.

RESULTS

CP-870,893 was well-tolerated; one dose-limiting toxicity (grade 4, cerebrovascular accident) occurred at the 0.2 mg/kg dose level, which was estimated as the MTD. The most common adverse event was cytokine release syndrome (grade 1 to 2). CP-870,893 infusion triggered immune activation marked by an increase in inflammatory cytokines, an increase in B-cell expression of costimulatory molecules, and a transient depletion of B cells. Four patients achieved a partial response (PR). 2-[(18)F]fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography (FDG-PET/CT) showed more than 25% decrease in FDG uptake within primary pancreatic lesions in six of eight patients; however, responses observed in metastatic lesions were heterogeneous, with some lesions responding with complete loss of FDG uptake, whereas other lesions in the same patient failed to respond. Improved overall survival correlated with a decrease in FDG uptake in hepatic lesions (R = -0.929; P = 0.007).

CONCLUSIONS

CP-870,893 in combination with gemcitabine was well-tolerated and associated with antitumor activity in patients with PDA. Changes in FDG uptake detected on PET/CT imaging provide insight into therapeutic benefit. Phase II studies are warranted.