Stephen Welch

Feasibility of real time next generation sequencing of cancer genes linked to drug response: results from a clinical trial.

The successes of targeted drugs with companion predictive biomarkers and the technological advances in gene sequencing have generated enthusiasm for evaluating personalized cancer medicine strategies using genomic profiling. We assessed the feasibility of incorporating real‐time analysis of somatic mutations within exons of 19 genes into patient management. Blood, tumor biopsy and archived tumor samples were collected from 50 patients recruited from four cancer centers. Samples were analyzed using three technologies: targeted exon sequencing using Pacific Biosciences PacBio RS, multiplex somatic mutation genotyping using Sequenom MassARRAY and Sanger sequencing. An expert panel reviewed results prior to reporting to clinicians. A clinical laboratory verified actionable mutations. Fifty patients were recruited. Nineteen actionable mutations were identified in 16 (32%) patients. Across technologies, results were in agreement in 100% of biopsy specimens and 95% of archival specimens. Profiling results from paired archival/biopsy specimens were concordant in 30/34 (88%) patients. We demonstrated that the use of next generation sequencing for real‐time genomic profiling in advanced cancer patients is feasible. Additionally, actionable mutations identified in this study were relatively stable between archival and biopsy samples, implying that cancer mutations that are good predictors of drug response may remain constant across clinical stages.

Phase II study of temsirolimus (CCI-779) in women with recurrent, unresectable, locally advanced or metastatic carcinoma of the cervix. A trial of the NCIC Clinical Trials Group (NCIC CTG IND 199)

OBJECTIVE HPV infection has been associated with deregulation of the PI3K-Akt-mTOR pathway in invasive cervical carcinomas. This 2-stage phase II study assessed the activity of the mTOR inhibitor, temsirolimus, in patients with measurable metastatic and/or locally advanced, recurrent carcinoma of the cervix. METHODS Temsirolimus 25mg i.v. was administered weekly in 4 week cycles. One response among the first 18 patients was required to proceed to the second stage of accrual. Correlative molecular studies were performed on archival tumor tissue. RESULTS Thirty-eight patients were enrolled. Thirty-seven patients were evaluable for toxicity and 33 for response. One patient experienced a partial response (3.0%). Nineteen patients had stable disease (57.6%) [median duration 6.5 months (range 2.4-12.0mo)]. The 6-month progression free survival rate was 28% (95% CI: 14-43%). The median progression free survival was 3.52 months [95% CI (1.81-4.70)]. Adverse effects were mild-moderate in most cases and similar to other temsirolimus studies. No toxicity>grade 3 was observed. Assessment of PTEN and PIK3CA by IHC, copy number analyses and PTEN promoter methylation status did not reveal subsets associated with disease stability. CONCLUSION Single agent temsirolimus has modest activity in cervical carcinoma with about two-thirds of patients exhibiting stable disease. Molecular markers for treatment benefit remain to be identified.

Sorafenib in combination with gemcitabine in recurrent epithelial ovarian cancer: a study of the Princess Margaret Hospital Phase II Consortium.

Objectives: Antiangiogenic strategies have demonstrated efficacy in epithelial ovarian cancer (EOC). Sorafenib is a novel multitargeted kinase inhibitor with antiangiogenic activity. Gemcitabine has known activity against EOC. A phase 1 clinical trial of this combination suggested activity in ovarian cancer with no dose-limiting toxicity. This phase 2 study was designed to examine the safety and efficacy of gemcitabine and sorafenib in patients with recurrent EOC. Methods: Patients with recurrent EOC after platinum-based chemotherapy and who had subsequently received up to 3 prior chemotherapy regimens were eligible. Gemcitabine (1000 mg/m2 intravenous [IV]) was administered weekly for 7 of 8 weeks in the first cycle, then weekly for 3 weeks of each subsequent 4-week cycle. Sorafenib (400 mg p.o. bid) was given continuously. The primary end point for this trial was objective response rate by the Response Evaluation Criteria in Solid Tumors. Secondary endpoints included Gynecologic Cancer Intergroup (GCIG) CA-125 response, time to progression, overall survival, and toxicity. Results: Forty-three patients were enrolled, and 33 completed at least 1 cycle. Two patients had a partial response (Response Evaluation Criteria in Solid Tumors objective response rate = 4.7%). Ten patients (23.3%) maintained response or stable disease for at least 6 months. GCIG CA-125 response was 27.9%. The median time to progression was 5.4 months, and the median overall survival was 13.0 months. Hematologic toxicity was common but manageable. The most common nonhematologic adverse events were hand-foot syndrome, fatigue, hypokalemia, and diarrhea. Conclusion: This trial of gemcitabine and sorafenib in recurrent EOC did not meet its primary efficacy end point, but the combination was associated with encouraging rates of prolonged stable disease and CA-125 response.

