High-dose recombinant interleukin 2 therapy for patients with metastatic melanoma: analysis of 270 patients treated between 1985 and 1993

PURPOSE

To determine the short- and long-term efficacy and toxicity of the high-dose intravenous bolus interleukin 2 (IL-2) regimen in patients with metastatic melanoma.

PATIENTS AND METHODS

Two hundred seventy assessable patients were entered onto eight clinical trials conducted between 1985 and 1993. IL-2 (Proleukin [aldesleukin]; Chiron Corp, Emeryville, CA) 600,000 or 720,000 IU/kg was administered by 15-minute intravenous infusion every 8 hours for up to 14 consecutive doses over 5 days as clinically tolerated with maximum support, including pressors. A second identical treatment cycle was scheduled after 6 to 9 days of rest, and courses could be repeated every 6 to 12 weeks in stable or responding patients. Data were analyzed through fall 1996.

RESULTS

The overall objective response rate was 16% (95% confidence interval, 12% to 21%); there were 17 complete responses (CRs) (6%) and 26 partial responses (PRs) (10%). Responses occurred with all sites of disease and in patients with large tumor burdens. The median response duration for patients who achieved a CR has not been reached and was 5.9 months for those who achieved a PR. Twelve (28%) of the responding patients, including 10 (59%) of the patients who achieved a CR, remain progression-free. Disease did not progress in any patient responding for more than 30 months. Baseline performance status and whether patients had received prior systemic therapy were the only predictive prognostic factors for response to IL-2 therapy. Toxicities, although severe, generally reversed rapidly after therapy was completed. Six patients (2%) died from adverse events, all related to sepsis.

CONCLUSION

High-dose IL-2 treatment seems to benefit some patients with metastatic melanoma by producing durable CRs or PRs and should be considered for appropriately selected melanoma patients.

Rituximab using a thrice weekly dosing schedule in B-cell chronic lymphocytic leukemia and small lymphocytic lymphoma demonstrates clinical activity and acceptable toxicity

PURPOSE

Rituximab has been reported to have little activity in small lymphocytic lymphoma (SLL)/chronic lymphocytic leukemia (CLL) and to be associated with significant infusion-related toxicity. This study sought to decrease the initial toxicity and optimize the pharmacokinetics with an alternative treatment schedule.

PATIENTS AND METHODS

Thirty three patients with SLL/CLL received dose 1 of rituximab (100 mg) over 4 hours. In cohort I (n = 3; 250 mg/m(2)) and cohort II (n = 7; 375 mg/m(2)) rituximab was administered on day 3 and thereafter three times weekly for 4 weeks using a standard administration schedule. Cohort III (n = 23; 375 mg/m(2)) administered rituximab similar to cohort II for the first two treatments and then over 1 hour thereafter.

RESULTS

A total of 33 CLL/SLL patients were enrolled; only one patient discontinued therapy because of infusion-related toxicity. Thirteen patients developed transient hypoxemia, hypotension, or dyspnea that were associated with significant changes in baseline interleukin-6, interleukin-8, tumor necrosis factor alpha, and interferon gamma compared with those not experiencing such reactions. Infusion-related toxicity occurred more commonly in older (median age 73 v 62 years; P =.02) patients with no other pretreatment clinical or laboratory features predicting occurrence of these events. The overall response rate was 45% (3% CR, 42% PR; 95% CI 28% to 64%). Median response duration for these 15 patients was 10 months (95% CI, 6.8-13.2; range, 3 to 17+).

CONCLUSION

Rituximab administered thrice weekly for 4 weeks demonstrates clinical efficacy and acceptable toxicity. Initial infusion-related events seem to be cytokine mediated and resolve by the third infusion making rapid administration possible. Future combination studies of rituximab with other therapies in CLL seem warranted.

