Results of the phase I open label clinical trial SAKK 06/14 assessing safety of intravesical instillation of VPM1002BC, a recombinant mycobacterium Bacillus Calmette Guérin (BCG), in patients with non-muscle invasive bladder cancer and previous failure of conventional BCG therapy.

Background: VPM1002BC is a modified mycobacterium Bacillus Calmette Guérin (BCG) for the treatment of non-muscle invasive bladder cancer (NMIBC). The genetic modifications are expected to result in better immunogenicity and less side effects. We report on patient safety and immunology of the first intravesical application of VPM1002BC in human. Methods: Six patients with BCG failure received a treatment of 6 weekly instillations with VPM1002BC. Patients were monitored for adverse events (AE), excretion of VPM1002BC and cytokines, respectively. Results: No DLT (dose limiting toxicity) occurred during the DLT-period. No grade ≥3 AEs occurred. Excretion of VPM1002BC in the urine was limited to less than 24 hours. Plasma levels of TNFα significantly increased after treatment and blood-derived CD4+ T cells stimulated with PPD demonstrated significantly increased intracellular GM-CSF and IFN expression. Conclusion: The intravesical application of VPM1002BC is safe and well tolerated by patients and results in a potential Th1 weighted immune response.

Cancer-specific geriatric assessment and quality of life: important factors in caring for older patients with aggressive B-cell lymphoma.

PURPOSE: To evaluate the efficacy and tolerability of chemotherapy, a geriatric assessment is recommended in elderly patients with cancer. We aimed to characterize and compare patients with aggressive lymphoma by objective response and survival status based on pre-treatment cancer-specific geriatric (C-SGA) and quality of life (QoL) assessments. METHODS: Patients not eligible for anthracycline-based first-line therapy or intensive salvage regimens completed C-SGA and QoL assessment before and after a rituximab-bendamustine-lenalidomide (R-BL) treatment in a phase II clinical trial. Clinical outcomes were compared based on pre-treatment individual and summary C-SGA measures, their cutoff-based subcategories and QoL indicators, using Wilcoxon rank sum or chi-square tests. RESULTS: A total of 57 patients (41 included in the clinical trial) completed a C-SGA. Participants with pre-treatment impaired functional status (Vulnerable Elders Survey-13 score ≥3) were more likely to experience worse outcomes: a higher proportion were non-responders, died before the median follow-up of 31.6 months (interquartile range (IQR) 27.9-37.9) or died during treatment. Non-responders were patients categorized as having possible depression (Geriatric Depression Scale-5 score ≥2) and with worse QoL scores for functional performance. Patients with worse C-SGA summary scores and with greater tiredness were more likely to die during treatment. CONCLUSION: A pre-treatment impaired functional status is an important factor with respect to clinical outcomes in patients receiving an R-BL regimen. Individual geriatric and related QoL domains showed similar associations with clinical outcomes. Whether interventions targeting specific geriatric dimensions also translate in better symptom- or domain-specific QoL warrants further research.

Rituximab, bendamustine and lenalidomide in patients with aggressive B-cell lymphoma not eligible for anthracycline-based therapy or intensive salvage chemotherapy - SAKK 38/08.

An increasing number of older patients are suffering from aggressive lymphoma. Effective and more tolerable treatment regimens are urgently needed for this growing patient population. Patients with aggressive lymphoma not eligible for anthracycline-based first-line therapy or intensive salvage regimens were treated with the rituximab-bendamustine-lenalidomide (R-BL) regimen (rituximab 375 mg/m(2)  day 1, bendamustine 70 mg/m(2)  d 1, 2, lenalidomide 10 mg d 1-21) for six cycles every 4 weeks. Forty-one patients with a median age of 75 (range 40-94) years were enrolled: 33 patients had substantial co-morbidities. 13 patients were not eligible for anthracycline-based first-line chemotherapy, 28 patients had relapsed/refractory disease. The primary endpoint, overall response, was achieved by 25 (61%) patients (95% confidence interval 45-76%). Grade ≥ 3 toxicity comprised haematological (59%), skin (15%), constitutional (15%) and neurological (12%) events. 9 patients died during trial treatment: 5 from lymphoma progression, 2 from toxicity, 2 with sudden death. After a median follow-up of 25·9 (interquartile range 20·4-31·6) months, 13 patients were still alive. Median overall survival was 14·5 months. In conclusion, R-BL can be considered a treatment option for elderly patients with treatment naïve or relapsed/refractory aggressive lymphoma not eligible for standard aggressive regimens.

Mismatch repair-dependent metabolism of O6-methylguanine-containing DNA in Xenopus laevis egg extracts.

