Ernest C. Borden

Interferon alfa-2b adjuvant therapy of high-risk resected cutaneous melanoma: the Eastern Cooperative Oncology Group Trial EST 1684.

PURPOSE Interferon alfa-2b (IFN alpha-2b) exhibits antitumor activity in metastatic melanoma and on this basis has been evaluated as an adjuvant therapy following surgery for deep primary (T4) or regionally metastatic (N1) melanoma. METHODS A randomized controlled study of IFN alpha-2b (Schering-Plough, Kenilworth, NJ) administered at maximum-tolerated doses of 20 MU/m2/d intravenously (i.v.) for 1 month and 10 MU/m2 three times per week subcutaneously (SC) for 48 weeks versus observation, was conducted by the Eastern Cooperative Oncology Group (ECOG) in 287 patients. RESULTS A significant prolongation of relapse-free survival (P = .0023, one-sided) and prolongation of overall survival (P = .0237, one-sided) was observed with IFN alpha-2b therapy in this trial, which is now mature with a median follow-up time of 6.9 years. The impact of treatment on relapse rate is most pronounced early during the treatment interval. The overall benefit of treatment in this trial was analyzed stratified by tumor burden and the presence or absence of microscopic nonpalpable and palpable regional lymph node metastasis. The benefit of therapy with IFN alpha-2b was greatest among node-positive strata. Toxicity of IFN alpha-2b required dose modification in the majority of patients, but treatment at > or = 80% of the scheduled dose was feasible in the majority of patients through the IV phase of treatment, and for more than 3 months of SC maintenance therapy. Discontinuation of treatment due to toxicity was infrequent after the fourth month of therapy. CONCLUSION IFN alpha-2b prolongs the relapse-free interval and overall survival of high-risk resected melanoma patients. The increment in median disease-free survival (from 1 to 1.7 years) and overall survival (from 2.8 to 3.8 years) that results from this therapy is associated with a 42% improvement in the fraction of patients who are continuously disease-free after treatment with IFN (from 26% to 37%) in comparison to observation. IFN alpha-2b is the first agent to show a significant benefit in relapse-free and overall survival of high-risk melanoma patients in a randomized controlled trial.

Phase III Randomized, Intergroup Trial Assessing Imatinib Mesylate At Two Dose Levels in Patients With Unresectable or Metastatic Gastrointestinal Stromal Tumors Expressing the Kit Receptor Tyrosine Kinase : S0033

PURPOSE To assess potential differences in progression-free or overall survival when imatinib mesylate is administered to patients with incurable gastrointestinal stromal tumors (GIST) at a standard dose (400 mg daily) versus a high dose (400 mg twice daily). PATIENTS AND METHODS Patients with metastatic or surgically unresectable GIST were eligible for this phase III open-label clinical trial. At registration, patients were randomly assigned to either standard or high-dose imatinib, with close interval follow-up. If objective progression occurred by Response Evaluation Criteria in Solid Tumors, patients on the standard-dose arm could reregister to the trial and receive the high-dose imatinib regimen. RESULTS Seven hundred forty-six patients with advanced GIST from 148 centers across the United States and Canada were enrolled onto this trial in 9 months. With a median follow-up of 4.5 years, median progression-free survival was 18 months for patients on the standard-dose arm, and 20 months for those receiving high-dose imatinib. Median overall survival was 55 and 51 months, respectively. There were no statistically significant differences in objective response rates, progression-free survival, or overall survival. After progression on standard-dose imatinib, 33% of patients who crossed over to the high-dose imatinib regimen achieved either an objective response or stable disease. There were more grade 3, 4, and 5 toxicities noted on the high-dose imatinib arm. CONCLUSION This trial confirms the effectiveness of imatinib as primary systemic therapy for patients with incurable GIST but did not show any advantage to higher dose treatment. It appears reasonable to initiate therapy with 400 mg daily and to consider dose escalation on progression of disease.

