A phase I/IB trial of binimetinib in combination with erlotinib in NSCLC harboring activating KRAS or EGFR mutations

BACKGROUND

Activating mutations in EGFR or KRAS are highly prevalent in NSCLC, share activation of the MAPK pathway and may be amenable to combination therapy to prevent negative feedback activation.

METHODS

In this phase 1/1B trial, we tested the combination of binimetinib and erlotinib in patients with advanced NSCLC with at least 1 prior line of treatment (unless with activating EGFR mutation which could be treatment-naïve). A subsequent phase 1B expansion accrued patients with either EGFR- or KRAS-mutation using the recommended phase 2 dose (RP2D) from Phase 1. The primary objective was to evaluate the safety of binimetinib plus erlotinib and establish the RP2D.

RESULTS

43 patients enrolled (dose-escalation = 23; expansion = 20). 17 harbored EGFR mutation and 22 had KRAS mutation. The RP2D was erlotinib 100 mg daily and binimetinib 15 mg BID × 5 days/week. Common AEs across all doses included diarrhea (69.8%), rash (44.2%), fatigue (32.6%), and nausea (32.6%), and were primarily grade 1/2. Among KRAS mutant patients, 1 (5%) had confirmed partial response and 8 (36%) achieved stable disease as best overall response. Among EGFR mutant patients, 9 were TKI-naïve with 8 (89%) having partial response, and 8 were TKI-pretreated with no partial responses and 1 (13%) stable disease as best overall response.

CONCLUSIONS

Binimetinib plus erlotinib demonstrated a manageable safety profile and modest efficacy including one confirmed objective response in a KRAS mutant patient. While clinical utility of this specific combination was limited, these results support development of combinations using novel small molecule inhibitors of RAS, selective EGFR- and other MAPK pathway inhibitors, many of which have improved therapeutic indices.

CLINICAL TRIAL REGISTRATION

NCT01859026.

Phase 1 trial of enzalutamide in combination with gemcitabine and nab-paclitaxel for the treatment of advanced pancreatic cancer

Background Androgens were shown to play a key role in the growth and progression of pancreatic cancer. We evaluated the safety and tolerability of the combination of enzalutamide, a novel androgen receptor (AR) antagonist with gemcitabine and nab-paclitaxel as a first-line treatment in advanced pancreatic cancer. Methods We used the standard 3 + 3 dose escalation design with cohort expansion to evaluate 2 dose levels of enzalutamide: 80 mg and 160 mg/day orally (phase 1a) in combination with gemcitabine and nab-paclitaxel in metastatic pancreatic cancer patients. In the expansion phase (phase 1b), AR+ was a pre-requisite criterion. We also evaluated the full pharmacokinetic (PK) profile for nab-paclitaxel and enzalutamide. Results We enrolled 24 patients, 12 patients in phase 1a and 12 patients in phase 1b. The median age was 68 (range, 32-84) years. No DLTs were observed. Grade 3/4 treatment related adverse events included neutropenia (44%), anemia (40%), leukopenia (24%), nausea and vomiting (20%), diarrhea (16%), infections (12%), thrombocytopenia (8%), thromboembolic event (8%), hypertension (8%), hypokalemia (8%), hyponatremia (8%), and ALT elevation (8%). Median overall survival and progression-free survival was 9.73 [95%CI:9.73-13.5] and 7.53 (95%CI:6.05-12.8) months, respectively. PK analysis suggests that the combination therapy does not impact the kinetics of either drug evaluated. Enzalutamide reached steady-state levels between day 22 and 29 and the mean half-life of nab-paclitaxel was 19.6 ± 4.7 h. Conclusions Enzalutamide 160 mg daily in combination with gemcitabine and nab-paclitaxel can be safely administered with no unexpected toxicities. We also noticed preliminary signals of efficacy with this combination.

