Phase 2 study evaluating intermittent and continuous linsitinib and weekly paclitaxel in patients with recurrent platinum resistant ovarian epithelial cancer.

BACKGROUND: Linsitinib, an oral, dual inhibitor of insulin-like growth factor-1 receptor and insulin receptor, in combination with weekly paclitaxel, may improve clinical outcomes compared with paclitaxel alone in patients with refractory or platinum-resistant ovarian cancer. PATIENTS AND METHODS: This open-label phase 1/2 clinical trial (NCT00889382) randomized patients with refractory or platinum-resistant ovarian cancer (1:1:1) to receive either oral intermittent linsitinib (600mg once daily on Days 1-3 per week) combined with paclitaxel (80mg/m2 on Days 1, 8, and 15; Arm A) or continuous linsitinib (150mg twice daily) in combination with paclitaxel (Arm B), or paclitaxel alone (Arm C). Primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), overall response rate (ORR), disease control rate (DCR), and safety/tolerability. RESULTS: A total of 152 women were randomized to treatment (n=51 Arm A; n=51 Arm B, n=50 Arm C). In combination with paclitaxel, neither intermittent linsitinib (median PFS 2.8months; 95% confidence interval [CI]:2.5-4.4) nor continuous linsitinib (median PFS 4.2months; 95% CI:2.8-5.1) improved PFS over weekly paclitaxel alone (median PFS 5.6months; 95% CI:3.2-6.9). No improvement in ORR, DCR, or OS in either linsitinib dosing schedule was observed compared with paclitaxel alone. Adverse event (AE) rates, including all-grade and grade 3/4 treatment-related AEs, and treatment-related AEs leading to discontinuation, were higher among patients receiving intermittent linsitinib compared with the other treatment arms. CONCLUSION: Addition of intermittent or continuous linsitinib with paclitaxel did not improve outcomes in patients with platinum-resistant/refractory ovarian cancer compared with paclitaxel alone.

Nibrin is a marker of clinical outcome in patients with advanced serous ovarian cancer treated in the phase III OVA-301 trial.

OBJECTIVE: This study investigated the relationship between 13 proteins involved in DNA damage and the outcomes of patients with recurrent ovarian cancer (ROC). PATIENTS AND METHODS: Immunohistochemistry staining was performed in 114 diagnostic samples from patients with serous ROC who participated in the OVA-301 study, which compared pegylated liposomal doxorubicin (PLD) with a combination of trabectedin plus PLD. Percentage of positive cells for every marker was calculated and correlated with overall response rate (ORR), progression-free survival (PFS) and overall survival (OS). RESULTS: A statistically significant correlation between high levels of nibrin and lower ORR (P=0.03), shorter PFS (P=0.007) and shorter OS (P=0.01) was observed. After stratification, in patients with platinum-sensitive disease treated with the combination of trabectedin plus PLD, high levels of nibrin correlated with lower ORR (P=0.01) and shorter PFS (P=0.02). A better clinical outcome (ORR, PFS and OS) was also associated to low levels of CHK2 in trabectedin plus PLD treated patients. No correlations were found in PLD-treated patients. According to the results of a multivariate analysis, there was a statistically significant correlation between high nibrin (P=0.001) and low BRCA2 levels (P=0.03) and a worse PFS, and between high nibrin levels and a worse OS (P=0.006). CONCLUSION: Our results indicate that high nibrin expression seems to be associated with a worse clinical outcome in serous ROC, particularly in patients treated with the combination trabectedin plus PLD. Prospective studies to determine clinical usefulness of nibrin as a possible biomarker in other series of patients with ROC are warranted.

Patient-reported outcomes in relapsed ovarian cancer: results from a randomized Phase III study of trabectedin with pegylated liposomal doxorubicin (PLD) versus PLD alone.