Carfilzomib in multiple myeloma patients with renal impairment: pharmacokinetics and safety

This phase 2 study assessed the safety, pharmacokinetics, pharmacodynamics and efficacy of carfilzomib, a selective proteasome inhibitor, in patients with multiple myeloma and varying degrees of renal impairment, including patients on chronic hemodialysis. Patients were grouped by creatinine clearance: >80 ml/min, 50-80 ml/min, 30-49 ml/min, <30 ml/min and chronic hemodialysis. Carfilzomib was administered on days 1, 2, 8, 9, 15 and 16 in 28-day cycles: 15 mg/m(2) (Cycle 1), 20 mg/m(2) (Cycle 2) and 27 mg/m(2) (Cycles 3+). There were no differences in carfilzomib clearance or exposure among patients with normal renal function and any group with renal impairment. Grade 3/4 adverse events (AEs) included anemia (28.0%), thrombocytopenia (20.0%), lymphopenia (18.0%) and fatigue (14.0%). AEs were similar among groups. At 15 mg/m(2), proteasome inhibition up to 85% was observed and did not differ among groups. Although nearly 50% of patients were refractory to both bortezomib and lenalidomide, end of study partial response or better (overall response rate) was 25.5% with 7.9 months median duration of response. In conclusion, the pharmacokinetics and safety of carfilzomib were not influenced by the degree of baseline renal impairment, including in patients on dialysis, and carfilzomib was well tolerated and demonstrated promising efficacy.

Mapping of the X-linked agammaglobulinemia locus by use of restriction fragment-length polymorphism

A molecular linkage analysis in 11 families with X-linked agammaglobulinemia (XLA) localized the XLA gene to the proximal part of the long arm of the human X chromosome. Significant linkage was detected between XLA and loci defined by two polymorphic DNA probes called 19-2 for the DXS3 locus and S21 for the DXS17 locus. Both localize to the region Xq21.3-Xq22. Most likely recombination distances (theta) and associated logarithm of the odds (lod) scores for the XLA-DXS3 and XLA-DXS17 pairs were theta = 0.04 morgans (lod, 3.65) and theta = 0 (lod, 2.17), respectively. Tight linkage between XLA and the locus DXS43 defined by the X short arm probe D2 (localized to Xp22-Xp21) was strongly excluded and we obtained no evidence for significant linkage between XLA and any other X short arm probe. The probe pair 19-2 and S21 should be informative for molecular linkage-based analysis of XLA segregation in the majority of families afflicted with this disorder.

An exploratory open-label trial of aripiprazole as an adjuvant to clozapine therapy in chronic schizophrenia

OBJECTIVE

We conducted this 6-week open-label trial to examine the effects of adjunctive aripiprazole in clozapine-treated subjects on weight, lipid and glucose metabolism, as well as positive and negative symptoms of schizophrenia.

METHOD

Ten clozapine-treated subjects received aripiprazole augmentation; eight completed the 6-week trial and two ended at week 4. Eighty percent were male, the mean age was 38.7 +/- 8.9 years and the mean clozapine dose was 455 +/- 83 mg daily.

RESULTS

There was a significant decrease in weight (P = 0.003), body mass index (P = 0.004), fasting total serum cholesterol (P = 0.002) and total triglycerides (P = 0.04) comparing baseline to study endpoint. There was no significant change in total Positive and Negative Syndrome Scale scores.

CONCLUSION

This combination may be useful for clozapine-associated medical morbidity and must be studied in placebo-controlled double-blind randomized trials to determine efficacy and safety.

Genetic linkage relationships of seven DNA probes with Duchenne and Becker muscular dystrophy

The inheritance of seven restriction fragment length polymorphisms detected by DNA probes has been studied in families with Duchenne and Becker muscular dystrophies (DMD and BMD). The probes used have all been mapped to the short arm of the X-chromosome, four being distal and three proximal to the disease loci located within the Xp21 region. Linkage analysis of the DNA polymorphisms in relation to the two disorders showed similar genetic distances. Data obtained from DMD and BMD families have been combined to give more precise values for the different recombination fractions. Combined use of these polymorphic DNA markers will be of practical value in the genetic counselling of women at risk for Duchenne and Becker muscular dystrophy.

