Crizotinib in patients with tumors harboring ALK or ROS1 rearrangements in the NCI-MATCH trial

The NCI-MATCH was designed to characterize the efficacy of targeted therapies in histology-agnostic driver mutation-positive malignancies. Sub-protocols F and G were developed to evaluate the role of crizotinib in rare tumors that harbored either ALK or ROS1 rearrangements. Patients with malignancies that progressed following at least one prior systemic therapy were accrued to the NCI-MATCH for molecular profiling, and those with actionable ALK or ROS1 rearrangements were offered participation in sub-protocols F or G, respectively. There were five patients who enrolled on Arm F (ALK) and four patients on Arm G (ROS1). Few grade 3 or 4 toxicities were noted, including liver test abnormalities, and acute kidney injury. For sub-protocol F (ALK), the response rate was 50% (90% CI 9.8-90.2%) with one complete response among the 4 eligible patients. The median PFS was 3.8 months, and median OS was 4.3 months. For sub-protocol G (ROS1) the response rate was 25% (90% CI 1.3-75.1%). The median PFS was 4.3 months, and median OS 6.2 months. Data from 3 commercial vendors showed that the prevalence of ALK and ROS1 rearrangements in histologies other than non-small cell lung cancer and lymphoma was rare (0.1% and 0.4% respectively). We observed responses to crizotinib which met the primary endpoint for ALK fusions, albeit in a small number of patients. Despite the limited accrual, some of the patients with these oncogenic fusions can respond to crizotinib which may have a therapeutic role in this setting.

Image-guided biopsy in the age of personalised medicine: strategies for success and safety

Oncology has progressed into an era of personalised medicine, whereby the therapeutic regimen is tailored to the molecular profile of the patient's cancer. Determining personalised therapeutic options is achieved by using tumour genomics and proteomics to identify the specific molecular targets against which candidate drugs can interact. Several dozen targeted drugs, many for multiple cancer types are already widely in clinical use. Molecular profiling of tumours is contingent on high-quality biopsy specimens and the most common method of tissue sampling is image-guided biopsy. Thus, for radiologists performing these biopsies, the paradigm has now shifted away from obtaining specimens simply for histopathological diagnosis to acquiring larger amounts of viable tumour cells for DNA, RNA, or protein analysis. These developments have highlighted the central role now played by radiologists in the delivery of personalised cancer care. This review describes the principles of molecular profiling assays and biopsy techniques for optimising yield, and describes a scoring system to assist in patient selection for percutaneous biopsy.

Targeted and immunotherapies in BRAF mutant melanoma: where we stand and what to expect

The therapeutic landscape for melanoma has evolved drastically in the past decade. Currently, immune checkpoint inhibitors and small-molecule inhibitors targeting the mitogen-activated protein kinase (MAPK) pathway are the two mainstay therapies for BRAF^V600 mutant advanced melanoma. Although MAPK dependence has been variably demonstrated in melanomas lacking BRAF^V600 mutations, definitive evidence of benefit with MAPK inhibitors has not been demonstrated. Thus, in the BRAF^V600 'wild-type' setting, immune checkpoint inhibitors are the standalone option(s). In the BRAF^V600 mutant setting, there is no definitive evidence prioritizing one therapeutic modality over another. Herein, we review the updated data of the pivotal phase III randomized controlled trials that established the standard-of-care first-line treatment for advanced melanoma, as it provides insights into long-term benefit, which is a major factor in therapy selection. We discuss the clinical considerations for choosing between these therapies in the front-line setting and beyond, specifically for patients with BRAF^V600 mutant melanoma based on currently available evidence. We have previously proposed a time-dependent resistance paradigm in which future therapeutic development strategies can be rooted. We also discuss how these Food and Drug Administration (FDA)-approved therapeutic modalities are being pursued earlier in the course of disease management, namely in adjuvant and neoadjuvant settings. FDA-approved interlesional oncolytic virotherapy in the modern era is also briefly discussed.

Ado-trastuzumab emtansine (T-DM1) in patients with HER2-amplified tumors excluding breast and gastric/gastroesophageal junction (GEJ) adenocarcinomas: results from the NCI-MATCH trial (EAY131) subprotocol Q

BACKGROUND

The National Cancer Institute-Molecular Analysis for Therapy Choice (NCI-MATCH) is a national precision medicine study incorporating centralized genomic testing to direct refractory cancer patients to molecularly targeted treatment subprotocols. This treatment subprotocol was designed to screen for potential signals of efficacy of ado-trastuzumab emtansine (T-DM1) in HER2-amplified histologies other than breast and gastroesophageal tumors.

METHODS

Eligible patients had HER2 amplification at a copy number (CN) >7 based on targeted next-generation sequencing (NGS) with a custom Oncomine AmpliSeq™ (ThermoFisher Scientific) panel. Patients with prior trastuzumab, pertuzumab or T-DM1 treatment were excluded. Patients received T-DM1 at 3.6 mg/kg i.v. every 3 weeks until toxicity or disease progression. Tumor assessments occurred every three cycles. The primary end point was centrally assessed objective response rate (ORR). Exploratory end points included correlating response with HER2 CN by NGS. The impact of co-occurring genomic alterations and PTEN loss by immunohistochemistry were also assessed.

RESULTS

Thirty-eight patients were enrolled and 36 included in efficacy analysis. Median prior therapies in the metastatic setting was 3 (range 0-9; unknown in one patient). Median HER2 CN was 17 (range 7-139). Partial responses were observed in two (5.6%) patients: one mucoepidermoid carcinoma of parotid gland and one parotid gland squamous cell cancer. Seventeen patients (47%) had stable disease including 8/10 (80%) with ovarian and uterine carcinomas, with median duration of 4.6 months. The 6-month progression-free survival rate was 23.6% [90% confidence interval 14.2% to 39.2%]. Common toxicities included fatigue, anemia, fever and thrombocytopenia with no new safety signals. There was a trend for tumor shrinkage with higher levels of gene CN as determined by the NGS assay.

