Nilofer S. Azad

Combination Targeted Therapy With Sorafenib and Bevacizumab Results in Enhanced Toxicity and Antitumor Activity

PURPOSEnSorafenib inhibits Raf kinase and vascular endothelial growth factor (VEGF) receptor. Bevacizumab is a monoclonal antibody targeted against VEGF. We hypothesized that the complementary inhibition of VEGF signaling would have synergistic therapeutic effects.nnnPATIENTS AND METHODSnPatients had advanced solid tumors, Eastern Cooperative Oncology Group performance status of 0 to 1, and good end-organ function. A phase I dose-escalation trial of sorafenib and bevacizumab was initiated at below-recommended single-agent doses because of possible overlapping toxicity: sorafenib 200 mg orally twice daily and bevacizumab intravenously at 5 mg/kg (dose level [DL] 1) or 10 mg/kg (DL2) every 2 weeks. Additional patients were enrolled at the maximum-tolerated dose (MTD).nnnRESULTSnThirty-nine patients were treated. DL1 was the MTD and administered in cohort 2 (N = 27). Dose-limiting toxicity in DL2 was grade 3 proteinuria and thrombocytopenia. Adverse events included hypertension, hand-foot syndrome, diarrhea, transaminitis, and fatigue. Partial responses (PRs) were seen in six (43%) of 13 patients with ovarian cancer (response duration range, 4 to 22+ months) and one of three patients with renal cell cancer (response duration, 14 months). PR or disease stabilization >or= 4 months (median, 6 months; range, 4 to 22+ months) was seen in 22 (59%) of 37 assessable patients. The majority (74%) required sorafenib dose reduction to 200 mg/d at a median of four cycles (range, one to 12 cycles).nnnCONCLUSIONnCombination therapy with sorafenib and bevacizumab has promising clinical activity, especially in patients with ovarian cancer. The rapidity and frequency of sorafenib dose reductions indicates that sorafenib at 200 mg twice daily with bevacizumab 5 mg/kg every 2 weeks may not be tolerable long term, and alternate sorafenib dosing schedules should be explored.

Hand-foot skin reaction increases with cumulative sorafenib dose and with combination anti-vascular endothelial growth factor therapy

Purpose: Sorafenib, a vascular endothelial growth factor (VEGF) receptor-2 and RAF kinase inhibitor, commonly causes skin toxicity. We retrospectively analyzed dermatologic toxicity in patients receiving combined antiangiogenic therapy involving sorafenib and bevacizumab. Experimental Design: Castration-resistant prostate cancer and metastatic non-small cell lung cancer patients were accrued to phase II studies, receiving sorafenib 400 mg twice daily. A phase I study explored sorafenib 200 to 400 mg twice daily with bevacizumab 5 to 10 mg/kg every 2 weeks in patients with advanced solid tumors. The probability of development of maximum grade of dermatologic toxicity as a function of the cumulative dose of sorafenib was determined. Additional analyses compared extent of toxicity, pharmacokinetics, and patient risk factors. Results: Ninety-six patients were enrolled: 54 received sorafenib and 42 received bevacizumab/sorafenib. Hand-foot skin reaction (HFSR) was observed in 50 of 96 (52%) patients. Grade 2 to 3 HFSR developed in 16 of 54 (30%) sorafenib patients and 24 of 42 (57%) bevacizumab/sorafenib patients (P = 0.012) and was associated with cumulative sorafenib exposure (P = 0.0008). Twenty-four of 42 phase I patients randomized to start with bevacizumab had increased risk of grade 2 to 3 HFSR than those starting with sorafenib (P = 0.013) after adjusting for association between HFSR risk and hypertension (P = 0.01), which was the only toxicity associated with HFSR. There was no association between HFSR and baseline history of neuropathy, prior taxane/platinum treatment, or systemic sorafenib levels. Conclusions: Sorafenib-related HFSR is associated with increasing cumulative sorafenib dose. HFSR is increased in patients treated with bevacizumab/sorafenib combination anti-VEGF therapy, and this finding is not explained by pharmacokinetic interaction between the two agents. Our results suggest that the pathophysiology of HFSR may be related to VEGF inhibition.