OBJECTIVE: Trabectedin in combination with PLD improves progression-free survival (PFS) and overall response rate (ORR) in comparison to PLD alone in patients with relapsed ovarian cancer (J Clin Oncol; 2010 28:3107-14). Here we report the impact of the treatment combination on patient-reported functional status and symptoms. METHODS: Patient-reported outcome (PRO) questionnaires, EORTC-QLQ C30, OV28, and EQ-5D were completed by patients at screening and on Day 1 of every other treatment cycle starting with Cycle 1, and at the end-of-treatment visit. RESULTS: Of the 672 patients randomized in this study, 663 treated patients completed at least one of the baseline questionnaires. Median cycles of treatment was 6 (131 days) for the combination arm and 5 (143 days) for the monotherapy arm. Longitudinal data analyses showed no significant differences between the treatment arms for any of the pre-specified scales. Similar analyses of other scales, including Health Index scores and Health State on the Visual Analog Scale, support these findings. Start of subsequent therapy was significantly delayed in the combination arm compared with the monotherapy arm (p=0.0032). CONCLUSIONS: The addition of trabectedin to PLD led to little or no decrement in patient-reported functional status and symptoms in patients with relapsed ovarian cancer, as compared to treatment with PLD alone. The combination led to manageable and non-cumulative overall toxicity with a fewer PLD-associated adverse events, and a significant improvement in PFS and ORR compared to single agent.

Revisiting the role of antiandrogen strategies in ovarian cancer.

Androgen receptors are frequently expressed in epithelial ovarian cancer (EOC). Their role in the development of EOC is not fully understood. In the present review we first discuss the epidemiological data linking a hyperandrogen state to a higher risk for ovarian cancer, second describe in vitro studies of the role of androgens in influencing the growth of EOC, and finally review the completed clinical trials with compounds that exploit the androgen axis in patients with ovarian cancer. The therapeutic approaches that inhibit androgen signaling have so far produced only modest response rates. In the light of new data regarding the role of androgen stimulation in the evolution of EOC and the emergence of new compounds used for the treatment of other hormone-driven malignancies, such as prostate and breast cancer, we provide suggestions for new studies of antiandrogen therapeutics in the treatment of EOC. A specific example is the new agent abiraterone. In addition, we propose a panel of molecules that could be assessed as potential biomarkers that may aid patient selection for this approach in the future.

Efficacy and safety of sorafenib in a subset of patients with advanced soft tissue sarcoma from a Phase II randomized discontinuation trial.

AIM: Phase II multi-disease randomized discontinuation trial to assess the safety and efficacy of sorafenib including patients with advanced soft tissue sarcoma (STS). METHODS: Sorafenib (400 mg twice daily) was initially administered for 12 weeks. Patients with: ≥25% tumour shrinkage continued sorafenib; ≥25% tumour growth discontinued; other patients were randomized and received sorafenib or placebo. RESULTS: Twenty-six patients (median age 55 years) were enrolled. Common drug-related adverse events, including fatigue, hand-foot skin reaction, rash or gastrointestinal disturbances, were manageable, reversible and generally low grade. Fatigue, skin toxicity, nausea, diarrhoea and hypertension occurred at grade ≥3 in 19% of patients. After 12 weeks eight (31%) patients had not progressed. Three patients who experienced tumour shrinkage and continued on sorafenib, and five (19%) were randomized either to continue sorafenib or to receive placebo. Of the three patients randomized to sorafenib, one achieved a partial response and two had SD. Overall one patient achieved a partial response and three further patients achieved minor responses. CONCLUSIONS: There was evidence of disease activity in STS as defined by tumor regressions including one objective partial response. Further investigation in STS is warranted.

Circulating tumor cells predict progression free survival and overall survival in patients with relapsed/recurrent advanced ovarian cancer.

