David R. Parkinson

Considerations in the development of circulating tumor cell technology for clinical use

This manuscript summarizes current thinking on the value and promise of evolving circulating tumor cell (CTC) technologies for cancer patient diagnosis, prognosis, and response to therapy, as well as accelerating oncologic drug development. Moving forward requires the application of the classic steps in biomarker development–analytical and clinical validation and clinical qualification for specific contexts of use. To that end, this review describes methods for interactive comparisons of proprietary new technologies, clinical trial designs, a clinical validation qualification strategy, and an approach for effectively carrying out this work through a public-private partnership that includes test developers, drug developers, clinical trialists, the US Food & Drug Administration (FDA) and the US National Cancer Institute (NCI).

Phase I trial of subcutaneous interleukin-6 in patients with advanced malignancies.

PURPOSE Based on preclinical evidence in murine models that interleukin-6 (IL-6) mediates regression of metastatic tumors, we performed a phase I study of recombinant human IL-6 in patients with refractory advanced malignancies to determine its pharmacokinetics, toxicities, and possible immunologic and antitumor effects. PATIENTS AND METHODS Recombinant IL-6 was administered as a single subcutaneous dose daily for 7 days, with 7 days off therapy followed by another 7 days of IL-6. Doses were escalated in cohorts of three patients starting at 3 micrograms/kg/d, provided that toxicity at the preceding dose level was not dose-limiting. Dose-limiting toxicity was defined as grade III or IV major organ toxicity that did not resolve to grade II or less in 24 hours after stopping IL-6, using the National Cancer Institute Common Toxicity Criteria. Patients were treated with 3, 10, and 30 micrograms/kg/d IL-6 subcutaneously. RESULTS Three patients each were treated at the 3- and 10-micrograms dose levels. Two of five patients treated with 30 micrograms/kg/d IL-6 subcutaneously had grade III major organ toxicity that required IL-6 therapy to be discontinued. All patients experienced fever, chills, and minor fatigue. Significant increases in C-reactive protein (CRP), fibrinogen, platelet counts, and lymphocyte IL-2 receptor levels were seen in patients at the 10- and 30-micrograms/kg dose levels. Decreases in albumin and hemoglobin were observed, particularly at the 30-micrograms/kg dose level. The half-life (T1/2 beta) was 4.2 hours, with a peak IL-6 level at 5 hours. No antitumor responses were seen. CONCLUSION A safely tolerated dose of daily subcutaneous IL-6 is 10 micrograms/kg, with hepatotoxicity and cardiac arrhythmia being the dose-limiting toxicities at 30 micrograms/kg. Phase II trials of IL-6 administered subcutaneously daily for at least 7 days for two cycles with an intervening week of rest are recommended for phase II trials. However, patients with extensive replacement of liver by tumor and abnormal liver functions should receive IL-6 therapy with caution.

Rationale for Biomarkers and Surrogate End Points in Mechanism-Driven Oncology Drug Development

Recent progress in understanding the molecular basis of cancer has redefined the landscape for cancer drug discovery and development. Among the most exciting and promising benefits are molecular targeted cancer therapies, which can be seen as progress toward personalized medicine for cancer patients

Randomized comparison of high-dose and low-dose intravenous interleukin-2 for the therapy of metastatic renal cell carcinoma: an interim report.

PURPOSE A randomized prospective study was performed to compare the efficacy and toxicity of high-dose intravenous bolus interleukin-2 (IL-2) and a lower-dose intravenous bolus regimen for the treatment of metastatic renal cell carcinoma (RCC). PATIENTS AND METHODS Between March 1991 and April 1993, 125 patients with metastatic RCC were randomized to receive IL-2 by intravenous bolus every 8 hours at either 720,000 IU/kg (high-dose) or 72,000 IU/kg (low-dose) to the maximum-tolerated number of doses (or a maximum of 15 doses). After approximately 7 to 10 days, both treatment groups were re-treated with a second identical cycle of therapy. Those patients who were stable or responding to treatment 5 to 6 weeks later went on to receive re-treatment with another course (two cycles) of therapy. Response rates and toxicity were determined for the two treatment arms. RESULTS One hundred twenty-five patients received a total of 208 courses of therapy. Sixty patients were randomized to receive low-dose, and 65 to receive high-dose IL-2. There were no treatment-related deaths in either arm. There was a greater incidence of grade III or IV thrombocytopenia, malaise, and hypotension in patients who received high-dose IL-2, while patients who received low-dose IL-2 had significantly more infections. Three percent of treatment courses with low-dose IL-2 required vasopressor support, compared with 52% of courses with high-dose IL-2. Patients who received low-dose IL-2 had a 7% complete response (CR) and an 8% partial response (PR) rate, and patients who received high-dose IL-2 had a 3% CR and a 17% PR rate. CONCLUSION Low-dose intravenous bolus IL-2 represents an effective regimen for the treatment of metastatic RCC, with preliminary results comparable to those observed with high-dose IL-2. Low-dose IL-2 can be administered with significantly fewer complications, reduced use of vasopressor support, and fewer admissions to an intensive care unit (ICU).

Use of CA-125 in Clinical Trial Evaluation of New Therapeutic Drugs for Ovarian Cancer

##### Ovarian Cancer Incidence and Mortality Rates. Ovarian cancer is the fourth leading cause of death from cancer in women and accounts for the highest mortality rate of all of the gynecological cancers [(1)][1] . Despite aggressive treatment via radical surgery, radiotherapy, or chemotherapy,

Biologically targeted cancer therapy and marginal benefits: are we making too much of too little or are we achieving too little by giving too much?

