A matching-adjusted indirect comparison of combination nivolumab plus ipilimumab with BRAF plus MEK inhibitors for the treatment of BRAF-mutant advanced melanoma☆

Background

Approved first-line treatments for patients with BRAF V600–mutant advanced melanoma include nivolumab (a programmed cell death protein 1 inhibitor) plus ipilimumab (a cytotoxic T lymphocyte antigen-4 inhibitor; NIVO+IPI) and the BRAF/MEK inhibitors dabrafenib plus trametinib (DAB+TRAM), encorafenib plus binimetinib (ENCO+BINI), and vemurafenib plus cobimetinib (VEM+COBI). Results from prospective randomized clinical trials (RCTs) comparing these treatments have not yet been reported. This analysis evaluated the relative efficacy and safety of NIVO+IPI versus DAB+TRAM, ENCO+BINI, and VEM+COBI in patients with BRAF-mutant advanced melanoma using a matching-adjusted indirect comparison (MAIC).

Patients and methods

A systematic literature review identified RCTs for DAB+TRAM, ENCO+BINI, and VEM+COBI in patients with BRAF-mutant advanced melanoma. Individual patient-level data for NIVO+IPI were derived from the phase III CheckMate 067 trial (BRAF-mutant cohort) and restricted to match the inclusion/exclusion criteria of the comparator trials. Treatment effects for overall survival (OS) and progression-free survival (PFS) were estimated using Cox proportional hazards and time-varying hazard ratio (HR) models. Safety outcomes (grade 3 or 4 treatment-related adverse events) with NIVO+IPI and the comparators were compared.

Results

In the Cox proportional hazards analysis, NIVO+IPI showed improved OS compared with DAB+TRAM (HR = 0.53; 95% confidence interval [CI], 0.39-0.73), ENCO+BINI (HR = 0.60; CI, 0.42-0.85), and VEM+COBI (HR = 0.50; CI, 0.36-0.70) for the overall study period. In the time-varying analysis, NIVO+IPI was associated with significant improvements in OS and PFS compared with the BRAF/MEK inhibitors 12 months after treatment initiation. There were no significant differences between NIVO+IPI and BRAF/MEK inhibitor treatment from 0 to 12 months. Safety outcomes favored DAB+TRAM over NIVO+IPI, whereas NIVO+IPI was comparable to VEM+COBI.

Conclusion

Results of this MAIC demonstrated durable OS and PFS benefits for patients with BRAF-mutant advanced melanoma treated with NIVO+IPI compared with BRAF/MEK inhibitors, with the greatest benefits noted after 12 months.

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First-line treatments for BRAF V600-mutant melanoma include NIVO+IPI and BRAF/MEK inhibitors.

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Results from prospective RCTs comparing NIVO+IPI and BRAF/MEK inhibitors have not yet been reported.

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This MAIC evaluated NIVO+IPI versus BRAF/MEK inhibitors for BRAF-mutant advanced melanoma.

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OS and PFS benefits were noted with NIVO+IPI versus BRAF/MEK inhibitors beginning at 12 months.

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These findings may provide information relevant to the selection of treatments for BRAF-mutant advanced melanoma.

A multicenter phase II study of cetuximab in combination with chest radiotherapy and consolidation chemotherapy in patients with stage III non-small cell lung cancer

BACKGROUND

Cetuximab has demonstrated improved efficacy in combination with chemotherapy and radiotherapy. We evaluated the integration of cetuximab in the combined modality treatment of stage III non-small cell lung cancer (NSCLC).

METHODS

Patients with surgically unresectable stage IIIA or IIIB NSCLC were treated with chest radiotherapy, 73.5 Gy (with lung and tissue heterogeneity corrections) in 35 fractions/7 weeks, once daily (63 Gy without heterogeneity corrections). Cetuximab was given weekly during radiotherapy and continued during consolidation therapy with carboplatin and paclitaxel up to a maximum of 26 weekly doses. The primary endpoint was overall survival. Baseline tumor tissue was analyzed for EGFR by fluorescence in situ hybridization (FISH).

RESULTS

Forty patients were enrolled in this phase II study. The median overall survival was 19.4 months and the median progression-free survival 9.3 months. The best overall response rate in 31 evaluable patients was 67%. No grade 3 or 4 esophagitis was observed. Three patients experienced grade 3 rash; 16 patients (69%) developed grade 3/4 neutropenia during consolidation therapy. One patient died of pneumonitis, possibly related to cetuximab. EGFR gene copy number on baseline tumor tissues, analyzed by FISH, was not predictive of efficacy outcomes.

CONCLUSIONS

The addition of cetuximab to chest radiotherapy and consolidation chemotherapy was tolerated well and had modest efficacy in stage III NSCLC. Taken together with the lower incidence of esophagitis, our results support evaluation of targeted agents instead of chemotherapy with concurrent radiotherapy in this setting.