OBJECTIVE: Serial circulating tumor cell (CTC) counts have demonstrated predictive and prognostic value in patients with metastatic breast, colorectal, and prostate cancer. In a phase III study of pegylated liposomal doxorubicin (PLD) with trabectedin vs. PLD for relapsed ovarian cancer, we evaluated the correlation, if any, between numbers of CTCs and progression free survival, (PFS) and overall survival (OS). METHODS: CTCs were isolated from peripheral blood (10 mL) using the CellSearch system and reagents (Veridex). A CTC is defined as EpCAM+, cytokeratin+, CD45-, and is positive for the nuclear stain DAPI. The normal reference range for CellSearch is <2 CTC/7.5 mL of blood. Hazard ratios adjusted for known prognostic factors were estimated by Cox regression. RESULTS: Two-hundred sixteen patients had baseline CTC measurements of which 111 (51.4%) were randomized to the trabectedin+PLD arm; 143/216 patients (66.2%) were platinum-sensitive. Thirty-one of 216 patients (14.4%) had 2 or more CTCs detected prior to the start of therapy (range 2-566). Univariate Cox regression analyses indicated that patients with ≥2 CTCs prior to therapy had 1.89- (p=0.003) and 2.06-fold (p=0.003) higher risk for progression and death respectively. Multivariate analyses that include baseline CA-125, platinum sensitivity status, largest diameter lesion, number of tumor lesions, ECOG PS, and tumor grade show that patients with elevated baseline CTC had 1.58- (p=0.058) and 1.54-fold (p=0.096) higher risk for progression and death respectively. CONCLUSIONS: Results from this study indicate that elevated numbers of CTCs impart an unfavorable prognosis for ovarian cancer patients.

PPM1D is a potential therapeutic target in ovarian clear cell carcinomas.

PURPOSE: To identify therapeutic targets in ovarian clear cell carcinomas, a chemoresistant and aggressive type of ovarian cancer. EXPERIMENTAL DESIGN: Twelve ovarian clear cell carcinoma cell lines were subjected to tiling path microarray comparative genomic hybridization and genome-wide expression profiling analysis. Regions of high-level amplification were defined and genes whose expression levels were determined by copy number and correlated with gene amplification were identified. The effects of inhibition of PPM1D were assessed using short hairpin RNA constructs and a small-molecule inhibitor (CCT007093). The prevalence of PPM1D amplification and mRNA expression was determined using chromogenic in situ hybridization and quantitative real-time reverse transcription-PCR in a cohort of pure ovarian clear cell carcinomas and on an independent series of unselected epithelial ovarian cancers. RESULTS: Array-based comparative genomic hybridization analysis revealed regions of high-level amplification on 1q32, 1q42, 2q11, 3q24-q26, 5p15, 7p21-p22, 11q13.2-q13.4, 11q22, 17q21-q22, 17q23.2, 19q12-q13, and 20q13.2. Thirty-four genes mapping to these regions displayed expression levels that correlated with copy number gains/amplification. PPM1D had significantly higher levels of mRNA expression in ovarian clear cell carcinoma cell lines harboring gains/amplifications of 17q23.2. PPM1D inhibition revealed that PPM1D expression and phosphatase activity are selectively required for the survival of ovarian clear cell carcinoma cell lines with 17q23.2 amplification. PPM1D amplification was significantly associated with ovarian clear cell carcinoma histology (P = 0.0003) and found in 10% of primary ovarian clear cell carcinomas. PPM1D expression levels were significantly correlated with PPM1D gene amplification in primary ovarian clear cell carcinomas. CONCLUSION: Our data provide strong circumstantial evidence that PPM1D is a potential therapeutic target for a subgroup of ovarian clear cell carcinomas.

Transient ectopic expression as a method to detect genes conferring drug resistance.

Ectopic expression provides an alternative to RNAi to conduct functional genomic screens. We have determined whether transient expression can be used to identify genes which confer drug resistance. We constructed a bigenic vector that allows high throughput cloning and which also encodes a red fluorescent protein to monitor transfection. Assay conditions were optimized to allow detection of changes in sensitivity to carboplatin or paclitaxel. Following transient expression of MDR-1 and MCJ, changes in the sensitivity of Sk-Ov-3 cells to paclitaxel were detected whereas expression of Src, Bcl-2 and Bcl-X(L) decreased the sensitivity of Sk-Ov-3 cells to carboplatin. This approach may potentially be used as an independent screen or as a method to help rank hit identified in screens utilizing methods such as RNAi.

Potentiation of paclitaxel activity by the HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin in human ovarian carcinoma cell lines with high levels of activated AKT.

