Abstract CT013: SWOG S1320: Improved progression-free survival with continuous compared to intermittent dosing with dabrafenib and trametinib in patients with BRAF mutated melanoma

Background: BRAF and MEK inhibitors yield objective responses in the majority of BRAFV600E/K mutant melanoma patients, but acquired resistance limits response durations. Preclinical data suggests that intermittent dosing of these agents may delay acquired resistance by deselecting tumor cells that grow optimally in the presence of these agents. S1320 is a randomized phase 2 clinical trial designed to determine whether intermittent versus continuous dosing of dabrafenib and trametinib improves progression-free survival (PFS) in patients with advanced BRAFV600E/K melanoma.

Methods: All patients received continuous dabrafenib and trametinib for 8-weeks after which non-progressing patients were randomized to receive either continuous treatment or intermittent dosing of both drugs on a 3-week-off, 5-week-on schedule. Unscheduled treatment interruptions of both drugs for > 14 days were not permitted. Responses were assessed using RECIST v1.1 at 8-week intervals scheduled to coincide with on-treatment periods for patients on the intermittent dosing arm. Adverse events were assessed using CTCAE v4 monthly. The design assumed exponential PFS with a median of 9.4 months using continuous dosing, 206 eligible patients and 156 PFS events. It had 90% power with a two-sided α = 0.2 to detect a change to a median with an a priori hypothesis that intermittent dosing would improve the median PFS to 14.1 months using a Cox model stratified by the randomization stratification factors.

Results: 242 patients were treated and 206 patients without disease progression after 8 weeks were randomized, 105 to continuous and 101 to intermittent treatment. 70% of patients had not previously received immune checkpoint inhibitors. There were no significant differences between groups in terms of baseline patient characteristics. The median PFS was statistically significantly longer, 9.0 months from randomization, with continuous dosing vs. 5.5 months from randomization with intermittent dosing (p = 0.064). There was no difference in overall survival between groups (median OS = 29.2 months in both arms p = 0.93) at a median follow up of 2 years. 77% of patient treated continuously discontinued treatment due to disease progression vs. 84% treated intermittently (p = 0.34).

Conclusions: Continuous dosing with the BRAF and MEK inhibitors dabrafenib and trametinib yields superior PFS compared with intermittent dosing.

Support: NIH/NCI grants CA180888, CA180819, CA180820

Citation Format: Alain Algazi, Megan Othus, Adil Daud, Roger Lo, Janice Mehnert, Thach-Giao Truong, Robert Conry, Kari Kendra, Gary Doolittle, Joseph I. Clark, Michael Messino, Dennis F. Moore, Christopher Lao, Bryan A. Faller, Rangaswamy Govindarajan, Amy Harker-Murray, Luke Dreisbach, James Moon, Kenneth Grossman, Antoni Ribas. SWOG S1320: Improved progression-free survival with continuous compared to intermittent dosing with dabrafenib and trametinib in patients with BRAF mutated melanoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT013.

Abstract A084: DENALI: a 3-arm double-blind randomized phase 2 study of carboplatin, pemetrexed, and placebo (CPP) versus carboplatin, pemetrexed, and either 1 or 2 truncated courses of demcizumab (CPD) in patients with non-squamous non-small cell lung cancer (NSCLC)

