Accelerating cancer therapy development: the importance of combination strategies and collaboration. Summary of an Institute of Medicine workshop.

Cancer cells contain multiple genetic changes in cell signaling pathways that drive abnormal cell survival, proliferation, invasion, and metastasis. Unfortunately, patients treated with single agents inhibiting only one of these pathways--even if showing an initial response--often develop resistance with subsequent relapse or progression of their cancer, typically via the activation of an alternative uninhibited pathway. Combination therapies offer the potential for inhibiting multiple targets and pathways simultaneously to more effectively kill cancer cells and prevent or delay the emergence of drug resistance. However, there are many unique challenges to developing combination therapies, including devising and applying appropriate preclinical tests and clinical trial designs, prioritizing which combination therapies to test, avoiding overlapping toxicity of multiple agents, and overcoming legal, cultural, and regulatory barriers that impede collaboration among multiple companies, organizations, and/or institutions. More effective strategies to efficiently develop combination cancer therapies are urgently needed. Thus, the Institute of Medicine's National Cancer Policy Forum recently convened a workshop with the goal of identifying barriers that may be impeding the development of combination investigational cancer therapies, as well as potential solutions to overcome those barriers, improve collaboration, and ultimately accelerate the development of promising combinations of investigational cancer therapies.

Final 5-year results of Z-FAST trial: adjuvant zoledronic acid maintains bone mass in postmenopausal breast cancer patients receiving letrozole.

BACKGROUND: Postmenopausal breast cancer (BC) patients receiving adjuvant aromatase inhibitor therapy are at risk of progressive bone loss and fractures. Zoledronic acid inhibits osteoclastic bone resorption, is effective in maintaining bone health, and may therefore be beneficial in this setting. METHODS: Overall, 602 postmenopausal women with early, hormone receptor-positive BC receiving adjuvant letrozole were randomized (301 each group) to receive upfront or delayed-start zoledronic acid (4 mg intravenously every 6 months) for 5 years. The primary endpoint was the change in lumbar spine (LS) bone mineral density (BMD) at month 12. Secondary endpoints included changes in LS BMD, total hip BMD, and bone turnover markers at 2, 3, and 5 years; fracture incidence at 3 years; and time to disease recurrence. RESULTS: At month 61, the adjusted mean difference in LS and total hip BMDs between the upfront and delayed groups was 8.9% and 6.7%, respectively (P < .0001, for both). Approximately 25% of delayed patients received zoledronic acid by month 61. Only 1 patient experienced grade 4 renal dysfunction; no confirmed cases of osteonecrosis of the jaw were reported. Fracture rates (upfront, 28 [9.3%]; delayed, 33 [11%]; P = .3803) and Kaplan-Meier disease recurrence rates (upfront, 9.8 [95% confidence interval (CI), 6.0-10.3]; delayed, 10.5 [95% CI, 6.6-14.4]; P = .6283) were similar at month 61. CONCLUSIONS: Upfront zoledronic acid seems to be the preferred treatment strategy versus delayed administration, as it significantly and progressively increases BMD in postmenopausal women with early BC receiving letrozole for 5 years, and long-term coadministration of letrozole and zoledronic acid is well tolerated.

Perspectives on adherence and persistence with oral medications for cancer treatment.

Ensuring persistence, continuing treatment for the prescribed duration, and adherence-taking medication as prescribed-have been challenges for management of patients with oral cancer and for health care cost containment in real-world settings.

Negotiating for success: navigating the contracting process for an exemplary research program.

Developing successful contracts is imperative for research sites conducting company-sponsored or investigator-initiated clinical trials. Good contracts help ensure sustainability and guide how research will be conducted.

Critical review: updated recommendations for the prevention, diagnosis, and treatment of osteonecrosis of the jaw in cancer patients--May 2006.