CONCLUSION

T-DM1 was well tolerated. While this subprotocol did not meet the primary end point for ORR in this heavily pre-treated diverse patient population, clinical activity was seen in salivary gland tumors warranting further study in this tumor type in dedicated trials.

Vemurafenib in patients with BRAFV600 mutation-positive metastatic melanoma: final overall survival results of the randomized BRIM-3 study

Background

The BRIM-3 trial showed improved progression-free survival (PFS) and overall survival (OS) for vemurafenib compared with dacarbazine in treatment-naive patients with BRAFV600 mutation-positive metastatic melanoma. We present final OS data from BRIM-3.

Patients and methods

Patients were randomly assigned in a 1 : 1 ratio to receive vemurafenib (960 mg twice daily) or dacarbazine (1000 mg/m2 every 3 weeks). OS and PFS were co-primary end points. OS was assessed in the intention-to-treat population, with and without censoring of data for dacarbazine patients who crossed over to vemurafenib.

Results

Between 4 January 2010 and 16 December 2010, a total of 675 patients were randomized to vemurafenib (n = 337) or dacarbazine (n = 338, of whom 84 crossed over to vemurafenib). At the time of database lock (14 August 2015), median OS, censored at crossover, was significantly longer for vemurafenib than for dacarbazine {13.6 months [95% confidence interval (CI) 12.0-15.4] versus 9.7 months [95% CI 7.9-12.8; hazard ratio (HR) 0.81 [95% CI 0.67-0.98]; P = 0.03}, as was median OS without censoring at crossover [13.6 months (95% CI 12.0-15.4) versus 10.3 months (95% CI 9.1-12.8); HR 0.81 (95% CI 0.68-0.96); P = 0.01]. Kaplan-Meier estimates of OS rates for vemurafenib versus dacarbazine were 56% versus 46%, 30% versus 24%, 21% versus 19% and 17% versus 16% at 1, 2, 3 and 4 years, respectively. Overall, 173 of the 338 patients (51%) in the dacarbazine arm and 175 of the 337 (52%) of those in the vemurafenib arm received subsequent anticancer therapies, most commonly ipilimumab. Safety data were consistent with the primary analysis.

Conclusions

Vemurafenib continues to be associated with improved median OS in the BRIM-3 trial after extended follow-up. OS curves converged after ≈3 years, likely as a result of crossover from dacarbazine to vemurafenib and receipt of subsequent anticancer therapies.

ClinicalTrials.gov

NCT01006980.

Dabrafenib plus trametinib versus dabrafenib monotherapy in patients with metastatic BRAF V600E/K-mutant melanoma: long-term survival and safety analysis of a phase 3 study

Background

Previous analysis of COMBI-d (NCT01584648) demonstrated improved progression-free survival (PFS) and overall survival (OS) with combination dabrafenib and trametinib versus dabrafenib monotherapy in BRAF V600E/K-mutant metastatic melanoma. This study was continued to assess 3-year landmark efficacy and safety after ≥36-month follow-up for all living patients.

Patients and methods

This double-blind, phase 3 study enrolled previously untreated patients with BRAF V600E/K-mutant unresectable stage IIIC or stage IV melanoma. Patients were randomized to receive dabrafenib (150 mg twice daily) plus trametinib (2 mg once daily) or dabrafenib plus placebo. The primary endpoint was PFS; secondary endpoints were OS, overall response, duration of response, safety, and pharmacokinetics.

Results

Between 4 May and 30 November 2012, a total of 423 of 947 screened patients were randomly assigned to receive dabrafenib plus trametinib (n = 211) or dabrafenib monotherapy (n = 212). At data cut-off (15 February 2016), outcomes remained superior with the combination: 3-year PFS was 22% with dabrafenib plus trametinib versus 12% with monotherapy, and 3-year OS was 44% versus 32%, respectively. Twenty-five patients receiving monotherapy crossed over to combination therapy, with continued follow-up under the monotherapy arm (per intent-to-treat principle). Of combination-arm patients alive at 3 years, 58% remained on dabrafenib plus trametinib. Three-year OS with the combination reached 62% in the most favourable subgroup (normal lactate dehydrogenase and <3 organ sites with metastasis) versus only 25% in the unfavourable subgroup (elevated lactate dehydrogenase). The dabrafenib plus trametinib safety profile was consistent with previous clinical trial observations, and no new safety signals were detected with long-term use.

Conclusions

These data demonstrate that durable (≥3 years) survival is achievable with dabrafenib plus trametinib in patients with BRAF V600-mutant metastatic melanoma and support long-term first-line use of the combination in this setting.

PIPELINEs: Creating Comparable Clinical Knowledge Efficiently by Linking Trial Platforms

Adaptive, seamless, multisponsor, multitherapy clinical trial designs executed as large scale platforms, could create superior evidence more efficiently than single-sponsor, single-drug trials. These trial PIPELINEs also could diminish barriers to trial participation, increase the representation of real-world populations, and create systematic evidence development for learning throughout a therapeutic life cycle, to continually refine its use. Comparable evidence could arise from multiarm design, shared comparator arms, and standardized endpoints-aiding sponsors in demonstrating the distinct value of their innovative medicines; facilitating providers and patients in selecting the most appropriate treatments; assisting regulators in efficacy and safety determinations; helping payers make coverage and reimbursement decisions; and spurring scientists with translational insights. Reduced trial times and costs could enable more indications, reduced development cycle times, and improved system financial sustainability. Challenges to overcome range from statistical to operational to collaborative governance and data exchange.

