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Biomedical subjects

W M Stadler

Publications and source records attributed to W M Stadler.

At least 37 records · Page 2Linked to original sources

Angiogenesis inhibitors.

Angiogenesis inhibitors target the neovascular development that is hypothesized to underlie tumor growth. The inhibitors that are undergoing the clinical testing phase can be divided into five categories based on their target activity: 1) drugs that block matrix breakdown; 2) drugs that inhibit endothelial cells directly; 3) drugs that block angiogenesis activators; 4) drugs that inhibit endothelial cell integrins or survival signaling; and 5) drugs with a currently unknown mechanism of action. The properties of these drugs and some specific agents in each class are reviewed in this article. Because growth inhibition rather than tumor shrinkage is expected to be the clinical effect of angiogenesis inhibitors, some of the challenges and potential solutions for clinical trial design are also discussed.

Angiogenesis Inhibitors↗

Development of target-based antineoplastic agents.

The elucidation of multiple potential targets in cancer cells and the development of multiple target-based antineoplastic agents provide unique challenges in clinical trial design. Many of these agents are predicted to have cytostatic as opposed to cytotoxic effects and thus the traditional surrogate endpoint of radiologic tumor shrinkage may be inadequate. The ethical and safety issues of obtaining multiple tumor biopsies further complicate the assessment of appropriate target inhibition in patients. We discuss specific issues that need to be addressed during preclinical, phase I, II, and III testing of these agents. We propose clinical trial designs, including a randomized discontinuation design during phase II evaluation, that may be particularly useful for cytostatic antineoplastic agents.

Antineoplastic Agents↗

Phase II trial of weekly intravenous gemcitabine with continuous infusion fluorouracil in patients with metastatic renal cell cancer.

PURPOSE: To determine the clinical response rate of the combination of weekly intravenous (IV) gemcitabine with continuous infusion fluorouracil (5-FU) in patients with metastatic renal cell carcinoma (RCC). PATIENTS AND METHODS: Between June 1998 and February 1999, 41 patients with metastatic RCC were enrolled onto this multi-institutional phase II study of gemcitabine 600 mg/m(2) over 30 minutes on days 1, 8, and 15 and 5-FU 150 mg/m(2)/d via continuous IV infusion through a permanent catheter on days 1 to 21 of a 28-day cycle. Patients had a Cancer and Leukemia Group B performance status of 0 or 1, with a median time since diagnosis of metastatic disease of 10 months (range, 0 to 129 months). Thirty-three patients (80%) had multiple metastatic sites, and 34 patients (83%) had prior chemotherapy or immunotherapy. RESULTS: Of the 39 assessable patients, there were no complete responses but seven partial responses (objective response rate = 17%; 95% confidence interval, 8% to 34%). Five minor responses (25% to 50% decreased tumor size) were also observed. The duration of response for the seven partial responders was 2, 3, 7, 8, 10, 11, and 14 months. Median progression-free survival for the gemcitabine/5-FU group was 28.7 weeks versus 8 weeks for a similar cohort of patients treated on previous phase II studies at the University of Chicago (P =.008). The regimen was well tolerated, with fatigue, mucositis, nausea/vomiting, and grade 2 hematologic toxicities being most common. CONCLUSION: Weekly gemcitabine with continuous infusion 5-FU is an active combination in patients with metastatic RCC. Therapy was well tolerated and produced an improvement in progression-free survival over historical controls.

Adult↗

Flavopiridol, a novel cyclin-dependent kinase inhibitor, in metastatic renal cancer: a University of Chicago Phase II Consortium study.

