Unleashing NK- and CD8 T cells by combining monalizumab and trastuzumab for metastatic HER2-positive breast cancer: Results of the MIMOSA trial

The large majority of patients with HER2-positive metastatic breast cancer (MBC) will eventually develop resistance to anti-HER2 therapy and die of this disease. Despite, relatively high levels of stromal tumor infiltrating lymphocytes (sTILs), PD1-blockade has only shown modest responses. Monalizumab targets the inhibitory immune checkpoint NKG2A, thereby unleashing NK- and CD8 T cells. We hypothesized that monalizumab synergizes with trastuzumab by promoting antibody-dependent cell-mediated cytotoxicity. In the phase II MIMOSA-trial, HER2-positive MBC patients were treated with trastuzumab and 750 mg monalizumab every two weeks. Following a Simon's two-stage design, 11 patients were included in stage I of the trial. Treatment was well tolerated with no dose-limiting toxicities. No objective responses were observed. Therefore, the MIMOSA-trial did not meet its primary endpoint. In summary, despite the strong preclinical rationale, the novel combination of monalizumab and trastuzumab does not induce objective responses in heavily pre-treated HER2-positive MBC patients.

Adjuvant dose-dense doxorubicin-cyclophosphamide versus docetaxel-doxorubicin-cyclophosphamide for high-risk breast cancer: First results of the randomised MATADOR trial (BOOG 2004-04)

BACKGROUND

Dose-dense administration of chemotherapy and the addition of taxanes to anthracycline-based adjuvant chemotherapy have improved breast cancer survival substantially. However, clinical trials directly comparing the additive value of taxanes with dose-dense anthracycline-based chemotherapy are lacking.

PATIENTS AND METHODS

In the multicentre, randomised, biomarker discovery Microarray Analysis in breast cancer to Tailor Adjuvant Drugs Or Regimens (MATADOR) trial, patients with pT1-3, pN0-3 breast cancer were randomised (1:1) between six adjuvant cycles of doxorubicin 60 mg/m² and cyclophosphamide 600 mg/m² every 2 weeks (ddAC) and six cycles of docetaxel 75 mg/m², doxorubicin 50 mg/m² and cyclophosphamide 500 mg/m² every 3 weeks (TAC). The primary objective was to discover a predictive gene expression profile for ddAC and TAC benefit. Here we report the preplanned secondary end-point recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Between 2004 and 2012, 664 patients were randomised. At 5 years, RFS was 87% (95% confidence interval [CI] 83%-91%) in the ddAC-treated patients and 88% (84-92%) in the TAC-treated subgroup (hazard ratio [HR] 0.89, 95% CI 0.62-1.28, P = 0.53). OS at 5 years was 93% (90%-96%) in the ddAC-treated and 94% (91%-97%) in the TAC-treated patients (HR 0.89, 95% CI 0.57-1.39, P = 0.61). Anaemia was more frequent in ddAC-treated patients (62/327 patients [18.9%] versus 15/319 patients [4.7%], P < 0.001) and diarrhoea (21 [6.4%] versus 53 [16.6%], P<0.001) and peripheral neuropathy (15 [4.6%] versus 46 [14.4%], P < 0.001) were observed more often in TAC-treated patients.

CONCLUSIONS

With a median follow-up of 7 years, no significant differences in RFS and OS were observed between six adjuvant cycles of ddAC and TAC in high-risk breast cancer patients.

TRIAL REGISTRATION NUMBERS

ISRCTN61893718 and BOOG 2004-04.

Abstract P5-14-03: Adjuvant dose dense doxorubicin-cyclophosphamide (ddAC) or docetaxel-AC (TAC) for high-risk breast cancer: First results of the randomized MATADOR trial (BOOG-2004-04)

Background: Anthracycline-based adjuvant chemotherapy has substantially improved breast cancer survival. Both the addition of taxanes as well as using a dose dense treatment schedule can further ameliorate outcome, but inter-individual differences exist. Here we present the efficacy and toxicity of dose dense scheduled doxorubicin/cyclophosphamide (ddAC) versus docetaxel/doxorubicin/cyclophosphamide (TAC), which is, to our knowledge, the first direct comparison of these treatment regimens.