Pharmacokinetics and safety of vitamin E δ-tocotrienol after single and multiple doses in healthy subjects with measurement of vitamin E metabolites

PURPOSE

Vitamin E delta-tocotrienol (VEDT) has demonstrated chemopreventive and antineoplastic activity in preclinical models. The aim of our study was to determine the safety and pharmacokinetics of VEDT and its metabolites after single- and multiple-dose administrations in healthy subjects.

METHODS

Thirty-six subjects received from 100 to 1600 mg of oral VEDT as a single dose or twice daily for 14 consecutive days. A 3 + 3 dose escalation design was utilized. Pharmacokinetic data were derived from high-performance liquid chromatography (HPLC) assays. Serial blood and urine samples were collected before and during VEDT administration, with serum and urine metabolites assessed using HPLC.

RESULTS

No drug-related adverse events were observed. Pharmacokinetic parameters for single and multiple doses were, respectively, as follows (shown as range): time to maximum concentration of 4-9.3 and 4.7-7.3 h, maximum concentration of 795.6-3742.6 and 493.3-3746 ng/mL, half-life of 1.7-5.9 and 2.3-6.9 h, and 0-12 h area under the curve of 4518.7-20,781.4 and 1987.7-22,171.2 ng h/mL. Plasma tocotrienols were significantly increased after VEDT administration, indicating oral bioavailability of VEDT in humans. Plasma and urine levels of metabolites, δ-carboxyethyl hydroxychroman, and δ-carboxymethylbutyl hydroxychroman were elevated after VEDT administration in a dose-dependent manner and were 30-60 times significantly higher than δ-tocotrienol levels. VEDT can be safely administered at doses up to 1600 mg twice daily. Plasma VEDT concentrations were comparable to those obtained in VEDT-treated mice in which tumor growth was delayed.

CONCLUSIONS

Our results suggest that VEDT can be safely consumed by healthy subjects and achieve bioactive levels, supporting the investigation of VEDT for chemoprevention.

A phase I study of indoximod in patients with advanced malignancies

PURPOSE

Indoximod is an oral inhibitor of the indoleamine 2,3-dioxygenase pathway, which causes tumor-mediated immunosuppression. Primary endpoints were maximum tolerated dose (MTD) and toxicity for indoximod in patients with advanced solid tumors. Secondary endpoints included response rates, pharmacokinetics, and immune correlates.

EXPERIMENTAL DESIGN

Our 3+3 phase I trial comprised 10 dose levels (200, 300, 400, 600, and 800 mg once/day; 600, 800, 1200, 1600, and 2000 mg twice/day). Inclusion criteria were measurable metastatic solid malignancy, age ≥18 years, and adequate organ/marrow function. Exclusion criteria were chemotherapy ≤ 3 weeks prior, untreated brain metastases, autoimmune disease, or malabsorption.

RESULTS

In 48 patients, MTD was not reached at 2000 mg twice/day. At 200 mg once/day, 3 patients previously treated with checkpoint inhibitors developed hypophysitis. Five patients showed stable disease >6 months. Indoximod plasma AUC and Cmax plateaued above 1200mg. Cmax (~12 μM at 2000 mg twice/day) occurred at 2.9 hours, and half-life was 10.5 hours. C reactive protein (CRP) levels increased across multiple dose levels.

CONCLUSIONS

Indoximod was safe at doses up to 2000 mg orally twice/day. Best response was stable disease >6 months in 5 patients. Induction of hypophysitis, increased tumor antigen autoantibodies and CRP levels were observed.

Abstract B28: Phase I trial of gemcitabine, nab-paclitaxel and enzalutamide for treatment of advanced pancreatic cancer

Background: Androgens may play an important role in the growth and progression of pancreatic cancer. In this Phase I trial, we evaluated the safety and tolerability of the combination of enzalutamide, a novel androgen receptor (AR) antagonist with gemcitabine and nab-paclitaxel in patients with metastatic pancreatic cancer as a first-line treatment.

