MRTX-500 Phase 2 Trial: Sitravatinib With Nivolumab in Patients With Nonsquamous NSCLC Progressing On or After Checkpoint Inhibitor Therapy or Chemotherapy

INTRODUCTION

Sitravatinib, a receptor tyrosine kinase inhibitor targeting TYRO3, AXL, MERTK receptors, and vascular epithelial growth factor receptor 2, can shift the tumor microenvironment toward an immunostimulatory state. Combining sitravatinib with checkpoint inhibitors (CPIs) may augment antitumor activity.

METHODS

The phase 2 MRTX-500 study evaluated sitravatinib (120 mg daily) with nivolumab (every 2 or 4 wk) in patients with advanced nonsquamous NSCLC who progressed on or after previous CPI (CPI-experienced) or chemotherapy (CPI-naive). CPI-experienced patients had a previous clinical benefit (PCB) (complete response, partial response, or stable disease for at least 12 weeks then disease progression) or no PCB (NPCB) from CPI. The primary end point was objective response rate (ORR); secondary objectives included safety and secondary efficacy end points.

RESULTS

Overall, 124 CPI-experienced (NPCB, n = 35; PCB, n = 89) and 32 CPI-naive patients were treated. Investigator-assessed ORR was 11.4% in patients with NPCB, 16.9% with PCB, and 25.0% in CPI-naive. The median progression-free survival was 3.7, 5.6, and 7.1 months with NPCB, PCB, and CPI-naive, respectively; the median overall survival was 7.9 and 13.6 months with NPCB and PCB, respectively (not reached in CPI-naive patients; median follow-up 20.4 mo). Overall, (N = 156), any grade treatment-related adverse events (TRAEs) occurred in 93.6%; grade 3/4 in 58.3%. One grade 5 TRAE occurred in a CPI-naive patient. TRAEs led to treatment discontinuation in 14.1% and dose reduction or interruption in 42.9%. Biomarker analyses supported an immunostimulatory mechanism of action.

CONCLUSIONS

Sitravatinib with nivolumab had a manageable safety profile. Although ORR was not met, this combination exhibited antitumor activity and encouraged survival in CPI-experienced patients with nonsquamous NSCLC.

Abstract P239: Safety and efficacy of copanlisib in combination with nivolumab: A phase Ib study in patients with advanced solid tumors

Introduction: Copanlisib (C) is a pan-class I PI3K inhibitor, with predominant activity against the PI3K-α and -δ isoforms, approved for patients (pts) with relapsed follicular lymphoma. The PD-1 inhibitor nivolumab (N) is approved for several advanced or metastatic solid tumors. Following preclinical demonstration of the immunomodulatory activity of C (Glaeske et al. AACR 2018), we report Phase Ib results evaluating the safety and efficacy of C+N in pts with advanced solid tumors (NCT03735628). Methods: PD-1 inhibitor-naive adult pts with advanced solid tumors received C 45 mg or 60 mg i.v. (days 1, 8, and 15; 28-day cycle) and N 240 mg (day 15 of cycle 1 and days 1 and 15 of subsequent cycles). The primary objective was determination of the recommended Phase II dose (RP2D) of C in combination with N. Secondary endpoints were safety/tolerability, pharmacokinetics (PK), and efficacy. Exploratory real-time evaluation of 77 pharmacodynamic and predictive immune cell biomarkers by flow cytometry on whole blood was performed. Results: 16 pts were treated (C 45 mg + N 240 mg, n=5; C 60 mg + N 240 mg, n=11). Median age was 65 years (range 37–89), 12 pts (75%) were male, and 8 pts (50%) had stage IV disease at diagnosis; the most common tumor types were head and neck squamous cell carcinoma (HNSCC; 7 pts) and bladder cancer (BC; 4 pts). No dose-limiting toxicities were reported. The RP2D of C+N 240 mg was 60 mg. As of 13 May 2020, 4 pts remain on treatment. The most common treatment-emergent adverse events (TEAEs) of any grade were hypertension and diarrhea (7 pts [44%] each, ≤ grade [G] 3) and maculo-papular rash and fatigue (6 pts [38%] each, ≤G3). C-related TEAEs were reported in 88% of pts, all ≤G3. AEs leading to C dose interruption/reduction were reported in 31%/19% of pts; TEAEs led to C discontinuation in 1 pt (60 mg; hematuria). Serious AEs occurred in 5 pts (31%). One G5 TEAE occurred (45 mg; general physical health deterioration, unrelated to C or N). No PK interactions were observed between C and N. Two pts had a partial response: 1 in the C 45 mg group (HNSCC) and 1 in the 60 mg group (BC; benefit sustained after 19 cycles). Stable disease was seen in 10 pts and disease progression in 3 pts; disease control rate (DCR) was 75%. Maximum decrease in circulating monocytic myeloid-derived suppressor cells (M-MDSCs; p<0.05) from baseline occurred on day 2 after C, returning to baseline on day 8. A significant increase in activated (HLA-DR+ and CD38+) natural killer and CD8+ T cells was seen 2 weeks post-treatment with C+N. Lower baseline levels of CD8+ Teffector memory (TEM) subset CD45RA-/CCR7- (CD3+/CD8+) seemed to associate with higher DCR. Conclusions: C+N showed acceptable safety and preliminary efficacy in pts with advanced solid tumors. The immunomodulatory effect of C on M-MDSCs was seen 2 days post-treatment, and lower TEM subset levels seemed to associate with better disease control. These results support further investigation of C+N in pts with advanced solid tumors. Funding: Bayer AG. Writing support: Complete HealthVizion.

