Antonio Cubillo

Stromal disrupting effects of nab-paclitaxel in pancreatic cancer

Background:Nab-paclitaxel and gemcitabine have demonstrated a survival benefit over gemcitabine alone in advanced pancreatic cancer (PDA). This study aimed to investigate the clinical, biological, and imaging effects of the regimen in patients with operable PDA.Methods:Patients with operable PDA received two cycles of nab-paclitaxel and gemcitabine before surgical resection. FDG-PET and CA19.9 tumour marker levels were used to measure clinical activity. Effects on tumour stroma were determined by endoscopic ultrasound (EUS) elastography. The collagen content and architecture as well as density of cancer-associated fibroblasts (CAFs) were determined in the resected surgical specimen and compared with a group of untreated and treated with conventional chemoradiation therapy controls. A co-clinical study in a mouse model of PDA was conducted to differentiate between the effects of nab-paclitaxel and gemcitabine.Results:A total of 16 patients were enrolled. Treatment resulted in significant antitumour effects with 50% of patients achieving a >75% decrease in circulating CA19.9 tumour marker and a response by FDG-PET. There was also a significant decrement in tumour stiffness as measured by EUS elastography. Seven of 12 patients who completed treatment and were operated had major pathological regressions. Analysis of residual tumours showed a marked disorganised collagen with a very low density of CAF, which was not observed in the untreated or conventionally treated control groups. The preclinical co-clinical study showed that these effects were specific of nab-paclitaxel and not gemcitabine.Conclusion:These data suggest that nab-paclitaxel and gemcitabine decreases CAF content inducing a marked alteration in cancer stroma that results in tumour softening. This regimen should be studied in patients with operable PDA.

A prospective pilot study of target-guided personalized chemotherapy with intensity-modulated radiotherapy in patients with early rectal cancer.

Purpose:To investigate the feasibility of personalizing chemotherapy in patients with rectal cancer. Methods:Patients with cT3 or cN1 and cM0 rectal cancer were eligible. A set of 6 molecular markers including KRAS, BRAF, and PI3K mutations and expression of topoisomerase-1 (Topo-1), ERCC-1, and thymidylate synthase (TS) using immunohistochemistry were performed in a tumor biopsy. All patients were treated with capecitabine 625 to 825 mg/m2/12 h M-F in combination with either irinotecan or oxaliplatin based on Topo-1 and ERCC-1 expression plus either bevacizumab or cetuximab based on the mutation status. All patients received intensity-modulated radiation therapy. A surgery was performed 6 to 8 weeks after the treatment. Results:Fifteen patients (94%) had T3 tumor and 10 (62%) N+ disease of 16 patients enrolled. In all patients, the full set of markers was analyzed within 10 days. Seven patients had K-ras mutation, and 4, 5, and 10 expressed Topo-1, ERRC-1 and TS, respectively. All patients had wild-type BRAF and PI3K tumors. The median time from obtaining informed consent to the treatment period was 18 days and all patients completed the chemoradiation treatment. Fifty percent achieved a complete pathologic response to treatment. Four patients (25%) developed grade 3 proctitis or diarrhea. There were no relevant surgical complications. Sixty-nine percent of the patients received adjuvant XELOX. Conclusions:The individualization of neoadjuvant chemotherapy in patients with rectal cancer is feasible and leads to a high rate of pathologic response.

Clinical validation of prospective liquid biopsy monitoring in patients with wild-type RAS metastatic colorectal cancer treated with FOLFIRI-cetuximab