Testing personalized medicine: patient and physician expectations of next-generation genomic sequencing in late-stage cancer care

Developments in genomics, including next-generation sequencing technologies, are expected to enable a more personalized approach to clinical care, with improved risk stratification and treatment selection. In oncology, personalized medicine is particularly advanced and increasingly used to identify oncogenic variants in tumor tissue that predict responsiveness to specific drugs. Yet, the translational research needed to validate these technologies will be conducted in patients with late-stage cancer and is expected to produce results of variable clinical significance and incidentally identify genetic risks. To explore the experiential context in which much of personalized cancer care will be developed and evaluated, we conducted a qualitative interview study alongside a pilot feasibility study of targeted DNA sequencing of metastatic tumor biopsies in adult patients with advanced solid malignancies. We recruited 29/73 patients and 14/17 physicians; transcripts from semi-structured interviews were analyzed for thematic patterns using an interpretive descriptive approach. Patient hopes of benefit from research participation were enhanced by the promise of novel and targeted treatment but challenged by non-findings or by limited access to relevant trials. Family obligations informed a willingness to receive genetic information, which was perceived as burdensome given disease stage or as inconsequential given faced challenges. Physicians were optimistic about long-term potential but conservative about immediate benefits and mindful of elevated patient expectations; consent and counseling processes were expected to mitigate challenges from incidental findings. These findings suggest the need for information and decision tools to support physicians in communicating realistic prospects of benefit, and for cautious approaches to the generation of incidental genetic information.

Phase II study of oral ridaforolimus in women with recurrent or metastatic endometrial cancer

OBJECTIVE The phosphatidylinositol-3 kinase/serine-threonine kinase PI3K/AKT pathway is postulated to be central to cancer cell development. Activation of this pathway is believed to promote angiogenesis, protein translation and cell cycle progression. A large percentage of endometrial carcinomas have demonstrated mutations within this regulation pathway which result in constitutional activation. The downstream effector protein mammalian target of rapamycin (mTOR) acts as a critical checkpoint in cancer cell cycling and is a logical target for drug development. The efficacy and tolerability of the oral mTOR inhibitor ridaforolimus were evaluated in this study. METHODS This phase II study evaluated the single agent tolerability and activity of oral ridaforolimus administered at a dose of 40mg for 5 consecutive days followed by a 2day break, in women with recurrent or metastatic endometrial carcinoma who had received no chemotherapy in the metastatic setting. RESULTS 31 of 34 patients were evaluable. Three partial responses (8.8%) were observed with response duration ranging between 7.9 and 26.5months. An additional 18 patients showed disease stabilization (52.9%) for a median duration of 6.6months. Response rates were not affected by previous chemotherapy exposure. No correlation was found between response and mutation status. CONCLUSION Oral ridaforolimus was reasonably tolerated and demonstrated modest activity in women with recurrent or metastatic endometrial cancers. Potential synergy between mTOR inhibition, angiogenesis and hormonal pathways warrants ongoing evaluation.

Combination Chemotherapy in Advanced Pancreatic Cancer: Time to Raise the White Flag?

Gemcitabine has been the standard palliative chemotherapy in advanced pancreatic cancer since 1997; this standard was established by a phase III trial that randomly assigned 126 symptomatic patients with advanced pancreatic cancer to either gemcitabine or fluorouracil (FU). 1 Treatment with gemcitabine versus FU was associated with improvements in 1-year survival (18% v 2%, respectively) and clinical benefit response (24% v 5%, respectively). Subsequently, thousands of patients have participated in large phaseIIItrialscomparinggemcitabinealonewithgemcitabineplus a second cytotoxic agent. 2-5 In the current issue, Herrmann et al 6 present another such study, comparing gemcitabine plus capecitabine with gemcitabine alone in advanced disease. The trial by Herrmann et al 6 is of high quality and was based on evidence from earlier phase studies that suggested the combination had sufficient activity to warrant further testing. 7,8 Similar to all prior studies

A phase II trial of sunitinib in women with metastatic or recurrent endometrial carcinoma: A study of the Princess Margaret, Chicago and California Consortia

OBJECTIVE Treatment options remain limited for women with relapsed/metastatic endometrial cancer (EC). Angiogenesis is one of the major components of tumor progression and thus an attractive target. The aim of this phase II trial was to assess the efficacy and tolerability of sunitinib, an oral multitargeted receptor tyrosine-kinase inhibitor with antiangiogenic and antitumor activity in the treatment of recurrent EC. METHODS We performed a multicenter, single arm, two-stage phase II study of sunitinib, 50mg daily administered on a 4 weeks on-2 weeks off schedule. Eligibility criteria included recurrent/metastatic EC or carcinosarcoma with no more than one prior line of chemotherapy. The primary endpoint was objective response rate. RESULTS 34 women were enrolled; 33 received at least one dose of sunitinib and were included in the analyses. Six women (18.1%) had a partial response and six additional women (18.1%) stable disease. In total, ten patients (30.3%) had disease control for at least 6 months and of these, seven were controlled for more than one year. Median progression free and overall survival times were 3 months and 19.4 months, respectively. Adverse events related to treatment were frequent. At least one grade 3 toxicity occurred in 30 patients and dose reductions were required in 17 patients (52%). The most common grade 3 toxicities were fatigue, hypertension, palmar-plantar erythrodysesthesia, diarrhea and hematologic. CONCLUSION Sunitinib therapy showed promising activity in women with recurrent EC. Toxicity was seen frequently but was manageable. Anti-angiogenic agents warrant further investigation in EC to define which patients will derive the greatest benefit.