Circulating Tumor Cells versus Imaging—Predicting Overall Survival in Metastatic Breast Cancer

Purpose: The presence of ≥5 circulating tumor cells (CTC) in 7.5 mL blood from patients with measurable metastatic breast cancer before and/or after initiation of therapy is associated with shorter progression-free and overall survival. In this report, we compared the use of CTCs to radiology for prediction of overall survival. Experimental Design: One hundred thirty-eight metastatic breast cancer patients had imaging studies done before and a median of 10 weeks after the initiation of therapy. All scans were centrally reviewed by two independent radiologists using WHO criteria to determine radiologic response. CTC counts were determined ∼4 weeks after initiation of therapy. Specimens were analyzed at one of seven laboratories and reviewed by a central laboratory. Results: Interreader variability for radiologic responses and CTC counts were 15.2% and 0.7%, respectively. The median overall survival of 13 (9%) patients with radiologic nonprogression and ≥5 CTCs was significantly shorter than that of the 83 (60%) patients with radiologic nonprogression and <5 CTCs (15.3 versus 26.9 months; P = 0.0389). The median overall survival of the 20 (14%) patients with radiologic progression and <5 CTCs was significantly longer than the 22 (16%) patients with ≥5 CTCs that showed progression by radiology (19.9 versus 6.4 months; P = 0.0039). Conclusions: Assessment of CTCs is an earlier, more reproducible indication of disease status than current imaging methods. CTCs may be a superior surrogate end point, as they are highly reproducible and correlate better with overall survival than do changes determined by traditional radiology.

Correlation of Kinase Genotype and Clinical Outcome in the North American Intergroup Phase III Trial of Imatinib Mesylate for Treatment of Advanced Gastrointestinal Stromal Tumor: CALGB 150105 Study by Cancer and Leukemia Group B and Southwest Oncology Group

PURPOSE Imatinib mesylate is standard treatment for patients who have advanced gastrointestinal stromal tumor (GIST), but not all patients benefit equally. In previous studies, GIST genotype correlated with treatment outcome and optimal imatinib dosing. PATIENTS AND METHODS We examined the relationship between kinase genotype and treatment outcome for 428 patients enrolled on the North American phase III study SWOG S0033/CALGB 150105 and treated with either 400 mg or 800 mg daily doses of imatinib. RESULTS The presence of KIT exon 11-mutant genotype (n = 283) correlated with improved treatment outcome when compared with KIT exon 9-mutant (n = 32) and wild-type (WT; n = 67) genotypes for objective response (complete response [CR]/partial response [PR], 71.7% v 44.4% [P = .007]; and 44.6% [P = .0002], respectively); time to tumor progression (TTP; median 24.7 months v 16.7 and 12.8 months, respectively); and overall survival (OS; median 60.0 months v 38.4 and 49.0 months, respectively). The survival outcomes for patients with exon 9-mutant, exon 11-mutant or WT GIST were not affected by imatinib dose. However, there was evidence of improved response rates for patients with exon 9-mutant tumors treated with imatinib 800 mg versus 400 mg (CR/PR, 67% v 17%; P = .02). Patients who had CD117-negative GIST had similar TTP but inferior OS compared with patients who had CD117-positive disease, which suggests that patients who have CD117-negative GIST may benefit from imatinib treatment. In addition, we identified novel but rare mutations of the KIT extracellular domain (exons 8 and 9). CONCLUSION We confirmed the favorable impact of KIT exon 11 genotype when compared with KIT exon 9 and wild-type genotype for patients with advanced GIST who are treated with imatinib.

Randomized comparison of three adriamycin regimens for metastatic soft tissue sarcomas.

This study addressed two major questions regarding therapeutic use of Adriamycin ([Adr] Adria Laboratories, Columbus, OH) in adult soft tissue sarcomas: the influence of dosing schedule and the value of adding imidazole carboxamide (DTIC) to Adr. Patients with objectively measurable metastatic soft tissue sarcomas were randomized to Adr 70 mg/m2 intravenously (IV) day 1 and every 3 weeks (94 patients); Adr 20 mg/m2 IV day 1, 2, and 3, and 15 mg/m2 IV day 8 and weekly thereafter (89 patients); and Adr 60 mg/m2 IV day 1 and DTIC 250 mg/m2 days 1 to 5, repeated every 3 weeks (92 patients). The regimens using Adr as a single agent resulted in an equivalent response frequency (18% and 16%) and survival (median, 8.0 and 8.4 months). DTIC significantly increased (P less than .02) the overall response frequency of Adr to 30%. However, DTIC did not influence survival (median, 8.0 months) or increase the number of complete responses. The toxicities of the two single-agent regimens differed: Adr weekly resulted in more stomatitis (P = .09) and less hematologic toxicity (P less than .05). DTIC resulted in substantially increased toxicity, primarily gastrointestinal (P less than .002); overall, 98% of patients receiving Adr-DTIC experienced moderate or worse toxicity. To decrease the potential for error in interpretation of treatment results, histopathological confirmation of diagnosis was undertaken by a panel of reference pathologists; pathology slides were submitted on 97% of entered patients. The on-study clinical diagnosis was affirmed in 199 of 316 patients (63%) with a final review. In 23% of patients, the panel agreed with the diagnosis of soft tissue sarcoma, but not with the type. In 14%, the panel concluded that a diagnosis of mesenchymal malignancy could not be affirmed. Final treatment results were based on the 275 pathologically confirmed, eligible patients. The most common histological subtype entered was leiomyosarcoma (99 patients). The response to Adr-DTIC of this subtype was higher (44%) than that of any other subtype. However, this difference alone was not responsible for the overall superiority of the combination. This confirmed that the combination of DTIC plus Adr adds to the response rate of Adr alone in soft tissue sarcomas. Whether the increased response frequency, without an impact on survival, is worth the significantly greater toxicity remains a subjective judgement that must be made within the context of the individual patient.

