Poly-adeninosinediphosphate-ribose polymerase inhibitors as sensitizers for therapeutic treatments in human tumor and blood mononuclear cells

14024

Background: Poly(ADP-ribose) (PAR) polymerase-1 (PARP-1) is a molecular sensor of DNA breaks that facilitates DNA repair and controls genomic stability. Treatment with single doses of ABT-888, a novel potent PARP-1 inhibitor, reduced PAR levels in peripheral blood mononuclear cells (PBMCs) and tumor biopsies in an on-going Phase-0 trial at the NIH Clinical Center. As a corollary to this study, we investigated whether ABT-888 can act as a sensitizer for radiation therapy and chemotherapy in human cancer cell culture, xenograft tumors and PBMCs to support future combination clinical trials. Methods: Inhibition of PARP-1 by ABT-888 was determined by a quantitative PAR chemiluminescence immunoassay validated for the Phase 0 trial. Since gamma-H2AX (?-H2AX) is a marker of DNA damage, we also developed and validated ?H2AX assays to monitor the effects of PARP-1 inhibition during treatment with Topo I inhibitors and radiation. Human monocytic leukemia (THP-1) and breast carcinoma (MCF-7) cell lines were treated with Topo I inhibitors including indenoisoquinoline, camptothecin and topotecan or irradiated with 0.5 to 10 Gy in the presence of ABT 888. We further evaluated these effects in human blood ex vivo to confirm the observations made in cell culture. Results: We found that ABT-888 inhibited PAR, but did not significantly increase DNA damage. Combination of ABT-888 with a Topo I inhibitor produced over 275% increase of DNA damage in THP-1 leukemia cells compared to indenoisoquinoline alone. ?H2AX foci per cell were 9.5 ± 0.8 in MCF-7 treated with 0.5 Gy/50 nM ABT-888 in comparison to 4.0 ± 0.6 with radiation alone. When whole blood was treated in the presence of ABT-888, camptothecin- induced DNA damage in PBMCs was also increased 2–3 fold, with maximum ?H2AX expression at 2 hours post treatment. Conclusions: We conclude that ABT-888 is a highly potent PARP-1 inhibitor that can enhance the DNA damaging effects of chemotherapy and radiation therapy of human cancer. Funded by NCI Contract N01-CO-12400.

No significant financial relationships to disclose.

Preclinical modeling of a phase 0 clinical trial protocol

14058

Background: The Exploratory IND program initiated at NCI (“Phase 0”) is designed to evaluate the pharmacodynamic effects (PD) of candidate drugs at the molecular level in the clinic. Trials employ patient biopsies and surrogate tissues (e.g. PBMCs) to determine the quantitative effect of the agent on its putative target, after a minimum number of doses. The approach requires repeated biopsy of the tumor, an understanding of the time-effect window, and some knowledge of the dose level likely to cause a measurable drug effect. Methods: Prior to initiating a Phase 0 study of the PARP (PolyAdenosyl-Ribose Polymerase) inhibitor, ABT-888, we developed a pre-clinical model to mirror the clinical protocol. Colo 829 and A375 xenografts in athymic nude [nu/nu (NCr)] mice were examined for time and dose effect on PARP using a validated, quantitative PAR assay. Extracts of entire xenografts, quartered xenografts and 18 gauge needle biopsies were examined for variability of baseline and post-treatment PAR levels. Results were cross-checked with Western analysis for polyADP-Ribose (PAR)-labeled proteins in treated mice. Pharmacokinetics (PK) were modeled using plasma drug levels. Additional studies examined the influence of previous biopsy, contralateral biopsy, vehicle treatment, and general anesthesia on PAR in xenografts. Results: A single dose of ABT-888 produced a significant decrease in intracellular PAR levels that could be measured 2 to 6 hours post-dose. PAR levels and drug effect on PAR levels were not influenced by repeated needle biopsies. Variation across xenografts was random for single and bilateral xenograft animal models in the ABT-888 treated, vehicle- and topotecan-treated control groups. Animal handling and socialization appeared to elevate baseline PAR levels, which could confound analysis of study results. Conclusions: Pre-clinical modeling of a specific Phase 0 clinical protocol for drug effects and biological variability provided valuable insights into the development, refinement, and analysis of the currently-active NCI Phase 0 clinical trial of ABT-888. Animal studies were conducted in an AAALAC approved facility under an approved IACUC protocol. Funded by NCI Contract N01-CO-12400.

No significant financial relationships to disclose.

Phase I trial of bortezomib in combination with topotecan in advanced solid tumor malignancies

12004

Background: Bortezomib (B) and topotecan (T) have been shown in pre-clinical testing to be synergistic. Based on this data we have performed a phase I study to determine the maximally tolerated dose and toxicities (tox) of B and T delivered sequentially. Methods: 24 pts (KPS<ECOG 3) with advanced malignancies were treated with T (2.0, 2.5, 3.0 or 3.5 mg/m2 in sequential cohorts) IV on days 1 and 8 of each three week cycle. B 1.3 mg/m2 iv was administered six hours following T on days 1 and 8, and alone on days 4 and 12. Pts were treated in cohorts of 3, the MTD dose was expanded to include 10 additional pts for PK analysis. There was no limit on prior therapies. DLT was defined as any gr 3 or 4 non-hematologic toxicity not reversible in 48h or any gr 3 thrombocytopenia lasting >7 days or associated with bleeding or any gr 4. Results: Tumor types included: breast (4), ovary (5), lung (3), others (12). 24 pts were entered (11M 13F). The median age was 55 (range: 34–83). DLT was thrombocytopenia, observed in two pts at 3.5 mg/m2 and one pt at 3.0 mg/m2 (MTD). Other grade 3 or 4 tox included fatigue, lymphopenia, hypomagnesemia, and hypertriglyceridemia. Of the 24 enrolled pts, stable disease was observed in 4 (4 or 5 cycles), 9 progressed, 5 were inevaluable and 6 are too early. PK analysis is pending. Conclusions: T and B delivered sequentially are well tolerated on a weekly schedule. DLT is thrombocytopenia. PK will be presented.(Supported by NCI Grant CA33572).