Methods: Standard 3+3 dose escalation design with cohort expansion was used to evaluate 2 dose levels of enzalutamide: 80 mg and 160 mg oral daily. In the expansion phase, AR+ was required as pre-screening criteria. Gemcitabine (1000 mg/m2) and nab-paclitaxel (125 mg/m2) was administered IV on days 1, 8 and 15 of a 28-day cycle. The dose limiting toxicity (DLT) period was 28-days or until the beginning of the second cycle for the phase Ia part. A full pharmacokinetic (PK) profile was evaluated for nab-paclitaxel after the initial dose through 48 hours post dose while enzalutamide was tested on day 1 at 1 and 2 hours post dose along with levels every 7 days to follow achievement of steady state by day 29 (Cycle 2 Day 1).

Results: Nineteen patients with stage IV pancreatic cancer were enrolled in this trial, 5 patients at the first dose level and 13 patients at the second dose level, including 6 patients in dose expansion. The median age was 65 years (51-82 years). Two patients were female. In the phase 1b/expansion part, 7 out of 19 (37%) patients were positive for AR. Common site of metastases were liver (11), LN (8) and lung (5). No DLTs were observed. Grade 3/4 treatment related adverse events included neutropenia (32%), anemia (32%), leukopenia (21%), thrombocytopenia (11%), infections (11%), febrile neutropenia (5%), ALT elevation (5%), pneumonitis (5%), diarrhea (5%), skin infection (5%) and hypoxia (5%). Among the 15 evaluable patients, 2 (13%) patients had partial response and 13 (87%) patients had stable disease. All patients with stable disease had initial decrease in target lesions. All patients had decreases in CA 19-9 levels with the median decrease of 1032 U/L.

PK analysis suggests that the combination therapy does not impact the kinetics of either drug evaluated. Enzalutamide reached steady state levels between day 22 and 29 and the mean half-life of nab-paclitaxel was 19.6 ± 4.7 hours. All other PK parameters estimates are similar to historical data.

Conclusions: Enzalutamide at the dose of 160 mg daily can be safely administered in combination with gemcitabine and nab-paclitaxel. No unexpected toxicity has been observed. Preliminary signals of efficacy were observed with this combination. Patients with AR+ tumors continue to being enrolled in phase 1b part.

Citation Format: Amit Mahipal, Gregory Springett, Nancy Burke, Anthony Neuger, Domenico Copolla, Richard Kim. Phase I trial of gemcitabine, nab-paclitaxel and enzalutamide for treatment of advanced pancreatic cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B28.

A Phase I Safety, Pharmacokinetic, and Pharmacodynamic Presurgical Trial of Vitamin E δ-tocotrienol in Patients with Pancreatic Ductal Neoplasia

Background

Vitamin E δ-tocotrienol (VEDT), a natural vitamin E from plants, has shown anti-neoplastic and chemoprevention activity in preclinical models of pancreatic cancer. Here, we investigated VEDT in patients with pancreatic ductal neoplasia in a window-of-opportunity preoperative clinical trial to assess its safety, tolerability, pharmacokinetics, and apoptotic activity.

Methods

Patients received oral VEDT at escalating doses (from 200 to 3200 mg) daily for 13 days before surgery and one dose on the day of surgery. Dose escalation followed a three-plus-three trial design. Our primary endpoints were safety, VEDT pharmacokinetics, and monitoring of VEDT-induced neoplastic cell apoptosis (ClinicalTrials.gov number NCT00985777).

Findings

In 25 treated patients, no dose-limiting toxicity was encountered; thus no maximum-tolerated dose was reached. One patient had a drug-related adverse event (diarrhea) at a 3200-mg daily dose level. The effective half-life of VEDT was ~ 4 h. VEDT concentrations in plasma and exposure profiles were quite variable but reached levels that are bioactive in preclinical models. Biological activity, defined as significant induction of apoptosis in neoplastic cells as measured by increased cleaved caspase-3 levels, was seen in the majority of patients at the 400-mg to 1600-mg daily dose levels.