Cancer genomics and translational medicine rely on the molecular profiling of patients tumor obtained during surgery or biopsy. Alternatively, blood is a less invasive source of tumor DNA shed, amongst other ways, as cell-free DNA (cfDNA). Highly-sensitive assays capable to detect cancer genetic events from patients blood plasma became popularly known as liquid biopsy (LqB). Importantly, retrospective studies including small number of selected patients with metastatic colorectal cancer (mCRC) patients treated with anti-EGFR therapy have shown LqB capable to detect the acquired clonal mutations in RAS genes leading to therapy resistance. However, the usefulness of LqB in the real-life clinical monitoring of these patients still lack additional validation on controlled studies. In this context, we designed a prospective LqB clinical trial to monitor newly diagnosed KRAS wild-type (wt) mCRC patients who received a standard FOLFIRI-cetuximab regimen. We used BEAMing technique for evaluate cfDNA mutations in KRAS, NRAS, BRAF, and PIK3CA in twenty-five patients during a 2-y period. A total of 2,178 cfDNA mutation analyses were performed and we observed that: a) continued wt circulating status was correlated with a prolonged response; b) smoldering increases in mutant cfDNA were correlated with acquired resistance; while c) mutation upsurge/explosion anticipated a remarkable clinical deterioration. The current study provides evidences, obtained for the first time in an unbiased and prospective manner, that reinforces the utility of LqB for monitoring mCRC patients.

Phase II Trial of Target-guided Personalized Chemotherapy in First-line Metastatic Colorectal Cancer.

Purpose:The aim of this study was to investigate the feasibility and efficacy of personalizing treatment of patients with advanced untreated colorectal cancer (CRC). Patients and Methods:Patients with untreated metastatic CRC, performance status 0-1, and candidates for systemic chemotherapy were eligible. Tumor tissues were analyzed for KRAS, BRAF, and PI3K mutations and expression of topoisomerase-1 (Topo-1), excision repair cross-complementing gene 1 (ERCC1), thymidylate synthase (TS), and thymidine phosphorylase (TP). Patients with Topo-1 expression received irinotecan, whereas patients with negative Topo-1 and ERCC1 expression received oxaliplatin. Otherwise, patients received physician’s choice of treatment. If TS was positive, no fluoropyrimidine was administered and if negative, 5-flurorouracil if TP was negative, or capecitabine if TP was positive. KRAS-mutated patients were treated with bevacizumab, whereas KRAS-native received cetuximab. The primary endpoint of the study was progression-free survival (PFS). Results:A total of 74 patients were enrolled and 67 received personalized treatment including irinotecan (n=27), oxaliplatin (n=16), FOLFIRI (n=12), and FOLFOX (n=12). Thirty-eight patients received cetuximab and 29 bevacizumab. With a median follow-up time of 18.3 months (95% confidence interval [CI], 4-36), the overall median PFS was 8.3 months (95% CI, 6.9-9.7), representing a 12-month PFS rate of 36.5% (95% CI, 25-48). Overall clinical benefit, including response rate and disease stabilization, was 86% (95% CI, 73%-97%). The overall median survival was 21 months (95% CI, 11-40). Conclusions:Real-time target-guided personalized first-line treatment of patients with advanced CRC is feasible but, with the approached used, did not result in a clear improvement in PFS to warrant phase III testing.

Efficacy of Sym004 in Patients With Metastatic Colorectal Cancer With Acquired Resistance to Anti-EGFR Therapy and Molecularly Selected by Circulating Tumor DNA Analyses: A Phase 2 Randomized Clinical Trial

