Validation of treatment induced specific adverse effect as a predictor of treatment benefit: A case study of NCIC CTG BR21

Hyperphosphatemia Secondary to the Selective Fibroblast Growth Factor Receptor 1-3 Inhibitor Infigratinib (BGJ398) Is Associated with Antitumor Efficacy in Fibroblast Growth Factor Receptor 3-altered Advanced/Metastatic Urothelial Carcinoma

BACKGROUND

Infigratinib (BGJ398) is a potent, selective fibroblast growth factor receptor (FGFR) 1-3 inhibitor with significant activity in metastatic urothelial carcinoma (mUC) bearing FGFR3 alterations. It can cause hyperphosphatemia due to the "on-target" class effect of FGFR1 inhibition.

OBJECTIVE

To investigate the relationship between hyperphosphatemia and treatment response in patients with mUC.

INTERVENTION

Oral infigratinib 125 mg/d for 21 d every 28 d.

DESIGN, SETTING, AND PARTICIPANTS

Data from patients treated with infigratinib in a phase I trial with platinum-refractory mUC and activating FGFR3 alterations were retrospectively analyzed for clinical efficacy in relation to serum hyperphosphatemia. The relationship between plasma infigratinib concentration and phosphorous levels was also assessed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Clinical outcomes were compared in groups with/without hyperphosphatemia.

RESULTS AND LIMITATIONS

Of the 67 patients enrolled, 48 (71.6%) had hyperphosphatemia on one or more laboratory tests. Findings in patients with versus without hyperphosphatemia were the following: overall response rate 33.3% (95% confidence interval [CI] 20.4-48.4) versus 5.3% (95% CI 0.1-26.0); disease control rate 75.0% (95% CI 60.4-86.4) versus 36.8% (95% CI 16.3-61.6). This trend was maintained in a 1-mo landmark analysis. Pharmacokinetic/pharmacodynamic analysis showed that serum phosphorus levels and physiologic infigratinib concentrations were correlated positively. Key limitations include retrospective design, lack of comparator, and limited sample size.

CONCLUSIONS

This is the first published study to suggest that hyperphosphatemia caused by FGFR inhibitors, such as infigratinib, can be a surrogate biomarker for treatment response. These findings are consistent with other reported observations and will need to be validated further in a larger prospective trial.

PATIENT SUMMARY

Targeted therapy is a new paradigm in treating bladder cancer. In a study using infigratinib, a drug that targets mutations in a gene called fibroblast growth factor receptor 3 (FGFR3), we found that elevated levels of phosphorous were associated with greater clinical benefit. In the future, these data may help inform treatment strategies.

Endocrine Treatment-Related Symptoms and Patient Outcomes in Breast Cancer: A Meta-Analysis

Purpose

An association between endocrine treatment-related symptoms and breast cancer recurrence has been suggested previously; however, conflicting results have been reported. We performed a meta-analysis of published studies to clarify this relationship.

Methods

We systematically searched PubMed, Embase, Scopus, and the Cochrane database for studies investigating the association between endocrine treatment-related symptoms and patient survival. Random-effects meta-analysis was conducted with recurrence rate as the primary outcome.

Results

Out of 7,713 retrieved articles, six studies were included. In patients who received endocrine treatment, the presence of any endocrine treatment-related symptom was found to be associated with a lower recurrence rate in comparison to an absence of any symptoms (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.66-0.87). This relationship persisted in patients presenting with only vasomotor or only musculoskeletal symptoms (HR, 0.74, 95% CI, 0.63-0.87; HR, 0.69, 95% CI, 0.55-0.86, respectively). At both time-points of symptom evaluation (3 months and 12 months), patients with endocrine treatment-related symptoms had a lower recurrence rate (HR, 0.74, 95% CI, 0.66-0.84; HR, 0.79, 95% CI, 0.69-0.90, respectively). This association was also significant in pooled studies including patients with and without baseline symptoms (HR, 0.73, 95% CI, 0.54-0.99; HR, 0.76, 95% CI, 0.69-0.85, respectively).

Conclusion

Endocrine treatment-related symptoms are significantly predictive of lower recurrence rate in breast cancer patients, regardless of the type of symptoms, time-point of evaluation, or inclusion of baseline symptoms. These symptoms could be biomarkers for the prediction of long-term responses to endocrine treatment in patients with breast cancer.

Combined action of EGFR tyrosine kinase inhibitors and whole-brain radiotherapy on EGFR-mutated non-small-cell lung cancer patients with brain metastasis

Background

Lung cancer is the most common type of cancer to spread to the brain (brain metastasis [BM]). This study assessed the effect of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in combination with whole-brain radiotherapy (WBRT) on EGFR-mutant non-small-cell lung cancer (NSCLC) patients with BM.

Patients and methods

Thirty-nine patients, who had receieved different EGFR TKIs plus 30 Gy WBRT until disease progression, were retrospectively analyzed between 2010 and 2014. Treatment response was evaluated and survival data were collected and analyzed.

