Pemigatinib in previously treated solid tumors with activating FGFR1-FGFR3 alterations: phase 2 FIGHT-207 basket trial

Fibroblast growth factor receptor (FGFR) alterations drive oncogenesis in multiple tumor types. Here we studied pemigatinib, a selective, potent, oral FGFR1-FGFR3 inhibitor, in the phase 2 FIGHT-207 basket study of FGFR-altered advanced solid tumors. Primary end points were objective response rate (ORR) in cohorts A (fusions/rearrangements, n = 49) and B (activating non-kinase domain mutations, n = 32). Secondary end points were progression-free survival, duration of response and overall survival in cohorts A and B, and safety. Exploratory end points included ORR of cohort C (kinase domain mutations, potentially pathogenic variants of unknown significance, n = 26) and analysis of co-alterations associated with resistance and response. ORRs for cohorts A, B and C were 26.5% (13/49), 9.4% (3/32) and 3.8% (1/26), respectively. Tumors with no approved FGFR inhibitors or those with alterations not previously confirmed to be sensitive to FGFR inhibition had objective responses. In cohorts A and B, the median progression-free survival was 4.5 and 3.7 months, median duration of response was 7.8 and 6.9 months and median overall survival was 17.5 and 11.4 months, respectively. Safety was consistent with previous reports. The most common any-grade treatment-emergent adverse events were hyperphosphatemia (84%) and stomatitis (53%). TP53 co-mutations were associated with lack of response and BAP1 alterations with higher response rates. FGFR1-FGFR3 gatekeeper and molecular brake mutations led to acquired resistance. New therapeutic areas for FGFR inhibition and drug failure mechanisms were identified across tumor types. ClinicalTrials.gov identifier: NCT03822117 .

A risk analysis of alpelisib-induced hyperglycemia in patients with advanced solid tumors and breast cancer

BACKGROUND

Hyperglycemia is an on-target effect of PI3Kα inhibitors. Early identification and intervention of treatment-induced hyperglycemia is important for improving management of patients receiving a PI3Kα inhibitor like alpelisib. Here, we characterize incidence of grade 3/4 alpelisib-related hyperglycemia, along with time to event, management, and outcomes using a machine learning model.

METHODS

Data for the risk model were pooled from patients receiving alpelisib ± fulvestrant in the open-label, phase 1 X2101 trial and the randomized, double-blind, phase 3 SOLAR-1 trial. The pooled population (n = 505) included patients with advanced solid tumors (X2101, n = 221) or HR+/HER2- advanced breast cancer (SOLAR-1, n = 284). External validation was performed using BYLieve trial patient data (n = 340). Hyperglycemia incidence and management were analyzed for SOLAR-1.

RESULTS

A random forest model identified 5 baseline characteristics most associated with risk of developing grade 3/4 hyperglycemia (fasting plasma glucose, body mass index, HbA1c, monocytes, age). This model was used to derive a score to classify patients as high or low risk for developing grade 3/4 hyperglycemia. Applying the model to patients treated with alpelisib and fulvestrant in SOLAR-1 showed higher incidence of hyperglycemia (all grade and grade 3/4), increased use of antihyperglycemic medications, and more discontinuations due to hyperglycemia (16.7% vs. 2.6% of discontinuations) in the high- versus low-risk group. Among patients in SOLAR-1 (alpelisib + fulvestrant arm) with PIK3CA mutations, median progression-free survival was similar between the high- and low-risk groups (11.0 vs. 10.9 months). For external validation, the model was applied to the BYLieve trial, for which successful classification into high- and low-risk groups with shorter time to grade 3/4 hyperglycemia in the high-risk group was observed.

CONCLUSIONS

A risk model using 5 clinically relevant baseline characteristics was able to identify patients at higher or lower probability for developing alpelisib-induced hyperglycemia. Early identification of patients who may be at higher risk for hyperglycemia may improve management (including monitoring and early intervention) and potentially lead to improved outcomes.

REGISTRATION

ClinicalTrials.gov: NCT01219699 (registration date: October 13, 2010; retrospectively registered), ClinicalTrials.gov: NCT02437318 (registration date: May 7, 2015); ClinicalTrials.gov: NCT03056755 (registration date: February 17, 2017).

A Phase 1/2A trial of idroxioleic acid: first-in-class sphingolipid regulator and glioma cell autophagy inducer with antitumor activity in refractory glioma

BACKGROUND

The first-in-class brain-penetrating synthetic hydroxylated lipid idroxioleic acid (2-OHOA; sodium 2-hydroxyoleate), activates sphingomyelin synthase expression and regulates membrane-lipid composition and mitochondrial energy production, inducing cancer cell autophagy. We report the findings of a multicentric first-in-human Phase 1/2A trial (NCT01792310) of 2-OHOA, identifying the maximum tolerated dose (MTD) and assessing safety and preliminary efficacy.

METHODS

We performed an open-label, non-randomised trial to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and anti-tumour activity of daily oral treatment with 2-OHOA monotherapy (BID/TID) in 54 patients with glioma and other advanced solid tumours. A dose-escalation phase using a standard 3 + 3 design was performed to determine safety and tolerability. This was followed by two expansion cohorts at the MTD to determine the recommended Phase-2 dose (RP2D).

RESULTS

In total, 32 recurrent patients were enrolled in the dose-escalation phase (500-16,000 mg/daily). 2-OHOA was rapidly absorbed with dose-proportional exposure. Treatment was well-tolerated overall, with reversible grade 1-2 nausea, vomiting, and diarrhoea as the most common treatment-related adverse events (AEs). Four patients had gastrointestinal dose-limiting toxicities (DLTs) of nausea, vomiting, diarrhoea (three patients at 16,000 mg and one patient at 12,000 mg), establishing an RP2D at 12,000 mg/daily. Potential activity was seen in patients with recurrent high-grade gliomas (HGG). Of the 21 patients with HGG treated across the dose escalation and expansion, 5 (24%) had the clinical benefit (RANO CR, PR and SD >6 cycles) with one exceptional response lasting >2.5 years.

CONCLUSIONS

2-OHOA demonstrated a good safety profile and encouraging activity in this difficult-to-treat malignant brain-tumour patient population, placing it as an ideal potential candidate for the treatment of glioma and other solid tumour malignancies.

CLINICAL TRIAL REGISTRATION

EudraCT registration number: 2012-001527-13; Clinicaltrials.gov registration number: NCT01792310.