[Table: see text]

Polymorphisms of DNA-repair genes associated with clinical outcome in metastatic breast cancer (MBC) patients treated with gemcitabine/cisplatin (GC) (California Cancer Consortium)

675

Background: DNA repair enzymes may play an important role in determining efficacy of chemotherapy in MBC. In particular, GC combination therapy may be dependent on activity of DNA repair enzymes in host cells, since cisplatin acts by inducing DNA damage. Cancer cells with increased DNA repair capacity may be resistant to GC, and specific genes may be responsible for this increased repair capacity. We examined whether polymorphisms in genes related to DNA repair were associated with clinical outcome in MBC patients treated with GC, enrolled in a parent phase II clinical trial (Ph II-14 A & B). Methods: Fifty-five patients with MBC were evaluated. Patients received the following regimen: 25 mg/m2 cisplatin on days 1–4; 1000 mg/m2 gemcitabine on days 2 and 8 of 21-day cycle. Thirteen polymorphisms in 10 cancer-related genes were tested for association with overall survival, time to tumor progression, and tumor response using a PCR RFLP based assay. Results: Of 55 patients evaluated, there were 17 responders (31%) and 33 non-responders (60%). Five patients (9%) inevaluable for response. Of 33 non-responders, 15 had stable disease, 18 had progressive disease. Median survival: 11.7 months with median follow-up 32.4 months for 4 patients alive at time of analysis. Median progression-free survival: 4.2 months. XPD Lys751Gln polymorphism was associated with overall survival and time to tumor progression (p=0.0003, p=0.006, respectively, log-rank test). Thirty-five patients carried Lys/Lys genotype, of which 29% resopnded. Fourteen patients carried Lys/Gln genotype, of which 54% resopnded. Five patients carried Gln/Gln genotype, with no responders. XRCC3 Thr241Met polymorphism was associated with time to tumor progression and tumor response (p=0.03, p=0.002, respectively). Eighteen patients had Met/Met genotype, of which 47% responded. Twenty-six patients had heterozygous genotype, of which 17% responded. Five patients had homozygous Thr/Thr, of which 100% responded. Conclusions: Our results suggest that polymorphisms in DNA repair genes XPD and XRCC3 may be important markers in predicting clinical outcome in MBC patients treated with GC. Supported by the following NCI grant: N01 CM1701.

[Table: see text]

Phase I trial of the oral histone deacetylase inhibitor MS-275 administered with food

13036

Background: The histone deacetylase (HDAC) inhibitor MS-275, a synthetic benzamide derivative, has demonstrated antitumor activity in vitro & in vivo. After determining maximum tolerable dose (MTD = 2 mg/m2) & dose limiting toxicity (DLT) for MS-275 given to fasting patients (pts) weekly ×4 q6 weeks, we explored toxicity profile, MTD, & pharmacokinetics (PK) of MS-275 when given po on the same schedule with food. Methods: MS-275 at 2, 4, or 6 mg/m2 was administered to pts with advanced malignancy & PS ≤2, LFTs ≤2.5 × normal, adequate hematopoietic & renal function, & normal resting MUGA. PK samples were analyzed by LC-MS. Data for pts in the fed state were compared to data obtained in previous cohorts of pts treated in the fasting state. Protein acetylation assessed by a novel flow cytometric assay & HDAC enzymatic activity were measured in peripheral blood mononuclear cells (PBMC). Results: 16 pts received a median of 2 cycles (1–5) of MS-275 2–6 mg/m2 with food. No DLT occurred on 2 or 6 mg/m2 (n = 3 each), while 1 pt on 4 mg/m2 (n = 10) had a DLT: grade 3 hypophosphatemia. For 2–6 mg/m2 other grade 3 toxicities were neutropenia & lymphopenia. Grade 1–2 toxicities in >1 pt were leucopenia, anemia, thrombocytopenia, fatigue, nausea, vomiting, headache, hypoalbuminemia, hypophosphatemia, hyponatremia, & hypocalcemia. MTD has not been reached; current dose level is 8 mg/m2. Comparing PK for fasting & fed pts on 2–4 mg/m2, there was no difference in Tmax (0.5h); average Cmax & AUC were 35% & 25% lower, respectively, in fed pts; this difference is not statistically significant. Interindividual variability in exposure to MS-275 increased from 52% in fasting pts to 100% in fed pts. PBMC protein acetylation & HDAC inhibition were seen at all dose levels (2–6 mg/m2) in fed pts. Of 9 pts evaluable for response (2–4 mg/m2), 2 of 6 pts on 4 mg/m2 had stable disease. Conclusions: MTD has not yet been established for MS-275 given with food on this schedule but is ≥4 mg/m2 weekly x4 q6 weeks. Interindividual variability in exposure increases with food. Whether intestinal absorption is decreased when MS-275 is given with food requires further evaluation with additional patients. Drug-related protein hyperacetylation & HDAC inhibition were observed.

[Table: see text]

Phase II study of hydroxyurea and gemcitabine in recurrent or persistent squamous cell cancer of the head and neck