Results

Among the 39 patients, 18 had an EGFR exon 19 deletion and 21 had an EGFR exon 21 point mutation. After therapy, 19 (48.7%) patients had complete remission, 12 (30.8%) had partial remission, and eight (20.5%) had stable disease in the intracranial lesions. Besides, there was no single case of complete remission, 21 (53.8%) had partial remission, and 18 (46.2%) had stable disease of the extracranial lesions. The median progression-free survival (PFS) of intracranial lesions and extracranial lesions was 18 and 12 months, respectively. The median overall survival (OS) was 26 months. The univariate analysis showed that graded prognostic assessment (P=0.006) and Karnofsky Performance Scale (P=0.045) were associated with intracranial progression-free survival (iPFS), while recursive partitioning analysis (P=0.049) was associated with OS of patients.

Conclusion

EGFR TKIs plus concomitant WBRT controlled intracranial lesions of lung cancer metastasis and significantly improved OS of patients. Further studies will be needed to confirm whether this combination treatment could be used as a standard therapy for EGFR-mutated NSCLC patients with BM.

Mammalian target of rapamycin (mTOR) inhibitor-associated non-infectious pneumonitis in patients with renal cell cancer: predictors, management, and outcomes

OBJECTIVE

To characterise the incidence, onset, management, predictors, and clinical impact of mammalian target of rapamycin (mTOR) inhibitor-associated non-infectious pneumonitis (NIP) on patients with metastatic renal cell carcinoma (mRCC).

PATIENTS AND METHODS

Retrospective review of 310 patients with mRCC who received temsirolimus and/or everolimus between June 2007 and October 2010. Clinical correlations were made with serial radiological imaging. Fisher's exact, Wilcoxon rank-sum, and logistic regression analyses were used to evaluate the association of NIP with demographic or clinical factors. Log-rank and Cox proportional hazards regression analyses were used for the time-to-event analysis.

RESULTS

NIP occurred in 6% of temsirolimus-treated and 23% of everolimus-treated patients. Symptoms included cough, dyspnoea, and fever (median of two and three symptoms per patient, respectively). The median National Cancer Institute Common Toxicity Criteria for Adverse Events pneumonitis grade was 2 for both groups. Older age and everolimus treatment were predictive of NIP. Patients who developed NIP had a significantly longer time on treatment (median 4.1 vs 2 months) and overall survival (OS) (median 15.4 vs 7.4 months). NIP was a predictor of improved OS by multivariate analysis.

CONCLUSIONS

There was an increased incidence of NIP in everolimus-treated patients. Improved OS in patients who developed NIP is an intriguing finding and should be further investigated. Given the incidence, morbidity, and outcomes seen in patients on everolimus who develop NIP, management should include proactive monitoring and treatment of NIP with the goal of preserving mTOR inhibitor therapy.

Evaluation of a novel rash scale and a serum proteomic predictor in a randomized phase II trial of sequential or concurrent cetuximab and pemetrexed in previously treated non-small cell lung cancer

Background

Candidate predictive biomarkers for epidermal growth factor receptor inhibitors (EGFRi), skin rash and serum proteomic assays, require further qualification to improve EGFRi therapy in non-small cell lung cancer (NSCLC). In a phase II trial that was closed to accrual because of changes in clinical practice we examined the relationships among candidate biomarkers, quantitative changes in tumor size, progression-free and overall survival.

Methods

55 patients with progressive NSCLC after platinum therapy were randomized to receive (Arm A) cetuximab, followed by pemetrexed at progression, or (Arm B) concurrent cetuximab and pemetrexed. All received cetuximab monotherapy for the first 14 days. Pre-treatment serum and weekly rash assessments by standard and EGFRi-induced rash (EIR) scales were collected.

Results

43 patients (20-Arm A, 23-Arm B) completed the 14-day run-in. Median survival was 9.1 months. Arm B had better median overall (Arm B = 10.3 [95% CI 7.5, 16.8]; Arm A = 3.5 [2.8, 11.7] months P = 0.046) and progression-free survival (Arm B = 2.3 [1.6, 3.1]; Arm A = 1.6 [0.9, 1.9] months P = 0.11). The EIR scale distributed ratings among 6 rather than 3 categories but ordinal scale rash severity did not predict outcomes. The serum proteomic classifier and absence of rash after 21 days of cetuximab did.

Conclusions

Absence of rash after 21 days of cetuximab therapy and the serum proteomic classifier, but not ordinal rash severity, were associated with NSCLC outcomes. Although in a small study, these observations were consistent with results from larger retrospective analyses.

Trial registration

Clinicaltrials.gov Identifier NCT00203931

Treatment outcomes in elderly with advanced-stage non-small cell lung cancer

Purpose

Lung cancer remains the top cause of cancer morbidity and mortality in the world. Although the identification of epidermal growth factor receptor (EGFR) gene mutations could predict efficacy of tyrosine kinase inhibitor (TKI), testing for predictive biomarkers are not always possible due to tissue availability. The overall therapeutic decision remains a clinical one for a significant proportion of elderly patients with advanced stage lung cancer but no known EGFR mutation status. The purpose of this study was to compare the outcome of drug treatment modalities in progression-free survival (PFS) and overall survival (OS) for elderly with advanced-stage non-small cell lung cancer (NSCLC) and to identify clinical parameters that could predict treatment outcome.

