Dabrafenib plus trametinib in patients with BRAF V600E–mutant anaplastic thyroid cancer: updated analysis from the phase II ROAR basket study

Background:

Combined therapy with dabrafenib plus trametinib was approved in several countries for treatment of BRAF V600E-mutant anaplastic thyroid cancer (ATC) based on an earlier interim analysis of 23 response-assessable patients in the ATC cohort of the phase II Rare Oncology Agnostic Research (ROAR) basket study. We report an updated analysis describing the efficacy and safety of dabrafenib plus trametinib in the full ROAR ATC cohort of 36 patients with ~4 years of additional study follow-up.

Patients and methods:

ROAR (NCT02034110) is an open-label, nonrandomized, phase II basket study evaluating dabrafenib plus trametinib in BRAF V600E-mutant rare cancers. The ATC cohort comprised 36 patients with unresectable or metastatic ATC who received dabrafenib 150 mg twice daily plus trametinib 2 mg once daily orally until disease progression, unacceptable toxicity, or death. The primary endpoint was investigator-assessed overall response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1. Secondary endpoints were duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety.

Results:

At data cutoff (14 September 2020), median follow-up was 11.1 months (range, 0.9–76.6 months). The investigator-assessed ORR was 56% (95% confidence interval, 38.1% to 72.1%), including three complete responses; the 12-month DOR rate was 50%. Median PFS and OS were 6.7 and 14.5 months, respectively. The respective 12-month PFS and OS rates were 43.2% and 51.7%, and the 24-month OS rate was 31.5%. No new safety signals were identified with additional follow-up, and adverse events were consistent with the established tolerability of dabrafenib plus trametinib.

Conclusions:

These updated results confirm the substantial clinical benefit and manageable toxicity of dabrafenib plus trametinib in BRAF V600E-mutant ATC. Dabrafenib plus trametinib notably improved long-term survival and represents a meaningful treatment option for this rare, aggressive cancer.

Biomarker analyses of second-line ramucirumab in patients with advanced gastric cancer from RAINBOW, a global, randomized, double-blind, phase 3 study

BACKGROUND

The RAINBOW trial showed that second-line ramucirumab with paclitaxel prolongs overall survival (OS) and progression-free survival (PFS) compared with placebo plus paclitaxel for treatment of advanced gastric/gastroesophageal junction cancer. Plasma samples were collected from patients during the trial and tested to identify predictive and prognostic biomarkers.

PATIENTS AND METHODS

Circulating factors in plasma samples from mutually exclusive subsets of RAINBOW patients were assayed using: Intertek assays (24 markers, 380 samples, 57% of patients) and Lilly-developed assay (LDA) platform (5 markers, 257 samples, 39% of patients). Time-trend plots were generated for each marker from the Intertek assays. Baseline patient data were dichotomized into low- and high-marker subgroups. Markers were analyzed for predictive effects using interaction models and for prognostic effects using main-effects models.

RESULTS

The Intertek and LDA populations were representative of the full trial population. Plasma levels of VEGF-D and PlGF increased from baseline levels during treatment, then declined after treatment discontinued. Angiopoietin-2 exhibited a decrease during treatment, then increased after treatment discontinuation. No clear time trend was evident with the other markers. Analyses of baseline biomarker expression and its relationship with efficacy variables found no biomarker was predictive for efficacy outcomes, including VEGF-D. However, CRP, HGF, ICAM-3, IL-8, SAA, and VCAM-1 were identified as potential prognostic markers with low baseline levels corresponding to longer OS and PFS.

CONCLUSIONS

Pharmacodynamic and prognostic relationships were found from the exploratory biomarker analyses in RAINBOW; however, no predictive markers for ramucirumab in gastric cancer were identified in this trial.

Abstract P3-14-07: Evaluation of the effects of talazoparib on QT interval prolongation

Background: Talazoparib (TAL), an oral poly ADP-ribose polymerase inhibitor, is under investigation in multiple oncologic clinical trials and has been submitted to the US FDA for use in patients (pts) with germline BRCA-mutated, HER2-negative advanced breast cancer.

International Conference on Harmonisation guidance recommends all new drugs be evaluated for effects on cardiac repolarization in a well-controlled clinical study. For drugs for which such evaluation cannot be conducted in healthy volunteers (eg, most anticancer agents), collection of robust corrected QT (QTc) interval data from a dedicated QTc study (hybrid thorough QT/QTc study) in pts is required in the registration dossier. The effect of steady-state (ss) TAL (1 mg once daily) on cardiac repolarization in pts with advanced solid tumors was evaluated in an open-label phase 1 study (NCT03042910).