15524

Background: Preclinical studies demonstrate increased activity when hydroxyurea (HU) is given prior to gemcitabine (G). Clinical feasibility was demonstrated in a phase I trial (Yen, et. al. Cancer Chemother Pharmacol. 2002 ). We performed a phase II trial treating patients (pts) with squamous cell head and neck cancers (SCCHN). Methods: Pts had metastatic or incurable locally recurrent SCCHN. Prior chemotherapy was allowed, but not required. Serum creatinine ≤2.0 mg/dl, bilirubin <3.0 gm/dl, AST/ALT <5× ULN and KPS ≥60% were required. HU 500 mg orally every 6 hours for 4 doses was given on day 1 of a 21-day cycle. On day 2, 6 hours after HU, G 750 mg/m2 was given over 30 minutes. This sequence was repeated on day 8 and 9. After 8 pts, G was given at 500 mg/m2. G-CSF was given on day 10 and until the WBC count was >10k/μl. The primary endpoint was response rate (RR), with an early stopping rule for <3 objective responders among the first 18 pts. Results: 22 pts (17 M) were accrued, 16 with prior chemotherapy and 19 with prior radiation. The first 8 pts received G 750 mg/m2. Two pts died of neutropenic fever (NF) during course 1. Subsequently 14 pts received G 500 mg/m2. 18 pts were evaluable for response, with 1 still in follow-up. Partial response was seen in 1 pt, stable disease in 9, and progressive disease in 8. The overall median survival of the 22 pts was 6 months and the median progression free survival (PFS) was 2 months. The primary toxicity was hematologic. Grade 4 neutropenia was seen in 7/22 pts during the 1st cycle (5 at G 750 mg/m2) with 5 cases of NF. Grade 4 thrombocytopenia occurred in 1 pt at G 750 mg/m2. Conclusions: The RR and PFS of treated pts treated were not promising and further accrual is not planned. Analysis of biopsy materials is planned to see if responsive pts can be selected. (Supported by NCI Grant CA33572).

No significant financial relationships to disclose.

A phase II study of BAY 43–9006 (Sorafenib) in patients with relapsed non-small cell lung cancer (NSCLC)

17119

Background: Sorafenib is an inhibitor of multiple kinases including Raf-1 (C-Raf), b-Raf and pro-angiogenic tyrosine kinases (VEGFR-2/3 and PDGFR-β) and showed preclinical activity against NSCLC cell lines. Its anti-tumor activity may be attributable to inhibition of proliferative signaling through the RAS/Raf/MEK/ERK pathway and its anti-angiogenic effects. In NSCLC, the proliferation signaling of the Ras/Raf/MEK/ERK pathway is increased due to the increase in K-ras mutations. We initiated a single agent sorafenib trial in patients (pts) with relapsed NSCLC to assess clinical response and translational endpoints in tumor biopsies. Methods: This phase 2 trial uses a two-stage design targeting an objective response rate (RR) which can rule out 5% in favor of a more desirable 20% RR. Eligibility criteria: Pts with recurrent NSCLC with measurable disease who have received only one prior chemotherapy regimen, ECOG 0–1. Pts receive Sorafenib 400 mg bid continuously on 28-day cycle. Responses were evaluated every 8 weeks (wks) according to RECIST criteria. Dynamic contrast enhanced MRI (DCE-MRI) and tumor biopsy are performed before cycle 1 and at C1D15 to study early changes in tumor vascularity and translational endpoints. Results: 6 pts are evaluable for toxicity and 5 pts are evaluable for response. Best Response: 1PR (41% tumor reduction at wk 8, remained in PR until wk 28), 1 PR (unconfirmed) at wk 3, 2SD (16 and 19 wks respectively) and 1PD after 8 wks of treatment. Skin toxicity: Acne like drug-related rash (5 pts), hand-foot syndrome (6 pts), keratoacanthoma (1pt) and vasculitis (1pt). All skin toxicities are G1 or G2 and have responded to temporary withdrawal of Sorafenib and supportive care. Hypertension occurred in 1 pt (G2). No G4 toxicities have been observed. G3 toxicities include: anemia (1 pt), hyponatremia (2 pts), and nausea (1 pt). DCE-MRI results: 1 pt on C1D15 showed decrease in permibility parameters (ktrans and kep) and tumor size. DCE-MRI from the other 2 pts (1 PD, 1 SD for 16 weeks) showed no decrease in the permeability parameters. Conclusions: Sorafenib appears to be well-tolerated and active against relapsed NSCLC. Preliminary evidence of objective response warranting second stage accrual.

No significant financial relationships to disclose.

High-dose toremifene as a cisplatin modulator in metastatic non-small cell lung cancer: targeted plasma levels are achievable clinically

PURPOSE

The triphenylethylenes tamoxifen and toremifene have been reported to enhance the cytotoxicity of cisplatin by inhibition of protein kinase C (PKC) signal transduction pathways. However, the concentrations of tamoxifen and toremifene required for chemosensitization in preclinical models are generally > or =5 microM, at least tenfold higher than plasma levels observed in patients receiving these agents as antiestrogenic therapy. As part of a translational phase II trial investigating the efficacy and potential molecular mechanism of high-dose toremifene as a cisplatin modulator in metastatic non-small-cell lung cancer, plasma concentrations of toremifene and its active metabolite N-desmethyltoremifene were measured to determine whether targeted levels could be achieved clinically.

METHODS

Treatment consisted of toremifene, 600 mg orally on days 1-7, and cisplatin, 50 mg/m2 intravenously on days 4 and 11, repeated every 28 days. Toremifene and N-desmethyltoremifene were measured by reverse-phase HPLC assay on days 4 and 11 prior to cisplatin infusion.

RESULTS

In the initial 14 patients, the mean total plasma concentrations of toremifene plus its N-desmethyl metabolite on days 4 and 11 were 14.04 (+/- 8.6) microM and 9.8 (+/- 4.4) microM, respectively. Variability in concentrations achieved did not correlate with renal or hepatic function, gender, or body surface area. Levels of N-desmethyltoremifene were higher on day 11 relative to toremifene concentrations.

CONCLUSIONS

We conclude that plasma levels achieved compare favorably with the levels required for cisplatin chemosensitization and PKC modulation in vitro. Targeted toremifene levels can be achieved clinically with 600 mg orally daily in combination with cisplatin and are well tolerated.

Twice-weekly paclitaxel and weekly carboplatin with concurrent thoracic radiation followed by carboplatin/paclitaxel consolidation for stage III non-small-cell lung cancer: a California Cancer Consortium phase II trial

PURPOSE

Recent studies have suggested the superiority of concurrent chemoradiotherapy and the efficacy of paclitaxel/carboplatin in advanced non-small-cell lung cancer (NSCLC). In view of those results, we sought to examine the safety and efficacy of administration of radiosensitizing paclitaxel twice weekly and carboplatin weekly with concurrent thoracic radiation therapy (XRT) followed by consolidation paclitaxel and carboplatin for stage III NSCLC in a multi-institutional phase II trial.

