FAST: a randomised phase II study of zolbetuximab (IMAB362) plus EOX versus EOX alone for first-line treatment of advanced CLDN18.2-positive gastric and gastro-oesophageal adenocarcinoma

BACKGROUND

Claudin 18.2 (CLDN18.2) is contained within normal gastric mucosa epithelial tight junctions; upon malignant transformation, CLDN18.2 epitopes become exposed. Zolbetuximab, a chimeric monoclonal antibody, mediates specific killing of CLDN18.2-positive cells through immune effector mechanisms.

PATIENTS AND METHODS

The FAST study enrolled advanced gastric/gastro-oesophageal junction and oesophageal adenocarcinoma patients (aged ≥18 years) with moderate-to-strong CLDN18.2 expression in ≥40% tumour cells. Patients received first-line epirubicin + oxaliplatin + capecitabine (EOX, arm 1, n = 84) every 3 weeks (Q3W), or zolbetuximab + EOX (loading dose, 800 mg/m² then 600 mg/m² Q3W) (arm 2, n = 77). Arm 3 (exploratory) was added after enrolment initiation (zolbetuximab + EOX 1000 mg/m² Q3W, n = 85). The primary endpoint was progression-free survival (PFS) and overall survival (OS) was a secondary endpoint.

RESULTS

In the overall population, both PFS [hazard ratio (HR) = 0.44; 95% confidence interval (CI), 0.29-0.67; P < 0.0005] and OS (HR = 0.55; 95% CI, 0.39-0.77; P < 0.0005) were significantly improved with zolbetuximab + EOX (arm 2) compared with EOX alone (arm 1). This significant PFS benefit was retained in patients with moderate-to-strong CLDN18.2 expression in ≥70% of tumour cells (HR = 0.38; 95% CI, 0.23-0.62; P < 0.0005). Significant improvement in PFS was also reported in the overall population of arm 3 versus arm 1 (HR = 0.58; 95% CI, 0.39-0.85; P = 0.0114) but not in high CLDN18.2-expressing patients; no significant improvement in OS was observed in either population. Most adverse events (AEs) related to zolbetuximab + EOX (nausea, vomiting, neutropenia, anaemia) were grade 1-2. Grade ≥3 AEs showed no substantial increases overall (zolbetuximab + EOX versus EOX alone).

CONCLUSIONS

In advanced gastric/gastro-oesophageal junction and oesophageal adenocarcinoma patients expressing CLDN18.2, adding zolbetuximab to first-line EOX provided longer PFS and OS versus EOX alone. Zolbetuximab + EOX was generally tolerated and AEs were manageable. Zolbetuximab 800/600 mg/m² is being evaluated in phase III studies based on clinical benefit observed in the overall population and in patients with moderate-to-strong CLDN18.2 expression in ≥70% of tumour cells.

An open randomised trial of second-line endocrine therapy in advanced breast cancer

It was previously shown that letrozole (Femara) was significantly more potent than anastrozole (Arimidex) in inhibiting aromatase activity in vitro and in inhibiting total body aromatisation in patients with breast cancer. The objective of this study was to compare letrozole (2.5 mg per day) and anastrozole (1 mg per day) as endocrine therapy in postmenopausal women with advanced breast cancer previously treated with an anti-oestrogen. This randomised, multicentre and multinational open-label phase IIIb/IV study enrolled 713 patients. Treatment was for advanced breast cancer that had progressed either during anti-oestrogen therapy or within 12 months of completing that therapy. Patients had tumours that were either positive for oestrogen and/or progesterone receptors (48%) or of unknown receptor status (52%). The primary efficacy endpoint was time to progression (TTP). Secondary endpoints included objective response, duration of response, rate and duration of overall clinical benefit (responses and long-term stable disease), time to treatment failure, and overall survival, as well as general safety. There was no difference between the treatment arms in TTP; median times were the same for both treatments. Letrozole was significantly superior to anastrozole in the overall response rate (ORR) (19.1% versus 12.3%, P=0.013), including in predefined subgroups (receptor status-unknown, and soft-tissue- and viscera-dominant site of disease). There were no significant differences between the treatment arms in the rate of clinical benefit, median duration of response, duration of clinical benefit, time to treatment failure or overall survival. Both agents were well tolerated and there were no significant differences in safety. These results support previous data documenting the greater aromatase-inhibiting activity of letrozole and indicate that advanced breast cancer is more responsive to letrozole than to anastrozole as second-line endocrine therapy.

