Use of amifostine in bone marrow purging.

One of the main obstacles for the use of high-dose chemotherapy with autologous hematopoietic progenitor cell support in the treatment of malignancies is the possibility of reinfusing clonogenic tumor cells with the hematopoietic graft. Purging of the graft with chemicals can reduce the number of tumor cells but can also damage the normal hematopoietic progenitors. Preclinical studies showed that the phosphorylated sulfhydryl compound amifostine (WR-2721) can protect normal hematopoietic progenitors from damage from alkylating agents. We conducted a randomized clinical trial in patients with breast cancer, non-Hodgkin's lymphoma, and Hodgkin's disease undergoing autologous bone marrow transplant. In this study, patients were randomized to have their bone marrow purged with 4-hydroperoxycyclophosphamide (4-HC) with (arm A) or without (arm B) amifostine. The percentage of colony-forming unit granulocyte-macrophages recovered after purging was higher in the amifostine arm, both in patients with breast cancer and in those with lymphoma, although this difference was not statistically significant. In addition, the time to engraftment was significantly shorter in the amifostine arm in both cohorts. We showed that pretreatment of bone marrow with amifostine prior to purging with 4-HC can protect normal hematopoietic progenitors from damage by 4-HC. This resulted in shorter engraftment rates and less need for supportive care.

Organic thiophosphate WR-151327 suppresses expression of HIV in chronically infected cells.

Reducing agents such as glutathione (GSH), glutathione ester (GSE), and N-acetylcysteine (NAC) have been shown to suppress the induction of HIV expression in chronically infected cells stimulated by cytokines. We present data which show the effects of the organic thiophosphate WR-151327 on the expression of latent HIV in U1 cells. The chronically infected promonocytic cell line U1 constitutively expresses low levels of HIV that can be increased by 13-phorbol 12-myristate acetate (PMA), tumor necrosis factor alpha (TNF-alpha), and granulocyte/monocyte colony-stimulating factor (GM-CSF). WR-151327 suppressed, in dose-dependent fashion, the reverse transcriptase (RT) activity induced by TNF-alpha, GM-CSF, and PMA. The maximal decrease in RT activity was 70, 80, and 50%, respectively. Pretreatment with WR-151327 also suppressed the induction of total HIV protein synthesis, as shown by Western blot analysis. In addition, WR-151327 suppressed HIV-LTR-CAT activity in transfected human rhabdomyosarcoma cells (RD). Suppression of HIV expression by WR-151327 was observed in the absence of a cytotoxic or cytostatic effect. Incubation of WR-151327 with human recombinant TNF-alpha for 6 hr at 37 degrees C did not alter the capacity of TNF-alpha to induce the expression of HIV. Our observations further support the hypothesis that reducing agents are important in the control of HIV replication and that the clinical evaluation of WR-151327 may be indicated.

Amifostine-mediated protection of normal bone marrow from cytotoxic chemotherapy.

Amifostine (US Bioscience, West Conshohocken, PA; Ethyol, WR-2721), a phosphorylated thiol developed by the United States Army as a protective agent for military personnel in the event of nuclear warfare, has shown protection of normal tissues from the cytotoxic effects of therapeutic radiation and chemotherapy with preservation of cytotoxic effects on the tumor. The basis of this selective protection derives from the relatively rapid uptake and anabolism of Amifostine into normal tissues and minimal, slower uptake into tumor tissue. Preclinical investigations have demonstrated protection of bone marrow stem cells from the toxic effects of radiation and chemotherapy. Several controlled clinical trials demonstrated this hematoprotective effect. In patients given 1.5 g/m2 cyclophosphamide and month later given Amifostine (740 mg/m2) followed by the same dose of cyclophosphamide, the median nadir neutrophil count was significantly increased and duration of neutropenia was significantly reduced by pretreatment with Amifostine. In women with stage III/IV ovarian cancer treated with 1 g/m2 cyclophosphamide and 100 mg/m2 cisplatin +/- Amifostine 910 mg/m2, treatment with Amifostine before cyclophosphamide and cisplatin resulted in a significant decrease in both the incidence and duration of hospital stays for neutropenic fever compared to cyclophosphamide and cisplatin alone. There were equivalent rates of response and duration of survival in both groups. Other studies have shown Amifostine protects bone marrow purged in vitro with 4-hydroperoxycyclophosphamide before autologous bone marrow transplantation. This preservation of marrow stem cells resulted in a statistically significant decrease in time to marrow engraftment, need for platelet transfusions and antibiotics, and duration of hospital stay. Amifostine-mediated protection of normal bone marrow illustrated in preclinical experiments is also evident in clinical trials. Amifostine preserves trilineage stem cells (red blood cells, platelets, and white blood cells) in contrast to the lineage-specific effects of the colony-stimulating factors. Theoretically, Amifostine and the colony-stimulating factors should provide complementary benefits to bone marrow recovery and function after cytotoxic therapies. These observations offer the promise of using high doses of chemotherapy to exploit antitumor, dose-response relationships in clinical trials.