In light of recent reports of osteonecrosis of the jaw (ONJ) in cancer patients whose treatment regimens include an intravenous bisphosphonate, Novartis convened an international advisory board of experts in the fields of oral surgery and pathology, medical oncology, metabolic bone disease, and orthopedics to review existing data and provide updated recommendations on the clinical diagnosis, prevention, and management of ONJ in the oncology setting. Recommendations were developed to help guide healthcare professionals in early diagnosis and patient management. It is recommended that patients be encouraged to receive a dental examination prior to initiating bisphosphonate therapy and, if possible, complete any necessary dental procedures (e.g., tooth extraction) prior to initiating bisphosphonate therapy. Patients should receive regular dental visits during bisphosphonate therapy. Patients should be encouraged to practice good oral hygiene and minimize possible jaw trauma. If possible, patients should avoid dental surgery during treatment with bisphosphonates. If exposed bone is observed or reported in the oral cavity at any time (suspected ONJ), refer the patient to a dental professional immediately.

Zoledronic acid inhibits adjuvant letrozole-induced bone loss in postmenopausal women with early breast cancer.

PURPOSE: Treatment with aromatase inhibitors decreases bone mineral density (BMD) and may increase the risk of fractures in postmenopausal women with early-stage breast cancer. The addition of zoledronic acid to adjuvant letrozole therapy may protect against bone loss. PATIENTS AND METHODS: Patients receiving adjuvant letrozole were randomly assigned to receive either upfront or delayed-start zoledronic acid (4 mg intravenously every 6 months). The delayed group received zoledronic acid when lumbar spine (LS) or total hip (TH) T score decreased to less than -2.0 or when a nontraumatic fracture occurred. The primary end point of this study was to compare the change in LS BMD at month 12 between the groups. Secondary end points included change in TH BMD and changes in serum bone turnover markers at month 12. RESULTS: The upfront and delayed groups each included 301 patients. At month 12, LS BMD was 4.4% higher in the upfront group than in the delayed group (95% CI, 3.7% to 5.0%; P < .0001), and TH BMD was 3.3% higher (95% CI, 2.8% to 3.8%; P < .0001). In the upfront group, mean serum N-telopeptide and bone-specific alkaline phosphatase concentrations decreased by 15.1% (P < .0001) and 8.8% (P = .0006), respectively, at month 12, whereas concentrations increased significantly in the delayed group by 19.9% (P = .013) and 24.3% (P < .0001), respectively. CONCLUSION: With 1 year of follow-up, results of the primary end point of the Zometa-Femara Adjuvant Synergy Trial (Z-FAST) indicate that upfront zoledronic acid therapy prevents bone loss in the LS in postmenopausal women receiving adjuvant letrozole for early-stage breast cancer.

A multicenter, randomized trial of long-acting octreotide for the optimum prevention of chemotherapy-induced diarrhea: results of the STOP trial.

Diarrhea is a well-recognized side effect of chemotherapy and can result in chemotherapy delay and/or dose reduction, potentially reducing the therapeutic benefit of treatment. Octreotide has been shown to be effective in controlling chemotherapy-induced diarrhea (CID). In this open-label, randomized, multicenter study, designed to asses the effects of two dose levels of octreotide long-acting release (LAR), patients with active or prior CID and scheduled for chemotherapy were randomized to receive up to six doses of either 30 or 40 mg of octreotide LAR. The primary endpoint was the proportion of patients experiencing severe diarrhea during the trial. Secondary endpoints included the proportion of patients requiring IV fluids due to diarrhea, unscheduled visits to healthcare professionals due to diarrhea, and changes in primary therapy, as well as treatment satisfaction and quality of life. In total, 147 patients were randomized and received at least 1 dose; 124 patients were efficacy-evaluable. Baseline characters were balanced in the 30-mg and 40-mg groups with the exception of gender. Fewer patients in the 40-mg group compared with those in the 30-mg group experienced severe diarrhea (61.7% vs 48.4%; P = 0.14), required IV fluid (31.7% vs 18.8%; P = 0.10), and had diarrhea-related unscheduled healthcare visits (41.7% vs. 28.1 %; P = 0.11); however, these differences were not statistically significant. No significant differences were observed between the treatment groups in either measured quality of life or treatment satisfaction. Adverse events were balanced between the two groups. No specific recommendations can be made from this trial regarding the use of 30 mg versus 40 mg of octreotide LAR for CID.