Activation of the phosphatidylinositol-3-kinase (PI3K)/AKT survival pathway is a mechanism of cytotoxic drug resistance in ovarian cancer, and inhibitors of this pathway can sensitize to cytotoxic drugs. The HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) depletes some proteins involved in PI3K/AKT signaling, e.g., ERBB2, epidermal growth factor receptor (EGFR), and phosphorylated AKT (p-AKT). 17-AAG and paclitaxel were combined (at a fixed 1:1 ratio of their IC(50)) in four ovarian cancer cell lines that differ in expression of p-AKT, EGFR, and ERBB2. The EGFR-overexpressing A431 and KB epidermoid cell lines were also included. Combination indices (CI) were calculated using the median-effect equation and interpreted in the context of 17-AAG-mediated inhibition of PI3K signaling. Synergy was observed in IGROV-1- and ERBB2-overexpressing SKOV-3 ovarian cancer cells that express a high level of constitutively activated p-AKT [CI at fraction unaffected (fu)(0.5) = 0.50 and 0.53, respectively]. Slight synergy was observed in A431 cells (moderate p-AKT/overexpressed EGFR; CI at fu(0.5) = 0.76) and antagonism in CH1 (moderate p-AKT), HX62 cells (low p-AKT), and KB cells (low p-AKT/overexpressed EGFR; CI at fu(50) = 3.0, 3.5, and 2.0, respectively). The observed effects correlated with changes in the rate of apoptosis induction. 17-AAG induced a decrease in HSP90 client proteins (e.g., C-RAF, ERBB2, and p-AKT) or in downstream markers of their activity (e.g., phosphorylated extracellular signal-regulated kinase or p-AKT) in SKOV-3, IGROV-1, and CH1 cells at IC(50) concentrations. A non-growth-inhibitory concentration (6 nmol/L) reduced the phosphorylation of AKT (but not extracellular signal-regulated kinase) and sensitized SKOV-3 cells to paclitaxel. In conclusion, 17-AAG may sensitize a subset of ovarian cancer to paclitaxel, particularly those tumors in which resistance is driven by ERBB2 and/or p-AKT.

Indolent peritoneal mesothelioma: PI3K-mTOR inhibitors as a novel therapeutic strategy.

Peritoneal mesothelioma (MPeM) is a scarce abdominal-pelvic malignancy that presents with non-specific features and exhibits a wide clinical spectrum from indolent to aggressive disease. Due to it being a rare entity, there is a lack of understanding of its molecular drivers. Most treatment data are from limited small studies or extrapolated from pleural mesothelioma. Standard treatment includes curative surgery or pemetrexed-platinum palliative chemotherapy. To date, the use of novel targeted agents has been disappointing. Described is the management of two young women with papillary peritoneal mesothelioma with widespread recurrence having received platinum-pemetrexed chemotherapy. Both patients obtained symptomatic and disease benefit with apitolisib, a dual phosphoinositide 3-kinase-mammalian target of rapamycin (PI3K-mTOR) inhibitor for subsequent relapses, with one patient having a partial response for almost 3 years. Both are alive and well 10-13 years from diagnosis. CONCLUSION: These case presentations highlight a subgroup of rare MPeM that behave indolently that is compatible with long-term survival. This series identifies the use of targeted therapies with PI3K-mTOR-based inhibitors as a novel approach, warranting further clinical assessment. Development of prognostic biomarkers is essential to aid identify tumour aggressiveness, help stratify patients and facilitate treatment decisions.

Modulation of Plasma Metabolite Biomarkers of the MAPK Pathway with MEK Inhibitor RO4987655: Pharmacodynamic and Predictive Potential in Metastatic Melanoma.

MAPK pathway activation is frequently observed in human malignancies, including melanoma, and is associated with sensitivity to MEK inhibition and changes in cellular metabolism. Using quantitative mass spectrometry-based metabolomics, we identified in preclinical models 21 plasma metabolites including amino acids, propionylcarnitine, phosphatidylcholines, and sphingomyelins that were significantly altered in two B-RAF-mutant melanoma xenografts and that were reversed following a single dose of the potent and selective MEK inhibitor RO4987655. Treatment of non-tumor-bearing animals and mice bearing the PTEN-null U87MG human glioblastoma xenograft elicited plasma changes only in amino acids and propionylcarnitine. In patients with advanced melanoma treated with RO4987655, on-treatment changes of amino acids were observed in patients with disease progression and not in responders. In contrast, changes in phosphatidylcholines and sphingomyelins were observed in responders. Furthermore, pretreatment levels of seven lipids identified in the preclinical screen were statistically significantly able to predict objective responses to RO4987655. The RO4987655 treatment-related changes were greater than baseline physiological variability in nontreated individuals. This study provides evidence of a translational exo-metabolomic plasma readout predictive of clinical efficacy together with pharmacodynamic utility following treatment with a signal transduction inhibitor. Mol Cancer Ther; 16(10); 2315-23. ©2017 AACR.