Interpretation

VEDT from 200 to 1600 mg daily taken orally for 2 weeks before pancreatic surgery was well tolerated, reached bioactive levels in blood, and significantly induced apoptosis in the neoplastic cells of patients with pancreatic ductal neoplasia. These promising results warrant further clinical investigation of VEDT for chemoprevention and/or therapy of pancreatic cancer.

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Vitamin E δ-tocotrienol is the bioactive form of one of the natural vitamin E with activity against cancer cells

•

Vitamin E δ-tocotrienol is safe in patients up to 3200 mg

•

Vitamin E δ-tocotrienol selectively kills pancreatic tumor cells when compared with normal cells at 400, 600, and 800 mg/day

•

The biomarker effect of vitamin E δ-tocotrienol suggest significant anticancer activity in patients, justifying further study

Vitamin E has been an intriguing vitamin to humans for its potential to promote human health. However, large-scale research with vitamin E to prevent cancer has had mixed results. Because recent laboratory studies have shown that the form of vitamin E used in previous interventions to reduce cancer risk have not been the active tocotrienol form of vitamin E, there is a question as to whether the lack of vitamin activity is due to the use of inactive forms of vitamin E in clinical trials. Based on our laboratory data, which showed that the vitamin E δ-tocotrienol (VEDT) form of vitamin E was active against pancreatic cancer, we tested the ability of VEDT to kill pancreatic tumor cells in patients using a window-of-opportunity design, with measurement of apoptosis as an intermediate endpoint. We found that VEDT was well tolerated at up to 3200 mg when taken for 2 weeks before surgery. We also found that, at doses of 400 to 800 mg, VEDT selectively killed pancreatic tumor cells.

Phase I study of bendamustine with concurrent whole brain radiation therapy in patients with brain metastases from solid tumors

A phase I study was conducted to evaluate the dose-limiting toxicities (DLTs) and to determine the maximum tolerated dose (MTD)/recommended phase II dose of bendamustine with concurrent whole brain radiation (WBR) in patients with brain metastases (BM) from solid tumors. Four doses of intravenous weekly bendamustine were administered with 3 weeks of WBR at three dose levels (60, 80, and 100 mg/m(2)) according to a standard 3 + 3 phase I design. A total of 12 patients with solid tumor BM were enrolled in the study (six with non-small cell lung cancer, four with melanoma, one with breast cancer, and one with neuroendocrine carcinoma). The first two dose levels had three patients each, and the third dose level had six total patients. Plasma pharmacokinetic studies of bendamustine demonstrated no significant differences from pharmacokinetic characteristics of bendamustine in other studies. No DLTs were noted at any dose levels, and no grade 4 toxicities occurred. The MTD of weekly bendamustine with concurrent WBR was 100 mg/m(2). The majority of trial patients died from progressive systemic disease rather than their brain disease. The combination of weekly bendamustine with concurrent WBR was acceptably tolerated. The efficacy of this combination may be evaluated in a phase II trial with stratification by histologies.

A phase I, pharmacokinetic, and pharmacodynamic study of panobinostat, an HDAC inhibitor, combined with erlotinib in patients with advanced aerodigestive tract tumors

PURPOSE

Panobinostat, a histone deacetylase (HDAC) inhibitor, enhances antiproliferative activity in non-small cell lung cancer (NSCLC) cell lines when combined with erlotinib. We evaluated this combination in patients with advanced NSCLC and head and neck cancer.

EXPERIMENTAL DESIGN

Eligible patients were enrolled in a 3+3 dose-escalation design to determine the maximum tolerated dose (MTD) of twice weekly panobinostat plus daily erlotinib at four planned dose levels (DL). Pharmacokinetics, blood, fat pad biopsies (FPB) for histone acetylation, and paired pre and posttherapy tumor biopsies for checkpoint kinase 1 (CHK1) expression were assessed.