Citation Format: Benedito A. Carneiro, Robert Jotte, Nashat Gabrail, Omid Hamid, Funan Huang, Shalini Chaturvedi, Matthias Herpers, Lidia Mongay Soler, Barrett H. Childs, Aaron Hansen. Safety and efficacy of copanlisib in combination with nivolumab: A phase Ib study in patients with advanced solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P239.

Continuous Versus 1-Year Fixed-Duration Nivolumab in Previously Treated Advanced Non-Small-Cell Lung Cancer: CheckMate 153

Limited data exist on the optimal duration of immunotherapy, including for non–small-cell lung cancer (NSCLC). We present an exploratory analysis of CheckMate 153, a largely community-based phase IIIb/IV study, to evaluate the impact of 1-year fixed-duration versus continuous therapy on the efficacy and safety of nivolumab.

Abstract A081: A phase 1b, open-label, dose escalation and expansion study of demcizumab plus pembrolizumab in patients with locally advanced or metastatic solid tumors

Introduction: Delta-like ligand 4 (DLL4) is a ligand that activates the Notch pathway. Demcizumab is a humanized, anti-DLL4 antibody that has been shown using an in vivo tumorigenicity limiting dilution assay to inhibit tumor growth and decrease cancer stem cell frequency in minimally passaged human xenograft models. In addition, inhibition of DLL4 has also been shown in preclinical studies to cause an antiangiogenic effect and to decrease the number of monocytic myeloid-derived suppressor cells (MDSCs) within the tumor. Finally, xenograft studies showed enhanced activity when demcizumab was combined with anti-PD1. Therefore, we hypothesized that demcizumab in combination with anti-PD1 may be effective in cancers that are refractory to anti-PD1 therapy and where MDSCs play a role in prognosis such as castrate-resistant prostate cancer and/or may augment the activity of anti-PD-1 in sensitive tumor types. Methods: This was an open-label, phase 1b dose study of demcizumab plus pembrolizumab in patients with advanced or metastatic solid tumors. Patients were enrolled in two stages: a dose-escalation stage and an expansion stage. In the dose escalation phase, patients received demcizumab 2.5 or 5 mg/kg administered IV once every 3 weeks for two 63-day truncated courses (second course starting on Day 168). Pembrolizumab was given at 2 mg/kg administered IV over 30 minutes every 3 weeks. Three cohorts of 10 patients each (anti-PD1 naïve 2L non-squamous NSCLC, anti-PD1 refractory, and advanced castrate-resistant prostate cancer) were planned to be enrolled in the dose escalation portion of the trial and treated with the MTD of demcizumab that was established in the dose escalation phase of the trial. Results: Twenty-seven patients were enrolled in the study: 9 in dose escalation and 18 in expansion. The MTD of demcizumab was determined to be 5 mg/kg (i.e., the highest dose tested). One partial response was observed in a NSCLC patient and 8 patients had stable disease. Peripheral MDSCs were measured over time in 5 of the prostate cancer patients, but no consistent impact was observed on the monocytic MDSCs. Demcizumab plus pembrolizumab was well tolerated. The most common adverse events were fatigue (44%), vomiting (41%), nausea (37%), headache (26%), BNP increased (22%), and decreased appetite (22%). Nine immune-related AEs occurred with only 2 being Grade 3 or greater. Conclusion: Demcizumab plus pembrolizumab therapy was well tolerated, but there was no evidence of enhanced antitumor activity.