Human Polyomavirus Infections with JC Virus and BK Virus in Renal Transplant Patients

Infection with the human polyomaviruses JC virus and BK virus was studied in 61 immunosuppressed renal transplant patients. Urine cytologic studies, indirect immunofluorescence microscopy, electron microscopy, and serologic studies were used to assess viral activity. Patients records were abstracted for events associated with polyomavirus infections. Polyomavirus excretion in urine was detected in 12 of 61 patients (20%). Eleven excreted JC virus and nine, BK virus. Fourfold hemagglutination-inhibition antibody titer rises occurred in 25 of 61 patients (41%). The serologic data suggested that most JC virus infections were primary, whereas most BK virus infections resulted from virus reactivation. During this 2-year study, 32 of 61 patients (52%) had evidence of active viral replication. Urinary tract excretion was associated with drug-requiring diabetes mellitus (P = 0.001), arterial occlusive disease (P = 0.03), and ureteral stricture with loss of renal function (P = 0.02). Antibody increases to BK virus were associated with a rising seurum creatinine (P = 0.02) and need for transplant biopsy (P = 0.02). Polyomavirus replication was therefore associated with an increased frequency of transplant related complications.

Myeloid-derived suppressor cell accumulation and function in patients with newly diagnosed glioblastoma.

To assess the accumulation of myeloid-derived suppressor cells (MDSCs) in the peripheral blood of patients with glioma and to define their heterogeneity and their immunosuppressive function. Peripheral blood mononuclear cells (PBMCs) from healthy control subjects and from patients with newly diagnosed glioma were stimulated with anti-CD3/anti-CD28 and T cells assessed for intracellular expression of interferon (IFN)-γ. Antibody staining of PBMCs from glioma patients and healthy donors (CD33, HLADR, CD15, and CD14) followed by 4-color flow cytometry analysis-defined MDSC levels in the peripheral blood. To assess the role of MDSCs in suppressing T cell IFNγ production, PBMCs were depleted of MDSCs using anti-CD33 and anti-CD15 antibody-coated beads prior to T cell stimulation. Enzyme-linked immunosorbent assays were used to assess plasma arginase activity and the level of granulocyte colony-stimulating factor (G-CSF). Patients with glioblastoma have increased MDSC counts (CD33+HLADR-) in their blood that are composed of neutrophilic (CD15(+); >60%), lineage-negative (CD15(-)CD14(-); 31%), and monocytic (CD14(+); 6%) subsets. After stimulation, T cells from patients with glioblastoma had suppressed IFN-γ production when compared with healthy, age-matched donor T cells. Removal of MDSCs from the PBMCs with anti-CD33/CD15-coated beads significantly restored T cell function. Significant increases in arginase activity and G-CSF levels were observed in plasma specimens obtained from patients with glioblastoma. The accumulation of MDSCs in peripheral blood in patients with glioma likely promotes T cell immune suppression that is observed in this patient population. Increased plasma levels of arginase and G-CSF may relate to MDSC suppressor function and MDSC expansion, respectively, in patients with glioma.

Interferon-Induced Indoleamine 2,3-Dioxygenase Activity in Human Mononuclear Phagocytes