A phase II study of single-agent RO4929097, a gamma-secretase inhibitor of Notch signaling, in patients with recurrent platinum-resistant epithelial ovarian cancer: A study of the Princess Margaret, Chicago and California phase II consortia

PURPOSE A phase II study was performed to evaluate the efficacy and safety of single-agent RO4929097 (a gamma-secretase inhibitor) in patients with recurrent platinum-resistant ovarian cancer. EXPERIMENTAL DESIGN Women with progressive platinum-resistant ovarian cancer treated with ≤2 chemotherapy regimens for recurrent disease were enrolled in this trial. Patients received oral RO4929097 at 20 mg once daily, 3 days on/4 days off each week in a three week cycle. The primary endpoint was progression-free survival (PFS) rate at the end of 4 cycles. Secondary objectives included assessment of the safety of RO4929097 and exploration of molecular correlates of outcome in archival tumor tissue and serum. RESULTS Of 45 patients enrolled, 40 were evaluable for response. Thirty-seven (82%) patients had high-grade ovarian cancer. No objective responses were observed. Fifteen patients (33%) had stable disease as their best response, with a median duration of 3.1 months. The median PFS for the whole group was 1.3 months (1.2-2.5). Treatment was generally well tolerated with 10% of patients discontinuing treatment due to an adverse event. In high grade serous ovarian cancer patients, the median PFS trended higher when the expression of intracellular Notch (NICD) protein by immunohistochemistry was high versus low (3.3 versus 1.3 months, p=0.09). No clear relationship between circulating angiogenic factors and PFS was found despite a suggestion of an improved outcome with higher baseline VEGFA levels. CONCLUSIONS RO4929097 has insufficient activity as a single-agent in platinum-resistant ovarian cancer to warrant further study as monotherapy. Future studies are needed to explore the potential for cohort enrichment using NICD expression.

Trends in the application of dynamic allocation methods in multi-arm cancer clinical trials

Background Dynamic allocation (DA) methods which attempt to balance baseline prognostic factors between treatment arms, can be used in multi-arm clinical trials to sequentially allocate patients to treatment. Although some experts express concern regarding the validity of inference from trials using DA, others believe DA methods produce more credible results. Purpose A review of published multi-arm cancer clinical trials was conducted to explore the frequency of DA use in oncology. Methods Multi-arm phase III clinical trials of at least 100 patients per arm, published in 13 major oncology journals from 1995—2005 were manually reviewed. Information about reported use of DA methods, or randomization via random permuted blocks (PB), was extracted along with trial characteristics. Results Of 476 published clinical trials, 112 (23.5%) reported using some form of DA method, while 103 (21.6%) reported using PB methods. Most trials (403 or 84.7%) reported stratifying on at least one baseline factor. The mean number of stratification factors was 2.70 per trial, and 78.6% of DA trials reported 3 or more stratification factors compared with 30.2% of non-DA trials (p < 0.001). The frequency of DA use increased over time, with 20.2%, 21.3%, 25.8%, 28.8% and 38.9% of trials reported use in 1995—2001, 2002, 2003, 2004, and 2005, respectively. Use of DA methods was more frequently reported in trials involving an academic co-operative group (28.4% vs. 13.8%), however, no difference was observed between industry-funded and other-funded trials (24.0% vs. 23.2%) or geographical region (19.7% of North American trials, 26.2% of European trials and 21.7% of multinational/other trials). Limitations As a retrospective analysis, the true frequency of DA use is likely underreported. Few trials gave complete details of the allocation method used, thus it is possible some manuscripts reported incorrect allocation methods. Journals were selected which were assumed to publish most large, multi-arm clinical trials in cancer from 1995—2005, however, some trials were likely reported in journals other than what was reviewed. Conclusions DA methods are frequently used in multi-arm cancer clinical trials. The use of DA appears to becoming more common over time and are used more frequently when an academic cooperative group is involved. No relationship between industry funded trials or geographic region and allocation method was observed. Clinical Trials 2010; 7: 227—234. http://ctj.sagepub.com

Erlotinib: success of a molecularly targeted agent for the treatment of advanced pancreatic cancer.

Epidermal growth factor receptor (EGFR) is overexpressed by several solid tumors, including pancreatic cancer, and has become an important target for novel anticancer pharmacotherapy. Erlotinib (Tarceva, OSI-774) is an orally available small-molecule inhibitor of the EGFR tyrosine kinase. The addition of erlotinib to gemcitabine has been shown to prolong survival of patients treated for advanced pancreatic cancer in the National Cancer Institute of Canada PA.3 trial. This survival advantage is small yet noteworthy, in that numerous gemcitabine-containing combinations have failed to show a statistically significant survival advantage over gemcitabine alone. The most frequent toxicities associated with the addition of erlotinib are diarrhea and rash. Erlotinib-induced rash appears to be predictive of outcome. Further clinical studies of erlotinib in the treatment of pancreatic cancer are ongoing.