Major therapeutic developments and current challenges in advanced melanoma

Malignant melanoma is rising in incidence. The treatment options have been very limited but advances in molecular biology and immunology have led to a greater understanding of the pathogenesis of the disease. Four drugs have been approved for the treatment of advanced melanoma in the past 2 years and two new classes of agents have recently been shown to lead to durable responses in a substantial minority of patients. The identification of biomarkers has helped clinicians and researchers segregate patients into molecular subgroups, which facilitates the selection of therapy. Preliminary work has begun on determining the ideal sequences of the various therapies. Investigations have been carried out on why these treatments work and what the mechanisms of resistance are to these therapies. It is hoped that combinations of therapies will emerge that lead to a high percentage of durable responses.

Cutaneous effects of BRAF inhibitor therapy: a case series

BACKGROUND

The cutaneous effects of rapidly accelerated fibrosarcoma kinase B (BRAF) inhibitors are not well understood. Squamous cell carcinoma (SCC), keratoacanthoma, and photosensitivity have been described in patients taking BRAF inhibitors.

PATIENTS AND METHODS

To characterize the timing and frequency of skin lesions in patients receiving BRAF inhibitor therapy, we utilized a retrospective case review of 53 patients undergoing treatment with BRAF inhibitors for 4-92 weeks of therapy. Patients were evaluated at baseline, and then followed at 4- to 12-week intervals. Charts were retrospectively reviewed, and the morphology and timing of cutaneous events were recorded.

RESULTS

Thirty-three of the 53 charts met exclusion/inclusion criteria, 15 were treated with vemurafenib, and 18 were treated with GSK 2118436/GSK 1120212. Of 33 patients treated with BRAF inhibitor, 13 developed photosensitivity (39.4%), 10 developed actinic keratoses (30.3%), 10 developed warts (30.3%), and 6 developed SCC (18.2%).

CONCLUSIONS

Multiple cutaneous findings were observed in the 33 patients taking BRAF inhibitors. The previously described association with SCC and photosensitivity was observed in these patients as well. Over half of the observed SCCs were invasive in nature. Photosensitivity continues to be frequent with BRAF inhibitors. Patients taking BRAF inhibitors should have regular full body skin exams. Further studies are necessary to better elucidate the rates of these adverse cutaneous effects.

Phase III randomized, open-label, multicenter trial (BRIM3) comparing BRAF inhibitor vemurafenib with dacarbazine (DTIC) in patients with V600EBRAF-mutated melanoma

LBA4

Background: About 50% of melanomas have an activating V600EBRAF mutation which led to the hypothesis that inhibition of the mutated BRAF kinase may be of clinical benefit. Phase I and II trials with vemurafenib (previously PLX4032/RO5185426), an orally available inhibitor of oncogenic BRAF kinase, showed response rates (RR; CR+PR) >50% in V600EBRAF- mutated melanoma patients (pts). We conducted a phase III trial to determine if vemurafenib improved overall survival (OS) and progression-free survival (PFS) in melanoma pts with V600EBRAF mutation. Methods: Pts with previously untreated, unresectable stage IIIC or stage IV melanoma that tested positive for V600EBRAF mutation by the cobas 4800 BRAF V600 Mutation Test were randomized (1:1) to vemurafenib (960 mg po bid) or DTIC (1,000 mg/m2, IV, q3w). Randomization was stratified by PS, stage, LDH, and geographic region. Pts were assessed for tumor responses after weeks 6, 12, and then q9 weeks. Co-primary endpoints were OS and PFS on the intent-to-treat population; secondary endpoints included RR, response duration, and safety. Final analysis was planned at 196 deaths. Results: 675 pts were enrolled at 103 centers worldwide between Jan and Dec 2010. Treatment cohorts were well-balanced. At the pre-planned interim analysis (50% of deaths needed for final analysis), the hazard ratios for OS and PFS were 0.37 (95% CI 0.26 to 0.55; p<0.0001) and 0.26 (95% CI 0.20 to 0.33; p<0.0001), respectively, both in favor of vemurafenib. The confirmed RR was 48.4% and 5.5% to vemurafenib and DTIC, respectively, among the 65% of pts evaluable for RR to date. Benefit in OS, PFS, and RR was seen in all subgroups examined. Due to these data, the DTIC cohort has been allowed to cross over to vemurafenib. At the time of data analysis, 66% of vemurafenib pts and 25% DTIC pts were still on treatment. The most common toxicities of vemurafenib were: diarrhea, rash, alopecia, photosensitivity, fatigue, arthralgia, and keratoacanthoma/skin squamous cell carcinoma. Conclusions: Vemurafenib is associated with significantly improved OS and PFS compared to DTIC in pts with previously untreated, V600EBRAF-mutated metastatic melanoma.

