Phase II study of capecitabine-based concomitant chemoradiation followed by durvalumab as a neoadjuvant strategy in locally advanced rectal cancer: the PANDORA trial

BACKGROUND

This study investigated the efficacy of chemoradiotherapy (CRT) followed by durvalumab as neoadjuvant therapy of locally advanced rectal cancer.

PATIENTS AND METHODS

The PANDORA trial is a prospective, phase II, open-label, single-arm, multicenter study aimed at evaluating the efficacy and safety of preoperative treatment with durvalumab (1500 mg every 4 weeks for three administrations) following long-course radiotherapy (RT) plus concomitant capecitabine (5040 cGy RT in 25-28 fractions over 5 weeks and capecitabine administered at 825 mg/m2 twice daily). The primary endpoint was the pathological complete response (pCR) rate; secondary endpoints were the proportion of clinical complete remissions and safety. The sample size was estimated assuming a null pCR proportion of 0.15 and an alternative pCR proportion of 0.30 (α = 0.05, power = 0.80). The proposed treatment could be considered promising if ≥13 pCRs were observed in 55 patients (EudraCT: 2018-004758-39; NCT04083365).

RESULTS

Between November 2019 and August 2021, 60 patients were accrued, of which 55 were assessable for the study's objectives. Two patients experienced disease progression during treatment. Nineteen out of 55 eligible patients achieved a pCR (34.5%, 95% confidence interval 22.2% to 48.6%). Regarding toxicity related to durvalumab, grade 3 adverse events (AEs) occurred in four patients (7.3%) (diarrhea, skin toxicity, transaminase increase, lipase increase, and pancolitis). Grade 4 toxicity was not observed. In 20 patients (36.4%), grade 1-2 AEs related to durvalumab were observed. The most common were endocrine toxicity (hyper/hypothyroidism), dermatologic toxicity (skin rash), and gastrointestinal toxicity (transaminase increase, nausea, diarrhea, constipation).

CONCLUSION

This study met its primary endpoint showing that CRT followed by durvalumab could increase pCR with a safe toxicity profile. This combination is a promising, feasible strategy worthy of further investigation.

Overall survival with 3 or 6 months of adjuvant chemotherapy in Italian TOSCA phase 3 randomised trial

BACKGROUND

Oxaliplatin-based adjuvant chemotherapy is the standard treatment of high-risk colon cancer (CC). A shorter duration (3 months) can achieve a similar outcome [in terms of relapse-free survival (RFS)] to a longer duration. This study reports the overall survival (OS) analysis of the three or six colon adjuvant (TOSCA) phase III study. It assessed different adjuvant chemotherapy durations in patients with resected high-risk stage II and stage III CC.

MATERIAL AND METHODS

TOSCA was an open-label, phase III, multicentre, non-inferiority trial conducted in 130 Italian centres. Patients were randomly assigned, in a 1 : 1 ratio, to receive 3 months of standard doses of FOLFOX/CAPOX, or 6 months of FOLFOX/CAPOX. Patients with histologically confirmed high-risk stage II and III CC were included, with RFS being the primary end point. OS was a secondary end point.

RESULTS

From June 2007 to March 2013, 3759 patients were accrued. At a median follow-up of 7 years, the hazard ratio (HR) for RFS of the 3-month versus 6-month arms was 1.13; 95% confidence interval (CI) 0.99-1.29, P for non-inferiority = 0.380, P for superiority = 0.068, crossing the non-inferiority limit of 1.20. This result did not allow us to reject the null hypothesis of the inferiority of the 3-month arm. The HR for OS of the 3-month versus 6-month arms was 1.09 (95% CI 0.93-1.26, P for superiority = 0.288). At the last follow-up analysis, the absolute OS difference between arms was <1%.

CONCLUSIONS

The present analysis of the TOSCA trial does not indicate any significant difference in OS between the treatment groups. The extra benefit provided by the longer treatment should be balanced against the extra toxicity of more prolonged therapy. The trial is registered with ClinicalTrials.gov, registration number: NCT0064660.

