Randomized Phase II Study of Two Doses of Pixantrone in Patients with Metastatic Breast Cancer (NCCTG N1031, Alliance)

BACKGROUND

Anthracycline use in metastatic breast cancer (MBC) is hindered by cumulative exposure limits and risk of cardiotoxicity. Pixantrone, a novel aza-anthracenedione with structural similarities to mitoxantrone and anthracyclines, is theorized to exhibit less cardiotoxicity, mainly due to lack of iron binding. We conducted a randomized phase II study to evaluate the efficacy and safety of 2 dosing schedules of pixantrone in patients with refractory HER2-negative MBC.

METHODS

Intravenous pixantrone was administered at 180 mg/m2 every 3 weeks (group A) versus 85 mg/m2 on days 1, 8, and 15 of a 28-day cycle (group B). Primary endpoint was objective response rate (ORR) and secondary endpoints included progression-free survival (PFS), median 6-month PFS, overall survival (OS), safety, quality of life, and serial assessment of circulating tumor cells. A 20% ORR was targeted as sufficient for further testing of pixantrone in this patient population.

RESULTS

Forty-five patients were evaluable, with 2 confirmed partial responses in group A and 1 in group B. The trial was terminated due to insufficient activity. Overall median PFS and OS were 2.8 (95% confidence interval [CI]: 2.0-4.1) and 16.8 (95% CI: 8.9-21.6) months, respectively. Notable overall grade 3-4 adverse events were the following: neutrophil count decrease (62%), fatigue (16%), and decrease in ejection fraction (EF) (4%).

CONCLUSION

Pixantrone has insufficient activity in the second- and third-line MBC setting. It appears, however, to have limited cardiotoxicity. (ClinicalTrials.gov ID: NCT01086605).

Randomized Phase II Trial of Triapine-Cisplatin-Radiotherapy for Locally Advanced Stage Uterine Cervix or Vaginal Cancers

Uterine cervix or vaginal cancers have inherent overactivity of ribonucleotide reductase (RNR), making these cancers rational targets for therapy based on interruption of cisplatin-radiotherapy-induced DNA damage repair. We conducted a pilot, open-label randomized phase II trial to evaluate the efficacy and safety of cisplatin-radiotherapy with or without triapine, a small molecule with RNR-inhibitory activity, in patients with advanced-stage uterine cervix or vaginal cancers (NCT01835171), as a lead in to a randomized phase III study (NCT02466971). A total of 26 women were randomly assigned to receive 6 weeks of daily radiotherapy followed by brachytherapy (80 Gy) and once-weekly cisplatin (40 mg m⁻²)—with or without three-times weekly intravenous triapine (25 mg m⁻²)—in one 56-days cycle. Primary end points were metabolic complete response by positron emission tomography and safety. Additional end points included the rate of clinical response, rate of methemoglobinemia, and progression-free survival. The addition of triapine to cisplatin-radiotherapy improved the rate of metabolic complete response from 69 to 92% (P = 0.32) and raised the 3-year progression-free survival estimate from 77 to 92% (hazard ratio for progression, 0.30; P = 0.27). The most frequent grade 3 or 4 adverse events in either treatment group included reversible leukopenia, neutropenia, fatigue, or electrolyte abnormalities. No significant differences were seen between the two groups in the rate of adverse events. Symptomatic methemoglobinemia was not encountered after triapine infusion. In conclusion, the addition of triapine to cisplatin-radiotherapy improved the rate of metabolic complete response in patients with advanced-stage uterine cervix or vaginal cancers without significant toxicity. A phase III trial adequately powered to evaluate progression-free and overall survival is underway (NCT02466971).

REVERCE: a randomized phase II study of regorafenib followed by cetuximab versus the reverse sequence for previously treated metastatic colorectal cancer patients

BACKGROUND

The objective of this randomized phase II trial was to evaluate efficacy and safety of the therapeutic sequence of regorafenib followed by cetuximab, compared with cetuximab followed by regorafenib, as the current standard sequence for metastatic colorectal cancer patients.