Safety and efficacy of decitabine in combination with temozolomide in metastatic melanoma: a phase I/II study and pharmacokinetic analysis

BACKGROUND

Temozolomide (TMZ) is widely used for chemotherapy of metastatic melanoma. We hypothesized that epigenetic modulators will reverse chemotherapy resistance, and in this article, we report studies that sought to determine the recommended phase 2 dose (RP2D), safety, and efficacy of decitabine (DAC) combined with TMZ.

PATIENTS AND METHODS

In phase I, DAC was given at two dose levels: 0.075 and 0.15 mg/kg intravenously daily × 5 days/week for 2 weeks, TMZ orally 75 mg/m(2) qd for weeks 2-5 of a 6-week cycle. The phase II portion used a two-stage Simon design with a primary end point of objective response rate (ORR).

RESULTS

The RP2D is DAC 0.15 mg/kg and TMZ 75 mg/m(2). The phase II portion enrolled 35 patients, 88% had M1c disease; 42% had history of brain metastases. The best responses were 2 complete response (CR), 4 partial response (PR), 14 stable disease (SD), and 13 progressive disease (PD); 18% ORR and 61% clinical benefit rate (CR + PR + SD). The median overall survival (OS) was 12.4 months; the 1-year OS rate was 56%. Grade 3/4 neutropenia was common but lasted >7 days in six patients.

CONCLUSIONS

The combination of DAC and TMZ is safe, leads to 18% ORR and 12.4-month median OS, suggesting possible superiority over the historical 1-year OS rate, and warrants further evaluation in a randomized setting.

Assessing oncologic benefit in clinical trials of immunotherapy agents

BACKGROUND

USA Food and Drug Administration approval for cancer therapy requires demonstration of patient benefit as a marker of clinical efficacy. Prolonged survival is the gold standard for demonstration of efficacy, but other end points such as antitumor response, progression-free survival, quality of life, or surrogate end points may be used.

DESIGN

This study was developed based on discussion during a roundtable meeting of experts in the field of immunotherapy.

RESULTS

In most clinical trials involving cytotoxic agents, response end points use RECIST based on the premise that 'effective' therapy causes tumor destruction, target lesion shrinkage, and prevention of new lesions. However, RECIST may not be appropriate in trials of immunotherapy. Like other targeted agents, immunotherapies may mediate cytostatic rather than direct cytotoxic effects, and these may be difficult to quantify with RECIST. Furthermore, significant time may elapse before clinical effects are quantifiable because of complex response pathways. Effective immunotherapy may even mediate transient lesion growth secondary to immune cell infiltration.

CONCLUSIONS

RECIST may not be an optimal indicator of clinical benefit in immunotherapy trials. This article discusses alternative clinical trial designs and end points that may be more relevant for immunotherapy trials and may offer more effective prediction of survival in pivotal phase III studies.

Phase II study of aflibercept (VEGF trap) in recurrent inoperable stage III or stage IV melanoma of cutaneous or ocular origin

9028

Background: Aflibercept is a fusion protein combining the Fc portion of human IgG1with the extracellular ligand-binding domains of human VEGFR1 and VEGFR2, acting as a high-affinity soluble VEGF receptor and potent angiogenesis inhibitor. Methods: Phase II study of aflibercept in patients with inoperable stage III or IV melanoma who had received no prior chemotherapy or hormonal therapy. A 2-stage design was adopted focusing upon response rate (RECIST) and 4-month PFS rate. First stage accrual of 21 patients was specified, while final accrual of 41 is planned, with adequate response/4 month PFSR. Aflibercept was given at 4 mg/kg IV every 2 weeks. Response was assessed every 8 weeks. Results: Twenty seven patients (16 male, 11 female), age 23–83 (median 58) have been enrolled to date. All had AJCC stage IV melanoma (3M1a, 3M1b, 21M1c). Karnofsky PS: 100 (13), 90 (11) or 80 (3). Nine patients had primary ocular melanoma, 16 cutaneous and 2 unknown primary site. A total of 160 cycles have been administered (median 4; range 1–18). Grade 3/4 toxicities included cerebral ischemia (1 patient; 4%), confusion (1; 4%), thrombocytopenia (1; 4%), hypertension (7; 26%), hypotension (1; 4%), left ventricular diastolic dysfunction (1; 4%), fatigue (1; 4%), proteinuria (4; 15%), extraocular muscle paresis (1; 4%), renal failure (1; 4%), back pain (1; 4%), headache (1; 4%). Interim analysis was conducted after the first 21 patients (stage 1). Eight (1 M1a, 1M1b, 6M1c; 4 ocular, 3 cutaneous, 1 unknown primary) of the first 21 patients had at least 4 months of PFS (10 out of 27; 2 additional patients with cutaneous melanoma had SD: 1M1a and 1M1c). One patient (23rd; cutaneous, M1c) had a confirmed complete remission. Four patients were taken off study prior to response evaluation for toxicity (3) or treatment refusal (1). One patient is currently disease free who was not evaluable for response (previous surgery and radiofrequency ablation of measurable disease site). Eleven patients had progression. Conclusions: Aflibercept can be administered with acceptable toxicity, and exhibits promising antitumor efficacy against advanced melanoma. This study continues second stage accrual with anticipated closure before June 2009.