PURPOSE: Flavopiridol is the first cyclin-dependent kinase (cdk) inhibitor to enter clinical trials. Serum levels of flavopiridol obtained during phase I studies were sufficient to inhibit in vitro cancer cell growth. Because responses were observed in kidney cancer patients in the phase I trials, we performed a phase II trial of flavopiridol in this patient population. PATIENTS AND METHODS: Thirty-five minimally pretreated patients were accrued using a standard two-step mechanism. Flavopiridol (50 mg/m(2)/d) was administered by continuous infusion for 72 hours every 2 weeks, and response was evaluated every 8 weeks. Peripheral blood mononuclear cells (PBMCs) were collected at baseline, at completion of drug infusion, and on day 7 of the first therapy cycle, and cell cycle parameters after phytohemagglutinin and interleukin-2 stimulation were assessed. RESULTS: There were two objective responses (response rate = 6%, 95% confidence interval, 1% to 20%). The most common toxicities were asthenia, occurring in 83% of patients (grade 3 or 4 in 9%), and diarrhea, occurring in 77% of patients (grade 3 or 4 in 20%). Also, nine patients (26%) experienced grade 3 or 4 vascular thrombotic events, including one myocardial infarction, two transient neurologic ischemic attacks, four deep venous thrombosis, and two pulmonary emboli. Cell cycle studies did not reveal any effect of flavopiridol on stimulated PBMCs. CONCLUSION: Flavopiridol, at the dose and schedule administered in this trial, is ineffective in metastatic renal cancer. In addition to the diarrhea observed in phase I studies, we also observed a higher incidence of asthenia and serious vascular thrombotic events than expected.

Adult↗

A G2/M growth arrest response to low-dose intermittent H2O2 in normal uroepithelial cells.

Studies in fibroblasts have shown that H2O2, as a model for oxidative damage, leads to a G1 growth arrest phenotypically similar to senescence. These observations as well as the observation that bladder cancer is associated with deletions of CDKN2, a gene important in normal senescence, led us to examine normal urothelial cell response to H2O2. We hypothesized that low dose H2O2 exposure would lead to p16 and/or p14arf mediated senescence. We show that H2O2 leads to endogenous beta-galactosidase expression similar to senescence, but instead of G1 arrest, it leads to G2/M growth arrest without induction of either p16 or p14arf. Lack of p21 induction and a similar G2/M growth arrest in E6 immortalized uroepithelial cells suggests that this response is independent of p53 as well. An increased level of cdc2 tyrosine-15 phosphorylation following H2O2 treatment suggests that the observed growth arrest is mediated by a G2 checkpoint mechanism.

Apoptosis↗

Detection of bladder cancer using a novel nuclear matrix protein, BLCA-4.

We have identified previously six nuclear matrix proteins (NMPs) that are bladder cancer specific. In this study, we analyzed the expression of one of these proteins, BLCA-4, in bladder tumors and normal bladder tissue. We also examined the appearance of BLCA-4 in the urine as a biomarker for bladder cancer. BLCA-4 was isolated from nuclear matrix preparations of bladder tumors, and its peptide sequence was determined. The antibodies generated against the resulting BLCA-4 peptides were then used to detect its presence in immunoblots and in urine samples by immunoassay. We analyzed tissue samples of bladder tumor and normal donor bladders and urine obtained from 51 normal individuals and 54 patients with pathologically confirmed bladder cancer. The BLCA-4 peptide sequences do not resemble any known human protein sequences. On immunoblot analysis, BLCA-4 expression was detectable in tumor and normal tissues from patients with bladder cancer but not in any of the normal bladder tissue obtained from organ donors. Using a prospectively determined cutoff level of 13 A (absorbance) units/microg protein, all 51 normal individuals tested were negative for BLCA-4 expression, whereas 53 of 55 samples from patients with bladder cancer were positive. These results suggest that BLCA-4 is present throughout the bladder in both the tumor and morphologically normal areas in bladder cancer patients. BLCA-4 is a very sensitive (96.4%) and specific (100%) marker for bladder cancer. BLCA-4 is a bladder cancer-specific marker that can be detected using a urine-based assay and can be used in the diagnosis of bladder cancer.

Adult↗

Flavopiridol metabolism in cancer patients is associated with the occurrence of diarrhea.