PATIENTS AND METHODS

Induction chemoradiotherapy consisted of paclitaxel 30 mg/m2 delivered intravenously (IV) for 1 hour twice weekly for 6 weeks, carboplatin at a dose based on an area under the concentration-time curve (AUC) of 1.5 mg/mL x min, given IV once weekly for 6 weeks, and concomitant XRT of 1.8 to 2.0 Gy daily for a total of 61 Gy. Patients who achieved a complete response, partial response, or stable disease received two 21-day cycles of consolidation chemotherapy consisting of paclitaxel 200 mg/m2 IV for 3 hours and carboplatin at a dose based on an AUC of 6 mg/mL x min.

RESULTS

Thirty-four patients were eligible. Their median age was 62 years (range, 39 to 73 years), 59% were female, 41% were male, 94% had a performance status of 0 or 1, 38% had stage IIIA NSCLC, and 62% had stage IIIB NSCLC. Common grade III and IV toxicities during the induction chemoradiation phase included esophagitis (38%) and neutropenia (12%). The most common adverse reaction during consolidation chemotherapy was grade III neutropenia in five patients (15%). The overall response rate was 71%, which was achieved in the induction phase. The median follow-up was 20 months, the median survival was 17 months, and 2-year actuarial survival rate was 40% (95% confidence interval, 20% to 65%).

CONCLUSION

This regimen is tolerable and results are promising. We recommend further evaluation of this regimen in a phase III trial.

Concurrent twice-weekly paclitaxel and thoracic irradiation for stage III non-small cell lung cancer

Concurrent twice-weekly paclitaxel and thoracic radiation (XRT) for stage III non-small cell lung cancer were studied in a phase I trial. Radiation was delivered in fractions of 1.8 to 2.0 Gy/d to a total dose of 61 Gy. Paclitaxel, at a starting dose of 25 mg/m2/d, was administered intravenously over 1 hour before daily XRT on Mondays and Thursdays for 6 weeks for a total of 12 doses. The paclitaxel dose was escalated by 5 mg/m2/d for each cohort of patients to determine the maximum tolerated dose. The highest dose of paclitaxel reached was 40 mg/m2, which resulted in dose-limiting toxicities of esophagitis and local skin desquamation. For each dose group, the median total number of paclitaxel doses administered was 12 and the median total XRT dose delivered was 61 Gy. The overall response rate was 80%. The overall median survival was 20 months and the 3-year survival rate was 20%. We conclude that the maximum tolerated dose of paclitaxel is 35 mg/m2 given twice weekly for 6 weeks concurrently with XRT. This study provides the basis for using paclitaxel, given twice weekly at 30 mg/m2, with weekly carboplatin and concurrent XRT for stage III non-small cell lung cancer in an ongoing phase II trial.

Phase II trial of pyrazine diazohydroxide in androgen-independent prostate cancer

No effective therapy has been demonstrated for hormone refractory prostate cancer (HRPC). Pyrazine diazohydroxide (PZDH) is a novel antineoplastic agent with a broad range of activity in preclinical studies and a moderate toxicity profile in Phase I trials. We undertook a Phase II study of PZDH in HRPC utilizing decline in PSA as the primary end point. Fifteen patients were enrolled, median age of 70 (55-86), median pretherapy PSA 206 ng/ml (range 42-10,000). Four patients were African American. Sites of disease: bone only 7, soft tissue only 2, both 6. All were evaluable for toxicity and response. PZDH was administered at 250 mg/m2 i.v. every three weeks. The median number of cycles administered was two (range 1-6). Toxicity was mild, with only one patient manifesting serious (grade 3-4) toxicity. Unfortunately, activity was minimal with only a single patient demonstrating a >75% decline in PSA. As this patient's PSA began to rise almost immediately the response was considered transient and not felt to justify pursuing a second stage of the trial. Supporting this conclusion was the disappointing median survival of 220 days. In summary, we conclude that PZDH, while well tolerated at this dose and schedule has only minimal activity in HRPC.

Twice-weekly paclitaxel and radiation for stage III non-small cell lung cancer

A phase I study was conducted to investigate the safety and efficacy of twice-weekly paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) and concurrent thoracic irradiation in patients with stage III non-small cell lung cancer. Radiation therapy beginning on day 1 was delivered in 1.8- to 2.0-Gy daily fractions, to a total dose of 61 Gy. Paclitaxel at a starting dose of 25 mg/m2/d was administered intravenously over 1 hour before daily radiation on days 1, 4, 8, 11, 15, 18, 22, 25, 29, 32, 36, and 39, for a total of 12 doses over 6 weeks. The paclitaxel dose was escalated by 5 mg/m2/d in each cohort of patients to determine the maximum tolerated dose. The highest paclitaxel dose reached was 40 mg/m2/d, as defined by dose-limiting toxicities of esophagitis and desquamation within the radiation fields. For each dose group, the median total number of paclitaxel doses administered was 12 and the median total radiation dose was 61 Gy. Response rates ranging from 50% to 100% were observed (three of six patients at paclitaxel 25 mg/m2, four of six at 30 mg/m2, seven of seven at 35 mg/m2, six of six at 40 mg/m2), for an overall response rate of 80%. We conclude that the maximum tolerated dose of paclitaxel is 35 mg/m2 given twice weekly in a 1-hour infusion for 6 weeks concurrently with thoracic irradiation. This study provides the basis for an ongoing trial combining twice-weekly paclitaxel and carboplatin with concurrent thoracic irradiation for patients with stage III non-small cell lung cancer.

Outpatient subcutaneous interleukin-2 and interferon-alpha for metastatic renal cell cancer: five-year follow-up of the Cytokine Working Group Study

PURPOSE

A phase II trial of outpatient subcutaneous (SC) interleukin-2 (rIL-2) plus interferon-alpha (IFN-alpha 2B) was performed in patients with metastatic renal cell cancer. A 5-year follow-up of that Cytokine Working Group study is presented.