Importance Acquired resistance to anti-EGFR therapy (epidermal growth factor receptor) is frequently due to RAS and EGFR extracellular domain (ECD) mutations in metastatic colorectal cancer (mCRC). Some anti-EGFR–refractory patients retain tumor EGFR dependency potentially targetable by agents such as Sym004, which is a mixture of 2 nonoverlapping monoclonal antibodies targeting EGFR. Objective To determine if continuous blockade of EGFR by Sym004 has survival benefit. Design, Setting, and Participants Multicenter, phase 2, randomized, clinical trial comparing 2 regimens of Sym004 with investigator’s choice from March 6, 2014, through October 15, 2015. Circulating tumor DNA (ctDNA) was analyzed for biomarker and tracking clonal dynamics during treatment. Participants had wild-type KRAS exon 2 mCRC refractory to standard chemotherapy and acquired resistance to anti-EGFR monoclonal antibodies. Interventions Participants were randomly assigned in a 1:1:1 ratio to Sym004, 12 mg/kg/wk (arm A), Sym004, 9 mg/kg loading dose followed by 6 mg/kg/wk (arm B), or investigator’s choice of treatment (arm C). Main Outcomes and Measures Overall survival (OS). Secondary end points included preplanned exploratory biomarker analysis in ctDNA. Results A total of 254 patients were randomized (intent-to-treat [ITT] population) (median age, 63 [range, 34-91] years; 63% male; n = 160). Median OS in the ITT population was 7.9 months (95% CI, 6.5-9.9 months), 10.3 months (95% CI, 9.0-12.9 months), and 9.6 months (95% CI, 8.3-12.2 months) for arms A, B, and C, respectively (hazard ratio [HR], 1.31; 95% CI, 0.92-1.87 for A vs C; and HR, 0.97; 95% CI, 0.68-1.40 for B vs C). The ctDNA revealed high intrapatient genomic heterogeneity following anti-EGFR therapy. Sym004 effectively targeted EGFR ECD-mutated cancer cells, and a decrease in EGFR ECD ctDNA occurred in Sym004-treated patients. However, this did not translate into clinical benefit in patients with EGFR ECD mutations, likely owing to co-occurring resistance mechanisms. A subgroup of patients was defined by ctDNA (RAS/BRAF/EGFR ECD-mutation negative) associated with improved OS in Sym004-treated patients in arm B compared with arm C (median OS, 12.8 and 7.3 months, respectively). Conclusions and Relevance Sym004 did not improve OS in an unselected population of patients with mCRC and acquired anti-EGFR resistance. A prospective clinical validation of Sym004 efficacy in a ctDNA molecularly defined subgroup of patients with refractory mCRC is warranted. Trial Registration clinicaltrialsregister.eu Identifier: 2013-003829-29

Overcoming docetaxel resistance in advanced castration-resistant prostate cancer (CRPC): A phase I/II trial of the combination of temsirolimus and docetaxel.

250 Background: Mechanisms of resistance to docetaxel (D) are not fully understood. Preclinical work showed that administration of temsirolimus (T) between courses of D delays the growth of PTEN deficient tumors in xenografts. (Wu et al. Cancer Res 2005) The current study aims to determine the recommended phase II dose (RPTD), toxicity, pharmacokinetics (PK) and preliminary activity of D in combination with T in CRPC patients (pts). METHODS Pts aged ≥ 18 with advanced solid tumors refractory to standard therapy, ECOG ≤2, adequate bone marrow and renal function were eligible. D was given once q. 3 weeks along with T on days 2, 9 &16. The protocol was later amended and day 9 of T omitted due to excessive myelotoxicity. A 3+3 rule dose escalation was used with the next dose levels (DL) planned: DL1: D 50mg/m2, T 15 mg; DL2: D 65mg/m2, T 15 mg; DL3: D 75mg/m2, T 15 mg; DL4: D 75mg/m2, T 25 mg. An expanded cohort for pts with CRPC who have progressed to D will enroll pts once the RPTD has been defined. RESULTS To date 13 pts have been enrolled, median age = 65 (range 35-76), 9 male and 8 ECOG 0, Forty-seven cycles (median: 2; range: 1-9) were administered. The most frequent related adverse events (AEs) of all grades expressed as % of cycles were: leucopenia (80.8%), hyperglycemia (70.2%), anemia (68.1%) and hypercholesterolemia (65.9%). The most common Grade 3-4 AEs as % of cycles were: leucopenia (27.6%), neutropenia (29.7%), and hypophosphatemia (23%). Two pts in DL2 experienced dose limiting toxicities (DLT) consisting of intolerable grade 2 mucositis and febrile neutropenia respectively. DL1 was expanded and 3 additional pts treated with no DLTs. No drug-drug PK interactions were observed. Among 13 pts evaluable for response, 6 (2 pancreas, 2 CRPC, 1 rectal and 1 sarcoma) achieved stable disease. One pt with CRPC who had previously progressed on docetaxel received 9 cycles of treatment with sustained clinical benefit. The expanded cohort for CRPC patients is opened and recruiting. CONCLUSIONS T and D can be safely combined at reduced doses of both agents with no PK interaction. Preliminary antitumor activity has been observed in CRPC patients. Data on the expanded cohort will be presented.