Phase I pharmacokinetic and pharmacodynamic study of 17-allylamino, 17-demethoxygeldanamycin in patients with advanced malignancies.

PURPOSE: To study the toxicity and pharmacokinetic-pharmacodynamic profile of 17-allylamino, 17- demethoxygeldanamycin (17-AAG) and to recommend a dose for phase II trials. PATIENTS AND METHODS: This was a phase I study examining a once-weekly dosing schedule of 17-AAG. Thirty patients with advanced malignancies were treated. RESULTS: The highest dose level reached was 450 mg/m(2)/week. The dose-limiting toxicities (DLTs) encountered were grade 3 diarrhea in three patients (one at 320 mg/m(2)/week and two at 450 mg/m(2)/week) and grade 3 to 4 hepatotoxicity (AST/ALT) in one patient at 450 mg/m(2)/week. Two of nine DLTs were at the highest dose level. Two patients with metastatic melanoma had stable disease and were treated for 15 and 41 months, respectively. The dose versus area under the curve-relationship for 17-AAG was linear (r(2) = .71) over the dose range 10 to 450 mg/m(2)/week, with peak plasma concentrations of 8,998 mug/L (standard deviation, 2,881) at the highest dose level. After the demonstration of pharmacodynamic changes in peripheral blood leukocytes, pre- and 24 hours post-treatment, tumor biopsies were performed and demonstrated target inhibition (c-RAF-1 inhibition in four of six patients, CDK4 depletion in eight of nine patients and HSP70 induction in eight of nine patients) at the dose levels 320 and 450 mg/m(2)/week. It was not possible to reproducibly demonstrate these changes in biopsies taken 5 days after treatment. CONCLUSION: It has been possible to demonstrate that 17-AAG exhibits a tolerable toxicity profile with therapeutic plasma concentrations and target inhibition for 24 hours after treatment and some indications of clinical activity at the dose level 450 mg/m(2)/week. We recommend this dose for phase II clinical trials.

Acquired resistance to combination treatment through loss of synergy with MEK and PI3K inhibitors in colorectal cancer.

Historically, understanding of acquired resistance (AQR) to combination treatment has been based on knowledge of resistance to its component agents. To test whether an altered drug interaction could be an additional factor in AQR to combination treatment, models of AQR to combination and single agent MEK and PI3K inhibitor treatment were generated. Combination indices indicated combination treatment of PI3K and MEK inhibitors remained synergistic in cells with AQR to single agent but not combination AQR cells. Differences were also observed between the models in cellular phenotypes, pathway signaling and drug cross-resistance. Genomics implicated TGFB2-EDN1 overexpression as candidate determinants in models of AQR to combination treatment. Supplementation of endothelin in parental cells converted synergism to antagonism. Silencing of TGFB2 or EDN1 in cells with AQR conferred synergy between PI3K and MEK inhibitor. These results highlight that AQR to combination treatment may develop through alternative mechanisms to those of single agent treatment, including a change in drug interaction.

Mucinous epithelial ovarian cancer: a separate entity requiring specific treatment.

