Multicenter phase 2 study of combination therapy with ruxolitinib and danazol in patients with myelofibrosis

Myelofibrosis is a myeloproliferative neoplasm that is characterized by splenomegaly, profound symptom burden, and cytopenias. JAK inhibitor therapy offers improvements in splenomegaly, symptom burden, and potentially survival; however, cytopenias remain a significant challenge. Danazol has previously demonstrated improvements in myelofibrosis-associated anemia. We conducted a phase II clinical trial evaluating the efficacy and tolerability of combination therapy with ruxolitinib, an oral JAK inhibitor, and danazol. Fourteen intermediate or high-risk MF patients were enrolled at 2 institutions. Responses per IWG-MRT criteria were stable disease in 9 patients (64.2%) clinical improvement in 3 (21.4%) all of which were spleen responses, partial response in 1 (7.1%) and progressive disease in 1 (7.1%). Despite limited IWG-MRT response, stabilization of anemia and thrombocytopenia was demonstrated. In JAK inhibitor naïve patients, 4/5 (80%) had stable or increasing hemoglobin. Of the 9 patients on prior JAK inhibitor, 5 patients (55.5%) and 8 patients (88.9%) had stable or increasing hemoglobin or platelet levels, respectively. Adverse events possibly related included grade 3 or greater hematologic toxicity in ten patients (71.4%) and non-hematologic toxicity in two patients (14.3%). Although combination therapy did not lead to increased hematologic response per IWG-MRT criteria, hematologic stabilization was observed and may be clinically useful.

Sonidegib phosphate: new approval for basal cell carcinoma

Basal cell carcinoma (BCC), although mostly locally confined, is the most common cancer. Most BCCs harbor inactivating mutations in the membrane receptor/gene Ptch, thereby activating the Hedgehog signaling pathway (Hh) via the essential signaling molecule Smoothened (SMO). Novel small-molecule inhibitors or antagonists of SMO have shown excellent response rates in patients with locally advanced, unresectable and metastatic BCC in roughly 35-60% of patients, with disease control rates and clinical benefit being even higher. Sonidegib is the second-in-class SMO inhibitor approved for locally advanced, unresectable and metastatic BCC. Sonidegib is given once daily continuously, with specific side effects as listed in the label indication. Resistance develops over time and knowledge gleaned from other SMO inhibitors indicates that SMO mutations preventing drug binding as well as mechanisms activating the Hh pathway downstream of SMO are responsible, ultimately reactivating Hh pathway signaling. The next challenge will be to define novel salvage and SMO combination strategies for BCC and other tumors.

Panel sequencing for clinically oriented variant screening and copy number detection in 142 untreated multiple myeloma patients

We employed a customized Multiple Myeloma (MM)-specific Mutation Panel (M³P) to screen a homogenous cohort of 142 untreated MM patients for relevant mutations in a selection of disease-specific genes. M³Pv2.0 includes 77 genes selected for being either actionable targets, potentially related to drug–response or part of known key pathways in MM biology. We identified mutations in potentially actionable genes in 49% of patients and provided prognostic evidence of STAT3 mutations. This panel may serve as a practical alternative to more comprehensive sequencing approaches, providing genomic information in a timely and cost-effective manner, thus allowing clinically oriented variant screening in MM.

Phase I ficlatuzumab monotherapy or with erlotinib for refractory advanced solid tumours and multiple myeloma

BACKGROUND

Ficlatuzumab, a humanised hepatocyte growth factor (HGF) IgG1κ inhibitory monoclonal antibody, was evaluated for recommended phase II dose (RP2D), safety, pharmacokinetics (PKs), antidrug antibody (ADA), pharmacodynamics (PDs) and antitumour activity as monotherapy or combined with erlotinib.

METHODS

Patients with solid tumours received ficlatuzumab 2, 5, 10 or 20 mg kg(-1) intravenously every 2 weeks (q2w). Additional patients were treated at the RP2D erlotinib.