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A phase II study of arsenic trioxide (ATO) in patients with metastatic melanoma

8569

Background: Arsenic trioxide (ATO) is a promising new agent in the treatment of both solid and hematologic tumors. ATO cytotoxicity and apoptosis induction has been demonstrated in vitro with numerous human cancer cell lines including human melanoma. Methods: We conducted a safety and efficacy single arm study of ATO in patients (18 years or older) with inoperable AJCC stage IV melanoma. One cycle consisted of a loading dose of 0.32 mg/kg/day for 4 days in week 1, followed by 0.25 mg/kg/day twice per week for 6 weeks, followed by 1 week of rest for a total cycle length of 8 weeks when response assessment was performed. Results: A total of 21 patients (5 females and 16 males) were accrued with a median age of 63.8 years (range 32.9 - 81.6). All patients had metastatic melanoma including AJCC stage IV M1a (2), M1b (6) and M1c (13). ECOG performance included 0 (11) and 1 (10). One patient had metastatic choroidal melanoma and 20 had cutaneous melanoma. Twenty patients had received prior therapy including chemotherapy (17), immunotherapy (11) and radiation (3). Six patients completed 1 cycle, seven 2 cycles, one 3 cycles, one 4 cycles and two 5 cycles of ATO. Four patients did not complete the first cycle and are not evaluable for response. Possible treatment related Grade 3/4 toxicities included one case of idiopathic thrombocytopenic purpura and one case of elevated LDH. Among 17 evaluable patients, 1 (6%) had partial response lasting 7 months, 8 (47%) had disease stabilization after 1 cycle, but all eventually progressed. A total of 19 patients have died and 2 are alive at a median follow up of 17.5 weeks. Median time to progression is 14 weeks, 95% CI (9, 38) and median survival is 52.9 weeks, 95% CI (14.4, 66.1). Conclusions: ATO as a single agent is well tolerated with modest activity in metastatic melanoma that may be enhanced in combination with other agents that induce apoptosis.

No significant financial relationships to disclose.

Interferon alfa-induced autoimmunity and serum S100 levels as predictive and prognostic biomarkers in high-risk melanoma in the ECOG-intergroup phase II trial E2696

8506

Background: Uncontrolled evidence demonstrates that adjuvant high-dose interferon alfa-2b (HDI) benefit in high-risk melanoma patients is predicted by autoimmunity induction, and the prognosis of melanoma has been correlated with levels of S-100 protein. We have evaluated these two serological markers in the context of a completed phase II study E2696. Methods: Patients with resectable AJCC stage IIB, III, and IV melanoma were randomly assigned to receive GM2-KLH/QS-1 (GMK vaccine) plus concurrent HDI (Arm A) or GMK plus sequential HDI (Arm B), or GMK without HDI (Arm C). Sera from 103 patients were banked at baseline and 3 additional time points, and have been tested for serum protein S100, and anti-nuclear, anti-thyroid peroxidase, anti-thyroglobulin, anti-mitochondrial, and total anti-cardiolipin autoantibodies (AA) using ELISA. Results: At a median follow-up of 96.5 mo (range: 17–109), the median relapse-free survival (RFS) was 28.3 mo, 95% CI (18.4, 43.6) (64 /103 patients relapsed). Median survival has not been reached (54/103 alive). AA were induced in 17 subjects (25%; n=69) receiving HDI and GMK versus 2 (6%; n=34) receiving GMK alone (2p-value=0.031). In HDI arms induced AA were detected = 12 weeks after therapy initiation. RFS was improved among HDI recipients with AA, but with the limited numbers in this phase II trial this trend does not achieve significance. In the multivariate (Cox regression model) analysis, adjusting for treatment (HDI vs. no HDI) and baseline S-100 value for later time points, S-100 level ≥0.08 microg/l was an independent prognostic factor for RFS at baseline (HR=1.96; p=0.0273), week 4–6 (HR=1.72; p=0.073), wk 12–14 (HR=1.81; p=0.048) and wk 52 (HR=4.3; p<0.001). The hazard ratio (HR) for OS was 1.86 at wk 12–14 (p=0.061), and 5.7 at wk 52 (p<.001). In the model using wk 52 S-100 value (at completion of HDI), the HR adjusted for treatment was 7.1 p=0.009. Conclusions: Autoimmunity is a predictive biomarker of RFS with HDI in the E2696 trial compared to GMK. Serum protein S-100 level ≥0.08 microg/l is an independent prognostic marker for RFS and OS most significant at baseline and 1 year of followup. Current studies will evaluate these markers in the larger phase III trial E1694 with 880 subjects.