The prognostic impact of primary tumour location in patients with stage II and stage III colon cancer receiving adjuvant therapy. A GISCAD analysis from three large randomised trials

PURPOSE

Because the role of the primary tumour location in the adjuvant setting has not been clearly established in colon cancer, we analysed the clinical outcome according to the primary tumour location from three Italian trials assessing adjuvant therapy in colon cancer.

PATIENTS AND METHODS

Overall survival (OS) and disease-free survival (DFS) were assessed globally and in each trial, according to right-sided, transverse and left-sided primary colon cancer. Analysis was planned to provide overall and stage-specific results.

RESULTS

Individual data of 5239 patients were included in this analysis. The right-sided tumours were 1540 (29%), tumours originating in the transverse were 815 (16%) and left-sided tumours were 2884 (55%). At the multivariate analysis, DFS findings from the comparison of the right-sided versus left-sided tumours (hazard ratio [HR] = 1.00; 95% confidence interval [CI] = 0.89-1.14) were not statistically associated with clinical outcomes in the overall population. On the contrary, OS findings, from the comparison of the right-sided versus left-sided tumours, were significantly associated with outcomes (HR = 1.20; 95% CI = 1.04-1.39). In stage II patients, there was no difference in terms of DFS and OS among the three different tumour locations, whereas in stage III patients, the left-sided tumours showed an improved prognosis in terms of OS (HR: 1.36 95% CI = 1.14-1.62, p < 0.001).

CONCLUSION

This is the largest analysis demonstrating a prognostic effect of the tumour location on patients with colon cancer receiving adjuvant chemotherapy. Nevertheless, the effect is limited to OS in stage III colon cancer. In stage II tumours, the primary location has a lesser impact. The transverse tumours should be prognostically considered in between the right-sided and left-sided tumours.

Effects of a Hydroxyapatite-based Biomaterial on Gene Expression in Osteoblast-like Cells

Biostite® is a hydroxyapatite-derived biomaterial that is used in periodontal and bone reconstructive procedures due to its osteoconductive properties. Since the molecular effects of this biomaterial on osteoblasts are still unknown, we decided to assess whether it may specifically modulate osteoblast functions in vitro. We found that a brief exposure to Biostite® significantly reduced the proliferation of MG-63 and SaOS-2 osteoblast-like cells to ~ 50% of the plateau value. Furthermore, gene array analysis of MG-63 cells showed that Biostite® caused a differential expression of 37 genes which are involved in cell proliferation and interaction, and related to osteoblast differentiation and tissue regeneration. Results were confirmed by RT-PCR, Western blot, and by an increase in alkaline phosphatase (ALP) specific activity. Biostite® also increased levels of polycystin-2, a mechano-sensitive Ca2+ channel, a promising new marker of bone cell differentiation. Biostite®, therefore, may directly affect osteoblasts by enhancing chondro/osteogenic gene expression and cytoskeleton-related signaling pathways, which may contribute to its clinical efficacy.

Phase III trial comparing 3-6 months of adjuvant FOLFOX4/XELOX in stage II-III colon cancer: safety and compliance in the TOSCA trial

BACKGROUND

Six months of oxaliplatin-based adjuvant chemotherapy is standard of care for radically resected stage III colon cancer and an accepted option for high-risk stage II. A shorter duration of therapy, if equally efficacious, would be advantageous for patients and Health-Care Systems.

PATIENTS AND METHODS

TOSCA ['Randomized trial investigating the role of FOLFOX-4 or XELOX (3 versus 6 months) regimen duration and bevacizumab as adjuvant therapy for patients with stage II/III colon cancer] is an open-label, phase III, multicenter, noninferiority trial randomizing patients with high-risk stage II or stage III radically resected colon cancer to receive 3 months (arm 3 m) versus 6 months (arm 6 m) of FOLFOX4/XELOX. Primary end-point was relapse-free survival. We present here safety and compliance data.