RESULTS

Forty-one patients enrolled at doses ⩽20 mg kg(-1). Common adverse events (AEs) included peripheral oedema, fatigue and nausea. Three patients experienced grade ⩾3 treatment-related hyperkalaemia/hypokalaemia, diarrhoea or fatigue. Best overall response (44%) was stable disease (SD); median duration was 5.5 months (0.4-18.7 months). One patient has been on therapy with SD for >4 years. Pharmacokinetics of ficlatuzumab showed low clearance (0.17-0.26 ml h(-1) kg(-1)), a half-life of 6.8-9.4 days and dose-proportional exposure. Ficlatuzumab/erlotinib had no impact on the PK of either agent. No ADAs were detected. Ficlatuzumab increased serum HGF levels.

CONCLUSIONS

Recommended phase II dose is 20 mg kg(-1) q2w for ficlatuzumab monotherapy or with erlotinib. Preliminary antitumour activity and manageable AEs were observed. Pharmacokinetics were dose-proportional and consistent with other IgG therapeutics. Ficlatuzumab was not immunogenic, and serum HGF was a potential PD marker.

A phase I and pharmacological study of MK-1775, a Wee1 tyrosine kinase inhibitor, in both monotherapy and in combination with gemcitabine, cisplatin, or carboplatin in patients with advanced solid tumors

3510

Background: MK-1775 is an inhibitor of Wee1, a kinase that phosphorylates CDC2 to inactivate the CDC2/cyclin B complex (regulating the G2 checkpoint). Since most human cancers harbor p53-dependent G1 checkpoint abnormalities, they are dependent on the G2 checkpoint. G2 checkpoint abrogation may therefore sensitize p53 deficient tumor cells to anti-cancer agents. Methods: This study is evaluating the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of MK-1775 administered as both monotherapy (MT) and combination therapy (CT) with gemcitabine (G), cisplatin (P), or carboplatin (C). PART 1 consists of a single dose of MK-1775 followed by 14 days observation. If well tolerated, the same pt continues on to one of three treatment arms in PART 2: a single lower dose of MK-1775 in combination with: 1) 1000 mg/m2 G, 2) 75 mg/m2 P or 3) C AUC 5. Maximum Tolerated Doses (MTDs) will be established for MK-1775 as both monotherapy and in combination. PD biomarkers include IHC analysis for pCDC2/CDC2 in plucked hair and skin biopsies, peripheral blood, and tumor biopsies. Wee1 gene expression signature is measured in plucked hair and tumor biopsies by qPCR. Results: To date, 37 pts (median age 61; up to 4 prior therapies) have been treated with MK-1775. 4 pts experienced DLT. One pt on G + 200mg MK-1775 had gr3 leucopenia and neutropenia; one pt on P + 200mg MK-1775 had gr3, fatigue, diarrhea and hypokalemia and another pt gr2 nausea/vomiting > 48hrs requiring hospitalization. One pt on C + 325mg MK-1775 was hospitalized for gr3 bilirubin. Linear PK was demonstrated at 100, 200, 325, 650 and 1300 mg MK-1775. Terminal T½ of MK-1775 was 7.6–12.2 hrs and Tmax was 1.0–6.0 hrs. Preliminary MTDs of MK-1775 in combination with G, C and P were 200, 325 and 200mg, respectively. Significant changes in Wee1 signature gene expression were observed in plucked hair. Of 28 evaluable pts, >50% regression of axillary lymphadenopathy was seen in 1 pt with melanoma on the P arm, and stable disease in 14 other pts (median duration). Conclusions: MK-1775 is a first in class Wee1 inhibitor that is well tolerated and shows promising anti-tumor activity in previously treated pts.

[Table: see text]

A first-in-human phase I study to evaluate the pan-PI3K inhibitor GDC-0941 administered QD or BID in patients with advanced solid tumors