Phase I/II study to assess safety, pharmacokinetics, and efficacy of the oral MEK 1/2 inhibitor GSK1120212 (GSK212) dosed in combination with the oral BRAF inhibitor GSK2118436 (GSK436)

CRA8503

Background: In preclinical models, the BRAF/MEK inhibitor (i) combination GSK436/GSK212 has demonstrated enhanced activity against BRAF-mutant cancer cells compared to either drug alone, delayed emergence of GSK436 resistance, and prevented proliferative skin lesions attributable to BRAFi exposure. Methods: Eligible patients (pts) had BRAF V600 mutation positive solid tumors. Part 1: pharmacokinetic (PK) drug-drug interaction (DDI) study. Part 2: Dose escalation of continuous daily dosing of the combination followed by expansion cohorts; Part 3: Randomized phase II trial in untreated stage IV melanoma. Results: 45 pts have received ≥ 1 dose of GSK212 + GSK436, including 43 melanoma (all BRAFi naïve), 1 NSCLC and 1 salivary duct carcinoma. PK results of 7 pts in Part 1 showed no effect of GSK212 on single dose of GSK436. There was no clinically meaningful DDI between GSK436 and GSK212 after repeat dosing of the combination (Part 2). GSK436 was dosed 75-150 mg BID in combination with GSK212 1.0, 1.5, 2.0 mg QD. The recommended dose was 2 mg QD GSK212 in combination with 150 mg BID GSK436. At 1.5 mg GSK212, there was one DLT, a recurrent grade (G) 2 neutrophilic panniculitis. The only G4 adverse event (AE) was a sepsis-like syndrome with fever/hypotension. G3 AEs included generalized rash (n=2, 4%) and neutropenia (n=2, 4%). Skin toxicity ≥ G2 occurred in 9 (20%) pts; of these, G2 rash (n=4, 8%) and G2 macular rash (n=1, 2%). No cutaneous squamous cell carcinoma (SCC) or hyperproliferative skin lesions have occurred at any dose level. Other common G2 toxicities were pyrexia (n=5, 11%), vomiting (n=2, 4%) and fatigue (n=2, 4%). Of 16 evaluable pts in Part 2, 13 pts had PR and 3 SD for an ORR of 81% (95% CI 54.4%-96.0%) and all but 2 pts remain on study. In 10 evaluable pts who received 150 mg BID GSK436 + ≥1 mg QD GSK212, 9 pts had PR and 1 SD. Conclusions: GSK212 at 2 mg QD combines safely with GSK436 150 mg BID, no SCC thus far and decreased frequency of rash compared to previous trials of single agent GSK436 and GSK212, respectively. The preliminary anti-tumor activity warrants further investigation; the randomized phase II trial (Part 3) is accruing.

Recovery of phospho-ERK activity allows melanoma cells to escape from BRAF inhibitor therapy

Background:

Resistance to BRAF inhibitors is an emerging problem in the melanoma field. Strategies to prevent and overcome resistance are urgently required.

Methods:

The dynamics of cell signalling, BrdU incorporation and cell-cycle entry after BRAF inhibition was measured using flow cytometry and western blot. The ability of combined BRAF/MEK inhibition to prevent the emergence of resistance was demonstrated by apoptosis and colony formation assays and in 3D organotypic cell culture.

Results:

BRAF inhibition led to a rapid recovery of phospho-ERK (pERK) signalling. Although most of the cells remained growth arrested in the presence of drug, a minor population of cells retained their proliferative potential and escaped from BRAF inhibitor therapy. A function for the rebound pERK signalling in therapy escape was demonstrated by the ability of combined BRAF/MEK inhibition to enhance the levels of apoptosis and abrogate the onset of resistance.

Conclusion:

Combined BRAF/MEK inhibition may be one strategy to prevent the emergence of drug resistance in BRAF-V600E-mutated melanomas.

PLX4032, a highly selective V600EBRAF kinase inhibitor: Clinical correlation of activity with pharmacokinetic and pharmacodynamic parameters in a phase I trial

9021

Background: PLX4032 is an oral, highly selective inhibitor of oncogenic V600EBRAF kinase currently in phase I trial. V600EBRAF mutation activates Raf/MEK/ERK pathway in multiple tumor types. We evaluated the relationship between PK, PD (pERK, Ki67, FDG-PET), tumor histology and clinical activity following PLX4032 administration in a phase I trial. Methods: In the phase I trial, 6 melanoma pts with V600EBRAF were treated with PLX4032 daily at several dose levels and tumor biopsies (baseline vs. day 15) were assessed histologically and by semi-quantitative IHC analysis (modified H-score) for pERK and Ki67. The first 4 pts received a crystalline formulation of PLX4032; the last 2 pts received a formulation with increased bioavailability. Plasma PK parameters were collected at frequent time points on Days 1, 8 and 15. FDG-PET was performed on Days 1 and 15 on last 2 pts. Results: In the first 4 pts, no histological changes were observed with treatment and all developed disease progression. All had decreased percentage of Ki67 positive nuclei (pre-Rx, range 20–60%, median 45%; post-Rx, range 5–25%, median 12.5%) and 3 of the 4 had decreased pERK levels (pre-Rx, range 50–100, median 60; post-Rx, range 10–40, median 11). Mean PLX4032 AUC0–24h ∼ 126 μM*h was in the range for preclinical tumor stasis but below the threshold for shrinkage. In the last 2 pts, striking tumor necrosis and tumor melanosis was observed in the post-Rx samples. One pt remains on study with a confirmed PR, the other showed a clinical response before disease progression occurred in cycle 2. The percentage of Ki67 positive nuclei declined substantially (pre-Rx, 30% and 50% to post-Rx, 5% and 3%), as did the levels of pERK in the pt with PR (pre-Rx: 70 to post-Rx: 2). Mean PLX4032 AUC0–24h was well above the preclinical threshold in the range of 500 - 1000 μM*h. Both pts had decreased FDG uptake on D15. Conclusions: Clinical activity of PLX4032 treatment correlates with drug exposure levels as measured by AUC0–24h and was associated with histological changes in V600EBRAF positive melanomas on Day 15. Reduction of pERK, along with evidence of reduced proliferation and FDG uptake was observed. Further analysis of PD markers with additional pts at the MTD is planned.