Flavopiridol, a cyclin-dependent kinase inhibitor currently undergoing clinical evaluation, has a dose-limiting toxicity of diarrhea. Preclinical data on flavopiridol metabolism indicate that flavopiridol undergoes hepatic glucuronidation. The purpose of this study is to evaluate whether the occurrence of diarrhea is related to the systemic glucuronidation of flavopiridol. Parent drug and metabolite concentrations in plasma were measured by high-pressure liquid chromatography in 22 metastatic renal cancer patients treated on a Phase II trial of 50 mg/m2/day of flavopiridol administered every 2 weeks as a 72-h continuous infusion. Pharmacokinetics of flavopiridol and its glucuronide were assessed during the first cycle at 23, 47, and 71 h during the infusion. Flavopiridol concentrations at 23, 47, and 71 h were 389 nM (296-567 nM), 412 nM (297-566 nM), and 397 nM (303-597 nM) [median (interquartile range)], respectively. Flavopiridol glucuronide reached a plateau of 358 nM (196-553 nM) at 47 h. Metabolic ratios of flavopiridol glucuronide:flavopiridol at 71 h showed an apparent bimodal distribution with an antimode of 1.2. Thirteen patients experienced diarrhea and had lower metabolic ratios [0.72 (0.53-0.86)] than patients without diarrhea [2.24 (1.76-2.3); P = 0.002]. Eight of 11 extensive glucuronidators (ratio > 1.2) did not develop diarrhea, whereas 10 of 11 poor glucuronidators (ratio < 1.2) developed diarrhea (P = 0.008). The glucuronidation of flavopiridol is apparently polymorphic, suggesting a genetic etiology. The systemic glucuronidation of flavopiridol is inversely associated with the risk of developing diarrhea.

Antineoplastic Agents↗

Mitogen-activated protein kinase kinase 4/stress-activated protein/Erk kinase 1 (MKK4/SEK1), a prostate cancer metastasis suppressor gene encoded by human chromosome 17.

The introduction of a discontinuous approximately 70-cM portion of human chromosome 17 significantly suppresses the metastatic ability of AT6.1 rat prostate cancer cells without affecting tumorigenicity (M. A. Chekmareva et al., Prostate, 33: 271-280, 1997). We have recently demonstrated that AT6.1 cells containing the approximately 70-cM region (AT6.1-17-4 cells) escape from the primary tumor and arrest in the lung but are growth-inhibited unless the metastasis suppressor region is lost (M. A. Chekmareva et al., Cancer Res., 58: 4963-4969, 1998). A series of in vivo studies indicated that the observed growth inhibition was due to the effect of a gene(s) at the metastatic site (M. A. Chekmareva et al., Cancer Res., 58: 4963-4969, 1998). We have now identified the mitogen-activated protein kinase kinase 4/stress-activated protein/Erk kinase 1 (MKK4/SEK1) gene as a candidate metastasis suppressor gene encoded by the approximately 70-cM region. AT6.1 cells were transfected with a MKK4/SEK1 expression construct, and the cells were tested in standard spontaneous metastasis assays. Whereas the metastatic ability of the AT6.1-MKK4/SEK1 cells was significantly reduced as compared with that of transfection controls, the growth rate of the primary tumors was not affected; the average tumor volume at day 29 after injection was approximately 2 cm. Furthermore, histological examination of the lungs of AT6.1-MKK4/SEK1 tumor-bearing animals revealed that the suppression by MKK4/SEK1 is due to an effect at the metastatic site, consistent with the phenotype conferred by the original approximately 70-cM chromosomal region. These studies implicate MKK4/SEK1 as a metastasis suppressor gene encoded by human chromosome 17.

Animals↗

In vitro evaluation of flavopiridol, a novel cell cycle inhibitor, in bladder cancer.

PURPOSE: To determine the in vitro effects of flavopiridol on bladder cancer cell lines, immortalized urothelial cell lines, and normal urothelial cells well characterized for defects in p53, pRb, and p16. METHODS: Growth inhibition was assessed via an MTT assay and apoptosis via DAPI nuclear staining. Cell cycle analysis was performed via propidium iodide staining and fluorescent activated cell sorting (FACS). Multidrug-resistant cells were generated by continuous exposure to doxorubicin. RESULTS: Growth inhibition was not correlated with inactivation of p53, pRb, or p16. All cells experienced G2/M arrest within 24 h of flavopiridol exposure. Modest apoptosis was observed but required 72 h of continuous drug exposure to become evident. There was no obvious synergistic or antagonistic toxicity when flavopiridol was combined with radiotherapy or cisplatin dosed at the IC50 despite the observation that radiotherapy and flavopiridol led to more profound G2/M arrest than either agent alone. Doxorubicin-resistant cells, demonstrated to overexpress the MDR1 multi-drug-resistance protein were equally as sensitive to flavopiridol as the parental cells. CONCLUSIONS: Flavopiridol is a novel cell cycle inhibitor that may be a useful agent in bladder cancers with tumor suppressor gene alterations and/or multidrug resistance.

Antineoplastic Agents↗

Gemcitabine and other new chemotherapeutic agents for the treatment of metastatic bladder cancer.