We describe the development and approval of biologically targeted agents in the clinic through examples chosen from the experience with inhibitors of the epidermal growth factor (EGF) and VEGF pathways. Despite extensive biological rationale for the use of these classes of molecules, marginal clinical benefits have been observed in broad patient populations, and the agents have entered into general clinical practice. We discuss why this situation is unsatisfactory because marginal general benefit may often be at the expense of toxicity to nonbenefiting or even harmed patients. Finally, we point out that emerging technologies bring the promise of allowing the identification of patients who might potentially benefit from a therapy. However, development of this technology will not move forward without broader recognition of its need by the range of stakeholders, including patients, advocates, academic and private oncologists, drug sponsors, and those who develop drugs and diagnostic tests. Clin Cancer Res; 16(24); 5972–80. ©2010 AACR.

Making personalized cancer medicine a reality: challenges and opportunities in the development of biomarkers and companion diagnostics.

The origins of this article stem from discussions at the American Association for Cancer Research Clinical and Translational Cancer Research Think Tank meeting held in San Francisco in early 2010. This article synthesizes the opinions and issues considered at that meeting, and discusses many of the important events that have since occurred in the field of personalized cancer medicine. Although investigators continue to make progress in better linking individual patient biology with risk determination, diagnosis, prognosis, and treatment selection, the pace of this progress continues to be limited by many of the issues identified in the meeting. Clin Cancer Res; 18(3); 619–24. ©2012 AACR.

Evidence of Clinical Utility: An Unmet Need in Molecular Diagnostics for Patients with Cancer

This article defines and describes best practices for the academic and business community to generate evidence of clinical utility for cancer molecular diagnostic assays. Beyond analytical and clinical validation, successful demonstration of clinical utility involves developing sufficient evidence to demonstrate that a diagnostic test results in an improvement in patient outcomes. This discussion is complementary to theoretical frameworks described in previously published guidance and literature reports by the U.S. Food and Drug Administration, Centers for Disease Control and Prevention, Institute of Medicine, and Center for Medical Technology Policy, among others. These reports are comprehensive and specifically clarify appropriate clinical use, adoption, and payer reimbursement for assay manufacturers, as well as Clinical Laboratory Improvement Amendments–certified laboratories, including those that develop assays (laboratory developed tests). Practical criteria and steps for establishing clinical utility are crucial to subsequent decisions for reimbursement without which high-performing molecular diagnostics will have limited availability to patients with cancer and fail to translate scientific advances into high-quality and cost-effective cancer care. See all articles in this CCR Focus section, “The Precision Medicine Conundrum: Approaches to Companion Diagnostic Co-development.” Clin Cancer Res; 20(6); 1428–44. ©2014 AACR.

HLA associations in the antitumor response against malignant melanoma

In this study we analyzed the human leukocyte antigen (HLA) pattern of North American Caucasian patients with metastatic melanoma as compared with the North American Caucasian (NAC) population. We also investigated whether the HLA type of melanoma patients had an effect on their tolerance and response to interleukin-2 (IL-2)-based therapy. Four hundred twelve serologic phenotypes of Caucasian melanoma patients referred to the National Cancer Institute, National Institutes of Health, from February 1989 through December 1993 were collected by typing the patients peripheral blood lymphocytes. Furthermore, 74 melanoma patients were typed for HLA class II by high-resolution sequence specific primer-polymerase chain reaction. Response rate and treatment-related toxicity in those patients receiving IL-2-based treatment (N = 272) were compared with HLA serologic types. The frequency of four HLA-B alleles was significantly different in the melanoma compared with the NAC population: Of these, HLA-B5, -B8, and -B15 had a frequency falling between the NAC and the Northern European population. No other significant differences between melanoma patients and NAC population were noted for other HLA loci. A correlation was noted between HLA-DR3 and -DR4 alleles and decreased tolerance to IL-2, whereas homozygosity for HLA-DR decreased the chance of response. There were no significant associations between HLA type and response. It is unlikely that the associations noted between some HLA-B alleles and melanoma bear significantly on the etiology of the disease. The differences seen between American melanoma patients and the NAC population are probably best explained by geographical ancestry. The association between HLA-DR and tolerance to IL-2 therapy noted in this study may offer insight toward the understanding of mechanisms regulating the cascade of events after the systemic administration of IL-2.

A Phase I Trial of Intravenous Interleukin-6 in Patients with Advanced Cancer

Eighteen patients were treated with escalating doses of recombinant, Escherichia coli-derived human interleukin-6 (IL-6) intravenously every 8 h. Therapy was given for two cycles of 7 days each separated by a week off therapy. Fevers and chills were observed in most patients. Mild renal and liver function abnormalities were noted at higher doses of IL-6. Dose-limiting toxicity was reached at 30 micrograms/kg i.v. every 8 h due to reversible neurotoxicity, but significant rapidly reversible anemia and hyperglycemia were seen at lower doses. Platelet counts, white blood cell counts, and acute phase reactant levels were substantially elevated. No antitumor responses were seen. A maximum tolerated dose of 10 micrograms/kg i.v. every 8 h for two 7-day cycles is recommended for future phase II trials.