Methods: Continuous 12-lead electrocardiogram (ECG) recordings were collected at baseline (Day -1); time-matched pharmacokinetic (PK) samples and continuous ECG recordings were obtained on Days 1, 2, and 22 (when TAL concentrations achieved ss). On Day -1, pts had continuous 12-lead ECG recording starting at Time 0 (Day 1 dosing time) for 6 hrs. On Days 1 and 22, ECG recording started 45 min before TAL administration and continued for 6 hrs post dose and blood samples for PK were collected before dose and at 1, 2, 4, and 6 hrs post dose. On Day 2, a 30-min ECG recording and a PK sample were obtained before dose at Time 0.

Continuous ECG recordings were submitted to a central laboratory; triplicate 10-sec ECGs were extracted from a 5-min extraction window beginning 15 min before each PK collection time. ECG measurements were reported via blinded manual adjudication process and included PR interval, QT interval, RR interval, and QRS complex. The QT interval was corrected for effect of heart rate using Fridericia's correction (QTcF) and Bazett's correction (QTcB).

The estimate of change from time-matched baseline and its 2-sided 90% confidence interval (CI) was calculated for each nominal time point using PROC MEANS. Additionally, a prespecified PK/pharmacodynamic (PD) model was used to describe the relationship between plasma TAL concentrations ([TAL]) and QTc. The prespecified linear mixed-effects model included [TAL], time (categorical), and treatment with random pt effects on [TAL] and the intercept. If the upper bounds (UB) of 1-sided 95% CIs of time-matched ΔQTc for all ECG time points were <20 msec and the UB of 1-sided 95% CIs of the predicted ΔQTc at the mean ss maximum [TAL] was <20 msec, the effect of TAL on QTc was not of clinical relevance.

Results: 37 of 38 pts enrolled received TAL and were included in the ECG and PK/PD analyses. No pts had a postbaseline absolute maximum QTcF or QTcB ≥500 msec or ΔQTc ≥60 msec. The UB of the 1-sided 95% CI for the time-matched ΔQTcF and ΔQTcB were <12 msec at all nominal ECG time points. In the PK/PD analysis, the slopes (95% CI) of QTcF-[TAL] and QTcB-[TAL] relationships were -0.14 (-0.78 to 0.50) msec/ng/mL and -0.24 (-0.88 to 0.41) msec/ng/mL, respectively, indicating that TAL did not have a concentration-dependent effect on QTcF or QTcB.

Conclusion: TAL does not have a clinically relevant effect on QTc.

Funding: Medivation LLC, acquired by Pfizer.

Citation Format: Hoffman J, Chakrabarti J, Wainberg ZA, Plotka A, Babu S, Milillo Naraine A, Kanamori D, Moroose R, Nguyen L, Wang D. Evaluation of the effects of talazoparib on QT interval prolongation [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-14-07.

A phase II, randomised study of mFOLFOX6 with or without the Akt inhibitor ipatasertib in patients with locally advanced or metastatic gastric or gastroesophageal junction cancer

BACKGROUND

Akt activation is common in gastric/gastroesophageal junction cancer (GC/GEJC) and is associated with chemotherapy resistance. Treatment with ipatasertib, a pan-Akt inhibitor, may potentiate the efficacy of chemotherapy in GC/GEJC.

PATIENTS AND METHODS

In this randomised, double-blind, placebo-controlled, multicentre, phase II trial, patients with locally advanced or metastatic GC/GEJC not amenable to curative therapy were randomised 1:1 to receive ipatasertib or placebo, plus mFOLFOX6 (modified regimen of leucovorin, bolus and infusional 5-fluorouracil [5-FU], and oxaliplatin). The co-primary end-point was progression-free survival (PFS) in the intent-to-treat (ITT) population and in phosphatase and tensin homolog (PTEN)-low patients. Secondary end-points included PFS in patients with PI3K/Akt pathway-activated tumours; overall survival, investigator-assessed objective response rate and duration of response in the ITT population; and safety assessments.

RESULTS

In 153 enrolled patients, the median PFS (ITT) was 6.6 months (90% confidence interval [CI], 5.7-7.5) with ipatasertib/mFOLFOX6 versus 7.5 months (90% CI, 6.2-8.1) with placebo/mFOLFOX6 (hazard ratio, 1.12; 90% CI, 0.81-1.55; P = 0.56). No statistically significant PFS benefit was observed in biomarker-selected patient subgroups (PTEN-low and PI3K/Akt pathway-activated tumours) with ipatasertib/mFOLFOX6 versus placebo/mFOLFOX6. Other secondary end-points did not favour the ipatasertib/mFOLFOX6 treatment arm. The percentages of patients with ≥1 adverse event (AE, 100% versus 98%) and grade ≥3 AEs (79% versus 74%) were similar between arms. Higher rates of AEs leading to treatment withdrawal (16% versus 6%) and serious AEs were reported in the ipatasertib arm (54% versus 43%). Thirty-nine and 29 deaths occurred in the ipatasertib and placebo arms, respectively.