Citation Format: Melissa Johnson, Drew Rasco, Brian Schneider, Catherine Shu, Robert Jotte, Hema Parmer, Robert Stagg, Juanita Lopez. A phase 1b, open-label, dose escalation and expansion study of demcizumab plus pembrolizumab in patients with locally advanced or metastatic solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A081.

Outcomes in patients with aggressive or refractory disease from REVEL: A randomized phase III study of docetaxel with ramucirumab or placebo for second-line treatment of stage IV non-small-cell lung cancer

OBJECTIVES

The REVEL study demonstrated improved efficacy for patients with advanced non-small cell lung cancer treated with ramucirumab plus docetaxel, independent of histology. This exploratory analysis characterized the treatment effect in REVEL patients who were refractory to prior first-line treatment.

MATERIALS AND METHODS

Refractory patients had a best response of progressive disease to first-line treatment. Endpoints included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), quality of life (QoL), and safety. Kaplan-Meier and Cox proportional hazards regression were performed for OS and PFS, and Cochran-Mantel-Haenszel test was used for response. QoL was assessed with the Lung Cancer Symptom Scale. Sensitivity analyses were performed on subgroups of the intent-to-treat population with limited time on first-line therapy.

RESULTS

Of 1253 randomized patients in REVEL, 360 (29%) were refractory to first-line treatment. Baseline characteristics were largely balanced between treatment arms. In the control arm, median OS for refractory patients was 6.3 versus 10.3 months for patients not meeting this criterion, demonstrating the poor prognosis of refractory patients. Median OS (8.3 vs. 6.3 months; HR, 0.86; 95% CI, 0.68-1.08), median PFS (4.0 vs. 2.5 months; HR, 0.71; 95% CI, 0.57-0.88), and ORR (22.5% vs. 12.6%) were improved in refractory patients treated with ramucirumab compared to placebo, without new safety concerns or further deteriorating patient QoL.

CONCLUSIONS

The effect of ramucirumab in refractory patients is similar to that in the intent-to-treat population. The benefit/risk profile for refractory patients suggests that ramucirumab plus docetaxel is an appropriate treatment option even in this difficult-to-treat population.

Randomized Phase III Trial of Amrubicin Versus Topotecan As Second-Line Treatment for Patients With Small-Cell Lung Cancer

Purpose

Amrubicin, a third-generation anthracycline and potent topoisomerase II inhibitor, showed promising activity in small-cell lung cancer (SCLC) in phase II trials. This phase III trial compared the safety and efficacy of amrubicin versus topotecan as second-line treatment for SCLC.

Patients and Methods

A total of 637 patients with refractory or sensitive SCLC were randomly assigned at a ratio of 2:1 to 21-day cycles of amrubicin 40 mg/m2 intravenously (IV) on days 1 to 3 or topotecan 1.5 mg/m2 IV on days 1 to 5. Primary end point was overall survival (OS); secondary end points included overall response rate (ORR), progression-free survival (PFS), and safety.

Results

Median OS was 7.5 months with amrubicin versus 7.8 months with topotecan (hazard ratio [HR], 0.880; P = .170); in refractory patients, median OS was 6.2 and 5.7 months, respectively (HR, 0.77; P = .047). Median PFS was 4.1 months with amrubicin and 3.5 months with topotecan (HR, 0.802; P = .018). ORR was 31.1% with amrubicin and 16.9% with topotecan (odds ratio, 2.223; P < .001). Grade ≥ 3 treatment-emergent adverse events in the amrubicin and topotecan arms were: neutropenia (41% v 54%; P = .004), thrombocytopenia (21% v 54%; P < .001), anemia (16% v 31%; P < .001), infections (16% v 10%; P = .043), febrile neutropenia (10% v 3%; P = .003), and cardiac disorders (5% v 5%; P = .759); transfusion rates were 32% and 53% (P < .001), respectively. NQO1 polymorphisms did not influence safety outcomes.

Conclusion

Amrubicin did not improve survival when compared with topotecan in the second-line treatment of patients with SCLC. OS did not differ significantly between treatment groups, although an improvement in OS was noted in patients with refractory disease treated with amrubicin.