[Table: see text]

Dosing patterns in patients with renal cell carcinoma treated with sorafenib or sunitinib: A retrospective claims database analysis

5097

Background: Tyrosine kinase inhibitors (TKIs; sorafenib [SR], sunitinib [SU]) are FDA approved for the treatment of advanced renal cell carcinoma (RCC). Dose reduction may be needed for management of treatment-related adverse events. We analyzed the dose reduction patterns in pts with RCC treated with SR, approved Dec 05, or SU, approved Jan 06. Methods: A retrospective analysis was conducted using data from a US claims-based database (MarketScan MedStat) covering ≥18 million lives for 2002–2008 in all US census regions. Inclusion criteria were ≥2 claims for RCC (ICD9 189.0 or 198.0), continuous healthcare coverage, >180 days of coverage before RCC diagnosis, no claim for SR or SU prior to RCC diagnosis, initial standard daily RCC dose per package insert recommendation (800 mg for SR or 50 mg for SU), and ≥2 consecutive dispensings. Initial episode was defined as the time from the date of the first drug dispensing (index date) to the first switch to another TKI, end of healthcare coverage, end of treatment, or March 31, 2008. Pt and pt-time level analyses for dose reductions between treatments were conducted. Results: SR- (n = 189) and SU-treated (n = 304) pts met the inclusion criteria. No significant differences in baseline demographics existed between the groups except for a higher incidence of stroke (7.9% vs 3.6%, p = 0.037) and other cancer site (93.7% vs 87.8%, p = 0.036) in the SR group. Significantly more pts who received SU (23%) required dose reductions during the first 3 months of therapy and for all initial episodes than did pts who received (4.2%) SR (p < 0.001 for both). For all episodes, the mean time to dose reduction was 104 days for SU versus 162 days with SR (p = 0.0028). The majority (65%) of dose reductions with SU occurred within the first 3 months, whereas dose reduction with SR was 25% during this time (p < 0.001). After controlling for different lengths of exposure time, 2 to 6 times more dose reductions were observed in pts who received SU than with SR (p < 0.001). Conclusions: This US retrospective claims analysis showed more dose reductions, including number of patients and total number of days, in pts who initially received sunitinib compared with those who received sorafenib.

[Table: see text]

Effect of BRAFV600E on response to sorafenib in advanced thyroid cancer patients

6002

Background: We are conducting an open-label phase II study of sorafenib in patients with metastatic, iodine-refractory thyroid carcinoma. Methods: 55 Patients were administered sorafenib 400 mg orally BID. Responses were monitored by PET and CT. Primary endpoints were response rate (RR) and progression free survival (PFS) by RECIST criteria. BRAF and RAS mutation status is determined by DNA sequencing. Outcome data is evaluated using the Kaplan-Meier method and log-rank test. Biologic activity in tissue obtained during treatment at response and progression is being explored using immunohistochemistry (IHC) to pERK, pAKT and Ki-67 among others, in pretreatment blocks from virtually all patients, and a subset of 14 patients in whom on-treatment tissue is available. Results: We have completed accrual of the 55 patients planned for enrollment; median time on study is 34 weeks and 25 pts (45%) are male. Histological subtypes include papillary (PTC): 25 pts (47%); follicular/Hürthle Cell (FTC): 19 pts (36%); medullary: 4 pts (8%), and poorly differentiated/anaplastic: 5 pts (9%). 52/55 patients are evaluable for response at this time. Median PFS was 84 wks. Genotyping of BRAF is complete in 16 patients. For patients with PTC/FTC, the PFS for those with BRAFwt was 54 wks compared to 84+ wks for patients with BRAFV600E (p = 0.028). On-treatment tissue at progression demonstrates heterogeneity, with p-ERK and p-AKT suppressed in some areas, but highly expressed in others. Data at 6 months post accrual of the last patient will be presented along with patient thyroglobulin levels, PET and CT scans. IHC and additional genotyping will also be presented. Conclusions: Sorafenib has activity in patients with advanced thyroid cancer with an overall PFS of 84 wks. While most patients with PTC or FTC achieve durable responses, patients whose tumors harbor BRAFV600E have significantly longer PFS than those that are BRAFwt.

[Table: see text]

A phase II trial of perifosine in patients with advanced renal cell carcinoma (RCC) who have failed tyrosine kinase inhibitors (TKI)

5101

Background: The recently demonstrated activity of inhibitors of TORC1 in RCC has raised the possibility that even greater effects may be achieved by targeting upstream of this pathway. Perifosine is a synthetic alkylphospholipid which inhibits Akt activity and also has cell-dependent effects upon the MAP-kinase pathway. Prior single-agent trials showed disease stabilization/regression in patients (pts) with advanced RCC; however, few pts were previously treated with a TKI. Therefore, we conducted a multi-center phase II trial to determine the safety and efficacy of perifosine in pts with advanced RCC refractory to VEGFR TKI. Methods: Primary objectives were to measure the % of pts progression-free at 12 weeks (wks) and overall progression-free survival (PFS) of perifosine (100 mg qhs). Secondary objectives included overall response rate (> PR), and safety, Eligibility: ECOG PS 0–1, pts with metastatic RCC who have RECIST defined progression on either sunitinib or sorafenib. Prior Rx with immunotherapy and bevacizumab was permitted. Normal organ and marrow function required. Results: From 4/07–10/08, 24 pts were treated at four sites. Median age 67 (range 47–78) and 16 were male; 90% of pts had predominantly clear cell histology. Prior sunitinib = 12; prior sorafenib = 12 (1.5 avg prior Rx). As of 12/08, all 24 pts were evaluable for PFS, response and toxicity as follows in the table . 6/24 pts remain on treatment (range 7 - 84 wks). Therapy was well tolerated with primarily Grade (G) 1 & 2 adverse events. G 3 & 4 events were: dyspnea (8%), hyponatremia (8%), pulmonary embolism (4%) and arthalgia (4%). Conclusions: Perifosine has promising activity in pts with RCC who have failed prior TKI therapy. The favorable toxicity profile suggests potential for combinational therapies with VEGF-targeted agents. Additional studies are under consideration to evaluate perifosine for clinical benefit in pts with previously treated RCC.