Interferon (IFN)‐induced tryptophan degradation, catalyzed by indoleamine 2,3‐dioxygenase (IDO), has been shown to mediate antimicrobial activity in epithelial cells. IDO activity has also been augmented in peripheral blood mononuclear cells (PBMC) treated with IFN or interleukin‐2 (IL‐2). The effector cells in this population have now been further characterized. PBMCs were isolated from normal donors, separated into monocyte and lymphocyte populations by plastic adherence, treated with IFN or IL‐2, and cultivated in medium supplemented with [3H]tryptophan. Culture supernatants were collected after a 48‐h incubation and fractionated by high‐performance liquid chromatography; radioactivity was determined in fractions corresponding to tryptophan and its metabolites. IFN‐γ and IFN‐β induced IDO activity only in monocytes (plastic‐adherent, nonspecific esterase‐positive PBMCs). The induction of IDO activity by IL‐2 required both monocytes and lymphocytes. Interaction was required between these populations for induction of IDO by IL‐2, due to production of IFN‐γ by T lymphocytes, with subsequent IFN‐γ‐mediated induction of IDO in monocytes. A number of myeloid cell lines as well as monocyte‐derived macrophages were also tested for their ability to be induced to degrade tryptophan in response to IFN treatment. Monocyte‐derived macrophages were found to retain their capacity to be induced by IFN‐γ and IFN‐β to degrade tryptophan after differentiation, and to possess seven times more IDO activity per cell than IFN‐induced monocytes. However, the presence of lipopolysaccharide (LPS) in the culture medium was required for the maximum induction of IDO activity by IFN‐β. Furthermore, higher concentrations of LPS were sufficient to induce IDO activity in macrophages in the absence of exogenous IFN.

Implications of Interferon-Induced Tryptophan Catabolism in Cancer, Autoimmune Diseases and Aids

Tryptophan (Trp) is an indispensable amino acid required for biosynthesis of proteins, serotonin and niacin. Indoleamine 2,3-dioxygenase (IDO) is induced by infections, viruses, lipopolysaccharides, or interferons (IFNs) and this results in significant catabolism of Trp along the kynurenine (Kyn) pathway. Intracellular growth of Toxoplasma gondii and Chlamydia psittaci in human fibroblasts in vitro is inhibited by IFN-gamma and this inhibition is negated by extra Trp in the medium. Similarly, growth of a number of human cell lines in vitro is inhibited by IFN-gamma and addition of extra Trp restores growth. Thus, in some in vitro systems, antiproliferative effects of IFN-gamma are mediated by induced depletion of Trp. We find that cancer patients given Type I or Type II IFNs can induce IDO which results in decreased serum Trp levels (20-50% of pretreatment) and increased urinary metabolites of the Kyn pathway (5 to 500 fold of pretreatment). We speculate that in vivo antineoplastic effects of IFNs and clinical side effects are mediated, at least in part, by a general or localized depletion of Trp. In view of reported increases of IFNs in autoimmune diseases and our earlier findings of elevated urinary Trp metabolites in autoimmune diseases, it seems likely that systemic or local depletion of Trp occurs in autoimmune diseases and may relate to degeneration, wasting and other symptoms in such diseases. We find high levels of IDO in cells isolated from synovia of arthritic joints. IFNs are also elevated in human immunodeficiency virus (HIV) patients and increasing IFN levels are associated with a worsening prognosis. We propose that IDO is induced chronically by HIV infection, is further increased by opportunistic infections, and that this chronic loss of Trp initiates mechanisms responsible for the cachexia, dementia, diarrhea and possibly immunosuppression of AIDS patients. In these symptoms, AIDS resembles classical pellagra due to dietary deficiency of Trp and niacin. In preliminary studies, others report low levels of Trp and serotonin, and elevated levels of Kyn and quinolinic acid in AIDS patients. The implications of these data in cancer, autoimmune diseases and AIDS are discussed.

Interferon alfa combined with cytotoxic chemotherapy for patients with non-Hodgkin's lymphoma.

BACKGROUND Interferon alfa has been found to be effective as an antitumor agent (with a response rate of 30 percent) in patients with low-grade non-Hodgkins lymphoma, but its effectiveness in those with intermediate-grade non-Hodgkins lymphoma has been less adequately tested. In a prospective randomized study we evaluated the effectiveness of adding interferon alfa to cytotoxic chemotherapy in patients with clinically aggressive, low-grade non-Hodgkins lymphoma and certain histologic variants of intermediate-grade non-Hodgkins lymphoma, not including diffuse histiocytic lymphoma. METHODS The patients were randomly assigned to a regimen of cyclophosphamide, vincristine, prednisone, and doxorubicin or to this regimen combined with recombinant interferon alfa. Treatment was administered every four weeks, for 8 to 10 cycles. RESULTS The two regimens produced comparable objective responses, but the regimen including interferon had a greater effect in prolonging the time to treatment failure (P < 0.001) and the duration of complete response (P = 0.03). Interferon alfa also had a greater effect on overall survival (P = 0.014) when the results were adjusted for important covariates. CONCLUSIONS Interferon alfa, when added to a four-drug doxorubicin-based chemotherapy regimen, is an effective antitumor agent in patients with clinically aggressive low-grade or intermediate-grade non-Hodgkins lymphoma.