Introduction: Delta-like ligand 4 (DLL4) is a ligand that activates the Notch pathway, which is important for cancer stem cell (CSC) survival. 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 CSC frequency in minimally passaged human xenograft models. In addition, inhibition of DLL4 has also been shown in preclinical studies to cause dysfunctional sprouting of new vessels, resulting in an antiangiogenic effect. Data from a phase 1b study of carboplatin (C), pemetrexed (P), and demcizumab (D) in patients with 1st-line metastatic non-squamous NSCLC led to this double-blind randomized 3-arm placebo (Pl)-controlled phase 2 study. Methods: Patients with non-squamous NSCLC were randomized (1:1:1) to 1st-line therapy with either Arm 1 -CPPl, Arm 2 -CPD with a single 70-day truncated course of demcizumab or Arm 3 - CPD with two 70-day truncated courses of demcizumab (second course starting on Day 168). CP were given at usual dose and schedule; P/D was given IV on days 1 and 15 in cycles 1-3 and 7-9. The primary endpoint was response rate and secondary endpoints included progression-free survival, survival, safety, immunogenicity, pharmacokinetics, and biomarkers of Notch signaling and CSCs in blood, hair follicles, and tumor cells. The primary study analyses compared CPPl to the two pooled CPD arms. Results: 82 patients were randomized and all 82 were treated. The median age was 61, the male/female ratio was 40/42, 80 pts had adenocarcinoma, 0 pts harbored EGFR mutation or ALK rearrangement, and 15 were KRAS mutated. The response/clinical benefit rates were 52%/92% and 28%/79% in the CPPl and pooled CPD arms, respectively (response p value = 0.04). The median progression-free survival (PFS) was 8.7 months (95% CI: 5.4-12.5) in the CPPl arm and 5.5 months (95% CI: 4.1-6.9) in the pooled CPD arms (HR = 2.3; 95%CI: 1.1-4.8). The interim median overall survival (OS) for the CPPl and pooled CPD arms was not reached (95% CI: 16.0—NR) and 15.5 months (95% CI: 8.3-NR) (HR= 2.4; 95% CI: 0.94-6.1), respectively. CPD was generally well tolerated with nausea, fatigue, constipation, anemia, and hypertension being the most common reported toxicities. The incidences of the Grade 3 or greater toxicities of special interest with demcizumab therapy were hypertension (8% vs 25%), pulmonary hypertension (0% vs 0%), heart failure (0% vs. 0%), and bleeding (0% vs. 3.4%) in the CPPl and pooled CPD arms, respectively. Conclusions: The addition of either 1 or 2 truncated courses of demcizumab to 1st-line carboplatin and pemetrexed did not improve the efficacy compared to CPPl in patients with 1st-line metastatic NSCLC. CPD therapy was generally well tolerated.

Citation Format: Brett Hughes, Andrew Dean, Ben Markman, Luke Dreisbach, Mariano Provencio, Libero Ciuffreda, Rachel Dear, Peter Graze, Alforia Nadal, Baerin Houghton, Teresa Moran, Rachel Roberts, Grace Dy, Taus Alvaro, Alex Martinez Marti, Rainer Brachmann, Robert Stagg, Ramaswamy Govindan. DENALI: a 3-arm double-blind randomized phase 2 study of carboplatin, pemetrexed, and placebo (CPP) versus carboplatin, pemetrexed, and either 1 or 2 truncated courses of demcizumab (CPD) in patients with non-squamous non-small cell lung cancer (NSCLC) [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 A084.

TRAIL receptor agonist conatumumab with modified FOLFOX6 plus bevacizumab for first-line treatment of metastatic colorectal cancer: A randomized phase 1b/2 trial

BACKGROUND

In patients with previously untreated metastatic colorectal cancer (mCRC), we conducted a phase 1b/randomized phase 2 trial to define the safety, tolerability, and efficacy of mFOLFOX6 plus bevacizumab (mFOLFOX6/bev) with conatumumab, an investigational, fully human monoclonal IgG1 antibody that specifically activates death receptor 5 (DR5).

METHODS

Twelve patients were enrolled in a phase 1b open-label dose-escalation trial of conatumumab with mFOLFOX6/bev; thereafter, 190 patients were randomized 1:1:1 to receive mFOLFOX6/bev in combination with 2 mg/kg conatumumab, 10 mg/kg conatumumab, or placebo. Therapy cycles were repeated every 2 weeks until disease progression or the occurrence of unacceptable toxicity.

RESULTS

In phase 1b, conatumumab with mFOLFOX6/bev was tolerated without apparent added toxicity over mFOLFOX6/bev alone. In phase 2, conatumumab with mFOLFOX6/bev did not confer a benefit in progression-free survival when compared with placebo with mFOLFOX6/bev. Toxicity was similar in all treatment arms. Following treatment, similar increases in circulating caspase-3 levels were observed in all arms.