A randomised, double-blind, placebo-controlled phase 2 study of trebananib (AMG 386) in combination with FOLFIRI in patients with previously treated metastatic colorectal carcinoma

Background:

This phase 2 study evaluated trebananib (AMG 386), an investigational peptide-Fc fusion protein that neutralises the interaction between angiopoietins-1/2 and the Tie2 receptor, plus FOLFIRI as second-line treatment for patients with metastatic colorectal cancer.

Methods:

Patients had adenocarcinoma of the colon or rectum with progression within 6 months of receiving only one prior fluoropyrimidine/oxaliplatin-based chemotherapy regimen for metastatic disease. All patients received FOLFIRI and were randomised 2 : 1 to also receive intravenous trebananib 10 mg kg⁻¹ once weekly (QW) (Arm A) or placebo QW (Arm B). The primary end point was investigator-assessed progression-free survival (PFS).

Results:

One hundred and forty-four patients were randomised (Arms A/B, n=95/49). Median PFS in Arms A and B was 3.5 and 5.2 months (hazard ratio (HR) 1.23; 95% CI, 0.81–1.86; P=0.33) and median overall survival (OS) was 11.9 and 8.8 months, respectively (HR 0.90; 95% CI; 0.53–1.54; P=0.70). Objective response rate (ORR) was 14% and 0% in Arms A and B, respectively. Incidence of grade ⩾3 adverse events was similar between treatment arms (Arm A, 61% Arm B, 65%) and included pulmonary embolism (1%/4%), deep vein thrombosis (5%/2%), and hypertension (1%/0%).

Conclusion:

Administration of trebananib plus FOLFIRI did not prolong PFS compared with placebo plus FOLFIRI. Toxicities were manageable and consistent with those known for FOLFIRI and trebananib.

A randomized phase II study of bortezomib and pemetrexed, in combination or alone, in patients with previously treated advanced non-small-cell lung cancer

BACKGROUND

This is a phase II randomized study to evaluate the efficacy and safety of bortezomib and pemetrexed alone or in combination, in patients with previously treated advanced non-small-cell lung cancer (NSCLC). The primary end point was assessment of response rate.

METHODS

A total of 155 patients were randomized (1:1:1) to pemetrexed (500mg/m(2)) on day 1 plus bortezomib (1.6mg/m(2)) on days 1 and 8 (Arm A) or pemetrexed (500mg/m(2)) on day 1 (Arm B) or bortezomib (1.6mg/m(2)) on days 1 and 8 (Arm C) of a 21 day cycle. Response rate was assessed by investigators using Response Evaluation Criteria In Solid Tumors (RECIST) criteria and toxicity assessed by the National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) grading system.

RESULTS

Response rate was 7% in Arm A, 4% in Arm B, and 0% in Arm C; disease control rates were 73%, 62%, and 43%, respectively. Median overall survival was 8.6 months in Arm A, 12.7 months in Arm B, and 7.8 months in Arm C; time to progression was 4.0 months, 2.9 months, and 1.4 months, respectively. Most common reported adverse events >/=grade 3 were neutropenia (19%), thrombocytopenia (15%), and dyspnea (13%) in Arm A, neutropenia (10%) in Arm B, and dyspnea (13%) and fatigue (10%) in Arm C.

CONCLUSION

In previously treated NSCLC the addition of bortezomib to pemetrexed was well tolerated but offered no statistically significant response or survival advantage versus pemetrexed alone, while bortezomib alone showed no clinically significant activity.

