Negative argininosuccinate synthetase expression in melanoma tumours may predict clinical benefit from arginine-depleting therapy with pegylated arginine deiminase.

BACKGROUND: Arginine-depleting therapy with pegylated arginine deiminase (ADI-PEG20) was reported to have activity in advanced melanoma in early phase I-II trial, and clinical trials are currently underway in other cancers. However, the optimal patient population who benefit from this treatment is unknown. METHODS: Advanced melanoma patients with accessible tumours had biopsy performed before the start of treatment with ADI-PEG20 and at the time of progression or relapse when amenable to determine whether argininosuccinate synthetase (ASS) expression in tumour was predictive of response to ADI-PEG20. RESULTS: Twenty-seven of thirty-eight patients treated had melanoma tumours assessable for ASS staining before treatment. Clinical benefit rate (CBR) and longer time to progression were associated with negative expression of tumour ASS. Only 1 of 10 patients with ASS-positive tumours (ASS+) had stable disease, whereas 4 of 17 (24%) had partial response and 5 had stable disease, when ASS expression was negative (ASS-), giving CBR rates of 52.9 vs 10%, P=0.041. Two responding patients with negative ASS expression before therapy had rebiopsy after tumour progression and the ASS expression became positive. The survival of ASS- patients receiving at least four doses at 320 IU m(-2) was significantly better than the ASS+ group at 26.5 vs 8.5 months, P=0.024. CONCLUSION: ADI-PEG20 is safe and the drug is only efficacious in melanoma patients whose tumour has negative ASS expression. Argininosuccinate synthetase tumour positivity is associated with drug resistance and tumour progression.

Relationship of Metabolic Alterations and PD-L1 Expression in Cisplatin Resistant Lung Cancer.

Despite numerous reports on immune checkpoint inhibitor for the treatment of non-small cell lung cancer (NSCLC), the response rate remains low but durable. Thus cisplatin still plays a major role in the treatment of NSCLC. While there are many mechanisms involved in cisplatin resistance, alteration in metabolic phenotypes with elevated levels of reactive oxygen species (ROS) are found in several cisplatin resistant tumors. These resistant cells become more reliant on mitochondria oxidative metabolism instead of glucose. Consequently, high ROS and metabolic alteration contributed to epithelial-mesenchymal transition (EMT). Importantly, recent findings indicated that EMT has a crucial role in upregulating PD-L1 expression in cancer cells. Thus, it is very likely that cisplatin resistance will lead to high expression of PD-L1/PD-1 which makes them vulnerable to anti PD-1 or anti PD-L1 antibody treatment. An understanding of the interactions between cancer cells metabolic reprogramming and immune checkpoints is critical for combining metabolism targeted therapies with immunotherapies.

Phase I trial of piritrexim capsules using prolonged, low-dose oral administration for the treatment of advanced malignancies.

A phase I trial of piritrexim was conducted by use of a prolonged, low-dose oral schedule. A number of different regimens were tested, including daily dosing for 21 days followed by 7 days of no drug therapy; continuous dosing; and daily dosing for 5 of 7 days for 3 consecutive weeks followed by a week of rest. Dose escalation was accomplished by increasing the dosing frequency from once a day to twice a day and then to three times a day and by increasing the number of days of administration. Fifty-one patients with advanced cancer were entered in the study. One hundred twenty-four (96%) of 129 courses were considered assessable. Myelosuppression proved to be the dose-limiting toxic effect. Other toxic effects included stomatitis, nausea and vomiting, anorexia, diarrhea, skin rash, fatigue, and elevation of liver transaminase levels. Antitumor activity was observed in patients with melanoma and bladder cancer, and disease stabilization occurred in those with sarcoma and pheochromocytoma. The recommended dosing schedule for phase II clinical trials is 25 mg three times a day for 5 days for 3 consecutive weeks followed by 1 week of no drug therapy.

Phase I study of tricyclic nucleoside phosphate using a five-day continuous infusion schedule.