RESULTS

From June 2007 to March 2013, 3759 patients were accrued from 130 Italian sites, 64% receiving FOLFOX4 and 36% XELOX in either arm. Treatment completion rate without any modification was 35% versus 12% and with delays or dose reduction 52% versus 44% in arm 3 and 6 m. Treatment was permanently discontinued in 8% (arm 3 m) and 33% (arm 6 m). In arm 6 m, 50% of patients discontinuing treatment did so after completing 80% of planned program. Grade 3+ toxicities were higher in arm 6 m than that in 3 m. Grade 2+ neuropathy was 31.2% versus 8.8% (P < 0.0001) while grade 3+ was 8.4 versus 1.3 (P < 0.0001), in arm 3 and 6 m. Seven deaths within 30 days from last treatment administration in arm 6 m and three deaths in arm 3 m were observed (0.3% versus 0.1%, P = 0.34).

CONCLUSIONS

TOSCA is the first trial comparing 3 versus 6 months of adjuvant chemotherapy completing accrual within the international initiative of treatment duration evaluation (International Duration Evaluation of Adjuvant, IDEA). High compliance to treatment in control arm will allow a correct assessment of potential differences between the two treatment durations.

CLINICALTRIALSGOV REGISTRATION NUMBER

NCT00646607.

Abstract 3512: Dielectrophoretic capture and genetic analysis of individual disseminated solid tumor cells

Background: The purpose of this study was to develop a novel approach for isolation and genetic analysis of individual circulating and disseminated tumor cells (CTC, DTC) from patient samples. This work is motivated by our desire to develop non-invasive molecular diagnostics and understand single tumor cell heterogeneity.

Methods: Here we used the DEPArray microelectronics and microfluidics platform for the manipulation and capture of individual tumor cells. A suspension of live or fixed cells, prelabeled with fluorochrome-conjugated antibodies, was loaded into the DEPArray cartridge, and application of non-uniform electrical fields (dielectrophoresis) was employed to trap individual cells into movable micro-cages. Cell images were acquired via the incorporated fluorescence microscope and CCD camera, and cells were selected based on morphology and expression of tumor antigens. To determine sensitivity and specificity of the capture process, cell lines were spiked into normal donor white blood cells (WBC) over a 5-log range. Pre-enrichment by FACSAria was employed when the starting tumor cell concentration was below 1 in 1,000 WBC. The whole genome amplification (WGA) product of single cells was then subjected to targeted sequencing. To apply this approach to patient samples, we obtained blood and bone marrow samples from patients with refractory high-risk neuroblastoma, a cancer with a high rate and quantity of distant metastatic disease.

Results: Single tumor cells were recovered from all spiking experiments, including spiked samples with a tumor cell concentration as low as 1 in 106 WBC. Recovery of EpCAM-negative single cells was accomplished with the neuroblastoma cell lines SY5Y, NB1643, and Kelly labeled with an antibody for the disialoganglioside GD2, the breast cancer cell line MCF-7 with a HER2 antibody, and for the lung cancer cell line H292 with EGFR labeling. Recovery of EpCAM-positive cells was achieved with the colon carcinoma cell line SW480. Captured single cells were WGA'd and specificity was verified using Sanger sequencing. For the 2 neuroblastoma spiking experiments for which sequencing has been completed, the known ALK mutation (F1174L) was detected in 100% of cells. The known KRAS mutation (G12V) was detected in 100% of single SW480 cells sequenced to date. No mutations were detected in isolated WBC. We next analyzed the post-Ficoll fraction of 12 patient bone marrow and 1 patient blood sample, with a median tumor cell concentration of 0.119% (range 0.003 - 80.0%). A minimum of 10 single tumor cells were captured per patient. Genome-wide analysis of DNA and RNA copy number and mutation status from these samples is ongoing.

Conclusion: These data demonstrate the development of a novel workflow for the reliable capture and genetic analysis of rare CTC. Efforts are ongoing to join this approach with a more comprehensive genome-wide analysis of single cells from neuroblastoma and other cancers.