PATIENTS AND METHODS

Forty-seven patients meeting eligibility criteria of previous Cytokine Working Group studies were treated on an outpatient basis with SC rIL-2 (Chiron, Emeryville, CA), 5 x 10(6) IU/m2/dose q 8 hr x 3, then daily, 5 days per week, and IFN-alpha 2B (Schering-Plough, Kenilworth, NJ), 5 x 10(6) IU/m2/dose three times weekly for 4 weeks. After a 2- to 4-week break, patients were scheduled to continue treatment for up to six cycles.

RESULTS

There were two complete and six partial responders (17% response rate, 95% CI: 8%-31%). Median duration of response was 12 months (range 1-49+ months), with complete responses of 15 and 49+ months. Responding sites of disease included lung, nodes, soft tissue, bone, and liver. Dose and schedule were adjusted to control toxicity at grade 2/3 levels, with 50% requiring dosage alterations. Grade 2/3 toxicity included fatigue, nausea/vomiting, diarrhea, anorexia, fluid overload, rash, CNS, injection site pain, chest pain/palpitations (including atrial fibrillation requiring treatment, two patients), and hypotension. Grade 4 toxicity included dehydration (seven patients), vomiting (one patient), and irreversible renal failure with crescentic glomerulonephritis requiring dialysis (one patient).

CONCLUSION

SC rIL-2 plus IFN-a2B is tolerated in the outpatient setting with frequent dose adjustments. The overall response rate of this regimen is similar to that seen with high-dose rIL-2 alone; however, the response duration appears to be shorter.

Prospective randomized trial of lisofylline for the prevention of toxicities of high-dose interleukin 2 therapy in advanced renal cancer and malignant melanoma

The therapeutic application of high-dose interleukin (IL) 2 in human malignancy is limited by severe multiorgan toxicities that are mediated, in part, by tumor necrosis factor (TNF) and IL-1. CT1501R (lisofylline; LSF) is one of several methyl xanthine congeners that inhibit the effects of TNF by the interruption of specific signal transduction pathways. This randomized, placebo-controlled trial was designed to assess the activity of LSF in reducing the toxicities of high-dose IL-2 therapy. Fifty-three patients with metastatic renal cancer or malignant melanoma were treated with i.v. bolus IL-2, 600, 000 IU/kg every 8 h for 5 days (14 doses), followed by 9 days of rest and another 5-day course of IL-2. Patients were randomly assigned to LSF, 1.5 mg/kg i.v. bolus, or placebo every 6 h during IL-2 therapy. All patients were to be treated to individual maximum tolerance of IL-2 at the intensive care unit level of support. The end points for statistical analysis were the number of IL-2 doses administered during the first cycle of treatment (maximum, 28) and the toxicities experienced by each group after the first 8 planned IL-2 doses. There was no difference between the LSF and placebo groups in the mean number of IL-2 doses tolerated in the entire first cycle of therapy (19.6 +/- 5.4 versus 19.5 +/- 5.8, P = 0.86) or in the first or second 5-day course of IL-2. The only significant difference in toxicities occurring through the eighth dose of IL-2 was in the maximum elevation of serum creatinine (mean, 1.7 +/- 0.8 for placebo versus 1.5 +/- 0.6 mg/dl for LSF, P = 0.013). A Monte Carlo analysis of major toxicities over the first 14-dose course of therapy showed a statistically significant difference favoring the LSF-treated group (P = 0.025). LSF was well tolerated, associated only with mildly increased nausea (P = 0.006 after eight IL-2 doses, but not significant for the entire first cycle). The antitumor activity was comparable in both groups (objective responses, 2 of 28 with LSF versus 4 of 24 with placebo). The mean peak plasma concentrations of LSF on days 1, 5, and 19 were 6.24, 3.83, and 5.04 micromol/liter, respectively. In conclusion, with this dose and schedule, LSF did not alter the toxicities of high-dose i.v. IL-2 sufficiently to impact the overall dose intensity of IL-2. Successful IL-2 toxicity modulation may require the use of higher doses of LSF, the development of agents with more potent anti-TNF activity, and/or combined modulating agents that function via distinct mechanisms to interrupt cytokine-mediated signaling.

NCCN Colorectal Cancer Practice Guidelines. The National Comprehensive Cancer Network

In summary, the committee believes that a multidisciplinary approach is necessary for the management of the patient with colorectal cancer. The committee endorses the concept that treatment of patients on a clinical trial has priority over standard or accepted therapy. The recommended surgical procedure for managing resectable colon cancer is an en bloc resection; laparoscopic surgery should be done only in the context of a clinical trial. For patients with stage III disease, 5-FU-based adjuvant chemotherapy is recommended. A patient who has metastatic disease in the liver or lung should be considered for surgical resection if he or she is a candidate for surgery and if surgery can extend survival. The committee advocates a conservative post-treatment surveillance program for colon and rectal cancer patients. A determination of CEA should be done only if CEA was elevated at baseline and decreased following primary resection. Abdominal and pelvic CT scans should be utilized only when there are clinical indications of possible recurrence. Patients whose disease progresses during 5-FU-based therapy should be considered for treatment with irinotecan or encouraged to participate in a phase I or II clinical trial.