PURPOSE: Invasive mucinous carcinoma of the ovary (mucinous epithelial ovarian cancer [mEOC]) is a histologic subgroup of epithelial ovarian cancer (EOC). Chemotherapy for mEOC is chosen according to guidelines established for EOC. The purpose of this study is to determine whether this is appropriate. PATIENTS AND METHODS: Women with advanced mEOC (International Federation of Gynecology and Obstetrics stage III or IV) who underwent first-line platinum-based chemotherapy were compared with women with other histologic subtypes of EOC in a case-controlled study. RESULTS: Eighty-one patients (27 cases, 54 controls) treated with platinum-based regimens were analyzed. The response rates for cases and controls were 26.3% (95% CI, 9.2% to 51.2%) and 64.9% (95% CI, 47.5% to 79.8%), respectively (P=.01). The odds ratio for complete or partial response to chemotherapy for mEOC was 0.19 (95% CI, 0.06 to 0.66; P=.009) compared with other histologic subtypes of EOC. Median progression-free survival was 5.7 months (95% CI, 1.9 to 9.6 months) versus 14.1 months (95% CI, 12.0 to 16.2 months; P<.001) and overall survival was 12.0 months (95% CI, 8.0 to 15.6 months) versus 36.7 months (95% CI, 25.2 to 48.2 months; P<.001) for cases and controls, respectively. The hazard ratio for progression and death was 2.94 (95% CI, 1.71 to 5.07; P<.001) and 3.08 (95% CI, 1.69 to 5.6; P<.001), respectively, for mEOC patients as compared with controls. CONCLUSION: Patients with advanced mEOC have a poorer response to platinum-based first-line chemotherapy compared with patients with other histologic subtypes of EOC, and their survival is worse. Specific alternative therapeutic approaches should be sought for this group of patients, perhaps involving fluorouracil-based chemotherapy.

Can patients with relapsed, previously untreated, stage I epithelial ovarian cancer be successfully treated with salvage therapy?

PURPOSE: The role of adjuvant chemotherapy in early-stage epithelial ovarian cancer (EOC) has been controversial. We have previously reported the cases of patients managed with a policy of observation only. We now present the salvage rate for the patients in that study who experienced relapse. PATIENTS AND METHODS: One hundred ninety-four patients with stage I EOC presenting between 1980 and 1994 received no adjuvant chemotherapy, but were treated with platinum-based chemotherapy at relapse. We calculated the progression-free survival (PFS) and overall survival (OS) for the whole cohort and the salvage rate for those who experienced relapse. We defined salvage as freedom from relapse for 5 years after platinum treatment. RESULTS: Sixty-one (31%) of 194 patients experienced relapse, and 55 received platinum-based chemotherapy. Twenty-four percent were progression-free at 5 years after this treatment. Clear-cell histology and cyst rupture before the patients' original surgery were independent prognostic factors for PFS after salvage chemotherapy. The OS for all 194 patients is 72% at 10 years (median follow-up, 8.7 years), with an 80% disease-specific survival (DSS). CONCLUSION: We have shown that some patients with stage I EOC can be successfully treated with a salvage chemotherapy regimen after a policy of observation only. Interestingly, approximately 30% of stage I patients who die within 10 years do so from causes other than EOC (OS, 72%; DSS, 80%). Our findings need to be taken into consideration when the results from recent randomized trials of adjuvant chemotherapy in this patient population (International Collaborative Ovarian Neoplasm Trial 1/European Organization for Research and Treatment of Cancer Adjuvant Chemotherapy in Ovarian Neoplasm Trial) are being discussed with patients.

Epithelial ovarian cancer metastasizing to the brain: a late manifestation of the disease with an increasing incidence.

PURPOSE: We present the Royal Marsden Hospital experience of cerebral metastases from primary epithelial ovarian carcinoma (EOC) over the last 20 years and examine the evidence for an increasing incidence of EOC metastasizing to this site. PATIENTS AND METHODS: A total of 3,690 women with EOC were seen at the Royal Marsden Hospital from 1980 to 2000. Eighteen of these patients developed cerebral metastases. RESULTS: Median age at diagnosis of EOC was 52 years (range, 39 to 67). All patients received at least one line of platinum-based chemotherapy; 56% (10 of 18) received more than one line of treatment; 17% (three of 18), two lines; 11% (two of 18), three lines; and 28% (five of 18), four lines. The median treatment interval between each line of chemotherapy was 12, 18, and 4 months. The median interval between diagnosis and CNS relapse was 46 months (range, 12 to 113), in comparison with 5 and 7.5 months for hematogenous relapse in lung or liver, respectively (P <.001). The incidence of CNS metastases in our population from 1980 to 1984 was 0.2%; from 1985 to 1989, 0%; from 1990 to 1994, 0.3%; and from 1995 to 1999, 1.3% (P <.001). An analysis of data from the literature also suggests that the incidence of cerebral metastases from EOC has increased over time. CONCLUSION: CNS metastases in EOC are a rare and late manifestation of the disease, occurring in patients with a prolonged survival caused by repeated chemosensitive relapses. An analysis of our data and the data from the literature suggests that the incidence of metastasis at this site in patients with EOC is increasing.