CONCLUSIONS

Ipatasertib/mFOLFOX6 compared with placebo/mFOLFOX6 did not improve PFS in unselected or biomarker-selected patients. No unexpected safety concerns were observed.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01896531).

Circulating tumour cells as a biomarker for diagnosis and staging in pancreatic cancer

BACKGROUND

Current diagnosis and staging of pancreatic ductal adenocarcinoma (PDAC) has important limitations and better biomarkers are needed to guide initial therapy. We investigated the performance of circulating tumour cells (CTCs) as an adjunctive biomarker at the time of disease presentation.

METHODS

Venous blood (VB) was collected prospectively from 100 consecutive, pre-treatment patients with PDAC. Utilising the microfluidic NanoVelcro CTC chip, samples were evaluated for the presence and number of CTCs. KRAS mutation analysis was used to compare the CTCs with primary tumour tissue. CTC enumeration data was then evaluated as a diagnostic and staging biomarker in the setting of PDAC.

RESULTS

We found 100% concordance for KRAS mutation subtype between primary tumour and CTCs in all five patients tested. Evaluation of CTCs as a diagnostic revealed the presence of CTCs in 54/72 patients with confirmed PDAC (sensitivity=75.0%, specificity=96.4%, area under the curve (AUROC)=0.867, 95% CI=0.798-0.935, and P<0.001). Furthermore, a cut-off of ⩾3 CTCs in 4 ml VB was able to discriminate between local/regional and metastatic disease (AUROC=0.885; 95% CI=0.800-0.969; and P<0.001).

CONCLUSION

CTCs appear to function well as a biomarker for diagnosis and staging in PDAC.

Ramucirumab combined with FOLFOX as front-line therapy for advanced esophageal, gastroesophageal junction, or gastric adenocarcinoma: a randomized, double-blind, multicenter Phase II trial

BACKGROUND

We report the first randomized, Phase II trial of ramucirumab, an anti-vascular endothelial growth factor receptor-2 monoclonal antibody, as front-line therapy in patients with advanced adenocarcinoma of the esophagus or gastric/gastroesophageal junction (GEJ).

PATIENTS AND METHODS

Patients from the USA with advanced esophageal, gastric, or GEJ adenocarcinoma randomly received (1:1) mFOLFOX6 plus ramucirumab (8 mg/kg) or mFOLFOX6 plus placebo every 2 weeks. The primary end point was progression-free survival (PFS) with 80% power to detect a hazard ratio (HR) of 0.71 (one-sided α = 0.15). Secondary end points included evaluation of response and overall survival (OS); an exploratory ramucirumab exposure-response analysis was undertaken.

RESULTS

Of 168 randomized patients, 52% of tumors were located in the stomach/GEJ and 48% in the esophagus. The trial did not meet the primary end point of PFS [6.4 versus 6.7 months, HR 0.98 (95% confidence interval 0.69-1.37)] or the secondary end point of OS (11.7 versus 11.5 months) in the intent-to-treat (ITT) population. Objective response rates (45.2% versus 46.4%) were similar between arms. Most Grade ≥3 toxicities did not differ significantly between arms, yet premature discontinuation of FOLFOX and ramucirumab (for reasons other than progressive disease) was more common among ramucirumab- versus placebo-treated patients. In an exploratory analysis that censored for premature discontinuation, the HR for PFS favored the ramucirumab arm (HR 0.76), particularly in patients with gastric/GEJ cancer. An exploratory exposure-response analysis indicated that patients with higher ramucirumab exposure had longer OS.

CONCLUSION

The addition of ramucirumab to front-line mFOLFOX6 did not improve PFS in the ITT population.

CLINICALTRIALSGOV IDENTIFIER

NCT01246960.

Abstract P2-09-02: BMN 673 is a PARP inhibitor in clinical development for the treatment of breast cancer patients with deleterious germline BRCA 1 and 2 mutations

Background: BMN 673 is the most potent and specific inhibitor of poly-ADP ribose polymerase (PARP) 1 and 2 in clinical development (IC50&lt;1nM). In BRCA-related tumors, which are genetically dependent on PARP-mediated DNA repair by base excision repair, PARP inhibition induces synthetic lethality. Initial phase 1 results have been presented (de Bono et al JCO 31:5s, 2013 suppl; abstr 2580), showing good tolerability and anti-tumor activity with an MTD on a daily, oral dosing schedule of 1000 μ/day.