Clinical characteristics predict response to antithymocyte globulin in paroxysmal nocturnal haemoglobinuria

Seven patients with paroxysmal nocturnal haemoglobinuria (PNH) were treated with antithymocyte globulin (ATG). Each patient received ATG (20 mg/kg/d) for 8 d and prednisone to prevent or control serum sickness. Three patients experienced a sustained improvement in at least one peripheral blood cytopenia, including one patient who had a complete trilineage response. Several pretreatment clinical features appeared to be associated with response to ATG. All responding patients had hypoproliferative features including depressed platelet counts (< 30 x 10(9)/l), and a minor degree of chronic haemolysis as indicated by relatively low reticulocyte counts (< 100 x 10(9)/l), lactate dehydrogenase (< 1000 U/l) and total bilirubin (< 17 mumol/l) levels. Responding patients continued to have chronic low-grade haemolysis after their response to immunosuppression that was similar to that observed prior to treatment. The non-responding patients had a classic haemolytic form of PNH characterized by elevated reticulocyte counts (> 100 x 10(9)/l), lactate dehydrogenase (> 2000 U/l) and total bilirubin (> 17 mumol/l) levels. The impaired haemopoiesis that occurs in hypoproliferative PNH may respond to ATG treatment, but the haemolytic component of the disease, and hence the PNH clone, is not altered by immunosuppressive therapy.

Cytologic and molecular analysis of 46,XXq- cells to identify a DNA segment that might serve as a probe for a putative human X chromosome inactivation center

Cloned human X chromosome-specific DNA segments, derived from a recombinant phage library enriched for the human X and previously localized to different regions of the X, were used as probes in Southern blots to confirm the nature of a deletion of the long arm of the X chromosome as del(X)(q13) in a patient with some features of Turner's syndrome and suspected from cytologic studies to have a 46,XXq- karyotype. Two dimensional scanning densitometry of autoradiograms of the Southern blots was used to quantitate hybridization of the 32P-labeled probes, reinforcing visual analysis and permitting distinction between sequences present at one or two copies per diploid genome. Once thus characterized, DNA from the patient's cells was used in quantitatively analyzed Southern blots to refine the location of an additional DNA segment, previously mapped to somewhere in the proximal part of the long arm of the X chromosome, to the juxtacentromeric region of Xq, which has been hypothesized to be critical for X-inactivation. Cloned DNA probes such as that localized to the juxtacentromeric region of Xq should be useful for evaluating this hypothesis.

Molecular heterogeneity of translocations associated with muscular dystrophy

Individual translocation chromosomes from six girls suffering from Duchenne or Becker muscular dystrophy (DMD or BMD) have been isolated in human-mouse somatic cell hybrids. DNA prepared from these hybrids was probed with sequences physically close to the locus; these include a junction fragment from the site of the X:21 translocation (pXJ1) and subclones from the pERT 87 (DXS164) region which are absent in a minority of male DMD patients. Both sets of sequences mapped within the area defined by the translocation breakpoints, confirming their close proximity to the DMD and BMD loci. Furthermore, the X chromosome breakpoints of the translocations can be divided into three categories depending upon their position in relation to the sequences recognised by pXJ1 and pERT 87. The genomic target disrupted by the translocations examined here is a minimum of 176 kb.

Does providing consumer health information affect self-reported medical utilization? Evidence from the Healthwise Communities Project

OBJECTIVE

To determine whether providing health information to residents of Boise ID had an effect on their self-reported medical utilization.

RESEARCH DESIGN

The Healthwise Communities Project (HCP) evaluation followed a quasi-experimental design.

SUBJECTS

Random households in metropolitan zip codes were mailed questionnaires before and after the HCP. A total of 5,909 surveys were returned.

MEASURES

The dependent variable was self-reported number of visits to the doctor in the past year. A difference-in-differences estimator was used to assess the intervention's community-level effect. We also assessed the intervention's effect on the variance of self-report utilization.