A Phase I trial of tricyclic nucleoside phosphate (1,4,5,6,8-pentaazaacenaphthylene-3-amino-1, 5-dihydro-5-methyl-1-beta-D-ribofuranosyl 5'-phosphate ester; NSC 280594) was conducted using a 5-day continuous infusion schedule. Thirty-seven patients with advanced cancer were entered on the study, of whom 33 patients were evaluable for response and toxicity. Dose levels ranged from 10 mg/sq m/day X 5 days to 40 mg/sq m/day X 5 days. Initially, courses were repeated every 3 to 4 weeks. As cumulative toxicity became manifested, the interval between courses was changed to every 6 weeks. Major toxicities included hyperglycemia, hepatotoxicity, and thrombocytopenia. Patients with a prior history of diabetes mellitus, extensive radiation therapy, or significant liver metastases were prone to severe toxicity. Other toxicities noted were nausea and vomiting, abdominal discomfort, anemia, and reduction in serum calcium, phosphorus, and albumin levels. Rare side effects included hypertriglyceridemia, hyperamylasemia, diarrhea, and stomatitis. Antitumor activity observed include improvement in s.c. metastases in a patient with papillary thyroid carcinoma, stabilization of disease in a patient with mesothelioma, and mixed responses in three patients (colon cancer, sarcoma, and tonsillar squamous cell cancer). Recommended schedule for Phase II studies is 20 mg/sq m/day for 5 days every 6 weeks.

Gas6/Axl is the sensor of arginine-auxotrophic response in targeted chemotherapy with arginine-depleting agents.

Many human malignancies lack de novo biosynthesis of arginine (Arg) as the key enzyme argininosuccinate synthetase 1 (ASS1) is silenced. These tumors acquire ectopic Arg for survival, and depleting this source by Arg-depleting recombinant enzyme ADI-PEG20 results in cell death. Mechanisms underlying Arg auxotrophy in these tumors and how they respond to Arg-auxotrophic stress are poorly understood. Here, we report that an immediate-early event of Arg-auxotrophic response involves reactive oxygen species-mediated secretion of Gas6, which interacts with its receptor Axl and activates the downstream Ras/PI3K/Akt growth signal leading to accumulation of c-Myc by protein stabilization. Arg-auxotrophic challenge also transcriptionally upregulates c-Myc expression, which provides a feedback mechanism to enhance Axl expression. c-Myc is a positive regulator of ASS1, but elevated ASS1 provides a feedback mechanism to suppress c-Myc and Axl. Our results revealed multiple inter-regulatory pathways in Arg-auxotrophic response, consisting of Axl, c-Myc and ASS1, which regulate Arg homeostasis and ADI-PEG20 sensitivity. These pathways provide potential targets for improving the efficacy of treating Arg-auxotrophic tumors using Arg-deprivation strategies.

Phase II trial of piritrexim in metastatic melanoma using intermittent, low-dose administration.

A phase II trial of piritrexim (2,4-diamino-6[2,5-dimethoxybenzyl]-5-methyl pyrido-[2,3d] pyrimidine, 301U74; PTX) was conducted for patients with metastatic malignant melanoma using an intermittent, low-dose oral administration schedule. PTX was administered at a starting dose of 25 mg orally three times per day for 5 days weekly for 3 weeks followed by 1 week of rest. Thirty-one patients were entered onto the study. Among 31 patients assessable for response, there were two complete responses (CRs) and five partial responses (PRs) for a response rate (CR plus PR) of 23% (95% confidence limit, 10% to 42%). Five responses occurred in soft tissue lesions, and two responses occurred in lung lesions. The initial dose schedule was well tolerated. The dose-limiting toxicity was myelosuppression. PTX administered in this schedule appears to be active against malignant melanoma. Further clinical trials to confirm these results are underway.

Autoantibodies against retinal bipolar cells in cutaneous melanoma-associated retinopathy.

PURPOSE: This study's goal was to determine the pathophysiology of the retinopathy that occurs in patients with metastatic cutaneous melanoma and sudden onset of night blindness, the so-called melanoma-associated retinopathy (MAR) syndrome. We tested the hypothesis that sera from two MAR patients contained autoantibodies that reacted with "on" bipolar cells of the human retina. METHODS: Immunofluorescence was performed on cryostat sections of unfixed normal human retinas. Sera and IgG fractions were tested from the two MAR patients and 38 control subjects (28 patients with metastatic melanoma, but no visual symptoms; two patients with non-MAR retinopathy; and eight normal subjects). RESULTS: The sera and IgG fractions from both MAR patients but from none of the control subjects produced heavy immunostaining of bipolar cells, which were identified as rod bipolars by a double labeling procedure using anti-protein kinase C. CONCLUSIONS: We hypothesize that MAR patients generate autoantibodies against a melanoma antigen that cross react with bipolar cells of the retina. These antibodies, by an unknown mechanism, may cause abnormalities of the rod and cone systems that are characteristic of MAR.