Phase I/Ib Study of Olaparib and Carboplatin in BRCA1 or BRCA2 Mutation-Associated Breast or Ovarian Cancer With Biomarker Analyses

BACKGROUNDnOlaparib has single-agent activity against breast/ovarian cancer (BrCa/OvCa) in germline BRCA1 or BRCA2 mutation carriers (gBRCAm). We hypothesized addition of olaparib to carboplatin can be administered safely and yield preliminary clinical activity.nnnMETHODSnEligible patients had measurable or evaluable disease, gBRCAm, and good end-organ function. A 3 + 3 dose escalation tested daily oral capsule olaparib (100 or 200mg every 12 hours; dose level1 or 2) with carboplatin area under the curve (AUC) on day 8 (AUC3 day 8), then every 21 days. For dose levels 3 to 6, patients were given olaparib days 1 to 7 at 200 and 400 mg every 12 hours, with carboplatin AUC3 to 5 on day 1 or 2 every 21 days; a maximum of eight combination cycles were permitted, after which daily maintenance of olaparib 400mg every12 hours continued until progression. Dose-limiting toxicity was defined in the first two cycles. Peripheral blood mononuclear cells were collected for polymorphism analysis and polyADP-ribose incorporation. Paired tumor biopsies (before/after cycle 1) were obtained for biomarker proteomics and apoptosis endpoints.nnnRESULTSnForty-five women (37 OvCa/8 BrCa) were treated. Dose-limiting toxicity was not reached on the intermittent schedule. Expansion proceeded with olaparib 400mg every 12 hours on days 1 to 7/carboplatin AUC5. Grade 3/4 adverse events included neutropenia (42.2%), thrombocytopenia (20.0%), and anemia (15.6%). Responses included 1 complete response (1 BrCa; 23 months) and 21 partial responses (50.0%; 15 OvCa; 6 BrCa; median = 16 [4 to >45] in OvCa and 10 [6 to >40] months in BrCa). Proteomic analysis suggests high pretreatment pS209-eIF4E and FOXO3a correlated with duration of response (two-sided P < .001; Pearsons R (2) = 0.94).nnnCONCLUSIONSnOlaparib capsules 400mg every 12 hours on days 1 to 7/carboplatin AUC5 is safe and has activity in gBRCAm BrCa/OvCa patients. Exploratory translational studies indicate pretreatment tissue FOXO3a expression may be predictive for response to therapy, requiring prospective validation.

Proteomics in Clinical Trials and Practice Present Uses and Future Promise

The study of clinical proteomics is a promising new field that has the potential to have many applications, including the identification of biomarkers and monitoring of disease, especially in the field of oncology. Expression proteomics evaluates the cellular production of proteins encoded by a particular gene and exploits the differential expression and post-translational modifications of proteins between healthy and diseased states. These biomarkers may be applied towards early diagnosis, prognosis, and prediction of response to therapy. Functional proteomics seeks to decipher protein-protein interactions and biochemical pathways involved in disease biology and targeted by newer molecular therapeutics. Advanced spectrometry technologies and new protein array formats have improved these analyses and are now being applied prospectively in clinical trials. Further advancement of proteomics technology could usher in an era of personalized molecular medicine, where diseases are diagnosed at earlier stages and where therapies are more effective because they are tailored to the protein expression of a patient’s malignancy.

Combination therapy: intermittent sorafenib with bevacizumab yields activity and decreased toxicity