RESULTS

Of 42 enrolled patients, 33 were evaluable for efficacy. Dose-limiting toxicities were prolonged-QTc and nausea at DL3. Adverse events included fatigue and nausea (grades 1-3), and rash and anorexia (grades 1-2). Disease control rates were 54% for NSCLC (n = 26) and 43% for head and neck cancer (n = 7). Of 7 patients with NSCLC with EGF receptor (EGFR) mutations, 3 had partial response, 3 had stable disease, and 1 progressed. For EGFR-mutant versus EGFR wild-type patients, progression-free survival (PFS) was 4.7 versus 1.9 months (P = 0.43) and overall survival was 41 (estimated) versus 5.2 months (P = 0.39). Erlotinib pharmacokinetics was not significantly affected. Correlative studies confirmed panobinostat's pharmacodynamic effect in blood, FPB, and tumor samples. Low CHK1 expression levels correlated with PFS (P = 0.006) and response (P = 0.02).

CONCLUSIONS

We determined MTD at 30 mg (panobinostat) and 100 mg (erlotinib). Further studies are needed to further explore the benefits of HDAC inhibitors in patients with EGFR-mutant NSCLC, investigate FPB as a potential surrogate source for biomarker investigations, and validate CHK1's predictive role.

A phase I study of indoximod in combination with docetaxel in metastatic solid tumors

3026

Background: The indoleamine-2, 3-dioxygenase (IDO) pathway catabolizes tryptophan to create a state of immunosuppression. Indoximod (1-methyl-(D)-tryptophan, D-1MT) is an IDO pathway modulator. Preclinical studies in MMTV-neu mouse models have shown indoximod combined with chemotherapy was more effective in causing tumor regression than either agent alone. Based on this data, a phase IB trial was designed to study the safety of the combination of docetaxel (Doc) and indoximod. The primary goal of this trial was to determine the MTD for the combination of Doc and oral indoximod. Secondary endpoints were PK data and efficacy for indoximod/Doc. Methods: This phase IB study consisted of 5 dose levels (DL). Doc was dosed IV q 3 wks at 60 mg/m2 in DL 1-4 and 75 mg/m2 at DL 5. Indoximod was dosed at 300, 600, 1,000, 2,000, and 1,200 mg PO BID continuously in DL 1-5 respectively. MTD was determined using a 3+3 design. The DLT rule was 1st cycle ≥G3 non-heme AEs or ≥G4 heme AEs despite supportive care or that delay therapy >14d. The PK of indoximod and Doc was analyzed using a HPLC assay. PK was measured on C1D1 and 8. Standard eligibility/exclusion criteria applied along with exclusion of patients previously treated with ipilumimab. Treatment was continued until disease progression, intolerance, or unacceptable side effects. Results: Total # of patients treated at DL1-5 were 7, 6, 6, 2, and 6 respectively, with 22 total patients evaluable for response. DLTs included: G3 dehydration (at 300 mg), G5 neutropenic colitis (at 600 mg), G3 hypotension (at 2,000 mg) and G3 mucositis (at 2,000 mg). DL 5 was well tolerated and is the recommended phase II dose. The most frequent adverse events were fatigue (58.6%), anemia (51.7%), hyperglycemia (48.3%), infection (44.8%), and nausea (41.4%). There were 4 PRs (2 breast, 1 NSCLC, 1 thymic), 9 SD, and 9 PD. There were no drug-drug interactions, and PK was similar to Doc and indoximod single-agent studies. Conclusions: The Doc+ indoximod combination was well tolerated with no increase in expected toxicities or unexpected PK interactions. It was active in a pretreated population of patients with metastatic solid tumors. The RP2D is 75 mg/m2 of Doc with 1,200 mg of indoximod BID for the current phase II metastatic breast cancer trial. NCT01191216 Clinical trial information: NCT01191216.