Citation Format: Erica L. Carpenter, JulieAnn Rader, Kateryna Krytska, Jacob Ruden, Eric Rappaport, Yael Mosse, Francesca Fontana, Manuela Banzi, Gianni Medoro, Nicolo Manaresi, Peter O'Dwyer, John Maris. Dielectrophoretic capture and genetic analysis of individual disseminated solid tumor cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3512. doi:10.1158/1538-7445.AM2013-3512

Sorafenib in patients with Child-Pugh class A and B advanced hepatocellular carcinoma: a prospective feasibility analysis

BACKGROUND

Sorafenib has shown survival benefits in patients with advanced hepatocellular carcinoma (HCC) and Child-Pugh (CP) class A liver function. There are few prospective data on sorafenib in patients with HCC and CP class B.

PATIENTS AND METHODS

A consecutive prospective series of 300 patients with CP class A or B HCC were enrolled in a dual-phase trial to determine survival and safety data according to liver function (class A or B) in patients receiving oral sorafenib 800 mg daily. [Results of this study were presented in part at the ASCO 2012 Gastrointestinal Cancers Symposium, 19-21 January 2012. J Clin Oncol 2012; 30 (Suppl 4): abstract 306.]

RESULTS

Overall progression-free survival (PFS), time to progression (TTP) and overall survival (OS) were 3.9, 4.1 and 9.1 months, respectively. For patients with CP class A versus B status, PFS was 4.3 versus 2.1 months, TTP was 4.2 versus 3.8 months and OS was 10.0 versus 3. 8 months. Extrahepatic spread was associated with worse outcomes but taken together with CP class, liver function played a greater role in reducing survival. Adverse events for the two CP groups were similar.

CONCLUSION

Although patients with HCC and CP class B liver function have poorer outcomes than those with CP class A function, data suggest that patients with CP class B liver function can tolerate treatment and may still benefit from sorafenib.

Abstract PD05-03: What is the appropriate sample (s) on which to perform sequencing for mutational analysis to guide the selection of targeted therapy?

BACKGROUND: Success of targeted therapy requires expression of the protein. Tumor tissue source can include diagnostic biopsy, surgical samples from initial or follow-up surgeries, fluids e.g. pleural or ascites and circulating tumor cells (CTC). The goal of using CTCs was 1. To determine whether CTC can be used as a “liquid” tumor biopsy and enable gene sequence information at the single cell level and 2. To determine the heterogeneity represented in the circulation compared to that seen in solid tumor by examining single cells (or a small cluster of cells) for the presence of a specific mutation which was detected in tissue tumor source.

METHODS: We performed sequencing for mutational analysis on tissue(s) from patients with inflammatory breast cancer (IBC). Tumor sources varied from mastectomy tissue, metastatic site(s) e.g. liver or skin from chest wall disease, pleural fluid and CTC isolated into pure single cell populations (or groups of cells) using Silicon Biosystems DEPArray. Ampli1™ WGA kit was used for CTC amplification. Of the 22 patients sequenced, mastectomy primary tumor was examined in 3, metastatic site skin chest wall disease in 15, other metastatic site in 4, pleural fluid in 2 and CTC collected to investigate p53 mutations in 8.

RESULTS: To date 22 patients have had mutational data performed, 14/22 had mutations in p53, 4/22 in RB1, 2/22 in each PI3K and ERBB2, 1/22 in each of BRAC1, BRAC2, ATM, KRAS, Notch 1, MEN1 and ESR1. Numerous amplifications were noted including AKT1, RPTOR, MLC1, MYC, CCND1 and ERBB2. For one patient's chest wall biopsy compared to two single CTCs and a cluster of 10 CTCs the same TP53C229fs*10 mutation was detected revealing the same 2bp deletion. No 2bp deletion was found in single white blood cells. Whereas, another patient which showed a TP53 S215G mutation in her skin biopsy of chest wall disease, only amplifications of AURKA, CCND1, IGF1R, MDM2 and SRC in pleural tumor cells were detected and no mutations in three single CTC, two single pleural tumor cells and in single white blood cells were seen. Primary tumor tissue is being sort for both of these patients. Mutational data reviewed to date suggest that IBC is not one disease but a multiplicity of diseases, revealing a variety of target(s). Aberrations are not consistent across tissue source.