Biomarker analyses from the phase III placebo-controlled SATURN study of maintenance erlotinib following first-line chemotherapy for advanced NSCLC

8020

Background: The SATURN (BO18192) study investigated whether erlotinib maintenance therapy improved PFS in patients (pts) with advanced NSCLC who had obtained clinical benefit from 1st-line chemotherapy. This study included a prospective analysis of the prognostic/predictive value of several molecular markers. Methods: 889 pts with advanced NSCLC whose disease had not progressed following 4 cycles of 1st-line platinum-doublet chemotherapy were randomized to erlotinib 150 mg/day or placebo. Mandatory tumor specimens were collected at baseline and tested for EGFR protein expression using immunohistochemistry (IHC), EGFR gene copy number using fluorescent in-situ hybridization (FISH), and EGFR and KRAS somatic mutations using DNA sequencing. Pts were stratified according to EGFR IHC status (any membranous staining in ≥10% tumor cells used as cut-off); the co-primary endpoint was PFS in EGFR IHC+ pts. Baseline whole blood samples were obtained for genotyping of EGFR (intron 1 CA-repeat polymorphisms). Results: In the overall population, erlotinib significantly prolonged PFS vs placebo (HR 0.71, p<.0001; primary endpoint). The co-primary endpoint was also met, with erlotinib significantly improving PFS in the EGFR IHC+ group (HR 0.69, p<.0001). Many tumor samples were assessable for molecular marker status (see table). Biomarker data suggest that patients derived a PFS benefit with erlotinib irrespective of EGFR FISH or EGFR intron 1 CA-repeat status. The magnitude of benefit with erlotinib was similar in both KRAS-mutant and KRAS wild-type pts. Conclusions: This is the largest biomarker analysis performed for erlotinib in a randomized, placebo-controlled setting, and answers key scientific questions regarding the prognostic and predictive value of potential biomarkers of efficacy. Full data will be presented.

[Table: see text]

[Table: see text]

Randomized comparison of weekly or every-3-week (q3w) nab-paclitaxel compared to q3w docetaxel as first-line therapy in patients (pts) with metastatic breast cancer (MBC)

1032

Background: 130-nM albumin-bound (nab™) paclitaxel combines paclitaxel with albumin without solvents or altering either component. A cross analysis of 2 clinical trials comparing solvent-based (SB) paclitaxel 175 mg/m2 q3w to nab- paclitaxel (Gradishar et al, JCO, 2005) and SB docetaxel (Jones et al, JCO, 2005) suggested comparable antitumor activity between nab-paclitaxel and SB docetaxel and better tolerability with nab-paclitaxel in pts with MBC. The aim of this study was to compare the toxicity and antitumor activity of 3 regimens of nab-paclitaxel (q3w and 2 weekly) with each other and that of SB docetaxel in MBC. Methods: In this open-label study, first-line pts with MBC were randomly assigned to nab-paclitaxel 300 mg/m2 q3w (A); nab-paclitaxel 100 mg/m2 (B) or 150 mg/m2 (C) days 1, 8, and 15, q28 days (q 3/4 w); or SB docetaxel 100 mg/m2 q3w (D). The primary endpoints were overall response rate (complete response + partial response, evaluated q8w) and toxicity. Progression-free survival (PFS) was also determined. Results: 302 pts (median age, 54 years; 99% Caucasian; 75% postmenopausal; ECOG PS =2 [94% =1]) either had at least 2 response assessments (94%) or had discontinued due to PD (6%). The efficacy results are shown in the Table . Neutropenia (N) was greater with D than with A, B, or C (p < 0.001). Grade 4 N was: A) 4%, B) 3%, C) 7%, and D) 74%. Febrile neutropenia (FN) was: A) 1%, B) 1%, C) 1%, and D) 7%. Gr 3 peripheral neuropathy was: A) 14%, B) 7%, C) 12%, and D) 5%. Conclusions: The response rates of q3w nab-paclitaxel and solvent-based docetaxel were comparable. Q 3/4 W nab-paclitaxel resulted in higher response rates than solvent-based docetaxel. Grade 4 N and FN were less frequent with nab-paclitaxel as compared with solvent-based docetaxel. To date, all 3 nab-paclitaxel regimens have a longer PFS than SB docetaxel although the data are not yet mature (33% of events). Final data for a radiological review of response data, PFS, and toxicity will be presented.

[Table: see text]

No significant financial relationships to disclose.