RESULTS

Boise residents had a higher adjusted odds of entering care (OR = 1.27, 95% CI 0.88, 1.85) and 0.1 more doctor visits compared with residents in the control cities; however, for both outcomes, the effects were small and not significant. Although the means changed little, the data suggest that the variance of utilization in Boise decreased.

CONCLUSIONS

The HCP had a small effect on overall self-reported utilization. Although the findings were not statistically significant, a posthoc power analysis revealed that the study was underpowered to detect effects of this magnitude. It may be possible to achieve larger effects by enrolling motivated people into a clinical trial. However, these data suggest that population-based efforts to provide health information have a small effect on self-reported utilization.

The impact of a community-wide self-care information project on self-care and medical care utilization

This study assesses the effects of the Healthwise Communities Project (HCP) on use of self-care resources and health care utilization. The intervention included the distribution of the Healthwise Handbook, the provision of a telephone advice line, and a Web site. All of these products use a symptom-based approach and are aimed at a general population. A quasi-experimental design was used with two comparison communities. Measurements over time assessed the effects of the HCP while controlling for secular trends. Survey and utilization data are used to assess the effect of the intervention. Findings indicate that the community intervention increased the use of self-care resources. Users believe that these products help them make better decisions regarding when to seek care and how to self-treat problems. Most believe that using the self-care resources saved them from seeking unnecessary care. The findings from the utilization data provide some evidence to support this conclusion.

High-dose chemotherapy followed by reinfusion of selected CD34+ peripheral blood cells in patients with poor-prognosis breast cancer: a randomized multicentre study

Seventy-one patients with poor-prognosis breast cancer were enrolled after informed consent in a multicentre randomized study to evaluate the use of selected peripheral blood CD34+ cells to support haematopoietic recovery following high-dose chemotherapy. Patients who responded to conventional chemotherapy were mobilized with chemotherapy (mainly high-dose cyclophosphamide) and/or recombinant human granulocyte colony-stimulating factor (rhG-CSF). Patients who reached the threshold of 20 CD34+ cells per microl of peripheral blood underwent apheresis and were randomized at that time to receive either unmanipulated mobilized blood cells or selected CD34+ cells. For patients in the study arm, CD34+ cells were selected from aphereses using the Isolex300 device. Fifteen patients failed to mobilize peripheral blood progenitors and nine other patients were excluded for various reasons. Forty-seven eligible patients were randomized into two comparable groups. CD34+ cells were selected from aphereses in the study group. Haematopoietic recovery occurred at similar times in both groups. No side-effect related to the infusion of selected cells was observed. The frequency of epithelial tumour cells in aphereses was low (8 out of 42 evaluated patients), as determined by immunocytochemistry. We conclude that selected CD34+ cells safely support haematopoietic recovery following high-dose chemotherapy in patients with poor-prognosis breast cancer.

Treatment of indolent lymphoma with fludarabine/mitoxantrone combination: a phase II trial

In an effort to reduce the risk of opportunistic infections, 25 patients with advanced indolent lymphoma (age range: 30-77 years) were treated, using a combination of fludarabine and mitoxantrone, without corticosteroids. Fludarabine was given at 25 mg/m2 for three daily doses, and mitoxantrone at 10 mg/m2. Cycles were repeated every four weeks for up to maximum response, and for no more than six months. Eight patients had follicular lymphoma, and 11 had CLL/SLL. Objective response was observed in 11 of 12 previously untreated patients, including five complete remissions, and in 10 of 13 previously treated patients, including three complete remissions. Only two relapsed patients failed to respond, whereas two patients were not evaluable. Hence, the overall response rate based on the intention-to-treat analysis was 84 per cent (95 per cent CI: 70-98 per cent). The median survival has not been reached after a 22-month follow-up. Median time to progression was 15 months. One patient on corticosteroids developed pneumocystis carinii pneumonia, and an elderly patient succumbed to neutropenic sepsis. Apart from granulocytopenia, the treatment was well tolerated. Omission of corticosteroids reduces the risk of opportunistic infections, while the activity of the combination against indolent lymphoma and CLL is maintained.