3501

Background: The PI3K-PTEN-AKT signaling pathway is deregulated in a wide variety of cancers. GDC-0941 is a potent and selective oral inhibitor of the class I PI3K with 3 nM IC50 for the p110-alpha subunit in vitro and 28 nM IC50 in a cell-based pAKT assay and demonstrates broad activity in breast, ovarian, lung, and prostate cancer models. Methods: A Phase I dose escalation study using a 3+3 design was initiated in patients (pts) with solid tumors. GDC-0941 was given on d1, followed by 1 wk washout to study single-dose PK and PD markers. GDC-0941 was then administered qd on a 3 wk on, 1 wk off, schedule. Steady-state PK and PD were evaluated after 1 wk of continuous dosing. A separate concurrent dose-escalation arm with bid dosing was initiated after the third qd cohort. Results: Nineteen pts have been enrolled in 5 successive dose-escalation cohorts in the qd arm with dose levels up to 80 mg daily. Seven pts were enrolled in 2 cohorts in the bid arm at total daily doses of 60 and 80 mg. The most frequently reported drug-related AEs were Grade 1/2 nausea, fatigue, diarrhea, peripheral edema, and dysgeusia; no drug related grade >3 events have been reported. PK data suggest dose-proportional increases in Cmax and AUC. Potential signs of anti-tumor activity have been observed with a soft tissue sarcoma pt on-study for >176 days with stable disease (30 mg qd), an ovarian cancer pt with an on-study 2.8-fold decrease in CA-125 response to normal levels (30 mg bid) and a pt with endometrial cancer with a decrease in tumor FDG-PET uptake (80 mg qd). Conclusions: GDC-0941 is generally well-tolerated with potential signs of anti-tumor activity. Preliminary PK data suggest dose-proportional increases in exposure over the dose levels evaluated. Dose-escalation on both the qd and bid schedules continues with updated data to be presented.

[Table: see text]

Pharmacokinetic and pharmacodynamic results of a 4-hr IV administration phase I study with EPC2407, a novel vascular disrupting agent

3569

Background: EPC2407 is a 4-aryl-chromene single isomer microtubulin inhibitor with vascular disrupting and apoptotic activity at nanomolar concentrations. In an earlier phase I study dosing by 1 hr infusions daily x3 on a 21 day cycle, DLT at 21 mg/m2 was pain at tumor sites and vasoconstriction with increases of BP and QTc. MTD was 13 mg/m2 over 1 hr (ASCO 2008, Abst 2531). All drug-related toxicities resolved within an hour of stopping the infusion. Prolonged infusion of EPC2407 to extend exposure of tumor vasculature was designed with administration of EPC2407 over 4 hrs for 3 consecutive days of a 21 day cycle. Eleven patients have received this schedule and their cancers included leiomyosarcoma, colo-rectal, ovary, hepatocellular (2), NSCLC, pancreas, carcinoid, hemangiopericytoma, larynx and small bowel. Results: Doses escalated from 13 to 30 mg/m2 over 4 hours, with MTD determined to be 24 mg/m2. DLTs at 30 mg/m2 were similar to those seen in the 1 hr infusion, with pain at tumor sites in 1 participant and asymptomatic ST depression in a second. Other toxicities were also similar and included transient hypertension. QTc increases were not significant and no new toxicities were encountered. T1/2 with 4 hr infusion was ∼2hr, also seen with 1 hr infusion. AUC and Cmax values were similar to that predicted from the 1 hr data except AUC at 13 mg/m2 was lower than expected. DCE-MRI was done at baseline and after infusion on day 3, cycle 1. Analysis to date of DCE-MRI data of 4 patients showed a median decrease of 40% in both tumor permeability (Ktrans) and tumor perfusion volume (Vp). The two patients with hepatocellular carcinoma had notable stable disease and clear clinical benefit. Both patients received 18 mg/m2 dose, with one receiving 7 cycles over 5 months, and the other still on study (cycle 6) with stable disease for at least 4 cycles. Conclusions: EPC2407 shows clinical promise, with infusion-associated toxicities characteristic of the VDA drug class but without sustained or cumulative toxicity. Studies combining EPC2407 with conventional cytotoxic/cytostatic regimens are being designed.

