Phase I pharmacokinetic and pharmacodynamic study of cetuximab, irinotecan and sorafenib in advanced colorectal cancer

Dual VEGF inhibition with sorafenib and bevacizumab as salvage therapy in metastatic colorectal cancer: results of the phase II North Central Cancer Treatment Group study N054C (Alliance)

Background

Bevacizumab (BEV), a monoclonal antibody against vascular endothelial growth factor-A (VEGF-A), is a standard component of medical therapy of metastatic colorectal cancer (mCRC). Activation of alternative angiogenesis pathways has been implicated in resistance to BEV. This phase II study examines the activity of combined vertical blockade of VEGF signaling with sorafenib and BEV as salvage therapy in patients with progressive disease (PD) on all standard therapy in mCRC.

Methods

mCRC patients with documented PD on standard therapy, received sorafenib (200 mg orally twice daily, days 1-5 and 8-12) and BEV (5 mg/kg intravenously, day 1) every 2 weeks. Primary endpoint was 3-month progression-free survival (PFS) rate and secondary endpoints were overall survival (OS), response rate (RR), safety, and feasibility.

Results

Of the 83 patients enrolled, 79 were evaluable. Of these, 42 (53%) were progression-free at 3 months. Median PFS was 3.5 months and median OS was 8.3 months. One patient had a partial response and 50 patients (63.3%) had at least one stable tumor assessment. Of 79 evaluable patients, 54 (68%) experienced grade 3/4 adverse events (AEs) at least possibly related to treatment. Most frequent grade 3/4 AEs were: fatigue (24.1%), hypertension (16.5%), elevated lipase (8.9%), hand-foot skin reaction (8.9%), diarrhea (7.6%), and proteinuria (7.6%). Reasons for treatment discontinuation were PD (72%), AEs (18%), patient refusal (8%), physician decision (1%), and death (1%).

Conclusions

The combination of BEV and sorafenib as salvage therapy in heavily pretreated mCRC patients is tolerable and manageable, with evidence of promising activity.

ClinicalTrialsgov identifier

NCT00826540, URL:http://clinicaltrials.gov/ct2/show/NCT00826540.

Enhanced oral absorption of sorafenib via the layer-by-layer deposition of a pH-sensitive polymer and glycol chitosan on the liposome

This study aimed to design the effective formulation of sorafenib (SF) to enhance the oral drug absorption. Three liposomal formulations of SF were prepared including uncoated liposome (SF-Lip), glycol chitosan-coated liposome (GC-SF-Lip), and Eudragit S100-glycol-chitosan coated liposome (SGC-SF-Lip). All formulations showed a narrow size distribution with a high encapsulation efficiency. Both GC-SF-Lip and SGC-SF-Lip exhibited good stability at acidic and neutral pHs without any significant drug leakage, while SF-Lip appeared to be unstable at pH 1.2. In the case of double coated SGC-SF-Lip, its size changed significantly at pH 7.4, due to the dissolution of Eudragit S100 coating layer into the surrounding medium. Compared to SF solution, all liposomal formulations demonstrated a higher cellular uptake in Caco-2 cells. In particular, SGC-SF-Lip displayed a lower cellular uptake than GC-SF-Lip at pH 6.5, but it achieved a similar cellular uptake to GC-SF-Lip at pH 7.4. Consistently, SGC-SF-Lip was less cytotoxic than GC-SF-Lip at pH 6.5, whereas it showed a comparable cytotoxicity to GC-SF-Lip at pH 7.4, implying the removal of the Eudragit S100 coating layer at pH 7.4. After an oral administration to rats, SGC-SF-Lip significantly improved the systemic exposure of SF, where its Cmax and AUC were approximately fourfold higher than the untreated drug. Collectively, SGC-SF-Lip appeared to be promising to enhance the oral absorption of SF.

Antiangiogenic tyrosine kinase inhibitors in colorectal cancer: is there a path to making them more effective?