Prevalence and predictors of the use of self-care resources

Health care reform goals are to reduce costs and increase access while maintaining quality of care. A potentially effective avenue for achieving these difficult goals is to activate the untapped potential of consumers in managing their own health care. This study focuses on three Northwest communities and examines the prevalence of the use of self-care resources and the correlates of use. A random sample of households was surveyed using a mail-out questionnaire. The findings indicated that the use of self-care resources was high in the three community populations. Consulting a self-care book was the most commonly used resource, followed by telephone advice nurses. Communities do vary in their level of self-care resource use. Understanding this variability may help communities to expand the use of such resources and lessen the demand for formal health care services. Suggestions for future studies are discussed.

Final results of PX-171–003-A0, part 1 of an open-label, single-arm, phase II study of carfilzomib (CFZ) in patients (pts) with relapsed and refractory multiple myeloma (MM)

8504

Background: CFZ is a novel proteasome inhibitor of the epoxyketone class that exhibits a high level of proteasome selectivityand demonstrates antitumor activity in bortezomib (BTZ)-resistant MM pts in phase I studies. Methods: PX-171–003-A0 was an open-label, multicenter study that enrolled MM pts who relapsed from >2 prior therapies, failed BTZ and at least 1 immunomodulatory agent [thalidomide (THAL) or lenalidomide (LEN)], and were refractory to last treatment [progressing on or within 60 d of last therapy or <25% response to last therapy]. Pts received CFZ 20 mg/m2 IV d 1, 2, 8, 9, 15 and 16 every 28 d for up to 12 cycles (C). Clinical benefit response (CBR) was defined as MR or better. Results: 46 pts were enrolled, including 78% with progression on or within 60 d of last therapy and 22% with no response to last therapy. 39 pts completed at least 1 C of CFZ, had measurable M-protein, and were evaluable for response. Median prior therapies was 5 (range 2–15). 100% of pts received prior BTZ, 91% prior THAL, 89% prior LEN, and 83% prior stem cell transplant (SCT) and all had failed combinations including anthracyclines (80%) and/or alkylating agents (94%). Pts received a median of 3 C (range 1–12); 13 pts completed ≥6 C. CBR was 26% (10/39 eval pts), including 5 pts achieving PR and 5 pts achieving MR. 5 BTZ-refractory pts achieved MR or PR. Median TTP was 6.2 mo, the median DOR for the MR + PR was 7.4 mo. 8/10 pts achieved response during C1. 16 additional pts achieved SD for at least 6 wks. The most common adverse events were fatigue, anemia, thrombocytopenia, nausea, upper respiratory infection, increased creatinine and diarrhea. Peripheral neuropathy occured in < 10% of pts with 1 Gr 3 in a pt with pre-existing Gr 2. Conclusions: Single-agent CFZ achieved a TTP of > 6 mo in relapsed and refractory MM pts who failed available therapies. 26% of patients had at least an MR and median duration of >7 mo with this steroid- and anthracycline-sparing regimen. CFZ toxicities were manageable and importantly, exacerbation of pre-existing PN was rare. The study has been expanded to enroll an additional 250 pts in this unmet medical need population at an escalated dose, and treatment has been extended beyond a year.

[Table: see text]

Transplantation of IL-2-mobilized autologous peripheral blood progenitor cells for adults with acute myelogenous leukemia in first remission