CONCLUSIONS: Successful treatment outcomes using standard of care chemotherapy combined with target therapies will require not one, but a panel, of tissue sources for sequencing to guide the selection of appropriate targeted therapies.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD05-03.

Nephrocystin-1 forms a complex with polycystin-1 via a polyproline motif/SH3 domain interaction and regulates the apoptotic response in mammals

Mutations in PKD1, the gene encoding for the receptor Polycystin-1 (PC-1), cause autosomal dominant polycystic kidney disease (ADPKD). The cytoplasmic C-terminus of PC-1 contains a coiled-coil domain that mediates an interaction with the PKD2 gene product, Polycystin-2 (PC-2). Here we identify a novel domain in the PC-1 C-terminal tail, a polyproline motif mediating an interaction with Src homology domain 3 (SH3). A screen for interactions using the PC-1 C-terminal tail identified the SH3 domain of nephrocystin-1 (NPHP1) as a potential binding partner of PC-1. NPHP1 is the product of a gene that is mutated in a different form of renal cystic disease, nephronophthisis (NPHP). We show that in vitro pull-down assays and NMR structural studies confirmed the interaction between the PC-1 polyproline motif and the NPHP1 SH3 domain. Furthermore, the two full-length proteins interact through these domains; using a recently generated model system allowing us to track endogenous PC-1, we confirm the interaction between the endogenous proteins. Finally, we show that NPHP1 trafficking to cilia does not require PC-1 and that PC-1 may require NPHP1 to regulate resistance to apoptosis, but not to regulate cell cycle progression. In line with this, we find high levels of apoptosis in renal specimens of NPHP patients. Our data uncover a link between two different ciliopathies, ADPKD and NPHP, supporting the notion that common pathogenetic defects, possibly involving de-regulated apoptosis, underlie renal cyst formation.

Polycystin-1 promotes PKCalpha-mediated NF-kappaB activation in kidney cells

Polycystin-1 (PC1), the PKD1 gene product, is a membrane receptor which regulates many cell functions, including cell proliferation and apoptosis, both typically increased in cyst lining cells in autosomal dominant polycystic kidney disease. Here we show that PC1 upregulates the NF-kappaB signalling pathway in kidney cells to prevent cell death. Human embryonic kidney cell lines (HEK293(CTT)), stably expressing a PC1 cytoplasmic terminal tail (CTT), presented increased NF-kappaB nuclear levels and NF-kappaB-mediated luciferase promoter activity. This, consistently, was reduced in HEK293 cells in which the endogenous PC1 was depleted by RNA interference. CTT-dependent NF-kappaB promoter activation was mediated by PKCalpha because it was blocked by its specific inhibitor Ro-320432. Furthermore, it was observed that apoptosis, which was increased in PC1-depleted cells, was reduced in HEK293(CTT) cells and in porcine kidney LtTA cells expressing a doxycycline-regulated CTT. Staurosporine, a PKC inhibitor, and parthenolide, a NF-kappaB inhibitor, significantly reduced the CTT-dependent antiapoptotic effect. These data reveal, therefore, a novel pathway by which polycystin-1 activates a PKCalpha-mediated NF-kappaB signalling and cell survival.

The cytoplasmic C-terminus of polycystin-1 increases cell proliferation in kidney epithelial cells through serum-activated and Ca(2+)-dependent pathway(s)