Methods: In this Dutch, multicenter phase III trial (ISRCTN61893718), patients with pT1-3, pN0-3, M0 breast cancer were randomized between six cycles of either A60C600 every 2 weeks or T75A50C500 every 3 weeks. All patients received pegfilgrastim. Patients were evaluated for recurrence-free survival (RFS) and overall survival (OS). Survival was compared in a Cox regression analysis and adjusted for known prognostic factors. These factors include age, type of surgery, tumor size, histological grade, ER/PR status, HER2 status, and lymph node status. Adverse events were reported according to the common toxicity criteria (CTCAE version 3.0).

Results: Between 2004 and 2012, 664 patients were enrolled of whom 531 (80%) had node positive disease. At a median follow up of 5 years, OS was 92% in the ddAC treated subgroup and 93% in the TAC treated subgroup (adjusted hazard ratio [HR] 0.75, 95% confidence interval [CI] 0.42-1.34, intention to treat population). Forty-two breast-cancer specific deaths were equally divided over both treatment arms. Similarly, no significant difference in RFS was observed between both treatment groups (adjusted HR 0.85, 95% CI 0.55-1.32). Molecular subtypes were defined by St. Gallen criteria: 548 patients (83%) had estrogen receptor positive disease and 102 patients (15%) triple negative disease. No heterogeneity regarding treatment efficacy was observed in these subtypes. In particular, there was no survival benefit for ddAC or TAC in the triple negative subtype. Both treatment regimens were well tolerated. Whereas anemia was more frequent in ddAC treated patients (19% vs 4.7%; p&lt;0.001), peripheral neuropathy occurred more frequently in TAC treated patients (4.6% vs 14.4%; p&lt;0.001). The frequency of febrile neutropenia was not significantly different between the treatment arms (11% vs 12.5%; n.s.). Six patients developed congestive heart failure: 2 ddAC treated patients, 4 TAC treated patients. One ddAC treated patient and one TAC treated patient were diagnosed with acute myeloid leukemia after study treatment; another patient in the ddAC treatment group developed myelodysplastic syndrome.

Conclusions: At a median follow up of 5 years no significant survival differences were observed between adjuvant ddAC and TAC, in all patients and in molecular subgroups, including triple negative. Our findings are in line with the Oxford overview, which reported no significant differences between taxane-based chemotherapy and more, non-taxane based chemotherapy given in a dose dense schedule. ddAC could be a reasonable alternative for patients with a contra-indication for TAC.

Citation Format: van Rossum AGH, Oosterkamp HM, van Werkhoven E, Opdam M, Mandjes IAM, van Leeuwen-Stok E, van Tinteren H, Kok M, Imholz ALT, Portielje JEA, Bos MMEM, van Bochove A, Wesseling J, Rutgers EJ, Rodenhuis S, Linn SC. Adjuvant dose dense doxorubicin-cyclophosphamide (ddAC) or docetaxel-AC (TAC) for high-risk breast cancer: First results of the randomized MATADOR trial (BOOG-2004-04) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-14-03.

Abstract OT2-01-11: Phase II of POSEIDON: A phase Ib / randomized phase II trial of tamoxifen plus taselisib or placebo in hormone receptor positive, HER2 negative, metastatic breast cancer patients with prior exposure to endocrine treatment