A phase I study of 1-methyl-D-tryptophan in combination with docetaxel in metastatic solid tumors

TPS2620

Background: The indoleamine 2, 3 dioxygenase pathway (IDO) can create immune suppression and unresponsiveness to tumor antigens in tumor-bearing hosts. 1-methyl-D-tryptophan (1-MT), an oral inhibitor of the IDO pathway, showed favorable toxicity profile and biologic activity in prior studies. Remarkably, in prior animal models (MMTV-neu mice), 1-MT in combination with chemotherapy produced 30% greater tumor regressions. Based on this data, a phase I trial was initiated to study the synergism of 1-MT with docetaxel. The primary goal of this trial is to determine the MTD and toxicity for the combination of docetaxel and oral 1-MT. A secondary endpoint will be to determine the PK data and the overall response rate. Methods: This phase I study utilizes a 3+3 design comprised of five dose levels. Dose levels 1-4 will evaluate docetaxel 60mg/m2 IV d1 q3wks plus 1-MT at 300mg, 600mg, 1000mg, and 2000mg PO BID d1-21 respectively. Dose level 5 is docetaxel 75mg/m2 IV d1 q3wks + 1-MT 2000mg PO BID d1-21. Eligibility for this study includes patients with measurable metastatic solid malignancy, no prior docetaxel for metastatic disease, age ≥18, life expectancy >4 months, and adequate organ/marrow function. Patients will be excluded if they meet any of the following criteria: chemotherapy within the past 3 weeks, untreated brain metastases, active autoimmune disease, or GI disease causing malabsorption. In addition, any patients who have received prior immunotherapy such as ipilimumab are excluded. Treatment will continue until disease progression, unacceptable toxicity, or patient/physician discretion. Accrual to dose level 3 is complete and dose level 4 accrual is underway. The PK of 1-MT and docetaxel will also be characterized, using an HPLC assay. PK measurements for 1-MT are drawn on C1D1 after a single dose of 1-MT is given and then on C1D8 after the morning dose of 1-MT is given. (Drawn at 0,1,2,4,8,12,24, and 48 hours) Because IDO is hypothesized to cause regulatory T cell expansion, circulating Tregs will be quantified utilizing flow cytometry for CD4+CD25+ FoxP3+ cells. (NCT01191216)

A phase I study of 1-methyl-D-tryptophan in patients with advanced malignancies

2501

Background: The indoleamine 2, 3 dioxygenase pathway (IDO) can create immune suppression and unresponsiveness to tumor antigens in tumor-bearing hosts. 1-methyl-D-tryptophan (1-MT) is an oral inhibitor of the IDO pathway, currently in development as an immune adjuvant for anti-tumor vaccines and chemotherapy. The primary goal of this trial is to determine the MTD and toxicity for oral 1-MT. Secondary endpoints include response rates, PK, serum tryptophan catabolites, circulating T-reg cells, and C reactive protein (CRP) levels. Methods: This phase I study utilizes a 3+3 design comprised of ten dose levels (200, 300,400,600,800,mg QD, 600, 800,1200,1600,2000mg BID). Inclusion criteria: patients with measurable metastatic solid malignancy, age ≥18, life expectancy >4 months, and adequate organ/marrow function. Exclusion criteria: chemotherapy in the past 3 weeks, untreated brain metastases, active autoimmune disease, or malabsorptive GI disease. Continuous toxicity monitoring early stopping rules were used. Results: At submission, 48 out of the planned 50 patients were accrued. MTD was not reached at 2000mg BID. At 200mg QD dose, 3 patients previously treated with active immunotherapy (ipilimumab, n=2, CD40-mAb, n=1) developed an autoimmune hypophysitis. Since IDO is closely linked to both CTLA-4 and CD40/CD40L pathways this was considered on-target effect. Subsequently, patients with prior immunotherapy were excluded and no additional treatment related G3-5 adverse events were observed. Five patients showed SD>6 months (2 melanoma, 2 sarcoma 1 colon) as well as some mixed responses were seen in some patients including regression of a liver visceral metastases. 1-MT plasma PK AUC and Cmax were proportional with dose. Cmax (~40 μM at 2000mg BID) is at 2.9 hours and the t1/2 is at 10 hours. Elevations in CRP levels and declines in T-reg cell counts were seen across multiple dose levels. Additional correlative data analysis is ongoing. Conclusions: The treatment was well tolerated and orally bioavailable. Biologic activity in terms of prolonged disease stabilization, induction of hypophysitis, and changes in T-reg levels and CRP were observed. Trials combining 1-MT with docetaxel and a dendritic cell vaccine are ongoing.