[Table: see text]

Final results of a phase I study of TH-302, a hypoxia-activated cytotoxic prodrug (HAP)

2573

Background: TH-302 is a 2-nitroimidazole prodrug of the DNA alkylator, bromo-isophosphoramide mustard (Br-IPM). TH-302 is essentially inactive under normoxia but in severe hypoxia and in the presence of certain reductases, it is reduced and Br-IPM is released. Methods: Eligible patients (pts) had ECOG ≤1, advanced or metastatic solid tumors, evaluable by RECIST, and acceptable hematologic, liver and renal function. A modified accelerated titration design was used. TH-302 was administered intravenously over 30–60 minutes on Day 1, 8 and 15 of a 28-day cycle. CT scans were obtained after every 2 cycles. Detailed pharmacokinetic sampling was performed on Days 1 and 15. The primary objectives of this study were to determine the dose limiting toxicity (DLT) and the maximum tolerated dose (MTD). Results: Twenty-nine pts enrolled at 3 sites at 9 dose levels from 7.5–670 mg/m2. Median age: 64y. 20 male/9 female. ECOG 0/1: 16/13. Primary tumor: prostate (8), colorectal (8), lung (5) other (8). Two of 5 pts at 670 mg/m2 had DLT: Herpes simplex perianal/rectal ulcers and dehydration due to mucositis. Reversible skin and mucosal adverse events (AE) occurred in 12 of 15 (80%) pts at ≥480 mg/m2 including grade 3 events in 3 pts. The most common TH-302-related AEs were nausea, skin lesions, vomiting and fatigue. Hematologic toxicity was mild and limited: two pts with grade 1 and one pt with grade 2 neutropenia and five pts with grade 1 thrombocytopenia. Five pts had grade 3 and one grade 4 lymphopenia. Four pts have enrolled at an intermediate dose of 575 mg/m2 with no DLT so this is likely the MTD and is well above the predicted biologic effective dose of 100 mg/m2. One pt with SCLC treated at 480 mg/m2 and one with melanoma treated at 670 mg/m2 had unconfirmed partial responses; 12 pts had stable disease (6 continuing after 4 or more cycles), 7 had PD, 4 were unevaluable and 4 are too early to assess. Cmax and AUC for TH-302 and Br-IPM increased linearly with no accumulation at Day 15. Conclusions: Weekly TH-302 has remarkably little hematologic toxicity. Skin and mucosal AEs have developed at the higher dose levels. Skin/mucosa are known to have hypoxic regions. TH-302 is the first HAP to demonstrate tumor responses in Phase I. The MTD is likely 575 mg/m2. Studies in combination with chemotherapy are ongoing.

[Table: see text]

Prospective evaluation of patient perceptions and willingness to undergo pharmacodynamic and pharmacokinetic tests in early phase oncology trials

6587

Background: Increasing numbers of clinical trials include optional or mandatory pharmaco-dynamic and -kinetic assays. Since little is known about patients’ (pts) perceived willingness to undergo specific tests and the number of tests pts would tolerate on a single trial, this study was conducted. Secondary purposes included correlating test number and type with demographics, prior test experience, coverage, and inconvenience. Methods: Exploratory correlative study using a multi-item self-report questionnaire to measure pts willingness (0–10 scale, 0 = not willing, 10 = very willing) to undergo imaging (e.g., MRI, ECHO), invasive (e.g., tumor, skin biopsies [bx]) and less invasive tests (e.g., blood, urine). 61 pts (22 female, 39 male) with advanced malignancies participating in phase I or II trials at one institution were enrolled from June 2008-December 2008. Descriptive and non-parametric statistics were used. Results: Statistically significant (p < 0.01) inverse relationships were found between the number of imaging studies (e.g., CT, ECHO), tests required (e.g., tumor, skin bx, blood draws) and pts reported willingness to undergo these tests. Pts were least willing to undergo tumor bx (median 5.5, interquartile range [IQR] 3.5–10), skin bx (6.8, 3.1–10), and unexpectedly MRIs (8, 4–10) (all p < 0.01). Surprisingly, inconvenience and prior negative experiences for the more invasive tests (e.g., skin bx) did not negatively affect willingness to undergo these tests in the future as opposed to most imaging studies. College-educated were more willing to undergo tests than non-college educated. Few pts were unwilling to undergo tests/procedures at all, if mandatory for enrollment. Conclusions: Results provide improved understanding of pts willingness to undergo trial requirements and suggest that adequate explanation (e.g., MRI) and test rationale may affect willingness to undergo tests. Findings can be used to improve study design and consent procedures to minimize patient discomfort and inconvenience. The overall willingness of advanced stage cancer pts to undergo study specific tests/procedures is high.

No significant financial relationships to disclose.