Pharmacokinetics of homoharringtonine in dogs.

We studied the pharmacokinetics and distribution of homoharringtonine (HHT), an antitumor alkaloid, in anesthetized dogs using chromatographic and radiochemical techniques. Uniformly tritiated HHT was administered i.v. to five dogs at doses of 0.05 to 0.34 mg/kg, 200 microCi per animal. Unchanged HHT disappeared in a triphasic manner from the plasma with an initial plasma t1/2 of 9.4 +/- 4.2 min, an intermediary t1/2 of 1.4 +/- 0.5 h, and a terminal t1/2 of 40.6 +/- 4.6 h. The plasma clearance was 114.0 +/- 20.1 ml/kg-1 h-1 and the steady-state volume of distribution was 6.2 +/- 0.7 1/kg. In 72 h, 40.1% +/- 4.0% of the administered radioactivity was excreted in the urine, 17.8% +/- 2.7% of which was unchanged HHT. HHT was metabolized extensively to one major and two minor metabolites. Biliary excretion of total radioactivity was 14.4% in 5 h, 2% of which was HHT. HHT concentration in the CSF was highest 4 h after drug administration, about 40% of the concentration in the concurrent plasma. At autopsy 5 h after dosing, the highest percentage of HHT was in the liver (7.4%), followed by the small intestine (2.5%), stomach (1.0%), pancreas (0.8%), kidneys (0.8%), and lungs (0.7%). The heart, spleen, large intestine, and brain each retained less than 0.5%. However, 24 h after dosing, 4% of the HHT still remained in the liver, 1% in the small intestine, and less than 1% in the other organs. HHT seems to be extensively metabolized in dogs and partially retained in the body.

Clinical pharmacology of intracarotid etoposide.

Pharmacokinetics studies were performed in ten patients who received VP-16 by intracarotid infusion at 100-300 mg/m2. VP-16 was analyzed by high-pressure liquid chromatography. ESTRIP and NONLIN were used to characterize VP-16 pharmacokinetics. VP-16 disappeared biphasically, with a t1/2 beta of 6.1 +/- 1.4 h; the total clearance was 26.8 +/- 2.8 ml/min/m2, and the Vss was 8.8 +/- 1.6 l/m2. The pharmacokinetics was not significantly different after administration by the IV route. However, at a lower dosage, less than 140 mg/m2, the half-life appears to be shorter. This may or may not be significant, since VP-16 pharmacokinetics is quite variable and the number of patients studied is relatively small. Overall, the brain and brain tumor do not appear to have any first-pass effect on VP-16 pharmacokinetics.

Clinical pharmacokinetics of 9, 10-anthracenedicarboxaldehyde-bis [(4,5-dihydro-1 H-imidazol-2-yl)hydrazone]dihydrochloride.

We studied the clinical pharmacokinetics of the anthracene derivative bisantrene using high-performance liquid chromatographic analysis. We administered the drug to ten patients at 120-250 mg/m2 IV; one of these patients also received a second dose of 120 mg/m2 6 weeks later, and another received 150 mg/m2 weekly for three doses. Bisantrene disappeared from the plasma biphasically, with an initial t1/2 of 0.6 +/- 0.3 h and a terminal t1/2 of 24.7 +/- 6.9 h after single doses. The apparent volume of distribution according to the area under the curve was 42.1 +/- 5.9 l/kg, and the total clearance was 1045.5 +/- 51.0 ml/kg/h. The 96-h cumulative urinary excretion was 3.4% +/- 1.1% of dose; thus, renal excretion was a minor route of elimination for this agent. Bisantrene pharmacokinetics in the patient who received a second dose after 6 weeks showed insignificant changes. However, in the patient who was given this drug weekly for 3 weeks, the plasma t1/2 of the drug during the terminal phase became increasingly longer, while the total clearance was significantly reduced. These results suggest that bisantrene may accumulate in the body and that caution is essential in the event of frequent administration.

Clinical pharmacology of 4-demethoxydaunorubicin (DMDR).