A multicenter, phase I, dose-escalation study to assess the safety, tolerability, and pharmacokinetics of etirinotecan pegol in patients with refractory solid tumors

PURPOSE

This study was designed to establish the maximum tolerated dose (MTD) and to evaluate tolerability, pharmacokinetics, and antitumor activity of etirinotecan pegol.

EXPERIMENTAL DESIGN

Patients with refractory solid malignancies were enrolled and assigned to escalating-dose cohorts. Patients received 1 infusion of etirinotecan pegol weekly 3 times every 4 weeks (w × 3q4w), or every 14 days (q14d), or every 21 days (q21d), with MTD as the primary end point using a standard 3 + 3 design.

RESULTS

Seventy-six patients were entered onto 3 dosing schedules (58-245 mg/m(2)). The MTD was 115 mg/m(2) for the w × 3q4w schedule and 145 mg/m(2) for both the q14d and q21d schedules. Most adverse events related to study drug were gastrointestinal disorders and were more frequent at higher doses of etirinotecan pegol. Late onset diarrhea was observed in some patients, the frequency of which generally correlated with dose density. Cholinergic diarrhea commonly seen with irinotecan treatment did not occur in patients treated with etirinotecan pegol. Etirinotecan pegol administration resulted in sustained and controlled systemic exposure to SN-38, which had a mean half-life of approximately 50 days. Overall, the pharmacokinetics of etirinotecan pegol are predictable and do not require complex dosing adjustments. Confirmed partial responses were observed in 8 patients with breast, colon, lung (small and squamous cell), bladder, cervical, and neuroendocrine cancer.

CONCLUSION

Etirinotecan pegol showed substantial antitumor activity in patients with various solid tumors and a somewhat different safety profile compared with the irinotecan historical profile. The MTD recommended for phase II clinical trials is 145 mg/m(2) q14d or q21d.

Randomized Phase II Trial of Single-Agent Amrubicin or Topotecan as Second-Line Treatment in Patients With Small-Cell Lung Cancer Sensitive to First-Line Platinum-Based Chemotherapy

Purpose

This phase II study evaluated the safety and efficacy of single-agent amrubicin versus topotecan in patients with small-cell lung cancer (SCLC) sensitive to first-line platinum-based chemotherapy.

Patients and Methods

Patients were randomly assigned 2:1 to amrubicin (40 mg/m2/d in a 5-minute intravenous [IV] infusion, days 1 through 3, every 21 days) or topotecan (1.5 mg/m2/d in a 30-minute IV infusion, days 1 through 5, every 21 days). The primary efficacy end point was overall response rate (ORR) for amrubicin. Secondary end points included time to progression, median progression-free survival (PFS), and median overall survival (OS).

Results

Of 76 patients enrolled, 50 patients were randomly assigned to amrubicin, and 26 patients were randomly assigned to topotecan. Amrubicin treatment resulted in a significantly higher ORR than topotecan (44% v 15%; P = .021). Median PFS and median OS were 4.5 months and 9.2 months with amrubicin and 3.3 months and 7.6 months with topotecan, respectively. Tolerability was similar with both agents. However, grade 3 or worse neutropenia and thrombocytopenia seemed to be more frequent in the topotecan group as compared with the amrubicin group (78% and 61% v 61% and 39%, respectively).

Conclusion

Amrubicin shows promising activity, with an ORR of 44% compared with an ORR of 15% for topotecan as second-line treatment in patients with SCLC sensitive to first-line platinum-based chemotherapy. In addition, the safety profiles were comparable; however, a trend was noted for more frequent grade 3 or worse neutropenia and thrombocytopenia in the topotecan group as compared with the amrubicin group. Additional studies are ongoing.

Phase II study of amrubicin as second-line therapy in patients with platinum-refractory small-cell lung cancer

PURPOSE

Amrubicin is a synthetic anthracycline with potent topoisomerase II inhibition. This phase II study was conducted to confirm safety and activity of amrubicin in the treatment of refractory small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients with refractory SCLC (either with progressive disease as best response or progression within 90 days of first-line therapy) received amrubicin (40 mg/m(2)/d for 3 every 21 days). The primary end point was overall response rate (ORR); secondary end points included progression-free survival (PFS), overall survival (OS), and change in left ventricular ejection fraction (LVEF).

