Nonresponse to neoadjuvant chemotherapy for muscle-invasive urothelial cell carcinoma of the bladder.

BACKGROUND: Cisplatin-based neoadjuvant chemotherapy (NC) is commonly used in the treatment of muscle-invasive urothelial cell carcinoma of the bladder (UC) and has been shown to improve survival. However, not all patients respond to NC, thus delaying the interval to potentially curative surgical therapy, risking disease progression and subjecting patients to potential morbidity from NC. In this study, we perform a retrospective analysis of patients who received NC prior to cystectomy to identify factors associated with nonresponse. PATIENTS AND METHODS: We identified 80 patients with clinical T2 to T4, N0 to N1 UC of the bladder who received NC and underwent radical cystectomy. Nonresponse was defined as patients with higher pathologic T stage than clinical stage or patients with nodal involvement identified on final pathology. RESULTS: Overall, 20% of patients were considered nonresponders. In multivariate analysis, age was predictive of nonresponse (P(trend) < .05). Compared with those < 60 years of age, those aged 60 to 69 years (odds ratio [OR], 2.9; 95% CI, 0.7-12) and those aged ≥ 70 (OR, 5.0; 95% CI, 0.9-28) had higher odds of nonresponse. Patients who received gemcitabine-carboplatin had higher odds of nonresponse compared with those who received gemcitabine-cisplatin (OR, 4.4; 95% CI, 0.8-21). CONCLUSION: A subset of patients receiving NC prior to cystectomy will experience disease progression. Future study will need to better identify methods to distinguish individuals more likely to benefit from NC and those that should receive upfront cystectomy.

Pathologic Response Rates of Gemcitabine/Cisplatin versus Methotrexate/Vinblastine/Adriamycin/Cisplatin Neoadjuvant Chemotherapy for Muscle Invasive Urothelial Bladder Cancer.

Objectives. To compare pathologic outcomes after treatment with gemcitabine and cisplatin (GC) versus methotrexate, vinblastine, adriamycin, and cisplatin (MVAC) in the neoadjuvant setting. Methods. Data was retrospectively collected on 178 patients with T2-T4 bladder cancer who underwent radical cystectomy between 2003 and 2011. Outcomes of interest included those with complete response (pT0) and any response (≤pT1). Odds ratios were calculated using multivariate logistic regression. Results. Compared to those who did not receive neoadjuvant chemotherapy, there were more patients with complete response (28% versus 9%, OR 3.11 (95% CI: 1.45-6.64), P = 0.03) and any response (52% versus 25%, OR 3.23 (95% CI: 1.21-8.64), P = 0.01). Seventy-two patients received GC (n = 41) or MVAC (n = 31). CR was achieved in 29% and 22% of GC and MVAC patients, respectively (multivariate OR 0.39, 95% CI 0.10-1.58). Any response (≤pT1) was achieved in 56% of GC and 45% of MVAC patients (multivariate OR 0.45, 95% CI 0.12-1.71). Conclusions. We observed similar pathologic response rates for GC and MVAC neoadjuvant chemotherapy in this cohort of patients with muscle invasive urothelial cancer (MIBC). Our findings support the use of GC as an alternative regimen in the neoadjuvant setting.

Pretargeted radioimmunotherapy using genetically engineered antibody-streptavidin fusion proteins for treatment of non-hodgkin lymphoma.

PURPOSE: Pretargeted radioimmunotherapy (PRIT) using streptavidin (SAv)-biotin technology can deliver higher therapeutic doses of radioactivity to tumors than conventional RIT. However, "endogenous" biotin can interfere with the effectiveness of this approach by blocking binding of radiolabeled biotin to SAv. We engineered a series of SAv FPs that downmodulate the affinity of SAv for biotin, while retaining high avidity for divalent DOTA-bis-biotin to circumvent this problem. EXPERIMENTAL DESIGN: The single-chain variable region gene of the murine 1F5 anti-CD20 antibody was fused to the wild-type (WT) SAv gene and to mutant SAv genes, Y43A-SAv and S45A-SAv. FPs were expressed, purified, and compared in studies using athymic mice bearing Ramos lymphoma xenografts. RESULTS: Biodistribution studies showed delivery of more radioactivity to tumors of mice pretargeted with mutant SAv FPs followed by (111)In-DOTA-bis-biotin [6.2 ± 1.7% of the injected dose per gram (%ID/gm) of tumor 24 hours after Y43A-SAv FP and 5.6 ± 2.2%ID/g with S45A-SAv FP] than in mice on normal diets pretargeted with WT-SAv FP (2.5 ± 1.6%ID/g; P = 0.01). These superior biodistributions translated into superior antitumor efficacy in mice treated with mutant FPs and (90)Y-DOTA-bis-biotin [tumor volumes after 11 days: 237 ± 66 mm(3) with Y43A-SAv, 543 ± 320 mm(3) with S45A-SAv, 1129 ± 322 mm(3) with WT-SAv, and 1435 ± 212 mm(3) with control FP (P < 0.0001)]. CONCLUSIONS: Genetically engineered mutant-SAv FPs and bis-biotin reagents provide an attractive alternative to current SAv-biotin PRIT methods in settings where endogenous biotin levels are high.