DMDR, a daunorubicin derivative with a higher therapeutic index and lower cardiotoxicity than either the parent drug or doxorubicin, is active when given PO in experimental animals. We studied its pharmacokinetics in ten patients receiving DMDR IV or PO or IV and PO sequentially at 10-12.5 mg/m2. DMDR and its metabolites were quantified by high-performance liquid chromatography and fluorometry. In nine patients who received DMDR IV the unchanged drug disappeared from the plasma biphasically with a mean terminal half-life of 27.0 +/- 5.5 h, an apparent volume of distribution of 63.9 +/- 12.61 kg-1, and a total clearance of 1.9 +/- 0.41 kg-1 h-1. In 24 h only 5.1% +/- 1.1% of the dose was excreted in the urine. In comparison, in 19 studies the plasma half-life of DMDR given PO was 34.8 +/- 6.7 h, 2.3% +/- 1.3% was excreted in the urine in 24 h, and the maximum plasma drug concentration was reached in about 1 h. The bioavailability of DMDR given PO was about 39% according to comparison of the areas under the plasma DMDR concentration versus time curves for the two routes, but 45% according to comparison of the 24-h cumulative urinary excretion rates. In one patient with severe liver dysfunction following oral administration, the plasma DMDR half-life was 56.8 h, more than twice the average length. By either route, the drug was quickly metabolized to one major metabolite, DMDR-ol. The plasma half-life of DMDR-ol was 72.5 +/- 24.7 h, or 35.7 +/- 7.4 when DMDR was administered IV or PO. In the plasma, DMDR-ol always exceeded DMDR in concentration. Moreover, the 24 h cumulative urinary excretion of DMDR-ol as a percentage of the dose of DMDR administered was 7.8 following IV and 7.4 following PO administration.

Human tissue distribution of 4'-(9-acridinylamino)-methanesulfon-m-anisidide (NSC 141549, AMSA).

Concentrations of AMSA were determined by HPLC in autopsy tissue samples from five patients who had received the drug antemortem. Relative organ concentrations of AMSA varied from patient to patient; however, concentrations were generally highest in gallbladder, liver, and kidney, while low levels were generally but not invariably found in lung, testicle, muscle, fat, spleen, bladder, pancreas, colon, prostate, and brain. One patient with ventricular fibrillation and seizures had high tissue AMSA concentrations in myocardium, but low concentrations in brain. Another patient with seizures during treatment had high brain concentrations of AMSA. Relative organ concentrations were similar to those found in mice, except that mice have high AMSA concentration in their spleens whereas our patients did not, even when the spleen was infiltrated with leukemic cells. High tissue concentrations of AMSA were still present 2 weeks after treatment. AMSA concentration was lower in a renal oncocytoma (1.1 micrograms/g) than in surrounding kidney (2.4 micrograms/g).

Phase II trial of recombinant interferon-alpha with BCNU, cisplatin, DTIC and tamoxifen in advanced malignant melanoma.

Since cytotoxic chemotherapy (BCNU, DTIC and cisplatin, tamoxifen) and interferon-alpha (IFN-alpha) have each produced responses in advanced malignant melanoma, a phase II trial was conducted to evaluate the response and toxicity of simultaneous administration of both therapies. Of 33 assessable patients, two (6%) had complete response (CR) and 12 patients (36%) had partial response (PR), for a total response rate (CR+PR) of 42% (95% confidence interval 26-58). Four patients had minor response (12%). Mixed responses occurred in five patients (15%). The remaining patients had progressive disease. The duration of CR was 3, 7 and 17 (+) months and the duration of PR was 3+ to 19+ months (median 6 months). The median overall survival for all patients entered into the study was 5 months. Main toxicities included myelosuppression and fatigue. Combined simultaneous cytotoxic chemotherapy and IFN produced a high response rate (42%) which is comparable to that reported for chemotherapy alone. Further studies are needed to determine the optimal schedule for combining chemotherapy and immunotherapeutic agents as well as the impact of biological agents on survival in the treatment of melanoma.

Tumor lysis syndrome after induction chemotherapy in small-cell lung carcinoma.

Small-cell lung cancer (SCLC) is responsive to combination chemotherapy. Response rates of 50-80% can be achieved depending on whether the cancer is limited or extensive. Rarely, patients with SCLC respond so rapidly to induction chemotherapy that they develop a tumor lysis syndrome. This syndrome may lead to azotemia and renal failure if not recognized early and treated appropriately. This complication of therapy is important to recognize as the treatment of SCLC is sometimes administered on an outpatient basis. In addition, certain chemotherapeutic agents used in SCLC, such as cis-platin, are nephrotoxic and could potentially aggravate the azotemia secondary to the tumor lysis syndrome.