Phase 1 study of GSK3368715, a type I PRMT inhibitor, in patients with advanced solid tumors

BACKGROUND

GSK3368715, a first-in-class, reversible inhibitor of type I protein methyltransferases (PRMTs) demonstrated anticancer activity in preclinical studies. This Phase 1 study (NCT03666988) evaluated safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of GSK3368715 in adults with advanced-stage solid tumors.

METHODS

In part 1, escalating doses of oral once-daily GSK3368715 (50, 100, and 200 mg) were evaluated. Enrollment was paused at 200 mg following a higher-than-expected incidence of thromboembolic events (TEEs) among the first 19 participants, resuming under a protocol amendment starting at 100 mg. Part 2 (to evaluate preliminary efficacy) was not initiated.

RESULTS

Dose-limiting toxicities were reported in 3/12 (25%) patients at 200 mg. Nine of 31 (29%) patients across dose groups experienced 12 TEEs (8 grade 3 events and 1 grade 5 pulmonary embolism). Best response achieved was stable disease, occurring in 9/31 (29%) patients. Following single and repeat dosing, GSK3368715 maximum plasma concentration was reached within 1 h post dosing. Target engagement was observed in the blood, but was modest and variable in tumor biopsies at 100 mg.

CONCLUSION

Based on higher-than-expected incidence of TEEs, limited target engagement at lower doses, and lack of observed clinical efficacy, a risk/benefit analysis led to early study termination.

TRIAL REGISTRATION NUMBER

NCT03666988.

A phase II study of TAS-117 in patients with advanced solid tumors harboring germline PTEN-inactivating mutations

PTEN acts as a potent tumor suppressor within the PI3K/AKT/mTOR pathway. Germline mutations in the PTEN gene are a hallmark of PTEN hamartoma tumor syndrome, which includes Cowden syndrome, where they appear to elevate lifetime risk of cancer. Targeted AKT directed therapy has been proposed as an effective approach in cancer patients having germline PTEN mutations. The mechanism of action, safety and dosing regimen for the novel allosteric AKT inhibitor TAS-117 have been explored in a phase I study in Japan in which activity was observed against certain tumor types. Here we describe the study protocol of an international, two-part phase II study evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics and antitumor activity of TAS-117 in patients with advanced solid tumors harboring germline PTEN-inactivating mutations.

First Nationwide Molecular Screening Program in Spain for Patients With Advanced Breast Cancer: Results From the AGATA SOLTI-1301 Study

Background

The SOLTI-1301 AGATA study aimed to assess the feasibility of a multi-institutional molecular screening program to better characterize the genomic landscape of advanced breast cancer (ABC) and to facilitate patient access to matched-targeted therapies in Spain.

Methods

DNA sequencing of 74 cancer-related genes was performed using FFPE tumor samples in three different laboratories with three different gene panels. A multidisciplinary advisory board prospectively recommended potential targeted treatments. The primary objective was to determine the success of matching somatic DNA alteration to an experimental drug/drug class.

Results

Between September 2014 and July 2017, 305 patients with ABC from 10 institutions were enrolled. Tumor sequencing was successful in 260 (85.3%) patients. Median age was 54 (29-80); most tumors were hormone receptor-positive/HER2-negative (74%), followed by triple-negative (14.5%) and HER2-positive (11.5%). Ninety-seven (37%) tumor samples analyzed proceeded from metastatic sites. Somatic mutations were identified in 163 (62.7%) patients, mostly in PIK3CA (34%), TP53 (22%), AKT1 (5%), ESR1 (3%), and ERBB2 (3%) genes. Significant enrichment of AKT1 mutation was observed in metastatic versus primary samples (9% vs. 2%; p=0.01). Genome-driven cancer therapy was recommended in 45% (n=116) of successfully screened patients, 11% (n=13) of whom finally received it. Among these patients, 46.2% had a PFS of ≥6 months on matched therapy.

Conclusions

AGATA is the first nationwide molecular screening program carried out in Spain and we proved that implementing molecular data in the management of ABC is feasible. Although these results are promising, only 11% of the patients with genome-driven cancer therapy received it.

476 First-in-human phase 1/2 study of the first-in-class SUMO-activating enzyme inhibitor TAK-981 in patients with advanced or metastatic solid tumors or relapsed/refractory lymphoma: phase 1 results

Background

SUMOylation is a post-translational modification that serves as an important modulator of immune responses via its role in constraining the type I interferon (IFN-1) response. TAK-981 is a small molecule that inhibits SUMOylation and increases IFN-1-dependent innate immune responses with the potential to enhance adaptive immunity. Here, we report dose-escalation data from a TAK-981 Phase 1/2 clinical study (NCT03648372), the first clinical data for a SUMOylation inhibitor.

Methods

Adults with advanced/metastatic solid tumors or relapsed/refractory lymphomas received TAK-981 IV twice-weekly (BIW; days 1, 4, 8, 11) or once-weekly (QW; days 1, 8) in 21-day cycles. Dose escalation was guided by a Bayesian Logistic Regression Model (BLRM) with overdose control, plus available pharmacokinetic/pharmacodynamic (PK/PD) data. Phase 1 objectives were to determine TAK-981 safety/tolerability and establish the recommended phase 2 dose (RP2D).

Results

Seventy-six patients received TAK-981 at 10 dose levels (3–40 mg BIW; 60–120 mg QW/BIW). Median age was 61 years (range, 38–79); 42 (55.3%) patients were female. Four dose-limiting toxicities were seen in 62 evaluable patients (transient grade 3 ALT/AST elevation, 60 mg BIW; grade 3 pneumonitis, 90 mg BIW; grade 3 stomatitis and grade 3 cognitive disturbance, 120 mg BIW). Per BLRM, 120 mg BIW was determined to be the maximum tolerated dose. At data cut-off, median treatment duration was 2 cycles (range, 1–12); 13 (17.1%) patients were ongoing. table 1 summarizes TAK-981 safety. The most common (≥20%) treatment-emergent adverse events (TEAEs) were fatigue (42.1%), nausea (39.5%), headache (31.6%), diarrhea (28.9%), pyrexia (27.6%), vomiting (23.7%), decreased appetite (22.4%). Common (≥5%) grade ≥3 TEAEs were hypokalemia (9.2%), anemia (7.9%), lymphocyte count decreased (6.6%), abdominal pain (5.3%). Grade 2 cytokine release syndrome was reported in 4 (5.2%) patients; symptoms resolved within 12–24 hours with supportive oxygen and/or IV fluids. One partial response was observed at 40 mg TAK-981 BIW in a patient with relapsed/refractory HER2-negative, hormone receptor-positive breast cancer. TAK-981 exhibited linear PK, with approximately dose-proportional exposure and a mean terminal half-life of 3.8–10.8 hours at ≥60 mg. Evidence of dose-dependent target engagement (figure 1), and PD (figures 2–4) in blood were observed. The single-agent TAK-981 RP2D was 90 mg BIW.