In order to improve leukemia-free survival we evaluated the feasibility and efficacy of autologous transplantation of interleukin-2 (IL-2)-mobilized peripheral blood progenitor cells for adult patients with acute myelogenous leukemia in first remission. Forty-nine consecutive patients (median age 49, range 21-70) with acute myelogenous leukemia in first remission were enrolled on a study of high-dose cytarabine/mitoxantrone consolidation chemotherapy with post-recovery IL-2 used as a method of in vivo purging for the purpose of autologous peripheral blood progenitor cell transplantation. A median of 2.08 x 10(6) CD34+ peripheral blood progenitor cells/kg were infused 1 day after preparative conditioning with 11.25 Gy total body irradiation and cyclophosphamide (120 mg/kg). Forty-one patients received myeloablative chemoradiotherapy followed by the infusion of IL-2-mobilized autologous peripheral blood progenitor cells. The median times to both neutrophil and platelet recovery were 16 days (range, 2-43) and 23 days (8-318+ days), respectively. Twenty-seven patients remain alive with 24 in continued first complete remission. Median remission duration for all eligible patients is 8 months, and actuarial leukemia-free survival is 49+/-15%. The actuarial risk of relapse is 43+/-16%. Toxicity of autologous peripheral blood progenitor cell transplant included treatment-related death in three patients and serious organ toxicity in 12. Advanced age was a negative prognostic factor for leukemia-free survival. Results were compared to an age-matched historical control treated with autologous transplantation of chemotherapy-mobilized progenitor cells; no significant difference in favor of IL-2 mobilization could be demonstrated. Our results demonstrate that autologous transplantation of IL-2-mobilized peripheral blood progenitor cells is feasible in an unselected population of adult patients with acute myelogenous leukemia in first remission with minimal toxicity but no clear evidence of benefit in leukemia-free survival.

PX-171–006: Phase Ib multicenter dose escalation study of carfilzomib (CFZ) plus lenalidomide (LEN) and low-dose dexamethasone (loDex) in relapsed and refractory multiple myeloma (MM): Preliminary results

8541

Background: CFZ is a highly specific proteasome inhibitor with single agent activity in relapsed/refractory MM (ASH 2008). The purpose of this study is to evaluate the safety and activity of CFZ in combination with LEN and loDex. Methods: This phase Ib trial evaluates 4 dose levels (≥ 3 pts each) to define the maximum tolerated dose (MTD) of CFZ/LEN/loDex in relapsed/refractory MM pts who failed 1–3 prior therapies, including prior LEN or bortezomib (BTZ). CFZ IV 15- 20 mg/m2 (d1,2,8,9,15,16), LEN 10–20 mg po (d1–21) and loDex 40 mg po (d1, 8, 15, 22) in 28-day cycles (C). An additional 10–15 pts will be evaluated at the highest dose level reached. Dose limiting toxicity (DLT) has been defined as grade (G) ≥ 3 non- hematologic; G4 neutropenia for > 7d and/or neutropenic fever; G4 thrombocytopenia > 7d or G3-G4 thrombocytopenia in association with bleeding. Overall response (CR/sCR, VGPR/PR) is assessed by IWG criteria, with secondary assessment by modified EBMT criteria which includes MR. Results: 11 pts have been enrolled. 8/11 are evaluable for response and toxicity. Median prior lines of therapy was 2 (range 2–3). Prior therapies included DEX (8/8), BTZ (6/8), LEN (7/8), alkylators (6/8), anthracyclines (5/8), stem cell transplant (5/8), and thalidomide (1/8); 6/8 pts had received both LEN and BTZ. MTD has not yet been reached after the first 2 dose cohorts. No drug related SAEs or G3/4 treatment emergent AEs were reported. Responses to date with a median of 2 C (range 1–4) are shown below. Responses were rapid and occurred within the first 28-day cycle. Conclusions: CFZ/LEN/loDex in combination was well tolerated in the first 2 cohorts. There have been no myleosuppressive or renal DLTs. The combination has achieved early encouraging responses in pts who had failed both LEN and BTZ at doses well below the single agent MTD of either LEN or CFZ. Dose escalation is ongoing. Updated data will be presented at the meeting.