A phase II trial of tricyclic nucleoside phosphate in patients with advanced squamous cell carcinoma of the cervix. A Gynecologic Oncology Group Study.

A Phase II trial of TCN-P was conducted in metastatic or recurrent squamous cell carcinoma of the cervix using a 5-day continuous infusion schedule. The starting dose was 35 mg/m2 x 5 days and courses were repeated every 6 weeks. Among 21 evaluable patients, 2 responses were observed. One patient had a complete response for 19+ months. Another patient had a partial response for 5+ months, but developed symptomatic hypocalcemia, requiring discontinuation of the drug. Using this dose and schedule TCN-P appears to have limited activity in metastatic or recurrent squamous cell cancer of the cervix.

Successful therapy of peritoneal mesothelioma with intraperitoneal chemotherapy alone. A case report.

Malignant peritoneal mesothelioma is a disease that remains relatively refractory to conventional intravenous chemotherapy with currently available agents. Single-agent and combination chemotherapy offer a response rate of 20%. Direct intraperitoneal administration of some chemotherapeutic agents results in a significant pharmacologic advantage with much greater area under the concentration versus time curve (AUC). We report a case of a patient with peritoneal mesothelioma treated with combination intraperitoneal cisplatin and Ara-C who achieved a pathologic complete remission. This patient is still alive and has been in complete remission for 53 months. This combination of intraperitoneal chemotherapy deserves further evaluation in malignant mesothelioma.

Spinal cord compression produced by osteomyelitis mimicking spinal epidural metastasis.

Spinal cord compression is a common neurological emergency. The causes of spinal cord compression may include primary or (more frequently) metastatic tumor, infections, trauma, and vertebral or intervertebral disc disease. In most instances the underlying etiology is known or easily ascertained. We present here three recent cases in which patients presented with spinal cord compression and lytic bone lesions suggesting metastatic cancer. In these cases, vertebral osteomyelitis was found to be the cause.

Phase II trial of mitoxantrone and cisplatin in advanced non-small-cell lung cancer.

Because in vitro data suggest that mitoxantrone may be synergistic with cisplatin, a Phase II trial of mitoxantrone and cisplatin was conducted in patients with advanced or metastatic non-small-cell lung cancer (NSLC). Twenty-four patients were evaluable for response. Toxicity was tolerable. Partial response occurred in three patients (13%). This response rate is similar to that reported for cisplatin alone in NSLC. Mitoxantrone did not improve the response rate when combined with cisplatin for patients with advanced NSLC.

Carcinoid tumor presenting as central nervous system symptoms. Case report and review of the literature.

Carcinoid tumors are relatively uncommon. They are known for their slow growing behavior and unique symptoms. Patients with carcinoid tumors usually present with signs and symptoms due either to local disease or to the carcinoid syndrome. During the course of these tumors, they tend to metastasize to different sites, including regional lymph nodes, lungs, liver, and bone. They rarely metastasize to the central nervous system (CNS) and very rarely present with signs and symptoms related to CNS metastasis. We report a patient who presented with CNS symptoms and was found to have a pulmonary carcinoid tumor involving the liver and the dura mater. In this article, CNS involvement in carcinoid tumors is discussed, and the literature is reviewed.

Combination chemotherapy and radiotherapy for small-cell carcinoma of the esophagus. A case report of long-term survival and review of the literature.

Small-cell carcinoma of the esophagus is a rare tumor and has received little attention until recent years. It should be differentiated from the far more common poorly differentiated squamous-cell carcinoma of the esophagus, because treatment by surgical resection alone or by radiation therapy results in limited survival of a few months. It is now recognized that esophageal small-cell carcinoma presents with early widespread dissemination and is chemosensitive, similar to primary small-cell carcinoma of the lung. We report on a patient with small-cell carcinoma of the esophagus treated with combination chemotherapy consisting of cyclophosphamide, vincristine, and VP-16 followed by local radiation therapy. Pathologic complete remission was achieved. The patient is currently in remission 22 months after diagnosis, the longest survival reported thus far.