Abstract 476 Table 1

Summary of TAK-981 safety profile

Abstract 476 Figure 1

PD in patients receiving TAK-981 on the BIW schedule: target engagement.

Blood samples were collected on Cycle 1 Day 1 pre-dose and at multiple timepoints after TAK-981 administration. Target engagement in T cells was detected by flow cytometry with an antibody recognizing the TAK-981-SUMO adduct formed during the inhibition of the SUMO-activating enzyme by TAK-981; Cycle 1 Day 1 signal increased at 1 hour post-end-of-infusion compared to the background level observed pre-dose.

Abstract 476 Figure 2

PD in patients receiving TAK-981 on the BIW schedule: SUMOylation.

SUMOylation in T cells, detected by flow cytometry with an antibody recognizing SUMO2/3, decreased at 1 hour post-end-of-infusion on Cycle 1 Day 1 compared to pre-dose, indicating that fewer SUMO2/3 chains are formed when the SUMO-activating enzyme is inhibited.

Abstract 476 Figure 3

PD in patients receiving TAK-981 on the BIW schedule: upregulation of CXCL10 expression.

Upregulation of mRNA levels of CXCL10, an IFN-I-regulated gene, in peripheral blood. Gene expression was measured using Nanostring nCounter at Cycle 1 Day 1 pre-dose and at several timepoints post-dose. Data for maximum increase at 8 or 24 hours, relative to pre-dose, is shown.

Abstract 476 Figure 4

PD in patients receiving TAK-981 on the BIW schedule: NK cell activation.

NK cell activation in peripheral blood measured by flow cytometry. Percentage of CD69-positive NK cells at Cycle 1 Day 1 pre-dose and at 24 hours post-end-of-infusion is shown by patient for each dose.

Conclusions

The data generated in this study support continued TAK-981 development for treatment of solid tumors and lymphoma. The Phase 2 study expansion is ongoing in patients with advanced/metastatic non-small-cell lung, cervical, and colorectal cancer, and in relapsed/refractory non-Hodgkin lymphoma.

Trial Registration

Clinical Trial identification:

ClinicalTrials.gov. Identifier: NCT03648372

Ethics Approval

The study was approved by the Institutional Review Board or Institutional Ethics Committee of all participating institutions

First-in-Human Phase I Study of MP0250, a First-in-Class DARPin Drug Candidate Targeting VEGF and HGF, in Patients With Advanced Solid Tumors

PURPOSE

A first-in-human study was performed with MP0250, a DARPin drug candidate. MP0250 specifically inhibits both vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) with the aim of disrupting the tumor microenvironment.

PATIENTS AND METHODS

A multicenter, open-label, repeated-dose, phase I study was conducted to assess the safety, tolerability, and pharmacokinetics of MP0250 in 45 patients with advanced solid tumors. In the dose-escalation part, 24 patients received MP0250 as a 3-hour infusion once every 2 weeks at five different dose levels (0.5-12 mg/kg). Once the maximum tolerated dose (MTD) was established, 21 patients were treated with a 1-hour infusion (n = 13, 8 mg/kg, once every 2 weeks and n = 8, 12 mg/kg, once every 3 weeks) of MP0250 in the dose confirmation cohorts.

RESULTS

In the dose-escalation cohort, patients treated with 12 mg/kg MP0250 once every 2 weeks experienced dose-limiting toxicities. Therefore, MTD was 8 mg/kg once every 2 weeks or 12 mg/kg once every 3 weeks. The most common adverse events (AEs) were hypertension (69%), proteinuria (51%), and diarrhea and nausea (both 36%); hypoalbuminemia was reported in 24% of patients. Most AEs were consistent with inhibition of the VEGF and HGF pathways. Exposure was dose-proportional and sustained throughout the dosing period for all patients (up to 15 months). The half-life was about 2 weeks. Signs of single-agent antitumor activity were observed: 1 unconfirmed partial response with a time to progression of 23 weeks and 24 patients with stable disease, with the longest duration of 72 weeks and a median duration of 18 weeks.

CONCLUSION

MP0250 is a first-in-class DARPin drug candidate with suitable tolerability and appropriate pharmacokinetic properties for further development in combination with other anticancer therapies.

Leptospira seroprevalence in owned dogs from Spain

Leptospira is a widespread zoonosis that has been linked to transmission between dogs and humans. The main purposes were to determine the seroprevalence of anti-Leptospira serum antibody and to identify the most common serovars in dogs in Spain. This is a cross-sectional study with 1,310 records of canine Leptospira testing data from Spain since 2015 to 2017. Inclusion criteria were individual cases with MAT test results for 8 serovars (Bratislava, Icterohaemorrhagiae, Australis, Pomona, Grippotyphosa, Autumnalis, Canicola and Saxkoebing) and to have the zip code data. Three hundred and thirty-eight samples (25.8%; 95%CI 23.6–28.4) were seropositive (≥1:100). According to geographic areas, North had the highest seroprevalence (38.0%; 95%CI 28.9–47.1) followed by South (29.4%; 95%CI 20.1–38.8), Center (28.6%; 95%CI 24.3–33.0), Mediterranean (22.3%; 95%CI 19.1–25.6) and Northwest (22.2%; 95%CI 7.9–36.4). Seropositivity (MAT ≥1:100) was most common to serovars Icterohaemorrhagiae (19.4%; 95%CI 17.2–21.5) and Bratislava (8.5%; 95%CI 7.0–10.0), followed by Grippotyphosa (7.2%; 95%CI 5.8–8.6), Australis (6.4%; 95%CI 5.0–7.7), Autumnalis (5.0%; 95%CI 3.8–6.2), Pomona (4.5%; 95%CI 3.3–5.6), Canicola (3.4%; 95%CI 2.4–4.4) and Saxkoebing (0.8%; 95%CI 0.3–1.3). An association was found between positivity (MAT ≥1:100) and males (P = 0.003) and dogs that were 6 years old or older were at higher risk of exposure (P = 0.001; OR 4.61; 95%CI 1.86–11.43). This study has shown that dogs in Spain are commonly exposed to Leptospira infection and points out the necessity to control the prevalence of this severe widespread zoonosis in dogs and humans.