An improved quality of life secondary to reduced chemotherapy toxicity is an important end point in the treatment of all patients with metastatic cancer. In this review, we have demonstrated that gemcitabine and gemcitabine/cisplatin combinations appear to have a reduced toxicity profile compared with MVAC. Phase II studies with gemcitabine and cisplatin have shown good response rates that are possibly equivalent to MVAC, and a Phase III trial is now completed. Similar data have been reported for the paclitaxel/carboplatin combination and a Phase III trial comparing that combination with MVAC is planned. For patients with TCC who are in mild renal failure or who have significant underlying medical conditions, gemcitabine can also be considered as a reasonable single agent therapy. Complete responses can be seen, even in patients who are older than the age of 70. Moore et al., for example, demonstrated near complete responses to gemcitabine monotherapy in 4 patients older than 80 years of age. In conclusion, chemotherapy options for patients with metastatic bladder cancer have changed significantly with the addition of gemcitabine and other drugs to the armentarium. The integration of gemcitabine into the initial chemotherapy plan for these patients is still being developed. It is clear that this agent should be included in the management discussions of all patients with metastatic bladder cancer.

Antimetabolites, Antineoplastic↗

In vitro evaluation of calphostin C as a novel agent for photodynamic therapy of bladder cancer.

OBJECTIVES: Calphostin C, a highly specific protein kinase C inhibitor, induces apoptosis in the presence of visible light. We report the photoactivatable cytotoxicity of calphostin C in a series of well-characterized human bladder cancer cell lines: RT4, UM-UC-3, and 5637. METHODS: The human bladder cancer cell lines RT4, UM-UC-3, and 5637 were chosen on the basis of their p53, pRb and 9p21 deletion status. Using standard tissue culture techniques, the cytotoxicity of 10 to 100 nM calphostin C in combination with increasing exposures of visible light was examined. Controls consisted of cells treated with calphostin C without visible light and cells exposed to visible light without calphostin C treatment. Cell viability was determined by MTT assay. The induction of apoptosis by activated calphostin C was determined by 4,6-diamidino-2-phenylindole (DAPI) staining/fluorescence microscopy of nuclei. RESULTS: In the absence of light, calphostin C did not demonstrate a cytotoxic effect on any of the cell lines tested. Increasing the duration of light exposure resulted in a concomitant decrease in cell viability. Significant cell death was seen with calphostin C concentrations as low as 10 nM. These studies also demonstrated that calphostin C induced apoptosis by a mechanism independent of p53 and pRb status and the presence or absence of 9p21 deletions. CONCLUSIONS: We demonstrated the ability of activated calphostin C to induce apoptosis in a light-dependent and concentration-dependent fashion in a bladder cancer model system. Activated calphostin C cytotoxicity is independent of tumor genetic background and the status of p53 and pRb. Further development of calphostin C as a photosensitizer for photodynamic therapy of superficial bladder cancer may be warranted.

Antibiotics, Antineoplastic↗

Multi-institutional study of the angiogenesis inhibitor TNP-470 in metastatic renal carcinoma.

PURPOSE: Renal cell carcinoma is resistant to most chemotherapy, and only a minority of patients respond to immunotherapy. Its highly vascular nature suggests that antiangiogenesis therapy might be useful. We thus performed a phase II study of the fumigillin analog TNP-470 in previously treated patients with metastatic renal cell carcinoma. PATIENTS AND METHODS: Metastatic renal cell carcinoma patients with good organ function were entered onto the study through five separate institutions. There were no exclusion criteria for prior therapy. All patients were treated at a dose of 60 mg/m(2) of TNP-470 infused over 1 hour three times per week. RESULTS: Thirty-three patients were enrolled. Therapy was generally well tolerated, but asthenia, fatigue, vertigo, dizziness, sense of imbalance, and loss of concentration were common and severe enough to lead to therapy discontinuation in five patients. There was only one partial response of short duration (response rate, 3%, 95% confidence interval, 0% to 16%), but six patients (18%) remained on study for 6 or more months without toxicity or disease progression. CONCLUSION: Long-term therapy with TNP-470 has manageable toxicities and is feasible in patients with metastatic renal cell carcinoma but does not lead to any significant objective responses. Further studies in this population using TNP-470 schedules that produce more prolonged drug levels and clinical trial end points other than objective tumor regression may be indicated.