RESULTS

Seventy-five patients with a median progression-free interval after first-line therapy of 38 days were enrolled; 69 patients received a median of four amrubicin cycles (range, one to 12 cycles). The ORR was 21.3% (95% CI, 12.7% to 32.3%), with one complete response (1.3%) and 15 partial responses (20%). Median PFS and OS were 3.2 months (95% CI, 2.4 to 4.0 months) and 6.0 months (95% CI, 4.8 to 7.1 months), respectively. The ORR in 43 patients who never responded to first-line therapy was 16.3% (95% CI, 6.8% to 30.7%). Most commonly reported grade 3 or 4 adverse events included neutropenia (67%), thrombocytopenia (41%), and anemia (30%), with febrile neutropenia in 12%. There was no decrease in mean LVEF with cumulative amrubicin doses exceeding 750 mg/m(2).

CONCLUSION

Single-agent amrubicin showed promising activity with a 21.3% ORR and an acceptable safety profile when used as second-line therapy patients with platinum-refractory SCLC. Amrubicin did not induce early cardiotoxicity, but its long-term effects are unknown.

Results of a phase II trial of single-agent amrubicin (AMR) in patients with extensive disease small cell lung cancer (ED-SCLC) refractory to first-line platinum-based chemotherapy: An update

8103

Background: Amrubicin (AMR), a third-generation synthetic anthracycline and potent topoisomerase II inhibitor, is approved in Japan for the treatment of lung cancer. Patients (pts) with SCLC, who are refractory to first-line chemotherapy or progress within 3 months (mos) of treatment completion, are less likely to respond to additional chemotherapy and have an expected median survival of 3–5 mos. Here, we investigate the efficacy and safety of single-agent AMR in the treatment of Western pts with refractory ED-SCLC. Methods: In this phase II trial, pts with ED-SCLC refractory to prior 1st-line platinum-based chemotherapy (defined as progression (PD) while on therapy or relapse within 90 days of treatment completion) and ECOG performance status (PS) ≤2 were eligible. Patients were treated with intravenous AMR 40 mg/m2/day x 3 days every 21 days until PD or intolerable toxicity. The primary endpoint was response rate (ORR, by RECIST), with a goal to demonstrate an ORR ≥18% (point estimate). Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Results: In all, 75 pts were enrolled with a median age of 63 years (range 43–88), 52% female, 17% PS 2. Response to 1st-line therapy was 5% complete remission (CR), 36% partial remission (PR) and 28% PD. Median time from completion of 1st-line therapy to PD was 1.3 mos. Sixty-nine pts received AMR for a median of 4 cycles (range 1–12). Six pts died or discontinued before receiving treatment. The primary endpoint was met with an ORR of 21% (16/75, 95% confidence interval [CI] 13.6% - 31.9%), including CR in 1 pt (1%) and PR in 15 pts (20%). Stable disease was achieved in 40% of pts. Two pts with PD as best response to 1st line chemotherapy achieved a PR. Median OS was 6.0 mos (95% CI 4.8–7.1 mos). Median PFS was 3.2 mos (95% CI 2.4–4.0 mos). The most common grade 3 or 4 adverse events were neutropenia (65%), thrombocytopenia (39%), and leukopenia (35%). Seven (10%) patients experienced febrile neutropenia. Dose reductions were required in 26 patients (38%). Conclusions: AMR shows promising activity, with an ORR of 21%, and an acceptable safety profile in patients with refractory ED-SCLC, and warrants further study in these pts.

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A prospective evaluation of quality of life (QOL) in a phase II trial of pemetrexed (P) plus carboplatin (Cb) ± enzastaurin (E) versus docetaxel (D) plus Cb as first-line treatment of patients (pts) with advanced non-small cell lung cancer (NSCLC)

e19050

Background: E is a selective, oral serine/threonine kinase inhibitor. PCb has shown promising clinical activity in two phase 2 trials of advanced NSCLC. This open-label, three-arm trial was designed to assess PCb ± E versus a control arm of DCb. QOL may be an important consideration with the introduction of targeted agents such as E that have a different toxicity profile than traditional chemotherapeutic agents. Methods: Pts with Stage IIIB (with pleural effusion) or IV NSCLC, ECOG PS of 0 or 1, and no prior systemic therapy were enrolled. Pts were equally randomized to one of three arms: (A) P 500 mg/m2 and Cb AUC 6 every 3 wks X 6 cycles with E given orally as a loading dose of 1200 mg or 1125 mg followed by 500 mg daily until disease progression; (B) The same regimen of PCb without E; or (C) D 75 mg/m2 and Cb AUC 6 every 3 wks X 6 cycles. Pts receiving P were also administered folic acid, vitamin B12 and steroid prophylaxis. Pts on D also received steroid prophylaxis. The Functional Assessment of Cancer Therapy-Lung (FACT-L) Questionnaire and FACT-Taxane toxicity subscale were used to evaluate QOL at baseline and every 3 weeks up to 18 weeks during treatment. A best overall response of improved or worsened was defined as an increase or decrease from baseline to last patient visit of ≥ 0.5 standard deviations of baseline scores. Results: The intent-to-treat population of this study consisted of 218 randomized pts (PCE: 72, PC: 74, DC: 72). Baseline and ≥ 1 post-baseline score was obtained from 54 pts receiving PCE (75%), 62 pts receiving PC (84%), and 54 pts receiving DC (75%). QOL data are summarized in the table below. Conclusions: Across treatment groups, differences in mean scores were not statistically significant. In addition, differences in classification of improved, stable, or worsened were not statistically significant across treatment groups.