Protection against daunorubicin cytotoxicity by expression of a cloned human carbonyl reductase cDNA in K562 leukemia cells

Carbonyl reductase (CBR) catalyzes the reduction of daunorubicin (DN) to its corresponding alcohol, daunorubicinol (DNOL), and changes the pharmacological properties of this cancer chemotherapeutic drug. The DN reductase associated with CBR reduces the C13 methyl ketone group and does not metabolize the quinone ring of DN. Reports comparing DN and DNOL toxicity have resulted in various conclusions depending on the cells tested. Differences in toxicity could be due to variations in several enzymes involved in DN metabolism. In this report, the effects of CBR expression on DN metabolism and cell toxicity were determined by cloning and expressing a human CBR cDNA in DN reductase-deficient myeloid erythroleukemia K562 cells. CBR activity increased 83-fold in the K562-transfected cells and was associated with a 2-3-fold reduction in DN toxicity. Maximum protection occurred at 30 nM DN where 94% of the intracellular DN was converted to DNOL within 2 h. The reduced toxicity was specific for DN. Other CBR substrates such as menadione, phenanthrenequinone, and doxorubicin were equally toxic to both the CBR expresser cells and the control cells under the conditions tested. Our results suggest that high levels of CBR in tumor cells could contribute to drug resistance. The results also suggest that reduction of DN to DNOL protects against DN toxicity by altering interaction of the drug at one or more of the many target sites.

5-Fluorouracil and high-dose calcium leucovorin for hepatocellular carcinoma: a phase II trial

A phase II trial of 5-fluorouracil (5-FU) [250-450 mg/m2/day x 5 days as an intravenous (IV) bolus] combined with calcium leucovorin (500 mg/m2/day x 5 1/2 days by continuous IV infusion) administered on a 28-day schedule was performed in 15 patients with advanced hepatocellular carcinoma. The median age was 58 years; performance status ranged from 50 to 100%. Of 15 evaluable patients, 1 (7%) had a partial response lasting 2.4 months; 8 (53%) had stable disease with a median duration of 5.7 months; and 6 (40%) had progressive disease with a median time to progression of 2.7 months. Median survival was 3.8 months. Treatment with 5-FU and calcium leucovorin was moderately well tolerated; 9% of the treatment courses were complicated by grade 3 or 4 hematological toxicity, and 10% of the courses were complicated by grade 3 or 4 gastrointestinal toxicity. Despite the efficacy of the combination of 5-FU and leucovorin in advanced colorectal cancer, our results document the general resistance of hepatocellular carcinoma to modulated 5-FU.

Phase IB clinical trial of anti-CD3 followed by high-dose bolus interleukin-2 in patients with metastatic melanoma and advanced renal cell carcinoma: clinical and immunologic effects

PURPOSE

To determine the maximum-tolerated dose (MTD) of an anti-CD3 antibody, OKT3, in combination with high-dose interleukin-2 (IL-2), and to determine whether OKT3 can enhance the expansion of CD3+, CD25+ (IL-2 receptor alpha [IL-2R alpha])-expressing T cells in the peripheral blood of patients with advanced melanoma and renal cell carcinoma receiving high-dose IL-2.

PATIENTS AND METHODS

We performed a phase IB trial of a murine monoclonal anti-CD3 antibody (OKT3) with high-dose IL-2 in patients with advanced melanoma and renal cell carcinoma. Fifty-four patients were enrolled, with cohorts of 10 or more patients receiving escalating doses of OKT3 at 75, 200, 400, and 600 micrograms/m2 on day 1 followed by IL-2 at an initial dose 0.45 and then 1.33 mg/m2 every 8 hours on days 2 through 6 and 16 through 20 (maximum, 28 doses). An additional cohort of 14 patients received high-dose IL-2 (1.33 mg/m2 per dose) alone. Circulating CD3+, CD25+ cells were monitored before therapy and following the initial week of IL-2.

RESULTS

A total of 68 patients were enrolled. The MTD for OKT3 was defined as 400 micrograms/m2 based on a reduction in the number of IL-2 doses that could be administered. Increases in CD3+, CD25+ cells were observed within all cohorts; however, the increase was not OKT3 dose-dependent. On the other hand, we found that 60% (nine of 15) of patients tested at OKT3 dose levels of 200, 400, and 600 micrograms/m2 had increases in serum sCD25 (soluble IL-2R alpha) to more than 100,000 U/mL, while none of 10 patients who received IL-2 alone or with OKT3 at the 75-micrograms dose had increases greater than 60,000 U/mL. Of 29 patients with renal cell carcinoma who received OKT3 with IL-2 (1.33 mg/m2), there were three objective tumor responses (all partial responses). In the 16 patients with melanoma who received OKT3 plus IL-2, there was a single objective response (complete response).

CONCLUSION

The doses of OKT3 administered on this schedule failed to enhance significantly the number of circulating CD3+, CD25+ T cells and did not appear to increase the antitumor activity of IL-2 alone, which underscores the need for other approaches to enhance the efficacy of IL-2 therapy.

Multicenter phase II trial of brequinar sodium in patients with advanced squamous-cell carcinoma of the head and neck

A total of 19 patients with advanced squamous-cell carcinoma of the head and neck who had not previously been exposed to chemotherapy were treated with brequinar sodium as first-line chemotherapy. Brequinar was given intravenously at a median weekly dose of 1,200 mg/m2. The toxicity was moderate, with 7 patients (37%) experiencing grade 3 or 4 toxicity. In all, 16 patients who were evaluable for efficacy showed no objective response. We conclude that brequinar given at this dose and on this schedule has no significant activity in advanced squamous-cell carcinoma of the head and neck.

Genomic sequence and expression of a cloned human carbonyl reductase gene with daunorubicin reductase activity

Carbonyl reductase (NADPH: secondary-alcohol oxidoreductase; EC 1.1.1.184), a widely distributed NADPH-dependent enzyme considered as both an aldo-keto reductase and a quinone reductase, was cloned from a human liver genomic library and transiently expressed in COS7 cells. The gene contains 3142 bases comprising three exons and two introns. The absence of a CAAT and TATA box and the presence of a GC-rich island are characteristic of many "housekeeping" genes. Transient expression of the genomic gene in COS7 cells using an expression vector containing an SV40 origin of replication resulted in a greater than 50-fold increase in both menadione reductase activity and daunorubicin reductase activity, suggesting that both activities are derived from the same enzyme. Carbonyl reductase mRNA levels reflected enzyme activity levels in the transfected cells. Other parameters, such as pH profile, cofactor requirements, substrates, and inhibitors, were similar to those of carbonyl reductase purified by other investigators. Potential regulatory elements with consensus sequences for two GC boxes and the transcriptional activator protein AP-2 were present upstream of the transcriptional start site. Although the precise role of carbonyl reductase is unknown, the enzyme is involved in drug metabolism and in the reduction of activated carbonyl compounds. Its ability to act as a quinone reductase also implies a potential to modulate oxygen free radicals.