The cytotoxicity of SN1-type alkylating agents such as N-methyl-N'-nitrosourea (MNU), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), or the cancer chemotherapeutics temozolomide, dacarbazine and streptozotocin has been ascribed to the persistence of O(6)-methylguanine ((me)G) in genomic DNA. One hypothesis posits that (me)G toxicity is caused by futile attempts of the mismatch repair (MMR) system to process (me)G/C or (me)G/T mispairs arising during replication, while an alternative proposal suggests that the latter lesions activate DNA damage signaling, cell cycle arrest and apoptosis directly. Attempts to elucidate the molecular mechanism of (me)G-induced cell killing in vivo have been hampered by the fact that the above reagents induce several types of modifications in genomic DNA, which are processed by different repair pathways. In contrast, defined substrates studied in vitro did not undergo replication. We set out to re-examine this phenomenon in replication-competent Xenopus laevis egg extracts, using either phagemid substrates containing a single (me)G residue, or methylated sperm chromatin. Our findings provide further support for the futile cycling hypothesis.

Repair of cisplatin-induced DNA interstrand crosslinks by a replication-independent pathway involving transcription-coupled repair and translesion synthesis.

DNA interstrand crosslinks (ICLs) formed by antitumor agents, such as cisplatin or mitomycin C, are highly cytotoxic DNA lesions. Their repair is believed to be triggered primarily by the stalling of replication forks at ICLs in S-phase. There is, however, increasing evidence that ICL repair can also occur independently of replication. Using a reporter assay, we describe a pathway for the repair of cisplatin ICLs that depends on transcription-coupled nucleotide excision repair protein CSB, the general nucleotide excision repair factors XPA, XPF and XPG, but not the global genome nucleotide excision repair factor XPC. In this pathway, Rev1 and Polζ are involved in the error-free bypass of cisplatin ICLs. The requirement for CSB, Rev1 or Polζ is specific for the repair of ICLs, as the repair of cisplatin intrastrand crosslinks does not require these genes under identical conditions. We directly show that this pathway contributes to the removal of ICLs outside of S-phase. Finally, our studies reveal that defects in replication- and transcription-dependent pathways are additive in terms of cellular sensitivity to treatment with cisplatin or mitomycin C. We conclude that transcription- and replication-dependent pathways contribute to cellular survival following treatment with crosslinking agents.

Structure-dependent bypass of DNA interstrand crosslinks by translesion synthesis polymerases.

DNA interstrand crosslinks (ICLs), inhibit DNA metabolism by covalently linking two strands of DNA and are formed by antitumor agents such as cisplatin and nitrogen mustards. Multiple complex repair pathways of ICLs exist in humans that share translesion synthesis (TLS) past a partially processed ICL as a common step. We have generated site-specific major groove ICLs and studied the ability of Y-family polymerases and Pol ζ to bypass ICLs that induce different degrees of distortion in DNA. Two main factors influenced the efficiency of ICL bypass: the length of the dsDNA flanking the ICL and the length of the crosslink bridging two bases. Our study shows that ICLs can readily be bypassed by TLS polymerases if they are appropriately processed and that the structure of the ICL influences which polymerases are able to read through it.

The Fanconi anemia pathway promotes replication-dependent DNA interstrand cross-link repair.

Fanconi anemia is a human cancer predisposition syndrome caused by mutations in 13 Fanc genes. The disorder is characterized by genomic instability and cellular hypersensitivity to chemicals that generate DNA interstrand cross-links (ICLs). A central event in the activation of the Fanconi anemia pathway is the mono-ubiquitylation of the FANCI-FANCD2 complex, but how this complex confers ICL resistance remains enigmatic. Using a cell-free system, we showed that FANCI-FANCD2 is required for replication-coupled ICL repair in S phase. Removal of FANCD2 from extracts inhibits both nucleolytic incisions near the ICL and translesion DNA synthesis past the lesion. Reversal of these defects requires ubiquitylated FANCI-FANCD2. Our results show that multiple steps of the essential S-phase ICL repair mechanism fail when the Fanconi anemia pathway is compromised.

gamma-Glutamyltranspeptidase-dependent metabolism of 4-hydroxynonenal-glutathione conjugate.

A major pathway for detoxification of the highly reactive lipid peroxidation product, 4-hydroxy-2,3-trans-nonenal (HNE) is through the conjugation with glutathione (GSH). We have studied the metabolism of GS-HNE conjugate by the enzyme gamma-glutamyltranspeptidase (GGT) using its purified form, as well as a GGT-overexpressing fibroblast cell line (V79 GGT). Using mass spectrometry analysis we identified for the first time cysteinylglycine-HNE (CysGly-HNE) as the GGT metabolite of GS-HNE. Furthermore, the GGT-dependent metabolism of GS-HNE in the V79 GGT cell line was associated with a considerable increase of cytotoxicity as compared to a control cell line which does not express GGT (V79 Cl). The cytotoxic effect was dose- and time-dependent (100% cellular death at 200 microM GS-HNE after 24 h incubation) in V79 GGT cells, whereas no decrease of viability was observed in V79 Cl cells. A similar cytotoxic effect was obtained when cells were incubated directly with CysGly-HNE, demonstrating that this GGT-dependent metabolite unlike GS-HNE, exhibits cytotoxic properties.