Abstract P6-18-02: Primary and secondary results of the first nationwide molecular screening program in Spain for patients with advanced breast cancer (AGATA SOLTI-1301 study)

Background: Metastatic breast cancer is the second leading cause of death among women globally. A better understanding of tumor biology, and the availability of high-throughput technologies, have enabled the emergence of precision medicine bringing new expectations and giving rise to molecular screening programs (MSP). SOLTI, as a collaborative Spanish network, designed AGATA, the first multi-institutional MSP ever implemented in this country. Here, we report both the primary and some of the secondary results of the pilot study.

Methods: A total of 10 sites within SOLTI network in Spain participated. DNA-sequencing of 56 cancer related genes was performed using FFPE tumor samples (primary or metastatic). Each clinical case was reviewed by a multidisciplinary advisory board (MAB), which recommended, in a prospective manner, potential experimental treatments, mainly in the context of clinical trials. The primary objective was to determine the success rate of matching a DNA alteration to an experimental drug or drug class. Secondary objectives included a comprehensive molecular characterization of tumor samples by PAM50 subtyping and quantification of protein expression levels by MASS-SPEC (70 proteins panel).

Results: 305 patients (pts) were screened from September 2014 to July 2017 and 260 (85.3%) were finally evaluated by the MAB. Pts characteristics were: mean age 54 years (29-80), ER+/HER2- (n=192; 74%), HER2+ (n=30; 11.5%) and TNBC (n=38; 14.5%). 163 primary tumors and 97 metastatic samples were profiled. Regarding the primary objective, 116 pts (45%) presented at least one mutation (range 1-6) that could be matched to a drug or drug class. Of these, 13 pts (11.2%) received therapy matched to their molecular profile according to the MAB recommendation and their follow-up is still on-going. No mutation was detected in 97 (37%) pts (WT), and 47 patients (18.1%) presented a mutation but no match was possible. The most common mutations were PIK3CA (34%), TP53 (22%), AKT1 (5%), ESR1 (3%) and ERBB2 (3%). Intrinsic subtype distribution in 177 samples was as follows: 34% Luminal A (n=60); 21% Luminal B (n=36); 13% HER2E (n=22); 19% Basal-like (n=34) and 13% Normal-like (n=23). Compared to primary tumors (n=110), the proportion of HER2-enriched disease in metastatic tumors (n=63) was significantly higher (6% vs 20%; p=0.005). Protein expression analysis was performed in 146 samples (94 primary and 57 metastasis). In 19 cases (13%), the outlier expression of some targetable proteins (FGFR1 [n=4, 2.7%], IGF1R [n=4, 2.7%], EGFR [n=1, 0.7%], CEACAM5 [n=6, 4.1%], IDO1 [n=2, 1.37%], TROP2 [n=2, 1.37%]) were identified. Of note, HER2 overexpression (>740 amol/μg) was observed in 4 HER2- cases. Finally, among WT tumors, 21% presented a potential drug-matched protein target.

Conclusions: Nationwide molecular screening in Spain is feasible. Nearly half of patients had tumors with mutation(s), mostly PIK3CA, that could be matched to a potential drug or drug class. PAM50 profile might be helpful to navigate towards a therapeutic decision making, although the MAB could not make any targeted-driven recommendation yet with this data. More clinical evidence is needed to use MASS-SPEC as a diagnostic tool.

Citation Format: Pernas S, Villagrasa P, Nuciforo PG, Vivancos A, Scaltriti M, Rodón J, Burgués O, Canes J, Dueñas M, Cecchi F, Vidal M, Lluch A, Perelló A, Llombart A, Dorca J, Montaño A, Oliveira M, Ribas G, Rapado I, Paré L, Prat A, Ciruelos E. Primary and secondary results of the first nationwide molecular screening program in Spain for patients with advanced breast cancer (AGATA SOLTI-1301 study) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-02.

Alpelisib Plus Fulvestrant in PIK3CA-Altered and PIK3CA-Wild-Type Estrogen Receptor-Positive Advanced Breast Cancer: A Phase 1b Clinical Trial

Importance

The phosphatidylinositol 3-kinase (PI3K) pathway is frequently activated in patients with estrogen receptor-positive (ER+), endocrine therapy-resistant breast cancers.

Objective

To assess the maximum tolerated dose (MTD), safety, and activity of alpelisib, an oral, PI3Kα-specific inhibitor, plus fulvestrant in patients with ER+ advanced breast cancer (ABC).

Design, Setting, and Participants

An open-label, single-arm, phase 1b study of alpelisib plus fulvestrant was conducted at 10 centers in 5 countries. Participants were 87 postmenopausal women with PIK3CA-altered or PIK3CA-wild-type ER+ ABC, whose cancer progressed during or after antiestrogen therapy. The study began enrolling patients October 5, 2010, and the data cutoff was March 22, 2017.

Interventions

Escalating doses of alpelisib were administered once daily, starting at 300 mg, plus fixed-dose fulvestrant, 500 mg, in the dose-escalation phase; alpelisib at the recommended phase 2 dose plus fulvestrant in the dose-expansion phase.

Main Outcomes and Measures

The primary end point was determination of the MTD of once-daily alpelisib plus fulvestrant. Secondary end points included safety and preliminary activity.

Results

From October 5, 2010, to March 22, 2017, 87 women (median age: 58 years [range, 37-79 years]; median of 5 prior lines of antineoplastic therapy) received escalating once-daily doses of alpelisib (300 mg, n = 9; 350 mg, n = 8; 400 mg, n = 70) plus fixed-dose fulvestrant (500 mg). During dose escalation, dose-limiting toxic effects were reported in 1 patient (alpelisib, 400 mg): diarrhea (grade 2), vomiting, fatigue, and decreased appetite (all grade 3). The MTD of alpelisib when combined with fulvestrant was 400 mg once daily, and the recommended phase 2 dose was 300 mg once daily. Overall, the most frequent grade 3/4 adverse events with alpelisib, 400 mg, once daily (≥10% of patients), regardless of causality, were hyperglycemia (19 [22%]) and maculopapular rash (11 [13%]); 9 patients permanently discontinued therapy owing to adverse events. Median progression-free survival at the MTD was 5.4 months (95% CI, 4.6-9.0 months). Median progression-free survival with alpelisib, 300 to 400 mg, once daily plus fulvestrant was longer in patients with PIK3CA-altered tumors (9.1 months; 95% CI, 6.6-14.6 months) vs wild-type tumors (4.7 months; 95% CI, 1.9-5.6 months). Overall response rate in the PIK3CA-altered group was 29% (95% CI, 17%-43%), with no objective tumor responses in the wild-type group.