Phase I/II study of the Src inhibitor dasatinib in combination with erlotinib in advanced non-small-cell lung cancer

PURPOSE

Src family kinase (SFK) proteins are frequently activated in cancer and can coordinate tumor cell growth, survival, invasion, and angiogenesis. Given the importance of SFK signaling in cancer, known cooperation between SFK and epidermal growth factor receptor (EGFR) signaling, and efficacy of EGFR inhibitors, we performed a phase I trial combining dasatinib, an SFK and multikinase inhibitor, with erlotinib, an EGFR inhibitor, in patients with advanced non-small-cell lung cancer.

PATIENTS AND METHODS

Patients received erlotinib for 1 week before addition of dasatinib; pharmacokinetics were performed after weeks 1 and 2. Four cohorts were examined, including twice-daily and daily dasatinib dosing. Responses were assessed after 8 weeks. Plasma levels of angiogenic markers (vascular endothelial growth factor [VEGF], interleukin-8, and basic fibroblast growth factor [bFGF]) were determined before and during treatment.

RESULTS

Thirty-four patients were enrolled. The average duration of treatment was 73 days. The main adverse events include GI (diarrhea, anorexia, and nausea), skin rash, cytopenias, pleural effusions, and fatigue. No effect of escalating doses of dasatinib was observed on erlotinib pharmacokinetics. Two partial responses and one bone response were observed, and the disease control rate was 63%. Reductions in plasma VEGF and bFGF were observed, and reductions in VEGF correlated with disease control.

CONCLUSION

The combination of erlotinib and dasatinib is tolerable, with adverse effects consistent with the two agents. Disease control and inhibition of plasma angiogenesis markers were observed. Personalized strategies for deployment of SFK should receive further attention.

Clinical and biological effects of valproic acid as a histone deacetylase inhibitor on tumor and surrogate tissues: phase I/II trial of valproic acid and epirubicin/FEC

PURPOSE

The aim was to study the biological and molecular effects of the histone deacetylase (HDAC) inhibitor, valproic acid, in patients with solid tumor malignancies.

EXPERIMENTAL DESIGN

A phase I dose escalation of valproic acid given on days 1 to 3 followed by epirubicin (day 3) was followed by a dose expansion of valproic acid combined with 5-fluorouracil, epirubicin, and cyclophosphamide (FEC100). Pharmacodynamic and pharmacokinetic studies entailed valproic acid and epirubicin plasma levels and their interaction, the effects of valproic acid on histone acetylation in peripheral blood mononuclear cells (PBMC) and tumor cells at baseline and day 3, and baseline expression of HDAC2 and HDAC6 as therapeutic targets.

RESULTS

Forty-four patients were enrolled in the phase I part, with a disease-specific cohort expansion of 15 breast cancer patients (median age, 55 years; range, 28-66 years) receiving 120 mg/kg/day valproic acid followed by FEC100. Partial responses were seen in 9 of 41 (22%) patients during the phase I part. Objective responses were seen in 9 of 14 (64%) evaluable patients at the dose expansion with a median number of 6 administered cycles. Predominant toxicities were valproic acid-associated somnolence and epirubicin-induced myelosuppression. Valproic acid plasma levels were associated with short-term, reversible depletion of WBC and neutrophils within 48 hours. Histone acetylation in tumor samples and in PBMCs correlated with valproic acid levels and was further linked to baseline HDAC2 but not to HDAC6 expression.