Methods

Clinical records of patients aged 70 years or older with advanced-stage NSCLC who have received treatment were reviewed. A group of gender- and histology-matched subjects younger than age 70 years were identified as controls.

Results

Fifty-six elderly patients were included. The median age at diagnosis was 73 years; 60.7 % received only one line of treatment. Baseline performance status (PS) was the only predictor of improved PFS (p = 0.042) and OS (p = 0.002). There was no difference in survival between the upfront chemotherapy and the TKI groups

Conclusions

In elderly with advanced-stage NSCLC without known EGFR mutation status, use of EGFR–TKI and chemotherapy resulted in comparable survival benefits. Age was not predictive of worse treatment outcome. The baseline PS should be taken into consideration in the therapeutic decision in elderly with NSCLC where the EGFR mutation status is not known.

An evaluation of the possible interaction of gastric acid suppressing medication and the EGFR tyrosine kinase inhibitor erlotinib

OBJECTIVES

As the bioavailability of erlotinib is dependent on gastric pH, an increase in gastric pH via the concurrent use of gastric acid suppressive medications (AS) may reduce its bioavailability and efficacy. We retrospectively analyzed the BR.21 trial database to pragmatically evaluate the impact of AS use on the median plasma drug levels of erlotinib, adverse events and outcome of participants.

METHODS

Monthly median plasma levels of erlotinib were compared between participants utilizing AS and those who did not using a Wilcoxon test. Interaction p-value for AS users and AS non-users was performed using a multivariate Cox model with a time-dependent covariate for AS use. Grade 2 adverse events were compared using Fisher's Exact Test.

RESULTS

The median plasma erlotinib level was not significantly different between AS users and AS non-users, and AS use did not appear to incur a negative impact on PFS or OS (Interaction p-values: PFS p = 0.16; OS p = 0.81). AS users receiving erlotinib had a similar frequency of rash (50.5% vs. 42.0%, p = 0.08) and a statistically higher rate of diarrhea (27.9% vs. 15.6%, p = 0.001) compared to AS non-users. In addition, AS users had higher rates of infections (erlotinib arm: 33.7% vs. 20.0%, p < 0.0001; placebo arm: 22.7% vs. 10.8%, p = 0.02).

CONCLUSION

This retrospective analysis found that the co-administration of AS and erlotinib did not appear to have a significant impact on the median plasma drug levels or outcome.

Role of Epidermal Growth Factor Receptor Inhibitors in Epidermal Growth Factor Receptor Wild-Type Non–Small-Cell Lung Cancer

Worldwide, the majority of patients with advanced non–small-cell lung cancer (NSCLC) do not have activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR). These wild-type patients comprise a significant proportion of those treated with inhibitors of this pathway, and data from randomized trials suggest that some of these wild-type patients will derive a modest benefit from these agents. Although the detection of an activating mutation predicts for a greater likelihood of response and longer progression-free survival from an EGFR tyrosine kinase inhibitor, currently there are no biomarkers that consistently and reproducibly predict for lack of benefit in wild-type patients. Several strategies to increase the efficacy of these inhibitors in wild-type NSCLC are the subject of ongoing investigations.

Toxicity as a biomarker of efficacy of molecular targeted therapies: focus on EGFR and VEGF inhibiting anticancer drugs

In addition to being present in tumor cells, many targets of signal transduction inhibitors are also found in normal tissue. Side effects attributable to the mechanism of action of molecular targeted agents thus represent "on-target" modulation in normal tissues. These mechanism-based toxicities can be pharmacodynamic effects of pathway inhibition and, in tumors depending on the inhibited pathway for proliferation, might be biomarkers of efficacy. The development of rash with tyrosine kinase inhibitors or monoclonal antibodies targeting the epidermal growth factor receptor is associated with superior outcomes in lung, head and neck, colorectal, and pancreatic cancer studies. Correlated with superior efficacy in retrospective analyses of large studies in advanced colorectal, breast, and renal cell carcinoma, arterial hypertension as an adverse event of antiangiogenic agents may also be a marker of effective target inhibition. An association between hypothyroidism and the activity of multitargeted tyrosine kinase inhibitors has been identified in renal cell carcinoma patients. Tumor growth addiction to the specific pathway that is effectively targeted may be the link between a mechanism-based toxicity and efficacy. The biological basis for this correlation can be pharmacological, with higher drug exposure being associated with greater toxicity and antitumor activity, and can also be genetic, because single nucleotide polymorphisms play an important role in drug pharmacokinetic and pharmacodynamic processes. Investigators have proposed that interpatient differences and associated toxicities can be exploited for dose selection and titration, and clinical trials are currently exploring intrapatient "dosing-to-toxicity" strategies. Ultimately, the predictive value of a side effect of molecular targeted therapies requires validation in prospective trials.