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Phase II trial of sequential temozolomide (TMZ) and high-dose bolus (HDB) IL-2 in patients with metastatic melanoma

8037

Background: Previous biochemotherapy (BCT) regimens for metastatic melanoma have utilized lower doses of IL-2 and multiple chemotherapeutic agents, adding to toxicity, but not to efficacy. Methods: We designed a 2-stage Simon phase II study testing a unique BCT approach of single agent chemotherapy with TMZ given in an extended schedule (75 mg/m² per day for 3 weeks PO) followed by HDB IL-2 (600,000 U/Kg/dose, maximum 14 doses administered over 5 days). Cycles were repeated every 28 days with a two-week interval between alternate cycles. The first stage accrued 20 patients with promising activity and safety permitting enrollment of additional patients. Results: Thirty-one patients (20 male, 11 female), age 27–74 (median 47) have been enrolled to date. All had AJCC stage IV melanoma (7 M1a, 5 M1b, 19 M1c) and had not previously received therapy for metastatic disease. Twelve had received prior adjuvant interferon. A total of 88 cycles of therapy have been administered (median of 2 cycles per patient; 5 patients continue on therapy). The median number of doses was 9 (range 7–12) during cycle 1, and 6 (range 4–11) during cycle 2. Three patients did not receive any IL-2 due to disease progression, and 6 patients received only one cycle of IL-2. Twenty two patients who received at least 2 cycles are evaluable for response. All 31 patients are evaluable for toxicity. Grade 3 toxicities included hepatic (8), hematologic (4 leukopenia, 2 thrombocytopenia), diarrhea (1). No grade 3–4 cardiovascular or renal toxicities were noted. Overall response rate is 22.7% (2 complete lasting 10.8 and 17+ months, 3 partial lasting 3.7 and 16+ months, 1+ month). Responses were seen in both M1a and M1c disease. Fourteen patients had stable disease after 2 cycles and 10 of these have progressed. As of 12/31/2005, the 4 month PFS rate is 74% [40%, 88%], median TTP is 24 weeks [11, 32] and median OS is 71 weeks (31.4, inf). Conclusions: HDB IL-2 can be safely administered in combination with single agent temozolomide in an extended schedule and appears to have promising efficacy and lower toxicity than previously used BCT regimens. Further follow-up will determine if durability of response exceeds that of single agent HDB IL-2.

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Early results of modified fludarabine, cyclophosphamide, and rituximab (mFCR) for patients with previously untreated advanced chronic lymphocytic leukemia (CLL)

6599

Background: Recent data reporting results of FCR therapy in previously untreated advanced CLL patients (F-25 mg/m2 d1–3 q 4wk; C-250 mg/m2 d 1–3 q 4wk; R-500 mg/m2 d1 q 4wk for 6 cycles) demonstrated complete remission (CR) of 70% and overall response (OR) of 95% (J Clin Oncol 2005;23:4079). The major toxicity was grade 3/4 neutropenia during 52% of courses. One approach to decrease neutropenia without compromising efficacy could be by reducing the doses of F and C and increasing the dose of R as high-dose R has been reported to be more efficacious in CLL. Methods: We conducted a phase II study for previously untreated advanced CLL patients treated with mFCR (F-20mg/m2 d1–3 q 4 wk; C-150 mg/m2 d1–3 q 4 wk; R-500mg/m2 d1 and d14 q 4wks; maintenance R-500 mg/m2 q 3 months until progression). A Simon two-stage design was used where 15 patients were accrued in the first stage and because of acceptable toxicity and response rate in stage I an additional 35 patients will be treated. The primary endpoint was response rate. Results: Twenty patients (13 male, 7 female), age 36–85 years (median 59) were treated with a total of 105 mFCR courses. All 20 patients were evaluable for toxicity. Grade 3/4 neutropenia occurred during 11(10.5%) courses. There were no episodes of neutropenic fever. Grade 3/4 thrombocytopenia occurred during 4 (3.8%) courses. Two patients are currently on study and not evaluable for response and among the 18 evaluable patients, the CR was 68%, PR was 32% with an OR of 100%. Eleven of the 12 CR patients had no evidence of CD5+/CD19+ coexpressing cells in their bone marrow after therapy and one had <1%; all 12 were NED by CT scan. Conclusions: Our preliminary results suggest mFCR is highly effective with considerably less grade 3/4 neutropenia than standard FCR. Complete responders had minimal residual disease in their bone marrow following mFCR.

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