The role of hexamethylmelamine in the management of ovarian cancer.

Hexamethylmelamine has been recognized as having useful single-agent activity for the treatment of ovarian cancer for the past 25 years, with some patients surviving disease-free for periods in excess of 12 years. Data from recently analysed and mature trials demonstrate that the addition of hexamethylmelamine to first-line combination chemotherapy results in significant improvements in survival compared to what is achieved with regimens of cisplatin and cyclophosphamide with or without doxorubicin.

New protective agents for bone marrow in cancer therapy.

WR-2721 is a unique bone marrow protective agent which also protects other normal tissues against the toxic effects of radiation therapy and chemotherapy, especially with cisplatin and alkylating agents. In addition to protection against acute toxicities, WR-2721 has also been shown to protect against mutagenesis, cell transformation, and carcinogenesis which might be termed subacute and late toxicities. The protective mechanisms are not fully elucidated but oxygen free radical scavenging certainly plays a role and effects of enzymatic DNA repair mechanisms have also been reported. In the field of reduction of toxicity from anticancer treatment modalities, the properties of CSFs and other substances have been contrasted with WR-2721 the former being stimulators of bone marrow (and the immune system) rather than true protectors. Nonetheless, they also have a clinical role and combinations of a protector and stimulator may prove useful in the future. WR-2721 offers the prospect of increasing the therapeutic index of current cancer treatment and may allow the administration of higher than currently would be considered maximal tolerated doses (MTD). This may, in turn, lead to improved efficacy and the full potential of this agent is now being explored in a variety of randomized, controlled clinical trials.

New sugar mitomycin C analogues: preparation, murine P388 antitumor activity, and leukopenia induction.

Four new sugar:mitomycin C derivatives were synthesized by coupling of N-1 of mitomycin C with tetra-O-acetylglucopyranosyl isothiocyanate and 3,4,6-tri-O-acetyl-2-(N-acetylamino)-2-deoxyglucopyranosyl isothiocyanate. Conversion of each derivative to its water-soluble analogue was achieved by deacetylation, using saturated NH3:CH3OH. Antitumor activity, assessed using the in vivo murine P388 ascitic leukemia system, demonstrated efficacy comparable with the parent mitomycin C. However, unlike the highly myelosuppressive parent drug, optimal antitumor activity is achieved at doses which produce only limited leukopenia.

Murine anti-tumor activity of new water soluble platinum(II) complexes with reduced toxicity.

A series of new water soluble sugar and non-sugar containing platinum(II) complexes was synthesized and evaluated for effects of the sugar moiety on water solubility, anti-tumor activity, and acute leukopenia. When tested in vivo against the murine P388 and L1210 leukemias at LD10/maximally effective doses, the compound cis-[(gluconylamino)malonato-O,O'](1R,2R-cyclohexanediami ne-N,N')platinum (II), R,RG-AMP produced comparable or superior anti-tumor activity to cisplatin, carboplatin, and tetraplatin. Efficacy was also demonstrated for the L1210/DDP (cisplatin-resistant) leukemia. Further, R,R-G-AMP is non-nephrotoxic and produces less leukopenia than cisplatin, carboplatin, and tetraplatin.

A randomized trial comparing adjuvant fluorouracil, doxorubicin, and mitomycin with no treatment in operable gastric cancer. International Collaborative Cancer Group.