CONCLUSIONS

Conatumumab with mFOLFOX6/bev did not offer improved efficacy over the same chemotherapy with placebo in first-line treatment of patients with mCRC. These data do not support further development of conatumumab in advanced CRC.

Final results of a multicenter phase 1 study of lenalidomide in patients with relapsed or refractory chronic lymphocytic leukemia

Based on clinical activity in phase 2 studies, lenalidomide was evaluated in a phase 2/3 study in patients with relapsed/refractory chronic lymphocytic leukemia (CLL). Following tumor lysis syndrome (TLS) complications, the protocol was amended to a phase 1 study to identify the maximum tolerated dose-escalation level (MTDEL). Fifty-two heavily pretreated patients, 69% with bulky disease and 48% with high-risk genomic abnormalities, initiated lenalidomide at 2.5 mg/day, with dose escalation until the MTDEL or the maximum assigned dose was attained. Lenalidomide was safely titrated to 20 mg/day; the MTDEL was not reached. Most common grade 3-4 adverse events were neutropenia and thrombocytopenia; TLS was mild and rare. The low starting dose and conservative dose escalation strategy resulted in six partial responders and 30 patients obtaining stable disease. In summary, lenalidomide 2.5 mg/day is a safe starting dose that can be titrated up to 20 mg/day in patients with CLL.

Cetuximab and first-line taxane/carboplatin chemotherapy in advanced non-small-cell lung cancer: results of the randomized multicenter phase III trial BMS099

PURPOSE To evaluate the efficacy of cetuximab plus taxane/carboplatin (TC) as first-line treatment of advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS This multicenter, open-label, phase III study enrolled 676 chemotherapy-naïve patients with stage IIIB (pleural effusion) or IV NSCLC, without restrictions by histology or epidermal growth factor receptor expression. Patients were randomly assigned to cetuximab/TC or TC. TC consisted of paclitaxel (225 mg/m(2)) or docetaxel (75 mg/m(2)), at the investigator's discretion, and carboplatin (area under the curve = 6) on day 1 every 3 weeks for < or = six cycles; cetuximab (400 mg/m(2) on day 1, 250 mg/m(2) weekly) was administered until progression or unacceptable toxicity. The primary end point was progression-free survival assessed by independent radiologic review committee (PFS-IRRC); overall response rate (ORR), overall survival (OS), quality of life (QoL), and safety were key secondary end points. PFS and ORR assessed by investigators were also evaluated. Results Median PFS-IRRC was 4.40 months with cetuximab/TC versus 4.24 months with TC (hazard ratio [HR] = 0.902; 95% CI, 0.761 to 1.069; P = .236). Median OS was 9.69 months with cetuximab/TC versus 8.38 months with TC (HR = 0.890; 95% CI, 0.754 to 1.051; P = .169). ORR-IRRC was 25.7% with cetuximab/TC versus 17.2% with TC (P = .007). The safety profile of this combination was manageable and consistent with its individual components. CONCLUSION The addition of cetuximab to TC did not significantly improve the primary end point, PFS-IRRC. There was significant improvement in ORR by IRRC. The difference in OS favored cetuximab but did not reach statistical significance.

Lung cancer symptoms with cetuximab/taxane/carboplatin in first-line advanced NSCLC: Analysis of the BMS099 trial