Conclusions and Relevance

Alpelisib plus fulvestrant has a manageable safety profile in patients with ER+ ABC, and data suggest that this combination may have greater clinical activity in PIK3CA-altered vs wild-type tumors.

Trial Registration

ClinicalTrials.gov identifier: NCT01219699.

Abstract 3129: Patient-derived tumor xenografts (PDXs) recapitulate the antitumor activity of novel therapies in metastatic breast cancer (MBC) patients (pts)

PDXs are preferred laboratory models that recapitulate the biology of pts’ tumors. We aimed to assess if the antitumor activity of novel therapies in PDXs correlates with the observed activity in the corresponding MBC patient, which would support cross-analysis of drug/genotype vulnerabilities.

MBC pts eligible for clinical trials were offered a research biopsy and establishment of PDX, under an IRB-approved protocol. Biopsies were implanted in nude mice subcutaneously. Upon successful engraftment, models were expanded for drug testing, specifically with the same drug/combination given to the patient. This is a retrospective analysis of our MBC patient/PDX (Pt/PDX) co-clinical trial cohort. Pts’ outcomes were measured as: RECIST response, clinical benefit [CB: partial response (PR) or stable disease (SD) >4 months], and time to progression [TTP: time until RECIST progressive disease (PD), in months). PDX endpoints were measured as: TTP (time until 25% increase in tumor volume, in days), response (WHO criteria, at week 3), and relative area under the curve (rAUC) of treated versus vehicle. A concordant Pt/PDX response was defined as CB in pts whose paired PDX showed PR/SD, or no-CB in pts whose paired PDX showed PD. Pts outcomes and PDX endpoints were correlated using Spearman's test.

We identified 10 MBC pts (7 TNBC, 3 HR+; all biopsies from skin/subcutaneous lesions) with corresponding PDX, treated with paired therapies (7 molecularly matched): 3 lurbinectedin (BRCA1-mut), 3 olaparib (BRCA1-mut), 1 AZD5363 + fulvestrant (AKT1-mut), 1 AZD5363 + paclitaxel, 1 buparlisib, 1 eribulin. In 9/10 cases we found concordant Pt/PDX responses (6 cases with no-CB in patient/PD in PDX, 3 with CB/SD; and 1 lurbinectedin case with no-CB/PR). Two pts had biopsy for PDX implantation at progression of paired therapy and were excluded from TTP analyses. In cases with concordant Pt/PDX response, we found a significant correlation between RECIST response in pts and rAUC in PDX (ρ=0.82, p=0.03), a trend for comparable TTP in pts and TTP in PDX (ρ=0.67, p=0.10), but no correlation between RECIST response in pts and response at week 3 in PDX (ρ=0.46, p=0.30).

In this cohort of MBC pts, we found high concordance in Pt/PDX response. Our results suggest that rAUC in PDX may be the best read-out to identify relevant drug/genotype associations that can potentially be translated to patient benefit. Data will be updated with additional ongoing PDX experiments.

Citation Format: Mafalda Oliveira, Javier Pascual, Cristina Cruz, Alberto Gris, Marta Palafox, Alba Llop, Marta Castroviejo, Cristina Viaplana, Yasir H Ibrahim, Joaquin Arribas, Javier Cortés, José Baselga, Jordi Rodón, Judith Balmaña, Rodrigo Dienstmann, Cristina Saura, Violeta Serra. Patient-derived tumor xenografts (PDXs) recapitulate the antitumor activity of novel therapies in metastatic breast cancer (MBC) patients (pts) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3129. doi:10.1158/1538-7445.AM2017-3129

Clinical and molecular determinants of treatment benefit with phase I trials in patients (pts) with advanced pancreatic cancer (PC)

409

Background: PC is the 4th leading cause of cancer-related death, with limited efficacy of systemic treatment (tx) beyond first-line chemotherapy (chemo). We aimed to assess the potential benefit of phase 1 trials in this setting. Methods: From 2011 to 2016, 49 pts were enrolled in 54 phase 1 trials at our institution. Clinical and molecular data were retrospectively extracted from medical records. Time to progression (TTP) was calculated from time of tx start to discontinuation due to progressive disease, and clinical benefit rate (CBr) was defined as partial response or stable disease > 4 months. Results: Median age was 58 (41-75), 69% were male, 60% had metastases in liver. Most pts received gemcitabine-based regimens (47%) or Folforinox (32%) as first-line tx (median TTP of 5.63 months [CI 95% 4.0-8.1]). Median tx line of Phase 1 trial was 3 (range 2-5). Regimens included chemo or immunotherapies (chemo-imm group) in 16 cases (12 and 4, respectively), small molecule inhibitor (SMI) as single-agent in 19 cases (SMI.1 group), and SMI in combinations in 19 cases (SMI.2 group). In 17 cases, tx was matched to genomic profile; most frequent matches were PI3K + MEK SMI or RAF SMI ( KRAS mut in 7 pts), PI3K SMI ( PTEN loss/ PIK3CA mut in 3 pts) and PD1 blockade (PDL1 high in 4 pts). There were 3 (6%) partial responses (PI3K SMI unmatched, RAF SMI matched and anti-PD1 agent matched) and 12 (24%) disease stabilizations. Median TTP in phase 1 trial was 1.9 months [CI 95% 1.6-2.5], without significant differences if matched/unmatched agent (p = 0.5) or tx given as second-line/later regimen (p = 0.5). Median TTP was 2.7 months [CI95% 1.6-10.7] with chemo-imm (control arm), 2.0 months [CI95% 1.8-5.6] with SMI.2 (HR = 1.8, p = 0.13) and 1.4 months [CI95% 1.3-2.8] with SMI.1 (HR = 3.0, p = 0.004). This difference was maintained in a multivariable model (HR = 2.9, p = 0.005). CBr with chemo-imm (38%) or SMI.2 (21%) was higher as compared with SMI.1 (5%; p = 0.06). Conclusions: Selected PC pts are eligible to phase 1 trials and up to one-third derive substantial benefit from the intervention. In our experience, chemo-imm agents or targeted SMI given as combination regimens associate with longer TTP and CBr when compared with single-agent SMI.

A phase I pharmacokinetic and safety study of cabazitaxel in adult cancer patients with normal and impaired renal function

PURPOSE

Limited data are available on cabazitaxel pharmacokinetics in patients with renal impairment. This open-label, multicenter study assessed cabazitaxel in patients with advanced solid tumors and normal or impaired renal function.