Background: The combination of PI3K-AKT-mTOR pathway inhibitors with endocrine therapy can improve clinical outcomes of hormone receptor positive (HR+) metastatic breast cancer (MBC) patients. Taselisib is a potent and selective PI3K inhibitor, with greater selectivity against mutant (MUT) PI3Kα isoforms than wild-type (WT) via a unique mechanism. Phase Ib data of POSEIDON with Taselisib + tamoxifen (TAM) demonstrated encouraging activity in patients with heavily pre-treated MBC, with an acceptable toxicity profile (Baird et al, ASCO 2016). The recommended phase II dose (RP2D) was Taselisib 4mg plus TAM 20mg, both administered on a daily continuous schedule. ctDNA monitoring may have value in drug development by (1) assessing predictive biomarkers to therapy, (2) providing an early indication of treatment response, and (3) shedding light on potential mechanisms of acquired drug resistance. In some patients included in phase Ib of POSEIDON, tumor response was preceded by a corresponding early change in plasma PIK3CA ctDNA levels. Methods: The phase II portion of the POSEIDON trial is a two-arm, randomized, double blind study of Taselisib plus TAM versus placebo (PLA) plus TAM in pre- and postmenopausal women with HR+/HER2- MBC. In the first part of the Phase II, 180 patients will be randomized (1:1) to receive continuous TAM with either Taselisib at the RP2D or PLA until disease progression, unacceptable toxicity or patient / physician decision. Crossover is allowed upon progressive disease in those patients receiving PLA plus TAM, after collection of tumor and blood samples for exploratory biomarker analysis. Stratification is based on menopausal status, histology [lobular breast cancer (LBC) vs. ductal/others], PIK3CA mutation (WT vs. exon 9 vs. exon 20), prior everolimus, timing of recurrence/progression after prior endocrine therapy, number of prior chemotherapy (CT) lines, and treatment center. After recruiting the initial 180 patients, trial will focus in LBC, until a total number of 110 patients with LBC are enrolled. Other key eligibility criteria include presence of measurable or evaluable disease (RECIST 1.1), prior progression to endocrine treatment, maximum of 5 prior CT lines in the metastatic setting, absence of diabetes under medical treatment, and absence of chronic inflammatory bowel disease. Primary endpoint is investigator-assessed PFS. Key secondary endpoints are PFS in LBC, objective response rate, clinical benefit rate, safety, and exploratory biomarker analysis (including ctDNA). The study has a 90% power at a two-sided log-rank test significance level of 0.2 to detect an HR of 0.64, which corresponds to an increase in median PFS from 4.5 months in the PLA plus TAM arm to 7 months in the Taselisib plus TAM arm. Enrollment to POSEIDON Phase II started in June 2016 (Clinicaltrials.gov NCT02285179).

Citation Format: Oliveira M, Baird RD, van Rossum AGJ, Beelen K, Garcia-Corbacho J, Mandjes IAM, Vallier AL, van Werkhoven E, Garrigós L, Kumar S, van Tinteren H, Muñoz S, Linossi C, Rosing H, Miquel JM, Schrier M, de Vries Schultink A, Saura C, Gallagher WM, Bernards R, Tabernero J, Cortés J, Caldas C, Linn SC. Phase II of POSEIDON: A phase Ib / randomized phase II trial of tamoxifen plus taselisib or placebo in hormone receptor positive, HER2 negative, metastatic breast cancer patients with prior exposure to endocrine treatment [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-11.

The prognostic value of the neoadjuvant response index in triple-negative breast cancer: validation and comparison with pathological complete response as outcome measure

The Neoadjuvant response index (NRI) has been proposed as a simple measure of downstaging by neoadjuvant treatment in breast cancer. It was previously found to predict recurrence-free survival (RFS) in triple-negative (TN) breast cancer. It was at least as accurate as the standard binary system, the absence or presence of a pathological complete remission (pCR), which is the commonly employed outcome measure. The NRI was evaluated in an independent consecutive series of patients to validate the previous findings. Univariable and multivariable analyses were done to assess the predictive value of clinical parameters and of the NRI for RFS. We combined the original and validation series of patients to build a multivariable predictive model for RFS after neoadjuvant chemotherapy in TN breast cancer. The validation set (N = 108) confirmed that patients with a higher-than-median NRI (>0.7) had excellent RFS (P = 0.002), similar to that of patients who had achieved a pCR. Multivariable analysis in 191 patients showed that the NRI was a strong independent predictor of RFS (P = 0.0002), with N-stage (P = 0.001) and T-stage (P = 0.014) ranking second and third, respectively. Importantly, among patients who did not achieve a pCR (NRI values below 1), higher NRI values were still associated with better RFS. The NRI is a simple method and a practical tool to predict RFS in TN breast cancer patients treated with neoadjuvant chemotherapy. It adds prognostic information to the presence or absence of pCR and could be useful to compare the efficacies of different chemotherapy regimens.