Anti-CD45 pretargeted radioimmunotherapy using bismuth-213: high rates of complete remission and long-term survival in a mouse myeloid leukemia xenograft model.

Pretargeted radioimmunotherapy (PRIT) using an anti-CD45 antibody (Ab)-streptavidin (SA) conjugate and DOTA-biotin labeled with ß-emitting radionuclides has been explored as a strategy to decrease relapse and toxicity. α-emitting radionuclides exhibit high cytotoxicity coupled with a short path length, potentially increasing the therapeutic index and making them an attractive alternative to ß-emitting radionuclides for patients with acute myeloid leukemia. Accordingly, we have used (213)Bi in mice with human leukemia xenografts. Results demonstrated excellent localization of (213)Bi-DOTA-biotin to tumors with minimal uptake into normal organs. After 10 minutes, 4.5% ± 1.1% of the injected dose of (213)Bi was delivered per gram of tumor. α-imaging demonstrated uniform radionuclide distribution within tumor tissue 45 minutes after (213)Bi-DOTA-biotin injection. Radiation absorbed doses were similar to those observed using a ß-emitting radionuclide ((90)Y) in the same model. We conducted therapy experiments in a xenograft model using a single-dose of (213)Bi-DOTA-biotin given 24 hours after anti-CD45 Ab-SA conjugate. Among mice treated with anti-CD45 Ab-SA conjugate followed by 800 µCi of (213)Bi- or (90)Y-DOTA-biotin, 80% and 20%, respectively, survived leukemia-free for more than 100 days with minimal toxicity. These data suggest that anti-CD45 PRIT using an α-emitting radionuclide may be highly effective and minimally toxic for treatment of acute myeloid leukemia.

Conventional and pretargeted radioimmunotherapy using bismuth-213 to target and treat non-Hodgkin lymphomas expressing CD20: a preclinical model toward optimal consolidation therapy to eradicate minimal residual disease.

Radioimmunotherapy (RIT) with α-emitting radionuclides is an attractive approach for the treatment of minimal residual disease because the short path lengths and high energies of α-particles produce optimal cytotoxicity at small target sites while minimizing damage to surrounding normal tissues. Pretargeted RIT (PRIT) using antibody-streptavidin (Ab-SA) constructs and radiolabeled biotin allows rapid, specific localization of radioactivity at tumor sites, making it an optimal method to target α-emitters with short half-lives, such as bismuth-213 (²¹³Bi). Athymic mice bearing Ramos lymphoma xenografts received anti-CD20 1F5(scFv)(4)SA fusion protein (FP), followed by a dendrimeric clearing agent and [²¹³Bi]DOTA-biotin. After 90 minutes, tumor uptake for 1F5(scFv)4SA was 16.5% ± 7.0% injected dose per gram compared with 2.3% ± .9% injected dose per gram for the control FP. Mice treated with anti-CD20 PRIT and 600 µ Ci [²¹³Bi]DOTA-biotin exhibited marked tumor growth delays compared with controls (mean tumor volume .01 ± .02 vs. 203.38 ± 83.03 mm³ after 19 days, respectively). The median survival for the 1F5(scFv)4SA group was 90 days compared with 23 days for the control FP (P < .0001). Treatment was well tolerated, with no treatment-related mortalities. This study demonstrates the favorable biodistribution profile and excellent therapeutic efficacy attainable with ²¹³Bi-labeled anti-CD20 PRIT.

Design and synthesis of bis-biotin-containing reagents for applications utilizing monoclonal antibody-based pretargeting systems with streptavidin mutants.

Previous studies have shown that pretargeting protocols, using cancer-targeting fusion proteins, composed of 4 anti-CD20 single chain Fv (scFv) fragments and streptavidin (scFv(4)-SAv), followed by a biotinylated dendrimeric N-acetyl-galactosamine blood clearing agent (CA), 1, then a radiolabeled DOTA-biotin derivative (a monobiotin), 3a, can provide effective therapy for lymphoma xenografts in mouse models. A shortcoming in this pretargeting system is that endogenous biotin may affect its efficacy in patients. To circumvent this potential problem, we investigated a pretargeting system that employs anti-CD20 scFv(4)-SAv mutant fusion proteins with radioiodinated bis-biotin derivatives. With that combination of reagents, good localization of the radiolabel to lymphoma tumor xenografts was obtained in the presence of endogenous biotin. However, the blood clearance reagents employed in the studies were ineffective, resulting in abnormally high levels of radioactivity in other tissues. Thus, in the present investigation a bis-biotin-trigalactose blood clearance reagent, 2, was designed, synthesized, and evaluated in vivo. Additionally, another DOTA-biotin derivative (a bis-biotin), 4a, was designed and synthesized, such that radiometals (e.g., (111)In, (90)Y, (177)Lu) could be used in the pretargeting protocols employing scFv(4)-SAv mutant fusion proteins. Studies in mice demonstrated that the CA 2 was more effective than CA 1 at removing [(125)I]scFv(4)-SAv-S45A mutant fusion proteins from blood. Another in vivo study compared tumor targeting and normal tissue concentrations of the new reagents (2 and [(111)In]4b) with standard reagents (1 and [(111)In]3b) used in pretargeting protocols. The study showed that lymphoma xenografts could be targeted in the presence of endogenous biotin when anti-CD20 fusion proteins containing SAv mutants (scFv(4)-SAv-S45A or scFv(4)-SAv-Y43A) were employed in combination with CA 2 and [(111)In]4b. Importantly, normal tissue concentrations of [(111)In]4b were similar to those obtained using the standard reagents (1 and [(111)In]3b), except that the blood and liver concentrations were slightly higher with the new reagents. While the reasons for the higher blood and liver concentrations are unknown, the differences in the galactose structures of the clearance agents 1 and 2 may play a role.