Proteomic prediction in hormone receptor-positive breast cancer

541

Background: Hormone receptor-positive breast cancer (HR+BC) is heterogeneous. Attempts to use transcriptional analysis such as Oncotype Dx facilitate therapy planning but fail to identify patients who will relapse or potential therapy targets. Methods: We used reverse phase protein lysate arrays and Microvigene software to quantify expression of estrogen receptor (ERα) and 36 total/activated components of the HER2, phosphatidylinositol-3-kinase (PI3K), mitogen-activated protein kinase (MAPK), and STAT pathways in 64 HR+BCs and 40 breast cancer cell lines. Clustering was performed with Xcluster and Treeview. Results: 47/64 HR+BC patients were treated with adjuvant hormone therapy and 43/64 with chemotherapy. There were 12 recurrences including 5 patients diagnosed with metastases within 0–3 months of diagnosis. Unsupervised analysis using the expression of all 37 proteins revealed two large subclusters of HR+BCs. One large cluster was composed of tumors with lower ERα expression levels and was driven by an antibody group composed mostly of phosphoproteins indicative of activated growth factor signaling pathways. Thus, there were significant inverse correlations between ERα expression and the expression and activation of components of the PI3K/MAPK pathways including EGFR, src, AKT, 4EBP1, and PKCα (p≤0.05 for each). Similar inverse correlations were seen in 40 assayed breast cancer cell lines. The clinicoproteomic predictors of relapse among HR+BCs were nuclear grade (p=0.001), low expression of ERα (p=0.04), low p38 phosphorylation (p=0.02), and high p53 (p=0.02). There also was a trend (p≤0.1) to the association of low MAPK and S6 phosphorylation, low p27, and high cyclin B1 with relapse. Using these antibodies to perform a supervised analysis, we found a small group of p53-high, cyclin B1-high, ERα-low HR+BCs with a 75% likelihood of relapse, significantly greater than in other tumors (p<0.003). Since 10/12 relapses occurred in 26 grade 3 tumors, we searched for and found a ‘grade 3’ HR+BC 6 antibody signature associated with a recurrence-free survival at 20 months of 17% compared to 100% in other patients (p=0.002). Conclusion: Although patient numbers are small and the findings require validation, kinase signaling profiles have potential in breast cancer prediction.

No significant financial relationships to disclose.

Proteomic signatures of acute myeloid leukemia (AML) distinguishes different outcome groups across cytogenetics and identified potential therapy targets

6523

Background: Cytogenetics (CG) guide AML treatment but reliable markers predicting response and relapse within CG groups are missing. We therefore determined whether functional proteomic signatures can classify AML into groups with different outcomes and risk of relapse. Method: Using Reverse Phase Protein Array, total and phospho-site specific expression of 37 proteins in 73 primary AML was measured. Outcomes in the set were comprised equally of primary refractory (PR), relapsed (Rel) and continuous complete remission (CCR) patients. Cell lysates were spotted on nitrocellulose coated slides, probed with validated antibodies, expression intensities were quantified, data was standardized and analyzed for correlations using different clustering approaches. Results: Unsupervised hierarchical clustering based on Pearsons’ correlation distance yielded 4 large clusters. Subsequent perturbation bootstrap re-sampling arranged samples into four classes that correlated with initial response to therapy and risk of relapse (see Table ). Protein profiles in each of he 4 classes differed. Cytogenetic marker distribution were similar across the 4 clusters. Class 1 and 4 demonstrated a similar predictive value of patient outcome as cytogenetics. In classes at highest risk of relapse (2, 3) different proteins were predictive of response. In class 2, the most discriminatory proteins predicting CCR were elevated AMPK, p27, 4-EBP1, BclXL. In class 3, relapsed patients had elevated PTEN, phospho-Stat3, total Stat3, and phospho-PKCα compared to CCR patients. Conclusion: Pretreatment protein expression signatures divide AML into classes that predict for initial achievement of CR and subsequent relapse independent of CG. Poteomic profiling may suggest potential therapy targets as opposed to CG or transcriptional profiling. These preliminary results need to be confirmed in formal training and test sets prior to changing patient management.

[Table: see text]

No significant financial relationships to disclose.