METHODS

Cohorts A (normal renal function: creatinine clearance [CrCL] >80 mL/min/1.73 m²), B (moderate renal impairment: CrCL 30 to <50 mL/min/1.73 m²) and C (severe impairment: CrCL <30 mL/min/1.73 m²) received cabazitaxel 25 mg/m² (A, B) or 20 mg/m² (C, could be escalated to 25 mg/m²), once every 3 weeks. Pharmacokinetic parameters and cabazitaxel unbound fraction (F _U) were assessed using linear regression and mixed models. Geometric mean (GM) and GM ratios (GMRs) were determined using mean CrCL intervals (moderate and severe renal impairment: 40 and 15 mL/min/1.73 m²) versus a control (90 mL/min/1.73 m²).

RESULTS

Overall, 25 patients received cabazitaxel (median cycles: 3 [range 1-20]; Cohort A: 5 [2-13]; Cohort B: 3 [1-15]; and Cohort C: 5 [1-20]), of which 24 were eligible for pharmacokinetic analysis (eight in each cohort). For moderate and severe renal impairment versus normal renal function, GMR estimates were: clearance normalized to body surface area (CL/BSA) 0.95 (90% CI 0.80-1.13) and 0.89 (0.61-1.32); area under the curve normalized to dose (AUC/dose) 1.06 (0.88-1.27) and 1.14 (0.76-1.71); and F _U 0.99 (0.94-1.04) and 0.97 (0.87-1.09), respectively. Estimated slopes of linear regression of log parameters versus log CrCL (renal impairment) were: CL/BSA 0.06 (-0.15 to 0.28); AUC/dose -0.07 (-0.30 to 0.16); and F _U 0.02 (-0.05 to 0.08). Cabazitaxel safety profile was consistent with previous reports.

CONCLUSIONS

Renal impairment had no clinically meaningful effect on cabazitaxel pharmacokinetics.

Phase I Cancer Trials and Palliative Care: Antagonism, Irrelevance, or Synergy?

This article synthesizes the presentations and conclusions of an international symposium on Phase 1 oncology trials, palliative care, and ethics held in 2014. The purpose of the symposium was to discuss the intersection of three independent trends that unfolded in the past decade. First, large-scale reviews of hundreds of Phase I trials have indicated there is a relatively low risk of serious harm and some prospect of clinical benefit that can be meaningful to patients. Second, changes in the design and analysis of Phase I trials, the introduction of "targeted" investigational agents that are generally less toxic, and an increase in Phase I trials that combine two or more agents in a novel way have changed the conduct of these trials and decreased fears and apprehensions about participation. Third, the field of palliative care in cancer has expanded greatly, offering symptom management to late-stage cancer patients, and demonstrated that it is not mutually exclusive with disease-targeted therapies or clinical research. Opportunities for collaboration and further research at the intersection of Phase 1 oncology trials and palliative care are highlighted.

Consensus on precision medicine for metastatic cancers: a report from the MAP conference

Recent advances in biotechnologies have led to the development of multiplex genomic and proteomic analyses for clinical use. Nevertheless, guidelines are currently lacking to determine which molecular assays should be implemented in metastatic cancers. The first MAP conference was dedicated to exploring the use of genomics to better select therapies in the treatment of metastatic cancers. Sixteen consensus items were covered. There was a consensus that new technologies like next-generation sequencing of tumors and ddPCR on circulating free DNA have convincing analytical validity. Further work needs to be undertaken to establish the clinical utility of liquid biopsies and the added clinical value of expanding from individual gene tests into large gene panels. Experts agreed that standardized bioinformatics methods for biological interpretation of genomic data are needed and that precision medicine trials should be stratified based on the level of evidence available for the genomic alterations identified.

Survival determinants with matched targeted therapies in BRAF mutant metastatic colorectal cancer (mCRC)

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Background: BRAF mutation (mt) occurs in 5-8% of mCRC and is associated with poor prognosis. Matched targeted therapies for this population are increasingly available in clinical trials. Methods: From Nov 2010 to June 2015, a total of 32 chemorefractory BRAF mt mCRC patients (pts) were enrolled in phase I trials with anti-BRAF matched therapy at Vall d´Hebron Institute of Oncology. BRAF mt was determined by real-time PCR (50%), mass spectrometry (Sequenom, 28%) or next-generation sequencing (Amplicon MiSeq, 22%). All demographic, treatment and survival data were retrospectively analyzed. Results: Median age was 60.4 years (range 42.8-73.5), 62% had right-sided CRC primaries and 59% were stage IV at diagnosis. Median treatment lines before matched therapy was 2 (range 1-4). Co-existing RNFA43, PI3KCA and GNAS mt were found in 4, 2 and 1 pts, respectively. Median time from diagnosis to start of anti-BRAF therapy was 18.6 months (m) (CI95% 14-36) and median time from diagnosis of mCRC to death was 28.4m (CI95% 25-50). A total of 41 anti-BRAF matched therapies were delivered, 9 pts received more than 1 regimen. BRAF inhibitor (inh) monotherapy was delivered in 34% of cases; BRAF plus MEK/EGFR/WNT/PI3K/CDK inh doublets or triplets to 37% and 29% pts, respectively. Survival from start of anti-BRAF to death was 8.9m (CI95% 7-15), without significant differences if 1 or more than 1 anti-BRAF regimen was given (HR: 0.82, p=0.6). Partial responses were observed in 7 cases (17%, 4 doublets and 3 triplets) and complete response in 2 cases (5%, 1 doublet and 1 triplet). Median time on treatment (ToT) with anti-BRAF therapy was 2.83m (CI95% 2-5.5). Of note, ToT was significantly longer for triplets compared to mono/doublets: 5.5m (CI95% 2.7-not reached) vs. 1.9m (CI95% 1.6-3.7; HR: 0.46 [CI95% 0.2-1.0], p=0.05). Median BRAFmt allele fraction (adjusted for tumor purity) was 0.25 (0.13-0.68); no correlation with ToT on anti-BRAF therapy was observed (p=0.36). Conclusions: In a selected BRAF mt population enrolled in early trials with anti-BRAF matched therapy at our institution, survival in the metastatic setting was remarkably high. Triplet matched therapies seem to control disease for longer time than mono/doublets.