Neoadjuvant chemotherapy in ER+ HER2- breast cancer: response prediction based on immunohistochemical and molecular characteristics

A pathological complete remission (pCR) is rarely achieved by neoadjuvant chemotherapy in estrogen receptor-positive (ER+) HER2-negative (HER2-) tumors. Therefore, its use might be questionable in specific groups of this tumor type. To select which patients benefit and which could be spared neoadjuvant chemotherapy, we tested standard pathology and molecular markers in ER+ HER2- breast tumors. Pretreatment biopsies were available from 211 ER+ HER2- tumors, who had been treated with neoadjuvant chemotherapy (adriamycin/cyclophosphamide). mRNA expression data were available for 132 tumors. We determined progesterone receptor expression (PR), endocrine sensitivity, HER2 expression, histology, proliferation, and molecular subtypes. We correlated these data to chemotherapy response using pCR rates and the previously published neoadjuvant response index (NRI). PR-negative tumors (n = 65, 30.8%) and luminal B type tumors (n = 43, 20.4%) responded significantly better to chemotherapy than other tumors. These associations remained significant in multivariate analysis. However, even in the subgroup of patients with the lowest response rate, comprising tumors that had both a positive-PR expression and the luminal A subtype (n = 58, 44%), the majority of the patients had downstaging because of chemotherapy. For histology (lobular vs. ductal), endocrine sensitivity, and proliferation, no associations with chemotherapy response were observed. Gene expression array analysis resulted in 28 significant genes (FDR < 0.1). PR expression and luminal B status are associated with a better response to neoadjuvant chemotherapy. However, both markers had only weak response predictive power, and it was not possible to identify a subgroup with no or only minimal chemotherapy benefit. Therefore, the decision to refrain from neoadjuvant chemotherapy to ER+ HER2- breast tumors should not be based on predictive markers, but exclusively on estimates of prognosis.

Lapatinib: clinical benefit in patients with HER 2-positive advanced breast cancer

BACKGROUND

Lapatinib, a tyrosine kinase inhibitor of human epidermal growth factor receptor 2 (HER2), has shown activity in combination with capecitabine in patients with HER2-positive advanced breast cancer progressive on standard treatment regimens. We present results on preapproval drug access for this combination in such patients occurring in the general oncology practice in the Netherlands.

METHODS

Patients with HER2-positive advanced breast cancer progressive on schedules containing anthracyclines, taxanes, and trastuzumab were eligible. Brain metastases were allowed if stable. Lapatinib 1250 mg÷day was given continuously in combination with capecitabine 1000 mg÷m2 twice daily for two weeks in a three-week cycle. Efficacy was assessed by use of response evaluation criteria in solid tumours version 1.0. Progression-free survival (PFS) and overall survival (OS) were calculated.

RESULTS

Eighty-three patients were enrolled from January 2007 until July 2008. The combination was generally well tolerated and the most common drug-related serious adverse events were nausea and÷or vomiting (5%) and diarrhoea (2%). Seventy-eight patients were evaluable for response. Clinical benefit (response or stable disease for at least 12 weeks) was observed in 50 patients (64%) of whom 15 had a partial response and 35 stable disease. The median PFS and OS were 17 weeks (95% CI: 13 to 21) and 39 weeks (95% CI: 24 to 54), respectively. For OS, higher Eastern Cooperative Oncology Group (ECOG) status (p=0.016), brain metastases at study entry (p=0.010) and higher number of metastatic sites (p=0.012) were significantly negative predictive factors.