[Table: see text]

[Table: see text]

Phase II study of sorafenib and docetaxel in men with metastatic castration resistant prostate cancer (mCRPC)

e16055

Background: Previous trials of the antiangiogenic kinase inhibitor sorafenib in mCRPC have reported PSA elevation accompanying radiographic response, and evidence that sorafenib may potentiate docetaxel (dxl) myelosuppression. To assess the safety, antivascular effects, and activity of sorafenib and dxl in mCRPC, a phase II trial with dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) was conducted. Methods: Eligible men had mCRPC and no prior chemotherapy. Treatment consisted of dxl 75 mg/m2(day 1) and sorafenib (days 2–19) of a 21 day cycle. Patients received 7 days of sorafenib before cycle 1. Six patients received sorafenib 200mg BID and remaining patients received sorafenib 400 mg BID if <4/6 patients had grade 4 neutropenia. DCE-MRI was performed at baseline, days 8 and 28. The primary endpoint was PSA response rate (>50% PSA decline). Secondary endpoints were vascular response rate (>20% decline in area under the gadolinium curve [AUC60]), toxicity rates, and time to progression (TTP). PSA-only progression (2 consecutive PSA rises) was confirmed by a third PSA rise or radiographic progression after a 21-day drug holiday. Sample size of 69 patients in 1 stage was designed to maximize detection of significant correlations between DCE-MRI and clinical outcomes. Results: Six of 13 enrolled patients (46%) had a PSA response. A median PSA increase of 37% was observed in 73% of patients after 1 week of sorafenib. The median TTP was 8+ months. Two patients had complete disappearance of bone lesions. Grade 3 adverse events were neutropenia (77%), hand-foot syndrome (23%), anemia (15%), nausea (8%), and rash (8%). A median AUC60 decline of 40% from baseline was observed after 7 days of sorafenib, and only a 6% decline on day 28 during a scheduled sorafenib holiday. Conclusions: Sorafenib 400 mg po bid and dxl 75 mg/m2 are tolerable in men with mCRPC. Elevated PSA values in men treated with sorafenib and dxl does not always reflect disease progression. DCE-MRI can capture sorafenib's impairment of tumor vasculature in osseous metastases and rebound angiogenesis during drug holidays. Bone responses and TTP data provide evidence of encouraging activity.

No significant financial relationships to disclose.

Integrating BRAF/MEK inhibitors into combination therapy for melanoma

The discovery of BRAF mutations in melanoma has not yet translated into clinical success, suggesting that BRAF/MEK inhibitors will need to be combined with other agents. In the current review, we discuss other pathways likely to be important for melanoma progression and suggest possible drug combinations for future clinical testing.

A phase I and pharmacokinetic study of lapatinib in combination with infusional 5-fluorouracil, leucovorin and irinotecan

BACKGROUND

This study determined the optimally tolerated regimen (OTR) of oral lapatinib administered in combination with infusional 5-fluorouracil (5-FU), leucovorin and irinotecan (FOLFIRI) and assessed the safety, tolerability and pharmacokinetics of the combination.

PATIENTS AND METHODS

Twenty-five patients were enrolled; 12 patients were treated at three dose levels to determine OTR; then 13 patients were treated at OTR to evaluate the pharmacokinetics of the combination.

RESULTS

The 2-weekly OTR comprised lapatinib 1250 mg/day with irinotecan 108 mg/m(2) (day 1) and leucovorin 200 mg/m(2), 5-FU bolus 240 mg/m(2) and 5-FU infusion 360 mg/m(2) (days 1 and 2); doses of 5-FU and irinotecan represent a 40% reduction in dose compared to conventional FOLFIRI. Dose-limiting toxicities were grade 3 diarrhoea and grade 4 neutropenia. Co-administration of lapatinib increased the area under the plasma concentration-time curve of SN-38, the active metabolite of irinotecan, by an average of 41%; no other pharmacokinetic interactions were observed. Of 19 patients evaluable for disease response assessment, four patients had partial response and nine patients had stable disease.

CONCLUSION

The combination of lapatinib and FOLFIRI is safe and demonstrates clinical activity; the documented PK interaction can effectively be compensated by lowering the doses of 5-FU and irinotecan. This regime may be further tested in a phase II trial.

Updated results of a randomized phase II study comparing two schedules of temozolomide in combination with sorafenib in patients with advanced melanoma