Study of three weekly nab-paclitaxel regimens in combination with carboplatin as first-line therapy in advanced non-small cell lung cancer (NSCLC)

7659

Background: We previously reported that 130-nM albumin-bound form of paclitaxel (ABI-007, nab paclitaxel) 225 - 340 mg/m2 and carboplatin AUC of 6 mg/min·ml (C6), both administered on day (d) 1 every 3 weeks (q3w), produced an objective (PR/CR) response rate (ORR) of 27% in first line patients (pts) with NSCLC with median progression-free (PFS) and overall survivals of 6.0 and >10.3 months respectively [Hawkins et al., ASCO, 2006]. Grade 2 and 3 sensory neuropathy (SN) was 36–56%. The aim of the current study was to obtain clinical experience with weekly schedules of nab- paclitaxel in combination with C6 in NSCLC prior to initiating large scale clinical trials. Methods: 75 Pts with previously untreated, stage IIIB or IV NSCLC with measurable disease and a life expectancy of over 12 weeks were recruited into 3 cohorts (n = 25 each) of successive pts and received nab paclitaxel weekly using 3 different regimens (see table ). Results: Patient Characteristics: 75 pts (100% Caucasian; 84% male; median age, 60; performance status score: 0 [16%], 1 [84%]. Accrual was completed in each cohort and serious adverse events reviewed prior to accrual at the next dose level. The primary efficacy endpoints are provided in the table . Grade 3/4 hematologic toxicities were: neutropenia 32%/35%; thrombocytopenia, 19%/11%; anemia, 24%/3%. The most common non- hematologic toxicities (any grade) were fatigue, 48%; SN, 48%; nausea, 37%; alopecia, 40%; and vomiting, 26%. Grade 2 and 3 SN was 12–28%. Graded toxicity data by regimen will be presented. Conclusions: When combined with C6, the ORR was higher and there was less peripheral neuropathy for weekly nab-paclitaxel compared to our previous experience using q3w administration.

[Table: see text] [Table: see text]

Phase 1 study of picoplatin (pico) in combination with 5-fluorouracil (FU) and leucovorin (LV) as initial therapy in subjects with metastatic colorectal cancer (CRC)

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Background: Pico is a platinum analogue designed to overcome platinum resistance with improved safety and efficacy compared with conventional platinum agents. FOLFOX (FU, LV, oxaliplatin) has emerged as the standard of care in first and second-line therapy of advanced -stage CRC but significant neurotoxicity limits long-term use of oxaliplatin in this regimen. Pico has been well tolerated in >600 patients with rare clinically significant nephro-, oto-, or neurotoxicity (∼2% grade 3 and 0% grade 4), even in platinum pretreated patients. Pico has demonstrated synergy with FU in vitro and is thus an attractive candidate to replace oxaliplatin in the FOLFOX regimen. The objective of this Phase 1 study is to identify the maximum tolerated dose (MTD) of pico administered either every 2 wks or every 4 wks with FU and LV administered every 2 wks. Methods: Each patient receives q 2 wk FU and LV: LV, 400 mg/m2, 2-hr infusion, followed by 5- FU bolus, 400 mg/m2 and then 5-FU, 2,400 mg/m2, 46 hr continuous infusion. Subjects are randomized to pico administered either every 2 or every 4 wks. Starting dose of pico for q 2 weekly regimen was 45 mg/m2 and in subsequent cohorts pico increases by 15 mg/m2. Starting dose of pico for q 4 wk regimen was 60 mg/m2 and in subsequent cohorts pico increases by 30 mg/m2 until dose limiting toxicity (DLT) establishes the MTD. Results: 23 pts have been treated to date, the first have received 32 wks of therapy. Therapy has been well tolerated, with infrequent dose delays from non-cumulative platelet and ANC toxicity and 1 episode of mild diarrhea. No DLT has been seen through the first 3 cohorts, i.e. with picoplatin, 75 mg/m2 with every dose of FU-LV or120 mg/m2 with every other dose of FU-LV. Dose escalation continues. Response assessments for 12 patients in the first 2 cohorts (6 on each pico schedule, all below the MTD) after 16 wks show 4 partial responses, 5 stable disease and 3 progressive disease. Conclusions: Picoplatin can be safely administered with 5FU and LV. A phase 2 study of FU, LV and pico will begin as soon as the MTD is identified and a safe dose and schedule are defined.

No significant financial relationships to disclose.