Safety and pain palliation of zoledronic acid in patients with breast cancer, prostate cancer, or multiple myeloma who previously received bisphosphonate therapy.

An open-label study conducted in community centers assessed the safety of zoledronic acid 4 mg intravenously over 15 minutes every 3-4 weeks as treatment of bone metastases in patients with multiple myeloma, breast cancer, or prostate cancer with and without previous bisphosphonate exposure. Adverse events (AEs), pain, and quality-of-life (QOL) scores were recorded, and serum creatinine (SCr) levels were measured before each infusion. Of 638 patients, 415 patients (65%) had received prior bisphosphonate therapy. Fatigue, nausea, and arthralgia were the most frequent AEs. Nausea was more common in bisphosphonate-naive patients. SCr levels increased notably in 6.6% of patients: 7.7% of patients who received prior bisphosphonate therapy and 4.5% of bisphosphonate-naive patients. Treatment was delayed because of SCr-level increases in 1.4% of patients with prior bisphosphonate exposure and 0.4% of bisphosphonate-naive patients. SCr-level increases and treatment delays did not correlate with duration of prior bisphosphonate therapy. There was a trend towards more treatment discontinuations in patients with prior bisphosphonate exposure compared with bisphosphonate-naive patients. Pain scores decreased from baseline; total QOL scores remained constant. The results of this study suggest that, with proper SCr-level monitoring, cancer patients with bone metastases who have previously received intravenous bisphosphonate treatment can be safely converted to zoledronic acid therapy.

Zoledronic acid for the treatment of bone metastases in patients with breast cancer and other solid tumors.

Painful and life-threatening skeletal complications are common in patients with advanced cancer metastatic to bone. Patients with breast cancer and multiple myeloma who survive for 2 or more years after developing bone metastases/lesions are at chronic risk for skeletal complications. Patients with prostate cancer and other solid tumors are also at high risk for skeletal complications, and, until recently, no effective treatment had been identified. Zoledronic acid, a new-generation bisphosphonate, was recently shown to be safe and effective as treatment for the prevention of skeletal complications in three randomized, phase III trials involving more than 3000 patients with multiple myeloma, breast, prostate, and lung cancers, and other solid tumors. Zoledronic acid (4 mg) was at least as effective as pamidronate (90 mg) in preventing skeletal complications in the overall study population of patients with breast cancer and multiple myeloma and was superior to pamidronate in the subset of over 1000 patients with breast cancer. In patients with solid tumors, including prostate cancer and lung cancer, zoledronic acid significantly reduced the incidence and delayed the onset of skeletal complications compared with placebo. Zoledronic acid is the first bisphosphonate with broad clinical utility and may become the preferred bisphosphonate for the treatment of bone metastases in patients with advanced cancers.

EPO906 (epothilone B): a promising novel microtubule stabilizer.

EPO906 (epothilone B) is a potent member of a new class of microtubule-stabilizing cytotoxic agents known as epothilones. Although structurally unrelated to the clinically validated taxanes, EPO906 acts similarly to promote the formation and stabilization of microtubules, arresting proliferating cells in mitosis, and eventually causing cell demise by apoptosis. In preclinical studies, EPO906 has shown anticancer activity both in vitro and in vivo against several cancer types, including models that are paclitaxel-resistant. Importantly, in contrast to the taxanes, EPO906 retained activity against cancer cells either overexpressing the P-glycoprotein efflux pump or bearing tubulin mutations. Two phase I studies with EPO906 were conducted to determine the safety and maximal tolerated dose on two different dosing schedules: weekly and every 3 weeks. Diarrhea was the dose-limiting toxicity on both schedules. Tumor responses were seen in colorectal cancer as well as a variety of other tumor types, such as breast, ovarian, lung, and carcinoid in these two phase I trials. Based on the promising results from phase I studies, phase II studies in numerous indications are ongoing.