8527

Background: The preliminary results for 90 patients (pt) on this 4-arm phase II trial testing sorafenib (SO), an oral Raf kinase/VEGFR2 inhibitor, and temozolomide (TEM) in pt with metastatic melanoma (MM) were presented in 2006. Since then 88% of target accrual is completed and the study is open at a second institution. The primary objective of this study is to estimate the duration of progression- free survival (PFS). Secondary objectives are to determine the optimal dosing of TEM, response, and toxicity rates. Correlative studies include BRAF genotyping and assessment of intratumoral Raf inhibition, and apoptosis. Methods: Pt with MM and ECOG PS<2 are eligible. Prior therapy is allowed. Target accrual is 167 pt in 1 stage. All pt receive SO 400 mg po bid continuously. After 1 week of SO alone, pt without brain metastasis or prior TEM (A+B) are randomized to receive either extended dosing (ED): TEM 75 mg/m2 po qd for 6/8 weeks (Arm A), or standard dosing (STD): TEM 150 mg/m2 po qd for days1–5/28 (Arm B). Pt with prior TEM are treated with ED (Arm C) and pt with brain metastasis without prior TEM are treated with STD (Arm D). Responses are assessed using RECIST. Results: Accrual is complete for arms A and B. Results for 147 pt were evaluated ( Table ). SO + TEM resulted in a 19% overall response rate (ORR) [95% CI 11–30%] for pt on arms A+B. In this group, 3/78 pt (4%) developed CNS metastases while on study. Pt on arm D had a 17 % ORR [95% CI 7–34%]. Common grade 3 toxicities were hand-foot syndrome (14%), rash (9%), nausea (9%), and diarrhea (5%). Grade 3 lymphopenia was more common in arm A v. B (43% v. 16%, p=0.01). No significant difference in PFS was found between pt with WT v. mutant BRAF (n=33). Therapy-induced apoptosis was found in 8/9 serial biopsies. Analysis of MAPK phosphorylation in serial biopsies is planned. Conclusions: Updated results confirm the encouraging antitumor activity and tolerability of SO + TEM in pt with MM without a prior history of TEM.

No significant financial relationships to disclose.

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Assessment of PI3 kinase as a druggable target in melanoma

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Background: PI3 (phosphatidylinositol-3) kinase is central to a major intracellular signal transduction pathway that influences numerous cellular functions, including growth, differentiation and survival. Drugs that target PI3 kinase have demonstrated preclinical activity, and are undergoing further development. The PI3 kinase inhibitor, SF1126 is expected to enter clinical trials in 2007. The hallmarks for a valuable drug target include differential expression between normal and malignant cells and an association with disease progression. PI3 kinase expression has not been thoroughly evaluated in melanoma. We sought to determine the expression and prognostic value of PI3 kinase in a large cohort of primary and metastatic melanomas and to compare the expression with that of benign nevi. Methods: Tissue microarrays containing 548 melanomas and 540 benign nevi were employed to assess PI3 kinase expression. We used a novel method of in situ automated quantitative analysis (AQUA) of protein levels. We applied S100 conjugated to Cy3 to identify a melanoma tumor mask within a histospot, and measured PI3 kinase expression levels using Cy5 conjugated antibodies within the mask. Continuous AQUA scores were correlated with clinical and pathological variables. Results: PI3 kinase expression was higher in melanomas than in nevi by unpaired t-tests (p < 0.0001), and was significantly higher in metastatic than in primary specimens (p < 0.0001). High PI3 kinase scores were associated with Clark levels of IV-V (p = 0.0126), Breslow thickness > 2mm (p = 0.044) and absence of tumor infiltrating lymphocytes (p = 0.014). High PI3 kinase expression strongly correlated with decreased survival by Cox univariate analysis (p = 0.0024), but was not independent of disease stage. Conclusions: PI3 kinase expression is remarkably higher in malignant melanocytes than in benign nevi. Moreover, high PI3 kinase expression is associated with disease aggression, making PI3 kinase an attractive drug target for melanoma. This is the first large study assessing PI3 kinase levels in melanoma in a quantitative fashion. Assessment of the association between PI3 kinase levels and response to therapy is warranted.

No significant financial relationships to disclose.

VEGF, VEGFR1, and VEGFR2 expression in melanoma

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Background: Metastatic melanoma is a chemoresistant disease with poor prognosis. Angiogenesis plays a role in progression and metastasis of melanoma. Identifying angiogenic molecules that are differentially expressed between benign and malignant tissues may enable us to create an assay to predict sensitivity to antiangiogenic agents, thus guiding selection of patients for treatment. VEGF signals through its receptor VEGFR1/flt-1 (R1) but is thought to mediate most of its angiogenic and proliferative effects through VEGFR2/flk-1/kdr (R2). In smaller melanoma studies, VEGF, R2 and less commonly R1 expression was associated with disease aggression. We characterized VEGF, R1, and R2 expression on a cohort of 540 nevi and 548 melanomas. Methods: We stained tissue microarrays to assess VEGF, R1, and R2 expression by automated quantitative analysis (AQUA), an objective method for analysis of protein levels. We used S100 to define pixels as melanoma (tumor mask) within the array spot, and measured intensity of VEGF, R1, and R2 expression using Cy5 conjugated antibodies within the mask. Results: VEGF, R1, and R2 expression was significantly higher in melanomas than in nevi by unpaired t-tests (p<0.0001). VEGF and R2 expression was higher in metastatic than primary specimens (p<0.0001). Differential expression of R1 between metastatic and primary specimens was less pronounced (p=0.0158). R2 expression correlated with Breslow depth > 2 mm (p=0.0129). Cox univariate analysis revealed an association between decreased survival and expression of VEGF (p= 0.0488) and R2 (p=0.0035); however, this was not independent of disease stage. Conclusions: VEGF, R1, and R2 expression is higher in malignant melanocytes than in their benign counterparts and higher in metastatic than primary specimens. This association with disease aggression underscores the importance of these proteins as therapeutic targets. Differential expression of R2 was found to be more significant than R1, supporting the belief that VEGF mediates its effects through R2 in malignancy. To our knowledge, this is the largest study to examine the VEGF pathway in melanoma. Future clinical trials of antiangiogenic agents in melanoma should include correlative serum and tissue assays of VEGF, R1, and R2 as biomarkers of response to therapy.