PI3K inhibition results in enhanced estrogen receptor function and dependence in hormone receptor-positive breast cancer

Activating mutations of PIK3CA are the most frequent genomic alterations in estrogen receptor (ER)-positive breast tumors, and selective phosphatidylinositol 3-kinase α (PI3Kα) inhibitors are in clinical development. The activity of these agents, however, is not homogeneous, and only a fraction of patients bearing PIK3CA-mutant ER-positive tumors benefit from single-agent administration. Searching for mechanisms of resistance, we observed that suppression of PI3K signaling results in induction of ER-dependent transcriptional activity, as demonstrated by changes in expression of genes containing ER-binding sites and increased occupancy by the ER of promoter regions of up-regulated genes. Furthermore, expression of ESR1 mRNA and ER protein were also increased upon PI3K inhibition. These changes in gene expression were confirmed in vivo in xenografts and patient-derived models and in tumors from patients undergoing treatment with the PI3Kα inhibitor BYL719. The observed effects on transcription were enhanced by the addition of estradiol and suppressed by the anti-ER therapies fulvestrant and tamoxifen. Fulvestrant markedly sensitized ER-positive tumors to PI3Kα inhibition, resulting in major tumor regressions in vivo. We propose that increased ER transcriptional activity may be a reactive mechanism that limits the activity of PI3K inhibitors and that combined PI3K and ER inhibition is a rational approach to target these tumors.

Abstract B187: Prevalence of MET copy number variation, MET expression and MET related genomic alterations in all solid tumors pre-screening program. VHIO experience

Background: Aberrant MET activation occurs in many types of malignancies and includes protein overexpression, increased gene copy number, amplifications, mutations and deletions. The frequency of genomic alterations in MET varies widely among solid tumors. The criteria for MET amplification and MET overexpression have not been established as well as the relationship between MET amplification, MET expression and additional genomic alterations known to be important in tumor biology. Previous and current phase 1 clinical trials have selected patients without matching MET criterion.

Materials and Methods: From Dec/2012 to Dec/2014, 203 formalin fixed paraffin embedded tumor samples from 197 patients consented to undergo targeted MET analysis. Samples were 117 primary and 86 metastatic tumors. Tumor types included colorectal, gastric, lung, glioblastoma, and breast. Samples were analyzed by fluorescence in situ hybridization (FISH) for MET gene amplification (MET/CEN-7 FISH Zytolight SPEC assay Z-2087, Zytovision), and by immunohistochemistry (IHC) for MET protein expression [Met (D1C2) XP® Rabbit mAb #8198, Cell signaling]. Mutations in key oncogenes were determined using Sequenom (Mass Array) and Amplicon-Mi Seq (Illumina) Cancer Panel.

Results: MET gene copy number variation (&gt;5copies) was found in 11 of 203 samples (5%) and MET gene amplification (based on the definition of MET/CEN-7 ≥2.2) was found in 6 of 203 samples (3%). Eleven (5%) samples had ≥4 or ≤5 copies of MET gene. KRAS mutation was found in 28 of 167 samples (17%) and PIK3CA mutation in 6 of 167 samples (4%). Both mutations were observed in tumor samples with &lt; 4 copies of MET gene. MET IHC positive (≥ 50% positive cells 3+) was found in 11 of 203 samples (5%). Seven of 203 samples (3%) had MET IHC positive (≥ 50% positive cells 3+ and 2+). MET protein expression showed statistical association with MET gene copy number (P&lt;0.001). There was a statistically significant increased expression of MET in metastatic samples compared with primary tumor specimens (P = 0.001).

Conclusion: MET expression is higher in metastatic than primary tumor samples. There is a significant association between MET expression and gene copy number. High MET copy number was more frequent in tumors without KRAS and PIK3CA mutation. Quantitative MET protein expression data will be presented.

MET IHCMET FISH≥ 50% cells 3+≥ 50% cells 3+ and 2+&lt; 50% cells 3+and 2+&lt; 2 copies01 (0.7%)40 (28.2%)2- &lt;4 copies4 (2.8%)3 (2.1%)79 (55.6%)4-5 copies1 (0.7%)1 (0.7%)4 (2.8%)&gt;5 copies5 (3.5%)04 (2.8%)

Citation Format: Analía Azaro, Guillem Argilés, María Alsina, Elena Elez, Teresa Macarulla, Cristina Cruz, Donatella Marino, Cinta Hierro, Susana Cedres, Alejandro Navarro, María Ochoa de Olza, Irene Braña, Juan Martín-Liberal, Marta Vilaró, Debora Moreno, Paola Martínez, María Díaz, Ana Vivancos, Jordi Rodón, Josep Tabernero, Ludmila Prudkin, Paolo Nuciforo. Prevalence of MET copy number variation, MET expression and MET related genomic alterations in all solid tumors pre-screening program. VHIO experience. [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 B187.

Other targeted drugs in melanoma

Targeted therapy drugs are developed against specific molecular alterations on cancer cells. Because they are "targeted" to the tumor, these therapies are more effective and better tolerated than conventional therapies such as chemotherapy. In the last decade, great advances have been made in understanding of melanoma biology and identification of molecular mechanisms involved in malignant transformation of cells. The identification of oncogenic mutated kinases involved in this process provides an opportunity for development of new target therapies. The dependence of melanoma on BRAF-mutant kinase has provided an opportunity for development of mutation-specific inhibitors with high activity and excellent tolerance that are now being used in clinical practice. This marked a new era in the treatment of metastatic melanoma and much research is now ongoing to identify other "druggable" kinases and transduction signaling networking. It is expected that in the near future the spectrum of target drugs for melanoma treatment will increase. Herein, we review the most relevant potential novel drugs for melanoma treatment based on preclinical data and the results of early clinical trials.

Pharmacokinetic, pharmacodynamic and biomarker evaluation of transforming growth factor-β receptor I kinase inhibitor, galunisertib, in phase 1 study in patients with advanced cancer

Purpose Transforming growth factor-beta (TGF-β) signaling plays a key role in epithelial-mesenchymal transition (EMT) of tumors, including malignant glioma. Small molecule inhibitors (SMI) blocking TGF-β signaling reverse EMT and arrest tumor progression. Several SMIs were developed, but currently only LY2157299 monohydrate (galunisertib) was advanced to clinical investigation. Design The first-in-human dose study had three parts (Part A, dose escalation, n = 39; Part B, safety combination with lomustine, n = 26; Part C, relative bioavailability study, n = 14). Results A preclinical pharmacokinetic/pharmacodynamic (PK/PD) model predicted a therapeutic window up to 300 mg/day and was confirmed in Part A after continuous PK/PD. PK was not affected by co-medications such as enzyme-inducing anti-epileptic drugs or proton pump inhibitors. Changes in pSMAD2 levels in peripheral blood mononuclear cells were associated with exposure indicating target-related pharmacological activity of galunisertib. Twelve (12/79; 15%) patients with refractory/relapsed malignant glioma had durable stable disease (SD) for 6 or more cycles, partial responses (PR), or complete responses (CR). These patients with clinical benefit had high plasma baseline levels of MDC/CCL22 and low protein expression of pSMAD2 in their tumors. Of the 5 patients with IDH1/2 mutation, 4 patients had a clinical benefit as defined by CR/PR and SD ≥6 cycles. Galunisertib had a favorable toxicity profile and no cardiac adverse events. Conclusion Based on the PK, PD, and biomarker evaluations, the intermittent administration of galunisertib at 300 mg/day is safe for future clinical investigation.