[Table: see text]

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Final results of a randomized phase II trial of pemetrexed (P) + carboplatin (Cb) ± enzastaurin (E) versus docetaxel (D) + Cb as first-line treatment of patients (pts) with stage IIIB/IV non-small cell lung cancer (NSCLC)

8037

Background: E is a selective, oral serine/threonine kinase inhibitor. The combination of PCb has shown clinical activity in two phase 2 trials of advanced NSCLC. A phase 3 trial among pts with stage IIIB/IV NSCLC showed that P + cisplatin provides similar efficacy with better tolerability than gemcitabine + cisplatin (Scagliotti, JCO, 2008). The toxicity profile observed with P + platinum doublets makes these regimens attractive for the integration of novel agents with different mechanisms of action. In the TAX 326 trial, D + cisplatin was associated with a median survival of 11.3 mos vs. 10.1 mos for vinorelbine + cisplatin (P=.04). The current open-label three- arm trial was designed to assess PCb ± E versus a control arm of DCb. Methods: Between 3/06 and 5/08, pts with stage IIIB (with pleural effusion) or IV NSCLC, ECOG PS of 0 or 1, and no prior systemic therapy were enrolled. Pts were equally randomized to 3 arms: (A) P 500 mg/m2 and Cb AUC 6 every 3 wks × 6 cycles with E given orally as a loading dose of 1200 mg or 1125 mg followed by 500 mg daily until disease progression; (B) The same regimen of PCb without E; or (C) D 75 mg/m2 and Cb AUC 6 every 3 wks × 6 cycles. Pts receiving P were administered folic acid, vitamin B12 and steroid prophylaxis. Pts on D also received steroid prophylaxis. Results: See table . Conclusions: First-line treatment with PCb was associated with a significantly longer overall survival than DCb in advanced or metastatic NSCLC. E did not add to the activity of the PCb doublet. PCbE, PCb, and DCb appeared to be well tolerated. Complete results for all patients in the study will be available at the time of the meeting.

[Table: see text]

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Results of a randomized phase II trial of amrubicin (AMR) versus topotecan (Topo) in patients with extensive-disease small cell lung cancer (ED-SCLC) sensitive to first-line platinum-based chemotherapy

8028

Background: SCLC presents as ED-SCLC in 60%-70% of patients (pts). AMR, a synthetic anthracycline, is approved for these pts in Japan. We compare the efficacy and safety of single-agent AMR vs topotecan in non-Japanese pts with 2nd-line ED-SCLC sensitive to 1st-line platinum-based chemotherapy. Methods: This phase II, open-label, multicenter study enrolled pts with ED-SCLC sensitive to 1st-line platinum-based chemotherapy (recurrence or progression ≥90 days from 1st-line treatment). Pts aged ≥18 years with ECOG performance status (PS) ≤2 and only 1 prior therapy were eligible. Pts were randomized (2:1) to receive IV AMR 40 mg/m2/d (d, 1–3) or IV topotecan 1.5 mg/m2/d (d 1–5) and treated every 21 days until progression, unacceptable toxicity, or withdrawal. The primary endpoint, overall response rate (ORR, complete + partial response), used RECIST criteria. Secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Results: In all, 76 pts were randomized to AMR (n=50) or topotecan (n=26) with AMR given for a median of 6 cycles (range 1–16) and topotecan 3 cycles (1–16). AMR significantly improved ORR rates vs topotecan (p<0.012; Table ). Median PFS/OS was 4.3 months (95% CI 2.0, 6.1)/9.3 months (95% CI 5.7, 12.0) with AMR vs 3.5 months (95% CI 2.1, 6.3)/8.9 months (95% CI 4.8, 13.8) with topotecan. There was a higher proportion of ECOG PS 2 pts in the AMR group (n=6) vs the topotecan group (n=2). A trend towards improved OS was observed in the ECOG 0–1 subgroup of 68 pts: median OS was 10.5 months with AMR vs 9.7 months with topotecan. The most common grade ≥3 adverse events with AMR vs topotecan were neutropenia (53% vs 74%), thrombocytopenia (31% vs 52%) and leukopenia (27% vs 30%). Three AMR pts (6%) and 1 topotecan pt (4%) died of neutropenic infection. Conclusions: AMR significantly improves ORR and has acceptable tolerability as 2nd-line treatment in pts with sensitive ED-SCLC.