[Table: see text]

Phase 1, pharmacokinetic (PK) and pharmacodynamic (PD) study of oral alvespimycin (A; KOS-1022; 17-DMAG): Two different schedules in patients with advanced malignancies

14059

Background: A is ∼3–5 fold more potent compared to 17-AAG (the first Hsp90 inhibitor to enter clinical testing), based on in vitro cytotoxicity or the MTD in toxicology studies; it is water-soluble; and oral bioavailability in dogs is estimated at 40%. Toxicity in the dog included kidney, intestinal and liver findings. This study was conducted to determine the toxicity, MTD, recommended phase 2 dose (RP2D), PK and PD of A in pts with solid tumors. Methods: Escalating doses of A were given PO on 2 different schedules: every other day or daily for 4 out of 6 weeks. An initial IV dose was given to calculate absolute bioavailability. PK was evaluated after the IV dose, Day 1 and 21 of oral dosing. PBLs were collected to investigate changes in intracellular signaling proteins by immunoblot (Days 1 and 21 at 1, 3, 24 and 48 hours post-dose). Results: 28 pts were enrolled: 24 on the QOD schedule at doses of 5 (n=4), 10 (n=4), 20 (n=8), 30 (n=5) and 40 mg (n=3); 4 pts received 10mg on the QD schedule. 50% were male, median age/ECOG PS 55 and 0; median prior regimen 3. DLT has not yet been observed. Common drug-related toxicities (n=23): fatigue 43%, nausea 24%, anorexia 19%, proteinuria 19%, and peripheral edema 14%. Of these, fatigue and peripheral edema appear to be possibly dose-related. Drug-related Grade 3–4 toxicity (one patient each) included anemia, neutropenia, peripheral edema, hypokalemia, pain in extremity and hypoxia. For pts with full PK data (n=14), bioavailability equaled 51% and 49% on Day 1 and 21, and was not dose-dependent. Mean Day 21 AUCinf for the 5 to 30 mg/m2 levels equaled 91, 166, 542 and 1889 ng*h/mL. One pt with 3-fold increase in AUCinf comparing Day 1 and 21 dose had been started on dronabinol, a CYP2C9 inhibitor. One pt with fibrosarcoma (4 prior regimens) had necrotic changes in the tumor in the axilla with improved symptoms (active at 5+ months). Additional pts with SD include hemangioendothelioma (7 months), melanoma (6+ months), and renal cell (5 months). Induction in Hsp70 at the 30 mg dose level was seen pre-dose on Day 21 with maximal induction at 24 hours post-dose. Conclusions: Dose escalation continues on both schedules in order to define a RP2D. Toxicity is acceptable. Early signs of activity have been observed.

[Table: see text]

Ki67 expression levels are a better marker of reduced melanoma growth following MEK inhibitor treatment than phospho-ERK levels

The loss of tumour phospho-extracellular responsive kinase (pERK) positivity is the major treatment biomarker for mitogen-activated protein kinase/extracellular responsive kinase (MEK) inhibitors. Here, we demonstrate that there is a poor correlation between pERK inhibition and the anti-proliferative effects of MEK inhibitors in melanoma cells. We suggest that Ki67 is a better biomarker for future clinical studies.

Sorafenib in advanced melanoma: a Phase II randomised discontinuation trial analysis

The effects of sorafenib – an oral multikinase inhibitor targeting the tumour and tumour vasculature – were evaluated in patients with advanced melanoma enrolled in a large multidisease Phase II randomised discontinuation trial (RDT). Enrolled patients received a 12-week run-in of sorafenib 400 mg twice daily (b.i.d.). Patients with changes in bi-dimensional tumour measurements <25% from baseline were then randomised to sorafenib or placebo for a further 12 weeks (ie to week 24). Patients with ⩾25% tumour shrinkage after the run-in continued on open-label sorafenib, whereas those with ⩾25% tumour growth discontinued treatment. This analysis focussed on secondary RDT end points: changes in bi-dimensional tumour measurements from baseline after 12 weeks and overall tumour responses (WHO criteria) at week 24, progression-free survival (PFS), safety and biomarkers (BRAF, KRAS and NRAS mutational status). Of 37 melanoma patients treated during the run-in phase, 34 were evaluable for response: one had ⩾25% tumour shrinkage and remained on open-label sorafenib; six (16%) had <25% tumour growth and were randomised (placebo, n=3; sorafenib, n=3); and 27 had ⩾25% tumour growth and discontinued. All three randomised sorafenib patients progressed by week 24; one remained on sorafenib for symptomatic relief. All three placebo patients progressed by week-24 and were re-started on sorafenib; one experienced disease re-stabilisation. Overall, the confirmed best responses for each of the 37 melanoma patients who received sorafenib were 19% stable disease (SD) (ie n=1 open-label; n=6 randomised), 62% (n=23) progressive disease (PD) and 19% (n=7) unevaluable. The overall median PFS was 11 weeks. The six randomised patients with SD had overall PFS values ranging from 16 to 34 weeks. The most common drug-related adverse events were dermatological (eg rash/desquamation, 51%; hand-foot skin reaction, 35%). There was no relationship between V600E BRAF status and disease stability. DNA was extracted from the biopsies of 17/22 patients. Six had V600E-positive tumours (n=4 had PD; n=1 had SD; n=1 unevaluable for response), and 11 had tumours containing wild-type BRAF (n=9 PD; n=1 SD; n=1 unevaluable for response). In conclusion, sorafenib is well tolerated but has little or no antitumour activity in advanced melanoma patients as a single agent at the dose evaluated (400 mg b.i.d.). Ongoing trials in advanced melanoma are evaluating sorafenib combination therapies.