Pragmatic issues in biomarker evaluation for targeted therapies in cancer

Predictive biomarkers are becoming increasingly important tools in drug development and clinical research. The importance of using both guidelines for specimen acquisition and analytical methods for biomarker measurements that are standardized has become recognized widely as an important issue, which must be addressed in order to provide high-quality, validated assays. Herein, we review the major challenges in biomarker validation processes, including pre-analytical (sample-related), analytical, and post-analytical (data-related) aspects of assay development. Recommendations for improving biomarker assay development and method validation are proposed to facilitate the use of predictive biomarkers in clinical trials and the practice of oncology.

Genomic analyses across six cancer types identify basal-like breast cancer as a unique molecular entity

To improve our understanding of the biological relationships among different types of cancer, we have characterized variation in gene expression patterns in a set of 1,707 samples representing 6 human cancer types (breast, ovarian, brain, colorectal, lung adenocarcinoma and squamous cell lung cancer). In the unified dataset, breast tumors of the Basal-like subtype were found to represent a unique molecular entity as any other cancer type, including the rest of breast tumors, while showing striking similarities with squamous cell lung cancers. Moreover, gene signatures tracking various cancer- and stromal-related biological processes such as proliferation, hypoxia and immune activation were found expressed similarly in different proportions of tumors across the various cancer types. These data suggest that clinical trials focusing on tumors with common profiles and/or biomarker expression rather than their tissue of origin are warranted with a special focus on Basal-like breast cancer and squamous cell lung carcinoma.

PI3K inhibition impairs BRCA1/2 expression and sensitizes BRCA-proficient triple-negative breast cancer to PARP inhibition

PARP inhibitors are active in tumors with defects in DNA homologous recombination (HR) due to BRCA1/2 mutations. The phosphoinositide 3-kinase (PI3K) signaling pathway preserves HR steady state. We hypothesized that in BRCA-proficient triple-negative breast cancer (TNBC), PI3K inhibition would result in HR impairment and subsequent sensitization to PARP inhibitors. We show in TNBC cells that PI3K inhibition leads to DNA damage, downregulation of BRCA1/2, gain in poly-ADP-ribosylation, and subsequent sensitization to PARP inhibition. In TNBC patient-derived primary tumor xenografts, dual PI3K and PARP inhibition with BKM120 and olaparib reduced the growth of tumors displaying BRCA1/2 downregulation following PI3K inhibition. PI3K-mediated BRCA downregulation was accompanied by extracellular signal-regulated kinase (ERK) phosphorylation. Overexpression of an active form of MEK1 resulted in ERK activation and downregulation of BRCA1, whereas the MEK inhibitor AZD6244 increased BRCA1/2 expression and reversed the effects of MEK1. We subsequently identified that the ETS1 transcription factor was involved in the ERK-dependent BRCA1/2 downregulation and that knockdown of ETS1 led to increased BRCA1/2 expression, limiting the sensitivity to combined BKM120 and olaparib in 3-dimensional culture.

SIGNIFICANCE

Treatment options are limited for patients with TNBCs. PARP inhibitors have clinical activity restricted to a small subgroup of patients with BRCA mutations. Here, we show that PI3K blockade results in HR impairment and sensitization to PARP inhibition in TNBCs without BRCA mutations, providing a rationale to combine PI3K and PARP inhibitors in this indication. Our findings could greatly expand the number of patients with breast cancer that would benefit from therapy with PARP inhibitors. On the basis of our findings, a clinical trial with BKM120 and olaparib is being initiated in patients with TNBCs.

Molecular prescreening to select patient population in early clinical trials

The efficacy of targeted therapies in patient populations selected for treatment on the basis of the molecular features of their tumours is shifting the current focus of treatment to biomarker-driven clinical trials. Phase I trials provide an arena for early hypothesis testing, examining not only safety and toxicity, but also target engagement, biologically effective dosages, and the appropriate patient population. In this Perspectives article, we describe this new trend in early drug development, establishing the different approaches for building a pre-screening programme in an academic institution that is involved in early drug development. Our experience establishing the phase I programme at Vall d'Hebrón serves as an example of how these approaches can be integrated in ongoing trials, and we believe these considerations will help others to implement similar programmes in their institutions.

Emerging therapies for urothelial cancer

Urothelial carcinoma is one of the leading causes of death in Europe and the United States. Despite its chemosensitivity, median overall survival for advanced disease is still nearly 1 year. Most second-line chemotherapeutic agents tested have been disappointing. Thus, new treatment strategies are clearly needed. This review focuses on emerging therapies in urothelial carcinoma. Results from recent clinical trials, investigating the activity of new generation cytostatic agents, as well as results from studies assessing the toxicity and efficacy of novel targeted therapies, are discussed. In this setting, anti-epidermal growth factor receptor, angiogenesis, and phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitors account for the majority of phase I and II trials.

TGF-β Receptor Inhibitors Target the CD44(high)/Id1(high) Glioma-Initiating Cell Population in Human Glioblastoma

Glioma-initiating cells (GICs), also called glioma stem cells, are responsible for tumor initiation, relapse, and therapeutic resistance. Here, we show that TGF-β inhibitors, currently under clinical development, target the GIC compartment in human glioblastoma (GBM) patients. Using patient-derived specimens, we have determined the gene responses to TGF-β inhibition, which include inhibitors of DNA-binding protein (Id)-1 and -3 transcription factors. We have identified a cell population enriched for GICs that expresses high levels of CD44 and Id1 and tend to be located in a perivascular niche. The inhibition of the TGF-β pathway decreases the CD44(high)/Id1(high) GIC population through the repression of Id1 and Id3 levels, therefore inhibiting the capacity of cells to initiate tumors. High CD44 and Id1 levels confer poor prognosis in GBM patients.