Recent advances in novel radioimmunotherapeutic approaches for allogeneic hematopoietic cell transplantation.

PURPOSE OF REVIEW: Allogeneic hematopoietic cell transplantation (HCT) can be a curative treatment for hematologic malignancies and over the last three decades, novel approaches have resulted in significant reductions in morbidity and mortality. Despite current advances, two major limitations remain: patients continue to die from recurrent disease, and rates of nonrelapse mortality are relatively high due to regimen-related organ toxicities. The ability to target therapy with radiolabeled antibodies provides an innovative way to increase the tumoricidal dose of radiation to tumor sites, whereas sparing normal organs, as further dose escalation of chemotherapy and radiotherapy in HCT preparative regimens is not feasible due to dose-limiting toxicities. RECENT FINDINGS: This review discusses the most current allogeneic HCT data using radioimmunotherapy (RIT) and focuses on recent trials involving patients at the highest risk for relapse. The results from these studies have shown that standard-dose radiolabeled antibodies can be safely combined with reduced-intensity preparative regimens with encouraging results in a single institution phase II study. SUMMARY: Optimism remains that these RIT approaches will improve the cure rates of allogeneic HCT for the thousands of patients with leukemias and lymphomas who undergo this procedure each year.

Detection of catalase as a major protein target of the lipid peroxidation product 4-HNE and the lack of its genetic association as a risk factor in SLE.

BACKGROUND: Systemic lupus erythematosus (SLE) is a multifactorial disorder characterized by the presence of autoantibodies. We and others have implicated free radical mediated peroxidative damage in the pathogenesis of SLE. Since harmful free radical products are formed during this oxidative process, including 4-hydroxy 2-nonenol (4-HNE) and malondialdehyde (MDA), we hypothesized that specific HNE-protein adducts would be present in SLE red blood cell (RBC) membranes. Catalase is located on chromosome 11p13 where linkage analysis has revealed a marker in the same region of the genome among families with thrombocytopenia, a clinical manifestation associated with severe lupus in SLE affected pedigrees. Moreover, SLE afflicts African-Americans three times more frequently than their European-American counterparts. Hence we investigated the effects of a genetic polymorphism of catalase on risk and severity of SLE in 48 pedigrees with African American ancestry. METHODS: Tryptic digestion followed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis was used to identify the protein modified by HNE, following Coomassie staining to visualize the bands on the acrylamide gels. Genotyping analysis for the C --> T, -262 bp polymorphism in the promoter region of catalase was performed by PCR-RFLP and direct PCR-sequencing. We used a "pedigree disequilibrium test" for the family based association analysis, implemented in the PDT program to analyze the genotyping results. RESULTS: We found two proteins to be HNE-modified, migrating around 80 and 50 kD respectively. Tryptic digestion followed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis of the Coomassie stained 80 kD band revealed that the target of HNE modification was catalase, a protein shown to associate with RBC membrane proteins. All the test statistics carried out on the genotyping analysis for the C --> T, -262 bp polymorphism in the promoter region of catalase were non-significant (p > 0.05) in our data, which suggested that this SNP is not associated with SLE. CONCLUSION: Our results indicate that catalase is one of the proteins modified due to oxidative stress. However, catalase may not be a susceptibility gene for SLE. Nonetheless, catalase is oxidatively modified among SLE patients. This suggests a possible role between oxidative modification of catalase and its affects on enzymatic activity in SLE. An oxidatively modified catalase could be one of the reasons for lower enzymatic activity among SLE subjects, which in turn could favor the accumulation of deleterious hydrogen peroxide. Furthermore, HNE-products are potential neoantigens and could be involved in the pathogenesis of SLE. Decrease in catalase activity could affect the oxidant-antioxidant balance. Chronic disturbance of this balance in patients with SLE may work favorably for the premature onset of atherogenesis with severe vascular effect.