Three hundred fifteen patients with operable gastric cancer were randomized to receive fluorouracil, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and mitomycin (FAM) or no adjuvant treatment between September 1981 and July 1984. After excluding ineligible patients, 281 patients are included in this analysis. Treatment was moderately well tolerated by the majority of patients, the common side effects being nausea and vomiting (58%) and alopecia (57%). Three possible treatment-related deaths were seen, all due to cardiac failure. At median follow-up of 68 months, 164 patients have died, 73 in the treated arm and 91 in the control arm. There was no significant difference in disease-free or overall survival between the two arms of the study (P = 0.21). There is some evidence that patients with more advanced carcinoma (T3-T4) derived some benefit from treatment (P = 0.04). The interpretation of this finding must take into account that all subgroups were defined retrospectively, and this could, therefore, be a chance finding. We conclude that adjuvant chemotherapy as given in this trial is not indicated as routine treatment in operable gastric cancer, but that further evaluation in stage T3-T4 patients is warranted.

Phase I study of oral spirogermanium.

Thirty-three patients with advanced malignancy were treated with oral spirogermanium in a Phase I study to determine a maximum tolerated dose. Patients were entered in the study at doses of 100, 200, and 300 milligrams daily. The dose-limiting toxicity was gastrointestinal with moderate nausea and vomiting occurring with the 300 milligram dose. No myelosuppression or renal dysfunction was noted. Elevations of serum transaminase were seen in 41 percent of the patients at study entry. While abnormalities in hepatic function were recorded during the study, the relationship to spirogermanium could not be determined. No patient exhibited clinical hepatic dysfunction or elevation of serum bilirubin. It is recommended that future studies of oral spirogermanium incorporate careful monitoring of these parameters. Two patients with lymphoproliferative disorders had objective responses to therapy. A dose of 200 milligrams is recommended for further Phase II trials.

6-bis-(2-chloroethyl)amino-6-deoxy-D-galactopyranose hydrochloride: synthesis, chemical characterization, murine P388 antitumor activity, and bone marrow toxicity.

6-Bis-(2-chloroethyl)amino-6-deoxy-D-galactopyranose hydrochloride has been synthesized, characterized, and evaluated for antitumor activity and bone marrow toxicity in mice. The 1D- and 2D-NMR studies show the compound to exist as a beta-anomer chair conformation (23%), alpha-anomer chair conformation (22%), and several equilibrating boat conformations or furanose forms (55%). A single ip LD10 dose of 15.0 mg/kg produced antitumor activity against the murine P388 leukemia superior to that achieved with an equitoxic dose of nitrogen mustard. In normal mice, this 15.0-mg/kg dose produced minimal depression of peripheral white blood cells and no significant decrease in absolute neutrophil counts. A reduction in toxicity was also demonstrated for human bone marrow CFU-GM, as compared with nitrogen mustard and L-PAM. This and other sugar-containing mustard compounds may represent a class of antineoplastic alkylating agents with reduced bone marrow toxicity.

Cancer-associated hemolytic-uremic syndrome: analysis of 85 cases from a national registry.

A registry of suspected cases of cancer-associated hemolytic-uremic syndrome (C-HUS) was established in May 1984. Records of 85 patients from the registry, all with history of cancer, hematocrit less than or equal to 25%, platelet count less than 100,000, and serum creatinine greater than or equal to 1.6 mg/dL were subjected to in-depth analysis. Eighty-nine percent of patients had adenocarcinoma, including 26% with gastric cancer. Microangiopathic hemolysis was reported in 83 patients; coagulation studies were normal with rare exception. Bone marrow examination ruled out chemotherapy-induced myelosuppression in 68 of 85. Thirty-five percent of patients were without evident cancer at time of syndrome development. Mitomycin (MMC) was part of the treatment regimen in 84 patients; all but nine received a cumulative dose greater than 60 mg. Pulmonary edema, generally noncardiogenic, developed in 65% of patients, often after blood product transfusions. C-HUS has a high mortality: over 50% of patients died of or with syndrome, most within 8 weeks of syndrome development. Conventional treatment was ineffective, although ten of 21 treated with staphylococcal protein A (SPA) immunopheresis showed significant responses. Statistical analysis found only absence of obvious tumor and treatment with SPA to suggest favorable prognosis. C-HUS is distinguishable from related syndromes such as childhood HUS, thrombotic thrombocytopenic purpura (TTP), consumption coagulopathy, and microangiopathic hemolysis associated with advanced carcinoma. MMC is likely involved in the development of C-HUS; the risk of developing C-HUS after treatment with MMC is between 4% and 15%. However, possible bias in patients referred to the registry and reports of non-MMC C-HUS cases must be remembered. Recommendations include careful monitoring of renal and hematologic function in patients treated with MMC, aggressive nontransfusion in patients with suspected C-HUS, and consideration of treatment with SPA immunopheresis in patients with definite syndrome.