PATIENTS AND METHODS

Patients with KRAS exon 2 wild-type metastatic colorectal cancer after failure of fluoropyrimidine, oxaliplatin, and irinotecan were randomized to receive sequential treatment with regorafenib followed by cetuximab ± irinotecan (R-C arm), or the reverse sequence [cetuximab ± irinotecan followed by regorafenib (C-R arm)]. The primary end point was overall survival (OS). Key secondary end points included progression-free survival (PFS) with initial treatment (PFS1), PFS with second treatment (PFS2), safety, and quality of life. Exploratory end points included serial biomarker analyses, including oncogenic alterations from circulating tumor DNA or multiple serum or plasma proteins.

RESULTS

One-hundred one patients were randomized and eligible for efficacy analysis. Sequential treatment was successful in 86% patients in both arms. Median OS for R-C and C-R was 17.4 and 11.6 months, respectively (P = 0.0293), with a hazard ratio (HR) of 0.61 for OS [95% confidence interval (CI) 0.39-0.96]. The HR for PFS1 (regorafenib in R-C versus cetuximab in C-R) was 0.97 (95% CI 0.61-1.54), and PFS2 (C in R-C versus R in C-R) was 0.29 (95% CI 0.17-0.50). No unexpected safety signals were observed. The quality of life scores during the entire treatment period was not significantly different between the two arms. Circulating biomarker analyses showed emerging oncogenic alterations in RAS, BRAF, EGFR, HER2, and MET, which were more commonly detected after cetuximab than after regorafenib.

CONCLUSIONS

The therapeutic sequence of regorafenib followed by cetuximab suggests a longer OS than the current standard sequence.

Dual blockade of epidermal growth factor receptor and insulin-like growth factor receptor-1 signaling in metastatic pancreatic cancer: phase Ib and randomized phase II trial of gemcitabine, erlotinib, and cixutumumab versus gemcitabine plus erlotinib (SWOG S0727)

BACKGROUND

Targeting a single pathway in pancreatic adenocarcinoma (PC) is unlikely to affect its natural history. We tested the hypothesis that simulataneous targeting of the epidermal growth factor receptor (EGFR) and insulin-like growth factor receptor-1 (IGF-1R) pathways would significantly improve progression-free survival (PFS) by abrogating reciprocal signaling that promote drug resistance

METHODS

This was a phase Ib/II study testing cixutumumab, combined with erlotinib and gemcitabine (G) in patients with untreated metastatic PC. The control arm was erlotinib plus G. The primary end point was PFS. Eligibility included performance status 0/1 and normal fasting blood glucose. Polymorphisms in genes involved in G metabolism and in the EGFR pathway were also studied

RESULTS

The phase I results (n = 10) established the safety of cixutumumab 6 mg/kg/week intravenously, erlotinib 100 mg/day orally, and G 1000 mg/m(2) intravenously on days 1, 8, and 15 of a 28-day cycle. In the RP2 portion (116 eligible patients; median age, 63), the median PFS and overall survival (OS) were 3.6 and 7.0 months, respectively, on the cixutumumab arm, and 3.6 and 6.7 months, respecively, on the control arm. Major grades 3 and 4 toxicities with cixutumumab and control were elevation of transaminases, 12% and 6%, respectively; fatigue, 16% and 12%, respectively; gastrointestinal, 35% and 28%, respectively; neutropenia, 21% and 10%, respectively; and thrombocytopenia, 16% and 7%, respecively. Grade 3/4 hyperglycemia was seen in 16% of patients on cixutumumab. Grade 3 or 4 skin toxicity was similar in both arms of the study (< 5%). No significant differences in PFS by genotype were seen for any of the polymorphisms.

CONCLUSIONS

Adding the IGF-1R inhibitor cixutumumab to erlotinib and G did not lead to longer PFS or OS in metastatic PC.