The acquisition of hMLH1 methylation in plasma DNA after chemotherapy predicts poor survival for ovarian cancer patients.

Aberrant epigenetic regulation, such as CpG island methylation and associated transcriptional silencing of genes, has been implicated in a variety of human diseases, including cancer. Methylation of genes involved in apoptosis, including the DNA mismatch repair (MMR) gene hMLH1, can occur in tumor models of resistance to chemotherapeutic drugs. However, the relevance for acquired resistance to chemotherapy of patients' tumors remains unsubstantiated. Plasma DNA from cancer patients, including those with ovarian cancer, often contains identical DNA changes as the tumor and provides a means to monitor CpG island methylation changes. We have examined plasma DNA of patients with epithelial ovarian cancer enrolled in the SCOTROC1 Phase III clinical trial for methylation of the hMLH1 CpG island before carboplatin/taxoid chemotherapy and at relapse. Methylation of hMLH1 is increased at relapse, and 25% (34 of 138) of relapse samples have hMLH1 methylation that is not detected in matched prechemotherapy plasma samples. Furthermore, hMLH1 methylation is significantly associated with increased microsatellite instability in plasma DNA at relapse, providing an independent measure of function of the MMR pathway. Acquisition of hMLH1 methylation in plasma DNA at relapse predicts poor overall survival of patients, independent from time to progression and age (hazard ratio, 1.99; 95% confidence interval, 1.20-3.30; P = 0.007). These data support the clinical relevance of acquired hMLH1 methylation and concomitant loss of DNA MMR after chemotherapy of ovarian cancer patients. DNA methylation changes in plasma provide the potential to define patterns of methylation during therapy and identify those patient populations who would be suitable for novel epigenetic therapies.

Chemotherapy for Patients with BRCA1 and BRCA2-Mutated Ovarian Cancer: Same or Different?

Retrospective studies have shown an improved prognosis, higher response rates to platinum-containing regimens, and longer treatment-free intervals between relapses in patients with BRCA 1 and BRCA 2 (BRCA1/2)-mutated ovarian cancer (BMOC) compared with patients who are not carriers of this mutation. These features of BMOC are attributed to homologous-recombination repair (HR) deficiency in the absence of BRCA1/2 function, which results in an impaired ability of tumor cells to repair platinum-induced double-strand breaks (DSBs), thereby conferring increased chemosensitivity and increased sensitivity to poly(ADP-ribose) polymerase (PARP) enzyme inhibition and other DNA-damaging chemotherapeutic agents such as pegylated liposomal doxorubicin (PLD). Therefore, the chemotherapeutic approach for patients with BMOC should focus on treatment with platinum-based chemotherapy at first-line and recurrent-disease settings and measures to increase the platinum-free interval following early platinum-resistant relapse (i.e., progression-free survival of less than 6 months from last platinum-based chemotherapy) by using nonplatinum cytotoxic agents, with the aim of reintroducing platinum again at a later date. The role of first-line intraperitoneal platinum-based therapy in the specific context of BMOC also merits further analysis. Other than platinum, alternative DNA-damaging agents (including PLD and trabectedin) also may have a therapeutic role in patients with recurrent BMOC. The recent approval of olaparib for clinical use in Europe and the United States will also affect chemotherapeutic strategies for these patients. Further work to clarify the precise relationship between BRCA1/2 mutation genotype and clinical phenotype is crucial to delineating the optimal therapeutic choices in the future for patients with BMOC.

Higher Risk of Infections with PI3K-AKT-mTOR Pathway Inhibitors in Patients with Advanced Solid Tumors on Phase I Clinical Trials.