Background:We previously reported preliminary results of our phase I study of continuous daily sorafenib with bevacizumab every other week for solid tumours. Toxicity was moderate, leading to additional dose levels (DL) testing intermittent sorafenib dosing.Methods:Seventeen patients with advanced solid tumours were treated on three additional DLs testing sorafenib days 1–5 per week. Dose level 4 was sorafenib 200u2009mg twice daily (b.i.d.) and bevacizumab 5u2009mgu2009kg−1. DL5 alternated between bevacizumab 10u2009mgu2009kg−1-sorafenib 200u2009mg b.i.d. (A) and sorafenib 400u2009mg b.i.d. with bevacizumab 5u2009mgu2009kg−1 (B). Outcome and toxicity data from 19 epithelial ovarian cancer (EOC) patients from DL 1–5 were analysed.Results:Fewer patients required sorafenib dose reduction with the intermittent schedule (41 vs 74% daily, P=0.01). Hand–foot skin reaction (HFSR) remained the primary cause of dose reduction (n=5). Partial responses (12%) or disease stabilisation ⩾4 months (53%; median 6 (4–26)) occurred in most patients on the intermittent schedule. Partial response occurred in 47% EOC patients treated in pooled analysis of duration 4–37 months.Conclusion:Intermittent sorafenib dosing with bevacizumab has promising clinical activity and less sorafenib dose reduction and side effects, but does not ameliorate HFSR. We are conducting a phase II clinical trial with intermittent sorafenib and bevacizumab in patients with EOC.

Proteomics as a Tool for Biomarker Discovery

Novel technologies are now being advanced for the purpose of identification and validation of new disease biomarkers. A reliable and useful clinical biomarker must a) come from a readily attainable source, such as blood or urine, b) have sufficient sensitivity to correctly identify affected individuals, c) have sufficient specificity to avoid incorrect labeling of unaffected persons, and d) result in a notable benefit for the patient through intervention, such as survival or life quality improvement. Despite these critical descriptors, the few available FDA-approved biomarkers for cancer do not completely fit this definition and their benefits are limited to a small number of cancers. Ovarian cancer exemplifies the need for a diagnostic biomarker of early stage disease. Symptoms are present but not specific to the disease, delaying diagnosis until an advanced and generally incurable stage in over 70% of affected women. As such, diagnostic intervention in the form of oopherectomy can be performed in the appropriate at-risk population if identified such as with a new accurate, sensitive, and specific biomarker. If early stage disease is identified, the requirement for survival and life quality improvement will be met. One of the new technologies applied to biomarker discovery is tour-de-force analysis of serum peptides and proteins. Optimization of mass spectrometry techniques coupled with advanced bioinformatics approaches has yielded informative biomarker signatures discriminating presence of cancer from unaffected in multiple studies from different groups. Validation and randomized outcome studies are needed to determine the true value of these new biomarkers in early diagnosis, and improved survival and quality of life.

Lack of reliability of CA125 response criteria with anti-VEGF molecularly targeted therapy

CA125 is an accepted indicator of epithelial ovarian cancer (EOC) response and is used to monitor patients treated with cytotoxic chemotherapy. It is uncertain how CA125 is affected by molecularly targeted drugs. In this pilot study, the authors analyzed the utility of CA125 to predict disease behavior in patients who were receiving sorafenib, a Raf‐kinase/VEGFR2 inhibitor, and bevacizumab, an anti‐VEGF monoclonal antibody.

A Phase I study of paclitaxel and continuous daily CAI in patients with refractory solid tumors

Background: Carboxyamido-triazole (CAI) is a calcium influx inhibitor with anti-angiogenic and anti-invasive properties and stabilizes tumor progression in patients. We hypothesized daily oral micronized CAI with q3 week paclitaxel would be well-tolerated and active. Patients and Methods: Eligible patients with solid tumors received micronized CAI daily (150-250mg PO) and paclitaxel intravenously q3weeks (175-250mg/m2), sequentially escalating each drug. CAI preceded paclitaxel by one week to permit pharmacokinetic analysis. Patients were assessed for toxicity, pharmacokinetics, and disease outcome. Results: Twenty-nine heavily pretreated patients (median 3 [0-7]) were enrolled on 5 dose levels. No additive or cumulative toxicity was observed, and grade 3 nonhematological toxicity was rare. Neutropenia was the most common hematologic toxicity, seen in 79% of patients, with a trend towards increasing grade with higher paclitaxel doses. The recommended phase II dose defined by the maximum tolerated dose (MTD) was CAI 250 mg daily and paclitaxel 200 mg/m2 q3weeks. Pharmacokinetic analysis revealed paclitaxel increases CAI trough concentration at all dose levels by over 100% (p