e19011

Background: The phase III BMS099 trial investigated cetuximab (C) added to taxane/carboplatin (TC) for 1st line treatment of advanced NSCLC. Progression-free survival (PFS) was not significantly different with C; response rate (RR) was significantly higher. Median overall survival (OS) was longer, with a difference not statistically significant, but similar in magnitude to the significant OS improvement from the FLEX trial (cisplat/vinorelb±C). A secondary objective of the BMS099 study was to assess the effect of C on Lung Cancer Symptoms (LCS). Methods: Chemonaïve patients (pts) with stage IIIB/IV NSCLC (any histology or EGFR expression status) were randomized to TC±C. LCS were measured using the functional assessment of cancer treatment-lung cancer subscale questionnaire (FACT-LCS), given at baseline and before each therapy cycle until disease progression (scoring 7 symptoms: breath loss, weight loss, clear thinking, coughing, appetite, chest tightness, breath ease, on a 0–4 scale). The main endpoints were rates of symptom response/progression (≥ 2 point improvement/decrease from baseline in 2 consecutive assessments), compared between arms with a stratified Cochran-Mantel-Haenszel (CMH) test; a stratified log-rank test was used to compare time to symptomatic progression. A Wei-Lachin test was used to compare between arms the changes from baseline in LCS score, and a longitudinal model was constructed to measure treatment effect on those score changes. Results: With 676 patients randomized, the baseline compliance rates for the FACT-LCS questionnaire were 99.4% and 99.1% for CTC and TC respectively, decreasing by week 18 to 74.0% and 66.4%. Baseline FACT-LCS scores were similar across treatment arms (median, 19.0). Symptom response rates were similar with CTC vs TC (32.6% vs 28.5%, CMH P=0.26), and time to symptomatic progression was not significantly different (log-rank P=0.58). Changes from baseline in FACT-LCS scores did not differ significantly between arms (Wei Lachin P=0.912; longitudinal model P=0.81). Conclusions: The addition of C to TC for the 1st treatment of advanced NSCLC resulted in similar symptom response/progression rates and did not affect trends in LCS score changes throughout treatment.

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Phase 2 study of lenalidomide in transfusion-dependent, low-risk, and intermediate-1 risk myelodysplastic syndromes with karyotypes other than deletion 5q

Lenalidomide is approved for red blood cell (RBC) transfusion-dependent anemia due to low or intermediate-1 (int-1) risk myelodysplastic syndromes (MDSs) associated with a chromosome 5q deletion with or without additional cytogenetic abnormalities. We report results of a multicenter, phase 2 trial evaluating lenalidomide therapy for transfusion-dependent patients with low- or int-1-risk MDS without deletion 5q. Eligible patients had 50,000/mm(3) or more platelets and required 2 U or more RBCs within the previous 8 weeks; 214 patients received 10 mg oral lenalidomide daily or 10 mg on days 1 to 21 of a 28-day cycle. The most common grade 3/4 adverse events were neutropenia (30%) and thrombocytopenia (25%). Using an intention-to-treat analysis, 56 (26%) patients achieved transfusion independence (TI) after a median of 4.8 weeks of treatment with a median duration of TI of 41.0 weeks. In patients who achieved TI, the median rise in hemoglobin was 32 g/L (3.2 g/dL; range, 10-98 g/L [1.0-9.8 g/dL]) from baseline. A 50% or greater reduction in transfusion requirement occurred in 37 additional patients, yielding a 43% overall rate of hematologic improvement (TI response + ||>or= 50% reduction in transfusion requirement). Lenalidomide has clinically meaningful activity in transfusion-dependent patients with low- or int-1-risk MDS who lack the deletion 5q karyotypic abnormality.

A phase 2 study of ARQ 501 in combination with gemcitabine in adult patients with treatment naïve, unresectable pancreatic adenocarcinoma