Adult↗

Kidney cancer.

In the USA, the incidence of kidney cancer has increased 43% since 1973. The risk of the disorder is higher in men than in women and increases with age. The von Hippel-Lindau tumour-suppressor gene is inactivated in over 75% of sporadic cases. Metastatic disease is present in 20-30% of patients at diagnosis. Early-stage kidney cancer is treated with a radical nephrectomy, but under certain circumstances a partial nephrectomy may be done. Tumour thrombus into the vena cava or right atrium requires thoracotomy and hypothermic circulatory arrest for successful removal of the tumour, but should not be done if extensive nodal or frank metastatic disease is present. Interleukin-2 is the systemic therapy of choice for metastatic disease at present, with long-term relapse-free survival of 5-8%. Several treatments including anti-angiogenesis drugs, cyclin-dependent kinase inhibitors, and differentiating agents are being actively investigated. Fluorouracil has a 10-15% response rate, and surgical excision of isolated metastases should always be considered. Therapy for metastatic renal cancer remains inadequate, but recent developments in basic and clinical research suggest future improvement.

Age Distribution↗

Chromosome 17-mediated dormancy of AT6.1 prostate cancer micrometastases.

To improve the diagnosis and treatment of cancer, an increased understanding of the molecular and cellular changes that regulate metastatic ability is required. We have recently demonstrated a prostate cancer metastasis-suppressor activity encoded by a discontinuous approximately 70-cM region of human chromosome. The presence of this region suppresses the spontaneous metastatic ability of AT6.1 rat prostatic cancer cells by greater than 30-fold (M. A. Chekmareva et al., Prostate, 33: 271-280, 1997). Interestingly, a number of potentially important genes which have been mapped to human chromosome 17, including TP53, NM23, and BRCA1, are not retained (M. A. Chekmareva et al., cited above) or are not expressed in these microcell hybrids (B. A. Yoshida et al., In Vivo, in press), which suggests the presence of a novel metastasis-suppressor gene(s) or novel function of a known gene(s) encoded by this region(s). We hypothesize that identification of the "step" in the metastatic cascade that is inhibited by the presence of the approximately 70-cM metastasis-suppressor region will facilitate the identification of candidate metastasis-suppressor genes. For a cancer cell to metastasize, it must escape from the primary tumor, enter the circulation, arrest in the microcirculation, extravasate into a tissue compartment, and grow. This suppression of spontaneous macroscopic lung metastases could be due to the inhibition of a number of steps within this cascade. Results of the current study demonstrate that AT6.1 cells containing the approximately 70-cM region (AT6.1-17-4 cells) escape from the primary tumor and arrest in the lung but are growth-inhibited unless the metastasis-suppressor region is lost. This growth inhibition seems to result from an effect of one or more genes at the metastatic site and not from a circulating angiogenesis inhibitor. Our findings suggest that the approximately 70-cM region of human chromosome 17 may encode a gene(s) that regulates the "dormancy" of AT6.1-17-4 micrometastases.

Animals↗

Granulocyte-macrophage--colony stimulating factor in metastatic renal cell carcinoma: a phase II trial.

BACKGROUND: Due to lack of success with standard chemotherapy and only modest success with immunotherapy, metastatic renal cell carcinoma (RCC) is associated with a poor prognosis. Granulocyte-macrophage-colony stimulating factor (GM-CSF) is a cytokine with potential antitumor activity, including stimulation of tumor necrosis factor (TNF) and interleukin-1 secretion. It is also a potent growth factor for and activator of antigen-presenting dendritic cells. GM-CSF toxicity may be mediated by TNF, and inhibition of TNF release by pentoxifylline (PTX) may ameliorate these toxic effects. The authors conducted a Phase II trial to determine the activity of GM-CSF in metastatic RCC and to study the effect of PTX on GM-CSF toxicity. METHODS: Twenty-four eligible patients with metastatic RCC received 10 microg/kg of GM-CSF per day, administered subcutaneously, on a 14-days-on/14-days-off schedule. Twelve patients received concurrent PTX at a dose of 400 mg administered orally 4 times per day. RESULTS: One patient experienced prolonged stability of disease after having progressive disease on entry. Two other patients experienced substantial slowing of their progressive disease while on study. One of these patients had rapidly progressing metastases on other immunotherapy before receiving GM-CSF. Toxicity was not diminished in patients treated with PTX; it included hyperleukocytosis, nausea, vomiting, pain, fever, skin reactions, myalgia, and fatigue. CONCLUSIONS: GM-CSF at the dose and schedule described in this report has minor activity against metastatic RCC, and PTX does not ameliorate its side effects.