Phase II study of 4'-deoxydoxorubicin (esorubicin) in advanced or metastatic adenocarcinoma of the stomach

4'-deoxydoxorubicin (DxDx) was administered to 17 patients with locally advanced or metastatic gastric adenocarcinoma. Treatment cycles were repeated every 21 days. 15 eligible patients with a Karnofsky performance status of 50% or better (median: 70%) received at least one course of treatment; a median of 2 courses of DxDx was delivered (range 1 to 13). The median dose per treatment course was 26 mg/m2 (range 8.5 mg/m2 to 53 mg/m2). 69% of patients required dose reduction following the first course of therapy due to grade 3 or 4 myelosuppression, primarily neutropenia. The principal side effects included anemia, mild gastrointestinal toxicities, and alopecia; one patient experienced a 10% decrease in cardiac ejection fraction without clinical cardiac toxicity. Of the 15 patients assessable for response and toxicities, 1 patient had a partial response lasting 2.5 months. The median survival from the time of the first treatment was 3.3 months. We conclude that DxDx has only limited activity in the treatment of advanced gastric adenocarcinoma.

3-Deazaguanine: report of a phase I trial and drug-related cardiac toxicity

3-Deazaguanine (Dezaguanine), a purine antimetabolite, was evaluated in a phase I trial in 42 patients with advanced solid tumors. Dezaguanine was given as a weekly intravenous infusion for three consecutive weeks of a four-week cycle. The dose ranged from 30 to 2000 mg/m2; no consistent dose-limiting hematologic or gastrointestinal toxicity was observed. Some patients reported brief episodes of burning at the infusion site or transient facial flushing immediately following the administration of dezaguanine. Three patients experienced cardiac toxicity. Two patients, at doses of 1130 and 2000 mg/m2 respectively, developed congestive heart failure. In one case the heart failure was fatal; the second patient recovered within 8 weeks. The third patient had a progressive fall in left ventricular ejection fraction but did not develop clinical evidence of heart failure before his death from progressive cancer two months later. Postmortem cardiac pathology in the two patients who died early following therapy revealed nonspecific interstitial fibrosis without inflammatory cell infiltrates. The myocardium of the third patient, who died 20 months after receiving dezaguanine, was normal. Electron microscopic analysis of myocardium from the first patient did not show myofibrillar loss or mitochondrial disorganization characteristic of anthracycline cardiomyopathy. Due to the probable cardiotoxicity of dezaguanine in this study and the lack of objective antitumor response, further development of this agent has been discontinued.

Rat liver NAD(P)H:quinone oxidoreductase: cDNA expression and site-directed mutagenesis

Rat liver NAD(P)H:quinone oxidoreductase cDNA was cloned and expressed in a eukaryotic cell expression plasmid containing a cytomegalovirus (CMV) promoter. Transient expression of enzyme activity and RNA transcription were measured in COS7 cells. The expressed quinone reductase has kinetic properties similar to the rat liver enzyme and is inhibited by dicourmarol, a known inhibitor of NAD(P)H:quinone oxidoreductase. Site-directed mutagenesis experiments carried out using this expression system revealed possible regions involved in NAD(P)H binding.

Induction of a human carbonyl reductase gene located on chromosome 21

Carbonyl reductase (EC 1.1.1.184) belongs to the group of enzymes called aldo-keto reductases. It is a NADPH-dependent cytosolic protein with specificity for many carbonyl compounds including the antitumor anthracycline antibiotics, daunorubicin and doxorubicin. Human carbonyl reductase was cloned from a breast cancer cell line (MCF-7). The cDNA clone contained 1219 base paires with an open reading frame corresponding to 277 amino acids encoding a protein of Mr 30,375. Southern analysis of genomic DNA digested with several restriction enzymes and analyzed by hybridization with a labeled cDNA probe indicated that carbonyl reductase is probably coded by a single gene and does not belong to a family of structurally similar enzymes. Southern analysis of 17 mouse/human somatic cell hybrids showed that carbonyl reductase is located on chromosome 21. Carbonyl reductase mRNA could be induced 3-4-fold in 24 h with 10 microM 2,(3)-t-butyl-4-hydroxyanisole (BHA), beta-naphthoflavone or Sudan 1.

Treatment of metastatic malignant melanoma with trimetrexate: a phase II study

Trimetrexate glucuronate, a nonclassical antifolate, was administered to 14 patients with recurrent and progressive metastatic malignant melanoma. Thirteen patients were evaluable for response and toxicity. Five patients had received prior treatment consisting of immunotherapy (one patient), immunotherapy plus radiotherapy (one patient), radiotherapy (one patient), chemotherapy (one patient), or radiotherapy and chemotherapy (one patient). The starting dose of trimetrexate was 8 mg/m2 given as an intravenous bolus daily for 5 consecutive days of a 21-day cycle. Subsequent cycles of therapy were escalated by 25% based on individual patient tolerance. A median of two courses of trimetrexate was administered (range 1-4). No patient demonstrated a measurable objective response to this treatment regimen. Trimetrexate was well-tolerated; toxicity was mild and consisted primarily of myelosuppression or nausea and vomiting. At the dose level and schedule used in this study, trimetrexate was not effective for the treatment of disseminated malignant melanoma.