Quality-adjusted survival with combination nal-IRI+5-FU/LV vs 5-FU/LV alone in metastatic pancreatic cancer patients previously treated with gemcitabine-based therapy: a Q-TWiST analysis.

Background:In the NAPOLI-1 Phase 3 trial, nal-IRI+5-fluorouracil and leucovorin (5-FU/LV) significantly improved median overall survival (6.1 vs 4.2 months, P=0.012) and progression-free survival (3.1 vs 1.5 months, P=0.0001) vs 5-FU/LV alone in metastatic pancreatic adenocarcinoma patients previously treated with gemcitabine-based therapy. This analysis evaluated between treatment differences in quality-adjusted time without symptoms of disease progression or toxicity (Q-TWiST).Methods:Overall survival was partitioned into time with grade ⩾3 toxicity (TOX), disease progression (REL), and time without disease progression symptoms or grade ⩾3 toxicity (TWiST). Mean Q-TWiST was calculated by weighting time spent by a utility of 1.0 for TWiST and 0.5 for TOX and REL. In threshold analyses, utility for TOX and REL were varied from 0.0 to 1.0.Results:Patients in nal-IRI+5-FU/LV (n=117) vs 5-FU/LV (n=119) had significantly more mean time in TWiST (3.4 vs 2.4 months) and TOX (1.0 vs 0.3 months) but similar REL (2.5 vs 2.7 months). In the base case, nal-IRI+5-FU/LV patients had 1.3 months (95% CI, 0.4–2.1; 5.1 vs 3.9) greater Q-TWiST (threshold analyses range: 0.9–1.6 months).Conclusions:Within NAPOLI-1, nal-IRI+5-FU/LV resulted in statistically significant and clinically meaningful gains in quality-adjusted survival vs 5-FU/LV alone.

Mixed paratesticular liposarcoma with osteosarcoma elements

Spermatic cord sarcomas (SCS) are very infrequent and sometimes misdiagnosed malignancies. Moreover, their optimal management remains undefined with ongoing controversy about the indications for adjuvant therapy. Histologically, liposarcomas are the most common type. Osteosarcoma is rarely observed in this location and combined tumours with this component have not been described. We present a case of SCS with mixed differentiation with both liposarcoma and osteosarcoma elements.

Phase I/II trial of pimasertib plus gemcitabine in patients with metastatic pancreatic cancer: Pimasertib plus gemcitabine in pancreatic cancer

The selective MEK1/2 inhibitor pimasertib has shown anti‐tumour activity in a pancreatic tumour model. This phase I/II, two‐part trial was conducted in patients with metastatic pancreatic adenocarcinoma (mPaCa) (NCT01016483). In the phase I part, oral pimasertib was given once daily discontinuously (5 days on/2 days off treatment) or twice daily continuously (n = 53) combined with weekly gemcitabine (1,000 mg/m2) in 28‐day cycles to identify the recommended phase II dose (RP2D) of pimasertib. In the phase II part, patients were randomised to pimasertib (RP2D) or placebo plus weekly gemcitabine (n = 88) to investigate progression‐free survival (PFS), overall survival (OS) and safety. The RP2D was determined to be 60 mg BID. PFS and OS outcomes did not indicate any treatment benefit for pimasertib over placebo in combination with gemcitabine (median PFS 3.7 and 2.8 months, respectively, HR = 0.91, 95% CI: 0.58–1.42: median OS 7.3 vs. 7.6 months, respectively). KRAS status did not influence PFS or OS. The incidence of grade ≥3 adverse events was 91.1% and 85.7% for pimasertib/gemcitabine and placebo/gemcitabine respectively, but there was a higher incidence of ocular events with pimasertib/gemcitabine (28.9% vs. 4.8% for placebo/gemcitabine). In conclusion, no clinical benefit was observed with first‐line pimasertib plus gemcitabine compared with gemcitabine alone in patients with mPaCa.