CONCLUSION

In a patient population with heavily pretreated HER2-positive advanced breast cancer lapatinib plus capecitabine was well tolerated and offered clinical benefit.

A multi-center prospective phase II study of high-dose chemotherapy in germ-cell cancer patients relapsing from complete remission

PURPOSE

To prospectively determine the efficacy of repeated high-dose alkylating chemotherapy to salvage patients with germ-cell tumors who relapsed after adequate first-line chemotherapy.

PATIENTS AND METHODS

Patients with germ-cell cancers relapsing from a first, second or third complete remission induced by chemotherapy were offered to participate in a Dutch national prospective trial with broad entry criteria. The salvage treatment began with a conventional dose of ifosfamide (4 g/m2 on day 1) and etoposide (100 mg/m2 on days 1, 2 and 3) followed by daily s.c. administration of G-CSF (10 micrograms/kg) until peripheral blood progenitor cells had been harvested. Immediately after bone marrow recovery, an intermediate dose chemotherapy course of carboplatin (target AUC: 10 mg.ml-1 min on day 1) and etoposide (500 mg/m2 on days 1, 3 and 5) was given with G-CSF daily s.c. After bone marrow recovery, two subsequent courses of high-dose 'CTC' chemotherapy were given, each containing cyclophosphamide (6 g/m2), thiotepa (480 mg/m2) and carboplatin (target AUC: 20 mg.ml-1 min). The high-dose chemotherapy was administered as 30-60-minute infusions, divided over 4 days and the stem-cell transplants were given 48-72 hours after the last chemotherapy infusion. Whenever possible, residual masses were resected at the end of treatment.

RESULTS

Thirty-five patients were treated between January 1994 and October 1997. The toxicity of the treatment was manageable. Second CTC courses were administered in 25 patients and were associated with hemorrhagic cystitis and veno-occlusive disease in 3 and 4 patients, respectively. One patient who had recently undergone a partial hepatectomy, died of veno-occlusive disease. At the time of analysis, the median follow-up of the surviving patients was 37 months (range 12-56 months). The median progression-free survival for all patients was 44 months, and the median overall survival has not been reached. According to the internationally accepted criteria for predicting the outcome of salvage chemotherapy in germ-cell cancer (Beyer et al. J Clin Oncol 1996; 14: 2638-45), 30 patients had 'good risk' criteria. Of these, 29 received high-dose chemotherapy. Of this group, the salvage rate at two years was 65% (95% confidence interval: 49.5%-85.1%).

CONCLUSIONS

Over half of the germ-cell cancer patients relapsing from a chemotherapy-induced complete remission can be salvaged by a treatment strategy that incorporates high-dose chemotherapy, even when treatment is given in a multi-center setting. These data confirm the international prognostic model proposed by Beyer et al. in a prospectively studied, independent patient group and provide further evidence that high-dose therapy has a role in the salvage setting of patients with germ-cell cancer.

Pharmacologic study of 3-hour 135 mg M-2 paclitaxel in platinum pretreated patients with advanced ovarian cancer

Paclitaxel (Taxol(R)) is an active agent in platinum-refractory ovarian cancer. Since the available pharmacokinetic data of 135 mg m-2 paclitaxel administered by 3-h infusion are scarce and fragmented, we now describe a comprehensive pharmacologic study in a group of 13 patients who were pretreated with platinum for advanced ovarian cancer. The mean paclitaxel AUC was 10.3+/-2.4 h micromol l-1 (range 6.8-13.9 h micromol l-1). Quantification of the two major paclitaxel metabolites, 6alpha-hydroxypaclitaxel and 3'-p-hydroxypaclitaxel yielded AUCs of 0.44+/-0.30 h micromol l-1 and 0.31+/-0.20 h micromol l-1, respectively. The AUC of 3'-p-hydroxypaclitaxel was significantly different from that of patients with an altered hepatic function. The administration of 135 mg m-2 single-paclitaxel was safe, and the toxicities observed at higher doses in earlier studies were absent in this study. This is important, because the schedule and paclitaxel dose of 135 mg m-2 given by a 3-h infusion is expected to be used more frequently in combination with other cytotoxic agents with the aim of improving efficacy.