[Table: see text]

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An open-label, phase II trial of nanoparticle albumin bound paclitaxel (nab-paclitaxel), carboplatin, and bevacizumab in first-line patients with advanced non-squamous non-small cell lung cancer (NSCLC)

7610

Background: The development of nab-paclitaxel has circumvented many of the infusion difficulties that are associated with standard solvent based paclitaxel (in cremophor). In this open label, phase II trial, patients with advanced (stage IIIB or IV) nonsquamous NSCLC received the combination of nab-paclitaxel, carboplatin and bevacizumab. Methods: 50 patients were enrolled between October 2005 and April 2006. Patients received intravenous (IV) nab-paclitaxel 300 mg/m2, carboplatin IV AUC=6, and bevacizumab 15 mg/kg on day 1 of each 21-day cycle. Responding patients received at least 4 cycles of treatment; however, therapy was discontinued for patients with progression or intolerable toxicity. The primary endpoint was response rate based on RECIST. Results: The median patient age was 67 years; 80% were white and 56% were female. Patients received a median of 4 cycles (range, <1–6). The preliminary efficacy results are PR 30% and SD 48%; no complete responses were noted. Median progression-free survival was 7.1 months (range, <1–10.6); median survival has not yet been reached. Grade 3–4 treatment related toxicities were neutropenia (52%); fatigue (19%); neuropathy (15%); thrombocytopenia (10%) dyspnea (6%), anorexia, constipation, febrile neutropenia, hemoptysis, and nausea and/or vomiting (4% each). 64% of patients are currently alive. 32 patients have come off study, prior to 4 cycles due to disease progression (12%), adverse event (10%), investigator request (8%), sudden death (6%), and withdrawal of consent (2%); 16 patients had normal study completion (completed 4 cycles of therapy). Conclusions: This combination of nab-paclitaxel, carboplatin and bevacizumab was well tolerated, with moderate neutropenia. Adverse events were manageable. The preliminary analysis from this study indicates that this combination has promising activity in first-line patients with non-squamous NSCLC. This research was supported, in part, by a research grant from Abraxis BioScience, Inc., Santa Monica, CA.

No significant financial relationships to disclose.

Reovirus-induced alteration in expression of apoptosis and DNA repair genes with potential roles in viral pathogenesis

Reoviruses are a leading model for understanding cellular mechanisms of virus-induced apoptosis. Reoviruses induce apoptosis in multiple cell lines in vitro, and apoptosis plays a key role in virus-induced tissue injury of the heart and brain in vivo. The activation of transcription factors NF-kappaB and c-Jun are key events in reovirus-induced apoptosis, indicating that new gene expression is critical to this process. We used high-density oligonucleotide microarrays to analyze cellular transcriptional alterations in HEK293 cells after infection with reovirus strain T3A (i.e., apoptosis inducing) compared to infection with reovirus strain T1L (i.e., minimally apoptosis inducing) and uninfected cells. These strains also differ dramatically in their potential to induce apoptotic injury in hearts of infected mice in vivo-T3A is myocarditic, whereas T1L is not. Using high-throughput microarray analysis of over 12,000 genes, we identified differential expression of a defined subset of genes involved in apoptosis and DNA repair after reovirus infection. This provides the first comparative analysis of altered gene expression after infection with viruses of differing apoptotic phenotypes and provides insight into pathogenic mechanisms of virus-induced disease.