[Table: see text]

[Table: see text]

Phase II results of Study PX-171–007: A phase Ib/II study of carfilzomib (CFZ), a selective proteasome inhibitor, in patients with selected advanced metastatic solid tumors

3515

Background: CFZ is a novel proteasome inhibitor of the peptide epoxyketone class that exhibits a high level of selectivity for proteasome active sites. This phase 1/2 study assessed the maximum tolerated dose (MTD), safety, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of CFZ in patients (pts) with advanced metastatic solid tumors. Methods: Pts failing ≥ 2 prior treatments were enrolled in the phase 1 3+3 dose escalation study. Pts received CFZ IV Day (D) 1, 2, 8, 9, 15 and 16 every 28 d for up to 12 cycles (C) Cycle 1 D1, D2 dosing in all cohorts was at 20 mg/m2. Subsequent doses remained at 20 mg/m2 or were escalated to 27 or 36 mg/m2 in a stepped up regimen on D8. At 20/36 mg/m2, 1 pt had a DLT (Grade 3 fatigue) and established the phase 2 dose. Phase 2 is designed as a Simon 2 stage of 70 pts split into 5 subgroups (small cell lung [SCLC], non-small cell lung [NSCLC], ovarian, renal, and other cancer). Tumor response was measured every 2 C. ORR, defined as CR+PR+SD, to 16 wks of CFZ. Stage 2 will open if a 1 PR or better at 16 wks occurs in a selected subgroup. Results: 14 pts in phase 1 and 51 pts in phase 2 (23M/28F, mean age 61 yrs) received a total of 154.5 cycles of CFZ. Median cycles administered was 1.7 (range 1 to 12). To date, there were 6 SCLC, 10 NSCLC, 11 ovarian, 6 renal, and 18 other cancer patients enrolled to the Simon stage 1. Efficacy of SD or better is detailed in the table. The most common AEs included fatigue headache, diarrhea, nausea and constipation. Notable was the absence of grade > 1 peripheral neuropathy and severe hematologic toxicities. Final results of the PK and PD will be reported. Conclusions: CFZ is active as a single agent in relapsed solid tumors demonstrating PR in both renal and SCLC; and SD >16 wks in mesothelioma, ovarian, renal and NSCLC. The 20/36 mg/m2 QDx2 dose schedule was well tolerated and lacks severe myelosuppression, hepatotoxicity and neuropathy which make CFZ an attractive agent to combine with traditional or novel targeted agents.

[Table: see text]

[Table: see text]

Six-hour versus 12-hour protocols for AMI: CK-MB in conjunction with myoglobin

The objective was to test the hypothesis that a protocol using myoglobin and creatine kinase-MB (CK-MB) can rapidly and safely exclude myocardial infarction (MI). The study used a prospective, convenience cohort of ED patients with clinically suspected myocardial ischemia. Myoglobin was measured on presentation, 2 and 6 hours later; CK-MB was measured on presentation, 6, 12, and 18 hours later. Of 519 patients, 76 (15%) had MIs, all of whom "ruled in" within 12 hours using a combination of myoglobin and CK-MB, for a sensitivity of 100% (95% CI, 95% to 100%), specificity of 92% (95% CI, 89% to 94%), LR (+) of 12 (95% CI, 9 to 16), and an LR (-) of 0.03 (95% CI, 0.0 to 0.05). Of the 76 patients with MIs, 73 ruled in with a 6 hour protocol, also using a combination of CK-MB and myoglobin, for a sensitivity of 96% (95% CI, 89% to 99%), specificity of 92% (95% CI, 89% to 94%), LR (+) of 11 (95% CI, 8 to 16), and an LR (-) of 0.04 (95% CI, 0.01 to 0.12). Our results support the hypothesis that, using an abbreviated protocol with CK-MB and myoglobin, MI can be reliably ruled out in ED patients with suspected ischemia.