Adult↗

Overcoming cellular senescence in human cancer pathogenesis.

Elevation of p16, the CDKN2/p16 tumor suppressor gene (TSG) product, occurs at senescence in normal human uroepithelial cells (HUC). Immortal HUCs and bladder cancer cell lines show either alteration of p16 or pRb, the product of the retinoblastoma (RB) TSG. In addition, many human cancers show p16 or pRb alteration along with other genetic alterations that we associated with immortalization, including +20q and -3p. These observations led us to hypothesize that p16 elevation plays a critical role in senescence cell cycle arrest and that overcoming this block is an important step in tumorigenesis in vivo, as well as immortalization in vitro. Using a novel approach, we tested these hypotheses in the present study by examining p16 and pRb status in primary culture (P0) and after passage in vitro of transitional cell carcinoma (TCC) biopsies that represented both superficial bladder tumors and invasive bladder cancers. We demonstrated that all superficial TCCs showed elevated p16 after limited passage in vitro and then senesced, like normal HUCs. In contrast, all muscle invasive TCCs contained either a p16 or a pRb alteration at P0 and all spontaneously bypassed senescence (P = 0.001). Comparative genomic hybridization (CGH) was used to identify regions of chromosome loss or gain in all TCC samples. The application of a statistical model to the CGH data showed a high probability of elevated alteration rates of +20q11-q12 (0.99) and +8p22-pter (0.94) in the immortal muscle invasive TCCs, and of -9q (0.99) in the superficial TCCs. Three myoinvasive TCCs lost 3p13-p14. In this study, four of six myoinvasive TCCs also showed TP53 mutation that associated well with genome instability (P = 0.001), as previously hypothesized. Notably, TP53 mutation, which has been used as a marker of tumor progression in many human cancers, was less significant in associating with progression in this study (P = 0.04) than was p16 or pRb alteration (P = 0.001). Thus, these data support a new model in which overcoming senescence plays a critical role in human cancer pathogenesis and requires at least two genetic changes that occur in several combinations that can include either p16 or pRb loss and at least one additional alteration, such as +20q11-q12, -3p13-p14, or -8p21-pter.

Adult↗

Multicenter phase II trial of interleukin-2, interferon-alpha, and 13-cis-retinoic acid in patients with metastatic renal-cell carcinoma.

PURPOSE: To determine the response rate and toxicity of oral 13-cis-retinoic acid (CRA) added to an outpatient regimen of subcutaneous interleukin-2 (IL2) and interferon-alpha (IFNA) in previously untreated patients with metastatic renal-cell carcinoma (RCC). PATIENTS AND METHODS: Eligibility included a performance status of 2 or better, no significant end-organ dysfunction, and written informed consent. Characteristics of 47 of 48 assessable patients included a median performance status of 0, prior nephrectomy in 68% of patients, one metastatic site in 30% of patients, and lung-only metastatic disease in 21% of patients. Therapy consisted of IL2 11 x 10(6) IU 4 days per week for 4 weeks, IFNA 9 x 10(6) IU 2 days per week for 4 weeks, and CRA 1 mg/kg daily on a 6-week cycle. RESULTS: Eight of 47 patients (17%) responded (one complete response, seven partial responses). Three partial responders were rendered disease free by subsequent surgical resection. Four additional patients experienced a minor response in lung or soft tissue metastases. The median duration of response, which included minor responses, was 42 weeks, and median survival was 74 weeks (17 months). Grades 3 or greater toxicities during the first cycle included flu-like symptoms (21% of patients), fatigue (6% of patients), and nausea and vomiting (15% of patients). Significant cumulative toxicities were hyperlipidemia (four of 18 patients), and cardiomyopathy (one of 18 patients). There was one therapy-related death. CONCLUSION: Outpatient CRA plus IL2 and IFNA is feasible and modestly effective in metastatic RCC. The prolonged median survival is encouraging, but randomized trials are required to show that the combination represents an improvement over single-agent immunotherapy.

Adult↗