Pharmacokinetics of paclitaxel and three major metabolites in patients with advanced breast carcinoma refractory to anthracycline therapy treated with a 3-hour paclitaxel infusion: a European Cancer Centre (ECC) trial

BACKGROUND

Hepatic metabolism and biliary clearance play pivotal roles in the disposition of the anticancer drug paclitaxel. 6-alpha-hydroxypaclitaxel, 3'-p-hydroxypaclitaxel and 6-alpha,3'-p-dihydroxypaclitaxel were the major metabolic products of paclitaxel found in human bile. Recently, these metabolic products were detected in human plasma. The pharmacokinetics of paclitaxel and its metabolites were investigated in anthracycline-resistant breast cancer patients treated with high-dose paclitaxel and granulocyte colony-stimulating factor (G-CSF) support.

PATIENTS AND METHODS

Nine patients were entered into this study in which paclitaxel was administered at the relatively high dose of 250 mg/m2 during a 3-hour infusion. G-CSF was administered daily subcutaneously (s.c.)on days 2 to 19 following chemotherapy. Analysis of paclitaxel and metabolite concentrations was performed by a new highly sensitive reversed-phase high performance liquid chromatographic (HPLC) assay.

RESULTS

The dose-limiting toxicity in this study was cumulative neurotoxicity. One patient had a partial response and 2 patients had mixed responses of their skin metastases. Relatively low peak plasma concentration (Cmax), with mean values of 6.91 micromol/L (range 3.08 to 8.98) and area under the plasma concentration time curve (AUC), with mean values of 27.04 micromol/L.h (range 14.88 to 40.57), were observed. The total body clearance was 16.99 L/h (range, 10.25 to 27.39). The pharmacokinetic parameter for the prediction of leuko-neutropenia, the duration of the plasma concentration above the threshold of 0.1 micromol/L.h (T > or = 0.1 microM), was 19.72 h (range 10.54 to 26.31). The three major metabolites detected in human plasma were identified as 6-alpha-hydroxypaclitaxel, 3'-p-hydroxypaclitaxel and 6-alpha,3'-p-dihydroxypaclitaxel. Cmax and AUC values of these metabolites are reported.

CONCLUSIONS

The three main metabolic products of paclitaxel in human plasma are 6-alpha-hydroxypaclitaxel, 3'-p-hydroxypaclitaxel and the dihydroxymetabolite 6-alpha,3'-p-dihydroxypaclitaxel. Two patients with liver function disturbances showed a tendency to higher paclitaxel and 6-alpha-hydroxypaclitaxel AUC levels, with more pronounced neuropathy.

Phase I/II study of intraperitoneal mitoxantrone in refractory ovarian cancer

BACKGROUND

Mitoxantrone has demonstrable clinical activity when administered intravenously in a wide range of malignancies. The feasibility and toxicity of intra-peritoneal administration was established in a phase I study. The optimal dose from the phase I was subsequently evaluated in a phase II study.

PATIENTS AND METHODS

19 patients with refractory malignancies and extensive abdominal disease (13 ovarian cancer, 4 breast cancer, 2 mesothelioma) were entered in a phase I study. The dose of intraperitoneal mitoxantrone was escalated from 10 mg/m2, administered in 21 of fluid via a Tenckhoff catheter, to 55 mg/m2, in increments of 5 mg/m2. Cycles were repeated every three weeks. Sixty-seven cycles of mitoxantrone were administered, the maximum tolerable dose being 25 mg/m2. A phase II study at this dose was conducted in 14 patients with refractory ovarian cancer, all of whom had previously received systemic platinum based therapy. Five of the 14 had also previously been treated with intraperitoneal carboplatin. Fifty-one cycles were administered.