Reovirus-induced alterations in gene expression related to cell cycle regulation

Mammalian reovirus infection results in perturbation of host cell cycle progression. Since reovirus infection is known to activate cellular transcription factors, we investigated alterations in cell cycle-related gene expression following HEK293 cell infection by using the Affymetrix U95A microarray. Serotype 3 reovirus infection results in differential expression of 10 genes classified as encoding proteins that function at the G(1)-to-S transition, 11 genes classified as encoding proteins that function at G(2)-to-M transition, and 4 genes classified as encoding proteins that function at the mitotic spindle checkpoint. Serotype 1 reovirus infection results in differential expression of four genes classified as encoding proteins that function at the G(1)-to-S transition and three genes classified as encoding proteins that function at G(2)-to-M transition but does not alter any genes classified as encoding proteins that function at the mitotic spindle checkpoint. We have previously shown that serotype 3, but not serotype 1, reovirus infection induces a G(2)-to-M transition arrest resulting from an inhibition of cdc2 kinase activity. Of the differentially expressed genes encoding proteins regulating the G(2)-to-M transition, chk1, wee1, and GADD45 are known to inhibit cdc2 kinase activity. A hypothetical model describing serotype 3 reovirus-induced inhibition of cdc2 kinase is presented, and reovirus-induced perturbations of the G(1)-to-S, G(2)-to-M, and mitotic spindle checkpoints are discussed.

The contribution of impurities to the acute morbidity of illegal drug use

Although emergency physicians treat many patients who use illegal drugs, little is known about the relative toxicities of the abused drug versus those that result from drug impurities and additives. Although case reports suggest significant contribution of contaminants to the morbidity and mortality of street drugs, most physicians' clinical experience and a comprehensive review of the clinical and forensic science literature demonstrate that impurities and additives play only a minor role in the majority of drug-related emergency department presentations. The strengths and weaknesses of several of the currently available drug abuse information data bases are reviewed, and qualitative information concerning the scope of contaminants that have been reported in preparations of cocaine, heroin, and phencyclidine is presented. More research is needed in this area, and a closer liaison between law enforcement, forensic scientists, and emergency physicians should be developed.

The electrocardiographic manifestations of cyclic antidepressant therapy and overdose: a review

Cyclic antidepressants may cause changes in the electrocardiogram at therapeutic or toxic serum levels. The most serious complications of cyclic antidepressant toxicity are dysrhythmias, hypotension, and seizures. It is predominantly the cardiotoxic effects that cause mortality. Once cardiotoxicity is evident, the treatment of choice is serum alkalinization, preferably by sodium bicarbonate therapy. In order to predict which overdose patients are at high risk for complications, electrocardiographic criteria have been identified as reliable screens. For "first generation" tricyclic antidepressants, QRS prolongation (particularly greater than 100 msec) and a terminal 40-ms frontal plane axis greater than 120 degrees are the most sensitive. This article reviews antidepressant pharmacology, electrocardiographic manifestations of antidepressant cardiotoxicity, and approaches to treatment of antidepressant-induced conduction disturbances and dysrhythmias.

Interactions between T helper cells and dendritic cells during the rat mixed lymphocyte reaction

This paper describes the interactions between dendritic cells (DC) and T helper (Th) cells in the rat mixed lymphocyte reaction (MLR). Th blasts that are actively proliferating were generated in a 5 d primary MLR; resting Th memory cells were derived from a 10-12 d MLR. The DC were purified from thoracic duct lymph derived from rats whose mesenteric lymph nodes had been removed. The results show that DC are the major stimulators in the primary MLR and also for the restimulation of Th blasts and Th memory cells. Th blasts rapidly formed large clusters when cultured with DC but not with Ia+ macrophages or B cells. This interaction was not dependent on a major histocompatibility complex (MHC) difference between the T blasts and the DC. Con A-activated T and B blasts also formed clusters when cultured with DC. Th memory cells formed small clusters with DC, but, in a different assay in which clusters are dispersed, we detected an antigen-specific interaction between Th memory cells and DC. The monoclonal antibodies W3/25 (anti-rat CD4) and MRC OX-6 (anti-MHC class II) blocked proliferation in the primary MLR and also inhibited the restimulation of Th memory cells. However, the restimulation of Th blasts in a secondary MLR was only blocked by MRC OX-6. These results suggest that there are different requirements for the restimulation of T blasts than for the activation of primary or memory Th cells. W3/25 and MRC OX-6 did not affect the clustering of T blasts with DC but they both inhibited the antigen-specific binding of Th memory cells to DC. The data suggest that the CD4 (W3/25) antigen is involved in antigen-specific interactions between Th cells and DC.