Abstract B78: A Phase Ib study of demcizumab (DEM, anti-DLL4) with gemcitabine (GEM) in patients with first line locally advanced or metastatic pancreatic cancer.

Background: Delta-like ligand 4 (DLL4) is a ligand that activates the Notch pathway which is important for cancer stem cell (CSC) survival. DEM is a humanized IgG2 anti-DLL4 antibody that has been shown to inhibit tumor growth and decrease CSC frequency in minimally passaged human xenograft models. In addition, inhibition of DLL4 has also been shown in preclinical studies to cause dysfunctional sprouting of new vessels resulting in an antiangiogenic effect. DEM also showed synergistic activity when combined with GEM in human pancreatic tumor-derived xenograft models. Material and Methods: Patients with first line stage III or IV pancreatic cancer received DEM (2.5 every 2 or 4 wks or 5 mg/kg every 4 wks) and GEM 1000 mg/m2 7 of the 1st 8 wks and then 3 of every 4 wks until disease progression. The primary objective was to determine the maximum tolerated dose of DEM. Other objectives included: safety, efficacy, immunogenicity, pharmacokinetic, and biomarkers of Notch signaling and CSCs. Results: Twenty four patients were enrolled; 8 pts received 2.5 mg/kg every 2 wks, 8 received 2.5 mg/kg every 4 wks and 8 received 5 mg/kg every 4 wks of DEM. The median age was 65.5 yrs. Three (12.5%) and 21 (87.5%) patients had stage III and IV disease, respectively. Seven, 16 and 1 patients were ECOG performance status 0, 1, and 2, respectively. Related adverse events (all grades) in ≥10% of patients included: fatigue (29%), hypertension (29%), vomiting (29%), nausea (25%), thrombocytopenia (21%), decreased appetite (21%), increased B-type natriuretic peptide (BNP) (13%), anemia (13%), peripheral edema (13%), pulmonary hypertension (13%), dizziness (13%) and rash (13%). The hypertension was successfully managed with oral anti-hypertensives. Increased BNP values appear to be an early indicator of the cardiac effects of DEM and mildly elevated values are being used to initiate cardioprotective therapy with an ACE inhibitor or carvedilol. One patient who received 5 mg/kg developed reversible pulmonary hypertension and heart failure on study day 143. As a result, the duration of DEM will be limited to 70 days in subsequent cohorts and paclitaxel protein-bound particles will also be added to the regimen. Four of 16 (25%) evaluable patients had a RECIST partial response and 7 had stable disease. The median progression free survival for the 5 mg/kg cohort was 5.9 months. The pharmacokinetic and immunogenicity samples are being analyzed and these data will be presented. Conclusion: DEM plus GEM was generally well tolerated with fatigue, hypertension and vomiting being the most common drug related adverse events. The duration of demcizumab therapy is being limited to 70 days in subsequent cohorts due to cardiopulmonary toxicity which was observed following more prolonged administration. Encouraging early clinical activity has been observed. Subsequent cohorts will include paclitaxel protein-bound particles. Enrollment is ongoing and updated results will be presented. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B78. Citation Format: Antonio Cubillo, Michael Jameson, Enrique Grande, Francis Parnis, Peter Grimison, Prasad Cooray, Mark Jeffery, Robert Stagg, Jakob Dupont, Niall Tebbutt. A Phase Ib study of demcizumab (DEM, anti-DLL4) with gemcitabine (GEM) in patients with first line locally advanced or metastatic pancreatic cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B78.