RESULTS

The dose limiting toxicity in the phase I study was peritoneal irritation and pain. Leucopenia was frequent at doses equal or greater than 30 mg/m2. Three complete remissions were documented in the phase I study (2 breast cancer and 1 ovarian cancer). There was no significant haematological toxicity in the phase II assessment, though local toxicity precluded further therapy in 2 patients. No objective responses were seen in the phase II evaluation.

CONCLUSIONS

These studies demonstrate the feasibility of intra-peritoneal mitoxantrone therapy in patients with peritoneal disease, but do not support its routine use in ovarian cancer.

Feasibility and toxicity study of a high-dose chemotherapy regimen for autotransplantation incorporating carboplatin, cyclophosphamide and thiotepa

Sixteen patients received a high-dose chemotherapy regimen consisting of carboplatin (1600 mg/m2) and cyclophosphamide (6000 mg/m2) as daily two-hour infusions over four days (CC). All but two of them also received thiotepa (480 mg/m2) in eight 30-minute infusions given every 12 hours (CTC). Bone marrow and/or peripheral stem cell (PSC) reinfusions took place 72 hours after the last course of chemotherapy. The major toxicity was bone marrow suppression, the duration of which was markedly reduced in the patients receiving PSC reinfusions. Non-hematological toxicity was relatively mild and consisted of nausea and vomiting, minor mucositis and skin rashes. All but one patient had mild and completely reversible elevations of serum ALAT and/or LDH levels. One patient, who had received full-dose chemotherapy despite a creatinine clearance of 56 ml/min, developed significant toxicity consisting of transient cyclophosphamide-associated pancarditis, reversible neurotoxicity and partially reversible hearing loss and renal function impairment. There were no toxic deaths. In view of the high carboplatin dose, the CTC regimen may be particularly suitable for use in the salvage treatment of germ cell cancer. Since CTC causes no serious organ toxicity, further studies to determine its suitability for double or even triple transplantation programs are warranted.

Loss of heterozygosity in Wilms' tumors, studied for six putative tumor suppressor regions, is limited to chromosome 11

Studies on the loss of heterozygosity (LOH) in human malignancies have shown that a number of different chromosomal regions associated with putative tumor suppressor genes may be involved in any one given tumor. We have carried out a similar study on Wilms' tumor using a range of DNA markers for a number of tumor suppressor regions. We tested a total of 44 Wilms' tumors including material from bilateral cases and from patients with Beckwith-Wiedemann syndrome, Drash syndrome, Perlman syndrome, and hemihypertrophy. In 11 of 36 informative tumors we found LOH for markers for the short arm of chromosome 11; only one of these tumors had additional LOH for regions 5q and 17p. No LOH was found for regions 3p, 13q, and 22q. Thus our findings support a major role for chromosome 11p in Wilms' tumor development and apparent noninvolvement of other tumor suppressor genes. No correlation was found between allelic losses and the International Society of Paediatric Oncology tumor stage or histology.

Autosomal dominant aniridia linked to the chromosome 11p13 markers catalase and D11S151 in a large Dutch family

In a large pedigree with autosomal dominant aniridia, we found close linkage between the aniridia locus AN2 and the markers catalase (CAT) (zeta = 7.27 at theta = 0.00) and D11S151 (zeta = 3.86 at theta = 0.10) flanking the AN2 locus on 11p13. Positive lod scores were also obtained for the 11p13----11p14 markers D11S16 and FSHB with the linkage group CAT/AN2/D11S151. We conclude that the autosomal dominant aniridia in this family is due to a mutation at the AN2 locus on 11p13. We have excluded linkage (zeta less than -2 at theta less than 0.18) between the aniridia and the chromosome 2p25 marker D2S1 (linked to ACP1).