Polycystin-1 (PC1) is a large transmembrane protein important in renal differentiation and defective in most cases of autosomal dominant polycystic kidney disease (ADPKD), a common cause of renal failure in adults. Although the genetic basis of ADPKD has been elucidated, molecular and cellular mechanisms responsible for the dysregulation of epithelial cell growth in ADPKD cysts are still not well defined. We approached this issue by investigating the role of the carboxyl cytoplasmic domain of PC1 involved in signal transduction on the control of kidney cell proliferation. Therefore, we generated human HEK293 cells stably expressing the PC1 cytoplasmic tail as a membrane targeted TrkA-PC1 chimeric receptor protein (TrkPC1). We found that TrkPC1 increased cell proliferation through an increase in cytoplasmic Ca2+ levels and activation of PKC alpha, thereby upregulating D1 and D3 cyclin, downregulating p21waf1 and p27kip1 cyclin inhibitors, and thus inducing cell cycle progression from G0/G1 to the S phase. Interestingly, TrkPC1-dependent Ca2+ increase and PKC alpha activation are not constitutive, but require serum factor(s) as parallel component. In agreement with this observation, a significant increase in ERK1/2 phosphorylation was observed. Consistently, inhibitors specifically blocking either PKC alpha or ERK1/2 prevented the TrkPC1-dependent proliferation increase. NGF, the TrkA ligand, blocked this increase. We propose that in kidney epithelial cells the overexpression of PC1 C-terminus upregulates serum-evoked intracellular Ca2+ by counteracting the growth-suppression activity of endogenous PC1 and leading to an increase in cell proliferation.

Deficiency of polycystin‐2 reduces Ca2+channel activity and cell proliferation in ADPKD lymphoblastoid cells

Polycystin-2 (PC2), encoded by the PKD2 gene, mutated in 10-15% of autosomal-dominant polycystic kidney disease (ADPKD) patients, is a Ca2+-permeable cation channel present in kidney epithelia and other tissues. As PC2 was found expressed in B-lymphoblastoid cells (LCLs) and Ca2+ signaling pathways are important regulators of B cell function activities, we investigated whether PC2 plays some role in B-LCLs. In LCLs, PC2 was found mainly in ER membranes but ~8 times less than in kidney HEK293 cells. The same reductions were found in PKD2 and PKD1 RNA; thus, PKD genes maintained, in LCLs, the same reciprocal proportion as they do in kidney cells. In LCLs obtained from subjects carrying PKD2 mutations (PKD2-LCLs) and showing reduced PC2 levels, intracellular Ca2+ concentrations evoked by platelet-activating factor (PAF), were significantly lower than in non-PKD-LCLs. This reduction was also found in PKD1-LCLs but without PC2 reductions. Likewise, cell proliferation, which is controlled by Ca2+, was reduced in PKD2- and PKD1-LCLs. Moreover, in LCLs with PKD2 nonsense mutations, aminoglycoside antibiotics reduced the PC2 defect by promoting readthrough of stop codons. Therefore, PC2 and PC1 are functionally expressed in LCLs, which provide a model, easily obtainable from ADPKD patients, to study PKD gene expression and function.

Expression of polycystin-1 C-terminal fragment enhances the ATP-induced Ca2+ release in human kidney cells

Polycystin-1 (PC1) is a membrane protein expressed in tubular epithelia of developing kidneys and in other ductal structures. Recent studies indicate this protein to be putatively important in regulating intracellular Ca(2+) levels in various cell types, but little evidence exists for kidney epithelial cells. Here we examined the role of the PC1 cytoplasmic tail on the activity of store operated Ca(2+) channels in human kidney epithelial HEK-293 cell line. Cells were transiently transfected with chimeric proteins containing 1-226 or 26-226 aa of the PC1 cytoplasmic tail fused to the transmembrane domain of the human Trk-A receptor: TrkPC1 wild-type and control Trk truncated peptides were expressed at comparable levels and localized at the plasma membrane. Ca(2+) measurements were performed in cells co-transfected with PC1 chimeras and the cytoplasmic Ca(2+)-sensitive photoprotein aequorin, upon activation of the phosphoinositide pathway by ATP, that, via purinoceptors, is coupled to the release of Ca(2+) from intracellular stores. The expression of TrkPC1 peptide, but not of its truncated form, enhanced the ATP-evoked cytosolic Ca(2+) concentrations. When Ca(2+) assays were performed in HeLa cells characterized by Ca(2+) stores greater than those of HEK-293 cells, the histamine-evoked cytosolic Ca(2+) increase was enhanced by TrkPC1 expression, even in absence of external Ca(2+). These observations indicate that the C-terminal tail of PC1 in kidney and other epithelial cells upregulates a Ca(2+) channel activity also involved in the release of intracellular stores.