PURPOSE: Novel antitumor therapies against the PI3K-AKT-mTOR pathway are increasingly used to treat cancer, either as single agents or in combination with chemotherapy or other targeted therapies. Although these agents are not known to be myelosuppressive, an increased risk of infection has been reported with rapamycin analogues. However, the risk of infection with new inhibitors of this pathway such as PI3K, AKT, mTORC 1/2, or multikinase inhibitors is unknown. EXPERIMENTAL DESIGN: In this retrospective case-control study, we determined the incidence of infection in a group of 432 patients who were treated on 15 phase I clinical trials involving PI3K-AKT-mTOR pathway inhibitors (cases) versus a group of 100 patients on 10 phase I clinical trials of single agent non-PI3K-AKT-mTOR pathway inhibitors (controls) which did not involve conventional cytotoxic agents. We also collected data from 42 patients who were treated with phase I trials of combinations of PI3K-AKT-mTOR inhibitors and MEK inhibitors and 24 patients with combinations of PI3K-AKT-mTOR inhibitors and cytotoxic chemotherapies. RESULTS: The incidence of all grade infection was significantly higher with all single-agent PI3K-AKT-mTOR inhibitors compared with the control group [27% vs. 8%, respectively, OR, 4.26; 95% confidence intervals (CI), 1.9-9.1, P = 0.0001]. The incidence of grade 3 and 4 infection was also significantly higher with PI3K-AKT-mTOR inhibitors compared with the control group (10.3% vs. 3%, OR, 3.74; 95% CI, 1.1-12.4; P = 0.02). Also, the combination of PI3K-AKT-mTOR inhibitors and chemotherapy was associated with a significantly higher incidence of all grade (OR, 4.79; 95% CI, 2.0-11.2; P = 0.0001) and high-grade (OR, 2.87; 95% CI, 1.0-7.6; P = 0.03) infection when compared with single-agent PI3K-AKT-mTOR inhibitors. CONCLUSIONS: Inhibitors of the PI3K-AKT-mTOR pathway can be associated with a higher risk of infection. Combinations of PI3K-AKT-mTOR inhibitors and cytotoxic chemotherapy significantly increase the risk of infection. This should be taken into consideration during the design and conduct of trials involving PI3K-AKT-mTOR pathway inhibitors, particularly when combined with chemotherapy or myelosuppressive agents.

Docetaxel in ovarian cancer: phase III perspectives and future development.

In the mid 1990s, the incorporation of paclitaxel into platinum-based therapy for ovarian cancer marked a significant advance in treatment. Future progress will probably involve reductions in toxicity, which may be achieved by combining the less neurotoxic agent docetaxel with carboplatin. In an international phase III study, 1,077 chemotherapy-naive patients with stage Ic-IV ovarian cancer were randomized to receive carboplatin targeted to an AUC of 5 plus either docetaxel 75 mg/m(2) or paclitaxel 75 mg/m(2) for six cycles. Patients treated with paclitaxel plus carboplatin experienced significantly greater neurotoxicity than those treated with docetaxel plus carboplatin. Docetaxel/carboplatin and paclitaxel/carboplatin produced similar rates of objective response (66% and 62%, respectively), and initial data on progression-free survival indicate that the two treatments appear very similar in efficacy. Thus, docetaxel may prove to be a valid alternative to paclitaxel as part of first-line therapy in ovarian cancer. Nevertheless, there remains considerable scope for improvements in treatment. There is the possibility of using existing drugs more effectively, perhaps by the use of sequential rather than concurrent regimens. This would allow the most active drugs to be used at full dose, increase tolerability, and avoid the possibility of negative drug interaction. The integration of molecularly targeted agents, such as those directed at epidermal growth factor receptors, into existing regimens is highly promising but will need to be explored in randomized trials of first-line therapy. Because the prime obstacle to successful treatment is the acquisition of drug resistance, understanding the underlying mechanisms is an important future priority. One candidate is mismatch repair deficiency; the interest here is that experimental resistance reversal is achievable with hypomethylating agents, raising the possibility of future clinical trials if the clinical relevance of this mechanism can be confirmed.