PX-171–004, a multicenter phase II study of carfilzomib (CFZ) in patients with relapsed myeloma: An efficacy update

8537

Background: Carfilzomib (CFZ) is a proteasome inhibitor, active against hematologic malignancies. Preclinically, CFZ overcomes bortezomib (BTZ) resistance in multiple tumors, including myeloma (MM). PX-171–004 is an ongoing Phase II study evaluating safety and efficacy of CFZ in MM patients with relapsed disease after 1–3 prior therapies. Overall Response Rate (ORR) of 35.5% for all subjects was previously reported (ASH 2008); updated data are now available. Methods: Patients were divided into two cohorts: BTZ-naïve and BTZ-exposed. CFZ 20 mg/m2 was administered Days 1, 2, 8, 9, 15 and 16 in a 28-day cycle, for up to 12 cycles. Dexamethasone 4 mg po was administered prior to each dose in Cycle 1. The primary endpoint was ORR, defined as Partial Response (PR) or better. Secondary endpoints included Duration Of Response (DOR) and Time To Progression (TTP). Results: 31 patients were enrolled; 14 (45%) BTZ-naïve and 17 (55%) BTZ-exposed. Of the BTZ-exposed cohort, 2 subjects received BTZ exclusively as a single agent, 6 had BTZ in a chemotherapy combination, and 9 received BTZ in a transplant regime. Overall, 23 (74%) subjects had > 1 prior therapy and 27 (87%) received transplant. In BTZ-naïve patients, CFZ achieved an ORR of 57%; median DOR of 8.6 mos (range >1.9 to >9.7 mos). To date, 7 patients (50%) remain progression free and 3 patients have completed 12 cycles. The median follow-up was 10 mos and the median TTP has not been reached. For the BTZ- exposed group, CFZ achieved an ORR of 18%; median DOR not yet reached (>8.5 mos) (range >1 d to >8.5 mos). 7 patients (41%) are progression free and 3 patients have completed 12 cycles. Median follow-up and TTP were 9.2 and 8.9 mos, respectively. Conclusions: These preliminary results demonstrate that single-agent CFZ is tolerable for at least 1 yr and achieves sustained responses in relapsed MM. Prior BTZ mono/combination therapy does not preclude durable response with CFZ. These data support continuing evaluation of CFZ in the treatment of relapsed MM.

[Table: see text]

[Table: see text]

Anti-EpCAM XmAb antibodies with improved cytotoxicity

12506

Background: The epithelial cell adhesion molecule (EpCAM), also known as epithelial protein 2 (EGP-2) or 17–1A antigen, is a trans-membrane protein expressed on the surfaces of most carcinomas, including those of pancreatic, colorectal, prostate, breast, kidney, lung, and ovarian origins. Moderate affinity antibodies (Abs) such as 17–1A (Kd ∼ 10−7 nM) have been safe in humans albeit with limited clinical efficacy. Attempts to improve clinical efficacy by enhancing antigen affinity (Kd ∼ 10−9 nM) have led to serious clinical toxicity, including pancreatitis. These observations raise the question of whether a moderate affinity Ab with enhanced effector function will be both safe and clinically efficacious. Methods: We applied our proprietary XmAb™ technologies to humanize the 17–1A variable domain and engineer a human IgG1 Fc domain to increase affinity for the activating receptor FcγRIIIa. Ab binding to Ep-CAM or to Fc receptors was tested with Biacore and/or AlphaScreen binding assays. In vitro cytotoxic activity against representative cancer cell lines was measured with Antibody Dependent Cell-mediated Cytotoxicity (ADCC) assays, using human PBMC as effector cells. Results: Humanized anti-EpCAM Abs have affinity for EpCAM similar to the parent 17–1A. Affinity for the activating FcγRIIIa was increased 100-fold relative to a control Ab with an IgG1 Fc domain. As expected, these Abs exhibit dramatically enhanced ADCC against multiple cancer cell lines relative to 17–1A and IgG1 control Abs. Despite their moderate affinity for EpCAM, these novel Abs have in vitro cytotoxicity comparable to the high affinity Ab ING-1. CDC activities of these Abs were similar to chimeric 17–1A. Conclusions: We have demonstrated that antibodies with moderate affinity for EpCAM and increased FcγRIIIa affinity exhibit superior cancer cell killing via an ADCC mechanism. The humanized nature and the increased cytotoxicity of anti-EpCAM XmAb™ antibodies make them promising candidates for clinical development of a novel pan-carcinoma Ab that is superior to 17–1A.

[Table: see text]