Combination chemotherapy with cytosine arabinoside (Ara-C) and cis-diamminedichloroplatinum (CDDP) for squamous cancers of the upper aerodigestive tract

Based on the demonstration of in vitro and in vivo synergy between cytosine arabinoside (Ara-C) and cis-diamminedichloroplatinum (CDDP), we designed a Phase II trial of Ara-C plus CDDP for patients with advanced squamous cancers of the head and neck and esophagus. Sixteen patients were treated on a unique schedule of continuous-infusion Ara-C, 30 mg/m2/day over 72 h, plus CDDP, 30 mg/m2/day at hours 12, 36, and 60 of the Ara-C infusion. The objective response rate was 38% (95% confidence limits 14-62%), with two patients achieving complete clinical and radiographic response (9 and 27+ months duration) and four partial responses (median duration 4 months, range 1-7 months). There was no CDDP-related nephro- or neurotoxicities, but a flu-like syndrome of anorexia and asthenia was common. Myelosuppression was the dose-limiting toxicity, necessitating Ara-C dose adjustments in 11 cycles of therapy and leading to fatal sepsis in one patient. We conclude that the activity of this combination, though comparable to that of other CDDP-containing regimens, offers no significant therapeutic advantage, and given the excessive hematologic toxicity, should not be investigated further.

Cisplatin dose intensity in non-small cell lung cancer: phase II results of a day 1 and day 8 high-dose regimen

Between October 1985 and March 1987, 92 patients were registered on a phase II study of the Northern California Oncology Group investigating the importance of dose intensity in the treatment of advanced non-small cell lung cancer (NSCLC). Treatment consisted of high-dose cisplatin in hypertonic saline (200 mg/m2 on a 28-day cycle) given in a divided day 1 and day 8 schedule. The response rate among 76 assessable patients was 36% (27/76), with complete response (CR) in 8% (6/76) and partial response (PR) in 28% (21/76). If all patients receiving any drug therapy were considered, the overall response rate was 31% (27/87), with CR in 7% (6/87) and PR in 24% (21/87). Median survival times for all assessable patients and all patients receiving any therapy were 37 and 35 weeks, respectively. With the use of a protocol design specifying dose delays rather than dose reduction for toxicity, the mean dose intensity delivered was 47.2 mg/m2 per week, or 94% of projected. Compared with other dose-intensive regimens of cisplatin, this day 1 and day 8 schedule was relatively well tolerated, with peripheral neuropathy as the dose-limiting toxicity. The data on response and median survival times among patients receiving this single-agent therapy are encouraging. They support the potential importance of cisplatin dose intensity in the treatment of NSCLC. Whether these results represent a positive dose-response effect in NSCLC will be tested in a randomized comparative trial of high-dose versus standard-dose cisplatin therapy.

A prospective randomized trial of alpha 2B-interferon/gamma-interferon or the combination in advanced metastatic renal cell carcinoma

Eighty-nine patients with advanced measurable metastatic renal cell carcinoma were entered into a prospective randomized trial comparing alpha-interferon to gamma-interferon and to the combination. The trial was performed in order to confirm the activity of gamma-interferon and assess the potential clinical synergism. Response rates were 5, 10, and 5%, respectively. The low response rate may have been due to the inability to raise the doses of the interferons to higher levels. Clinical synergy at this dose, route, and schedule of administration in renal cell carcinoma does not exist.

Etoposide (VP-16) and cytosine arabinoside in the treatment of relapsed small-cell lung cancer

Seventeen patients with small-cell lung cancer refractory to combination chemotherapy were entered in a study of VP-16 and infusional Ara-C. All patients were evaluable for response and 14 were evaluable for toxicity (three deaths that occurred after the first cycle of therapy were due to progressive tumor, and toxicity could not be evaluated in these three patients). Ara-C was given as a continuous intravenous infusion of 45 mg/m2/day for 72 h; VP-16 was given as three daily intravenous bolus doses of 50 mg/m2 at hours 12, 36, and 50 of the 72-h Ara-C infusion. Because of excessive myelotoxicity in the first six patients, the last 11 patients began treatment at a lower dose of Ara-C, 25 mg/m2/day. Six of 17 patients had previously been exposed to VP-16 as part of their initial chemotherapy regimen. The 17 patients received 32 cycles of therapy. Myelotoxicity was severe, with nadir granulocyte counts less than 500/microliters or platelet counts less than 30,000/microliters in four treatment cycles (including two at the lower Ara-C dose). No patient experienced an objective response to this therapy. We conclude that the combination of VP-16 and infusional Ara-C at these doses is excessively toxic and does not warrant further investigation in refractory small-cell lung cancer.

Renal, volume, and hormonal changes during therapeutic administration of recombinant interleukin-2 in man

Changes in blood pressure, renal function, and fluid balance were studied in 12 patients receiving intravenous recombinant interleukin-2 (IL-2) (100,000 units/kg every eight hours) over five days for treatment of metastatic melanoma and renal and colorectal cancers. The IL-2 regimen produced progressive hypotension, azotemia, and sodium avidity (fractional excretion of sodium = 0.20 +/- 0.07 percent) despite massive fluid administration (mean: 18.4 liter per five days) and weight gain (mean: 4.0 kg). Plasma renin activity rose. Hypoalbuminemia developed rapidly (3.6 +/- 0.1 g/dl to 2.2 +/- 0.1 g/dl, p less than 0.01) with widespread edema formation despite normal central venous pressures. Hematocrit did not change during the IL-2 period, consistent with a "capillary-leak." Hemodynamic and renal functional changes reversed after the IL-2 regimen was discontinued, but hypoalbuminemia and elevated urinary n-acetyl-glucosaminidase levels persisted after six days. These studies demonstrate widespread hemodynamic and vascular effects of IL-2 administration that limit its safe use and suggest a possible role for the lymphokine in mediating cardiovascular instability under other circumstances, such as endotoxic shock.

Technical aspects of intraperitoneal chemotherapy in abdominal carcinomatosis

Between November 1983 and July 1985, 41 patients with abdominal carcinomatosis had peritoneal catheters surgically implanted for the purpose of intraperitoneal chemotherapy. Peritoneal fluid distribution was documented by computerized tomography examination prior to chemotherapy and was correlated with the surgical procedure performed and the pathological findings. In this series, peritoneal fluid distribution appeared to be an important prognostic factor in determining tumor response. The catheter-related complication rate was acceptable.