Lack of common haplotype among four family members with late-onset Kaposi's sarcoma.

Kaposi's sarcoma is associated with an increased frequency of HLA-DR5. The hypothesized model of a susceptibility gene in linkage disequilibrium with DR5 may be tested by haplotype analysis in familial Kaposi's sarcoma. Our finding of no common haplotype among afflicted members of a family provides evidence against the hypothesized linkage.

Therapy of advanced gastric carcinoma. The Georgetown-Lombardi Cancer Center experience.

Gastric carcinoma, despite a decreasing incidence in the United States over the past 40 years, is the seventh most common cause of cancer death in this country and remains a significant worldwide problem. The 5-fluorouracil, Adriamycin (doxorubicin), and mitomycin (FAM) chemotherapy regimen, which was initially reported by Georgetown in 1979, has become a standard for advanced gastric carcinoma with response rates in the 40% range. The FAM regimen as well as subsequent trials conducted at Georgetown and our current approach to management of this tumor are discussed. Despite a decade of intensive clinical research, we have not identified a modification or innovation that is superior to the original FAM.

Efficacy of tetrahydrocannabinol in patients refractory to standard antiemetic therapy.

Oral delta-9-tetrahydrocannabinol (THC), 15 mg/m2, was compared to prochlorperazine (PCZ), 10 mg. for the control of cancer chemotherapy-related emesis. Thirty-six patients whose vomiting was refractory to standard antiemetic therapy were entered in this randomized comparative cross-over study. THC decreased nausea and vomiting in 23 of 36 (64%) patients compared to 1 of 36 receiving PCZ. THC efficacy was not dependent on the class of antineoplastic-agent inducing the emetic symptoms, age of patients or type of sensorial change experienced. Using the 15 mg/m2 dose, all patients experienced transient sensorial changes, characterized as a pleasant "high" in 19 or a variable state of dysphoria in 17 cases. This study confirms the usefulness of THC in patients whose chemotherapy-induced nausea and vomiting is refractory to other standard antiemetics. While excellent antiemetic control was achieved at the dosage 15 mg/m2, dysphoria was encountered at this dose level and we recommend that an initial dose of 5 mg/m2 which, if necessary, can be carefully increased to achieve maximum antiemetic benefit.

Elevated DNA topoisomerase II activity in nitrogen mustard-resistant human cells.

A human Burkitt lymphoma cell line, Raji-HN2, made 10-fold more resistant to nitrogen mustard (HN2) than the parental Raji cell line, exhibited the following characteristics when compared to the parental Raji cells: (i) decreased HN2-induced DNA interstrand crosslinking; (ii) increased (3-fold) DNA topoisomerase II [DNA topoisomerase (ATP-hydrolyzing), EC 5.99.1.3] activity; (iii) increased (4- to 11-fold) sensitivity to topoisomerase II inhibitors; (iv) increased (2-fold) glutathione content; and (v) increased (2-fold) cell doubling time. The resistant phenotype was unstable and was maintained by weekly treatment of the cells with HN2. Growing the resistant cells in the absence of HN2 resulted in a time-dependent decrease in both resistance to HN2 and topoisomerase II activity and an increase in DNA interstrand crosslinking induced by HN2. We hypothesize that HN2 resistance is due to enhanced monoadduct repair with resultant decreased DNA crosslinking and that this process is mediated by topoisomerase II.