Methods: In this 2-stage study, patients with solid tumors including BRCA-related cancers, were enrolled during dose-escalation followed by an expansion phase at the MTD in breast, ovarian, and pancreatic cancer patients with deleterious germline BRCA mutations and in small cell lung cancer and Ewing sarcoma patients to further characterize safety and efficacy. This abstract summarizes demographics and safety for all patients and efficacy for patients with BRCA-related cancers.

Results: As of 17May2013, a total of 1 pancreatic, 18 breast (17F/1M), and 28 ovarian cancer pts with germline BRCA mutations were enrolled at doses from 100-1100 μg/day. All breast cancer patients were treated from 900-1100 μg/day. The median (range) age for all 70 patients is 51.5 (18-81), PS 0 (0-1) and # of prior therapies 4 (1-13), with 47 patients having deleterious BRCA mutations. An MTD of 1000 μg/day was established with thrombocytopenia being dose-limiting. Related adverse events occurring in &gt; 10% of all 70 patients included fatigue, nausea, alopecia, anemia, thrombocytopenia and neutropenia. One patient has had related grade 4 thrombocytopenia. Grade 3 related AE's included fatigue in 1 patient (1%), anemia and thrombocytopenia in 9 each (13%) and neutropenia in 4 (6%). Dose reductions occurred in 11 pts due to myelosuppression. No patients discontinued for adverse events.

Response in Germline BRCA PatientsBRCA Tumor TypeNDose Range (μ/day)ResponseBreast18900-11001CR/6PR/5SD≥12 weeksOvarian28100-11001CR/10PR/19GCIG/4SD≥24 weeksPancreas110001 SD ≥ 12weeksTwo of 2 BRCA breast responders had responded to prior platinum while 0 of 4 non-responders to prior platinum responded to BMN 673. Five of 12 breast cancer pts with no prior platinum have responded.

Conclusions: BMN 673 is well tolerated with impressive anti-tumor activity in pts with deleterious germ line BRCA mutations. Myelosuppression and fatigue are the primary side effects associated with need for dose reduction. A phase 3 trial in metastatic breast cancer patients with deleterious germ line BRCA mutations is planned with single-agent, once-daily oral dosing of 1000 μg (1 mg) per day.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-09-02.

Phase II trial of modified FOLFOX6 and erlotinib in patients with metastatic or advanced adenocarcinoma of the oesophagus and gastro-oesophageal junction

BACKGROUND

There is increased recognition that cancers of the upper GI tract comprise distinct epidemiological and molecular entities. Erlotinib has shown activity in patients with adenocarcinoma of the oesophagus/gastro-oesophageal junction (GEJ), but not in distal gastric cancer. mFOLFOX6 is one of several active regimens used to treat adenocarcinoma of the Eso/GEJ. This study evaluates the efficacy and safety of mFOLFOX6 and erlotinib in patients with metastatic or advanced Eso/GEJ cancers.

METHODS

Patients with previously untreated advanced or metastatic Eso/GEJ adenocarcinoma are treated with oxaliplatin 85 mg m(-2), 5-FU 400 mg m(-2), LV 400 mg m(-2) on day 1, 5-FU 2400 mg m(-2) over 48 h and erlotinib 150 mg PO daily. Treatment was repeated every 14 days. The primary objective was response rate (RR), secondary objectives include toxicity, progression-free survival (PFS), overall survival (OS) and to correlate clinical outcome with expression patterns and molecular alterations in the epidermal growth factor receptor-dependent pathways.

RESULTS

A total of 33 patients were treated and evaluable: there were two complete responses, 15 partial responses for an objective RR of 51.5% (95% CI, 34.5-68.6%). Median PFS was 5.5 months (95% CI, 3.1-7.5 months) and median OS was 11.0 months (95% CI, 8.0-17.4 months). The most common grade 3-4 toxicities were: diarrhoea (24%), nausea/vomiting (11%), skin rash (8%) and peripheral neuropathy (8%). The frequency of alterations was KRAS mutations (8%), EGFR mutations (0%) and HER2 amplification (19%).

CONCLUSION

In patients with Eso/GEJ adenocarcinoma, mFOLFOX6 and erlotinib is active, has an acceptable toxicity profile and FOLFOX ± erlotinib could be considered for further development.