15017

Background: ARQ 501 is a DNA damage checkpoint pathway activator whose effect is to induce selective cell death in cancer cells, independent of the tumor cell’s p53 status. Current evidence implicates a rapid and sustained increase of the pro-apoptotic protein E2F-1 by ARQ 501 as the mechanism of action. Cancer cells are selectively affected due to their pre-existing DNA damage. Induction of E2F-1 in combination with gemcitabine demonstrated potent anti-tumor activity in xenografts of human pancreatic cancer (PACA-2). A recommended phase 2 dose of 400 mg/m2 of ARQ 501 and 800 mg/m2 gemcitabine was identified. Methods: A Phase 2 study in adult patients with treatment naïve, non-resectable adenocarcinoma of the pancreas was initiated to assess the effect of ARQ 501 and gemcitabine on ORR in approximately 66 patients. Cycles consisting of weekly ARQ 501 (400mg/m2) and gemcitabine (800 mg/m2 were repeated every 4 weeks until progression, unacceptable toxicity, or another discontinuation criterion was met. Results: 73 patients were enrolled, with 58 treated to date with at least one infusion. Data is available for 27 patients (16M/11F, median age, 63 years). Of these 27, 5 did not reach a post baseline assessment (3 deaths, 2 PD prior to week 8), 20 are evaluable for response at eight weeks (1 PR, 12 SD of 8–24+ weeks), 7 PD) and 2 have yet to be assessed but are active. Tumor regressions have been observed in 6/20 patients assessed to date. This includes 1 PR, 4 MR (14.3% - 24%) and 1 patient with significant reduction (29.6%) in pancreatic lesions although new superficial liver lesions were observed. Adverse events (N=235) the most common being: anemia (54, 22%), hemolysis (17, 7%), fatigue (15, 6%), edema (7, 3%), and nausea (5, 2%). Conclusions: ARQ 501 has been administered to 58 patients with treatment-naïve, non-resectable adenocarcinoma of the pancreas. Enrollment is complete and early efficacy data is encouraging. A high proportion of patients (13/20) have achieved a minimum SD at the first tumor evaluation. In addition, objective tumor regressions has been observed in this study, providing preliminary confirmation of the utility of induction of E2F-1 in combination with gemcitabine.

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Fatal Bacillus cereus endocarditis masquerading as an anthrax-like infection in a patient with acute lymphoblastic leukemia: case report

A 38-year-old male farm worker with relapsing acute lymphoblastic leukemia spontaneously developed an ulcerating ulcer on his anterior thigh which was surrounded by a non-tender area of erythema. Bacillus cereus was isolated from the ulcer and blood, and the patient received intravenous penicillin and vancomycin for one week. When sensitivity studies were returned he was treated with gatifloxacin orally. After two weeks of combined antimicrobial therapy and negative blood cultures, the patient received combination chemotherapy with vincristine, prednisone, doxorubicin and cyclophosphamide. He was hospitalized a day after completing chemotherapy with neutropenic sepsis due to B. cereus. He received similar antimicrobial therapy as previously, but died three days later. At autopsy, the patient was found to have acute mitral valve endocarditis and bilateral brain abscesses. This was the first case of B. cereus endocarditis reported in a patient with acute lymphoblastic leukemia.

The relation of plasma androgen levels to sexual behaviors and attitudes of women

Four androgens: dehydroepiandrosterone (DHEA), androstenedione (A), testosterone (T), and dihydrotestosterone (DHT), a variety of sexual behaviors and attitudes, and several moods were determined regularly in two groups of healthy, married women who differed by three decades in age. The younger women exhibited significantly higher levels of each androgen, the differences being almost entirely attributable to ovarian failure in the older group. Although the older women reported the same levels of sexual desire and sexual arousal as the younger women, their intercourse frequencies and self-rated sexual gratification scores were significantly lower than the values obtained for the younger wives. One or more of the androgen levels related significantly and in the expected direction to each stage of the four-stage sexual response process. Global measures of so-called "sexual adjustment" and estimates of anxiety, depression, and hostility feelings experienced by these women did not relate significantly to any of the four androgen levels.

Phospholipid composition of blood plasma, erythrocytes, and "ghosts" in sickle cell disease

We examined the phospholipid composition of the plasma, of whole erythrocytes, and of "ghosts" of the erythrocytes from healthy volunteers, patients with sickle cell disease without crisis, and such patients in crisis, and found that phosphatidylglycerol in the plasma and "ghosts" was very significantly increased in sickle cell crisis but not in the absence of crisis. The significance of these findings is discussed.

Phospholipid composition of blood plasma, erythrocytes, and "ghosts" in sickle cell disease

We examined the phospholipid composition of the plasma, of whole erythrocytes, and of "ghosts" of the erythrocytes from healthy volunteers, patients with sickle cell disease without crisis, and such patients in crisis, and found that phosphatidylglycerol in the plasma and "ghosts" was very significantly increased in sickle cell crisis but not in the absence of crisis. The significance of these findings is discussed.