CONCLUSION

Valproic acid is a clinically relevant HDAC inhibitor, and PBMCs may serve as a surrogate for tumor histone acetylation in solid tumor malignancies. HDAC2 should be further considered as a relevant therapeutic target.

Potentiation of a topoisomerase I inhibitor, karenitecin, by the histone deacetylase inhibitor valproic acid in melanoma: translational and phase I/II clinical trial

PURPOSE

The novel topoisomerase I inhibitor karenitecin (KTN) shows activity against melanoma. We examined whether histone deacetylase inhibition could potentiate the DNA strand cleavage, cytotoxicity as well as the clinical toxicity, and efficacy of KTN in melanoma.

EXPERIMENTAL DESIGN

Apoptosis, COMET, and xenograft experiments were carried out as described previously. A phase I/II trial of valproic acid (VPA) and KTN was conducted in patients with stage IV melanoma, with any number of prior therapies, Eastern Cooperative Oncology Group performance status 0-2, and adequate organ function.

RESULTS

VPA pretreatment potentiated KTN-induced apoptosis in multiple melanoma cell lines and in mouse A375 xenografts. VPA increased KTN-induced DNA strand breaks. In the phase I/II trial, 39 patients were entered, with 37 evaluable for toxicity and 33 evaluable for response. Somnolence was the dose-limiting toxicity. The maximum tolerated dose for VPA was 75 mg/kg/d; at maximum tolerated dose, serum VPA was approximately 200 microg/mL (1.28 mmol/L). At the dose expansion cohort, 47% (7 of 15) of patients had stable disease; median overall survival and time to progression were 32.8 and 10.2 weeks, respectively. Histone hyperacetylation was observed in peripheral blood mononuclear cells at maximum tolerated dose.

CONCLUSION

VPA potentiates KTN-induced DNA strand breaks and cytotoxicity. VPA can be combined at 75 mg/kg/d for 5 days with full-dose KTN without overlapping toxicities. In metastatic poor prognosis melanoma, this combination is associated with disease stabilization in 47% of patients. Further testing of this combination appears warranted.

Phase 2 study of gemcitabine and irinotecan in metastatic breast cancer with correlatives to determine topoisomerase I localization as a predictor of response

BACKGROUND

Gemcitabine incorporation into DNA enhances cleavage complexes in vitro when combined with topoisomerase I inhibitors and demonstrates synergy in cancer cells when given with irinotecan. Topoisomerase I inhibitors require that topoisomerase I interacts with DNA to exert activity.

METHODS

Patients who had received previous anthracycline therapy or were not candidates for anthracycline therapy received gemcitabine at a dose of 1000 mg/m2 intravenously over 30 minutes followed by irinotecan at a dose of 100 mg/m2 over 90 minutes on Days 1 and 8 of a 21-day cycle. The primary endpoint was improvement in response from that historically observed with gemcitabine (from 25% to 45%) as measured by Response Evaluation Criteria in Solid Tumors. Correlative studies included characterization of cellular levels and nuclear distribution of topoisomerase I and pharmacokinetic analysis of gemcitabine and irinotecan.

RESULTS

Forty-nine patients were assessed for response. The response rate was approximately 25% (all partial responses [PRs], 12 patients; 95% confidence interval [95% CI], 13-39). Six patients had stable disease (SD) for > or =6 months for a clinical benefit rate (PR + SD) of 39%. The median time to disease progression was 3.7 months (95% CI, 2.5 months-4.6 months), and median survival was 11.6 months (95% CI, 8.9 months-15 months). Toxicities included neutropenia, nausea, and vomiting. Seven of 9 tissue biopsies were assessable for topoisomerase I. Tumors with the 2 lowest nuclear to cytoplasmic ratios demonstrated no response to irinotecan.

CONCLUSIONS

Gemcitabine and irinotecan are active in metastatic breast cancer, but response did not meet predetermined response parameters, and the null hypothesis was accepted. Topoisomerase I localization can be measured in metastatic breast cancer. Further validation is needed to determine whether this assay can predict response.