Antiangiogenic therapy has a proven survival benefit in metastatic colorectal cancer. Inhibition of the VEGF pathway using a variety of extracellular antibody approaches has clear benefit in combination with chemotherapy, while intracellular blockade using tyrosine kinase inhibitors (TKIs) such as sorafenib and regorafenib has had more limited success. Pharmacodynamic modeling using modalities such as DCE-MRI indicates potent antiangiogenic effects of these TKIs, yet numerous combination therapies, primarily with chemotherapy, have failed to demonstrate an additive benefit. The sole comparative study of a single agent TKI against placebo showed a survival benefit of regorafenib in patients with advanced, refractory disease. Preclinical data demonstrate synergy between antiantiogenic TKIs and targeted interventions including autophagy inhibition, and together with a renewed effort to define markers of susceptibility, such combinations may be a way to improve the limited efficacy of this once-promising drug class.

The Collagen Gel Droplet-embedded Culture Drug Sensitivity Test in Relapsed Hepatoblastoma

There are few treatment options for patients with unresectable or refractory hepatoblastoma which has failed to respond to the standard treatment. The rarity of the disease and lack of experimental materials have hampered the development of new treatments. In this study, the collagen gel droplet-embedded culture drug sensitivity test was used to evaluate the effectiveness of the multikinase inhibitors sorafenib and sunitinib, and other drugs, in relapsed hepatoblastoma tumor tissues. Tumor samples from 6 patients with relapsed hepatoblastoma were tested for drug sensitivity by the collagen gel droplet-embedded culture drug sensitivity test; evaluable results were obtained from 5 of them. All samples were judged to be sensitive to sorafenib with a 50% growth inhibitory concentration (IC50) of 0.5 to 3.1 μg/mL. Sunitinib did not achieve IC50 in 2 of 3 samples within the tested concentration range based on clinically observed serum concentrations. In the drug combination assay using a hepatoblastoma cell line, sorafenib showed synergistic effects with SN-38, an active metabolite of irinotecan. Our results provide the basic science background warranting future clinical trials of a combination of sorafenib and irinotecan for relapsed or refractory hepatoblastoma.

A Phase Ib Study of Sorafenib (BAY 43-9006) in Patients with Kaposi Sarcoma

LESSONS LEARNED

Oral targeted agents are desirable for treatment of Kaposi sarcoma (KS); however, in patients with HIV, drug-drug interactions must be considered. In this study to treat KS, sorafenib was poorly tolerated at doses less than those approved by the U.S. Food and Drug Administration for hepatocellular carcinoma and other cancers, and showed only modest activity.Sorafenib's metabolism occurs via the CYP3A4 pathway, which is inhibited by ritonavir, a commonly used antiretroviral agent used by most patients in this study. Strong CYP3A4 inhibition by ritonavir may contribute to the observed sorafenib toxicity.Alternate antiretroviral agents without predicted interactions are preferred for co-administration in patients with HIV and cancers for which sorafenib is indicated.

BACKGROUND

We conducted a phase Ib study of sorafenib, a vascular epithelial growth factor receptor (VEGFR), c-kit, and platelet derived growth factor receptor (PDGFR)-targeted treatment in Kaposi sarcoma (KS). We evaluated drug-drug interactions between sorafenib and ritonavir, an HIV medication with strong CYP3A4 inhibitory activity.

METHODS

Two cohorts were enrolled: HIV-related KS on ritonavir (Cohort R) and HIV-related or classical KS not receiving ritonavir (Cohort NR). Sorafenib dose level 1 in cohort R (R1) was 200 mg daily and 200 mg every 12 hours in cohort NR (NR1). Steady-state pharmacokinetics were evaluated at cycle 1, day 8. KS responses and correlative factors were assessed.

RESULTS

Ten patients (nine HIV+) were enrolled: R1 (eight), NR1 (two). Median CD4+ count (HIV+) was 500 cells/µL. Dose-limiting toxicities (DLTs) were grade 3 elevated lipase (R1), grade 4 thrombocytopenia (R1), and grade 3 hand-foot syndrome (NR1). Two of seven evaluable patients had a partial response (PR; 29%; 95% CI 4%-71%). Steady-state area under the curve of the dosing interval (AUCTAU) of sorafenib was not significantly affected by ritonavir; however, a trend for decreased AUCTAU of the CYP3A4 metabolite sorafenib-N-oxide (3.8-fold decrease; p = .08) suggests other metabolites may be increased.

CONCLUSION

Sorafenib was poorly tolerated, and anti-KS activity was modest. Strong CYP3A4 inhibitors may contribute to sorafenib toxicity, and ritonavir has previously been shown to be a CYP3A4 inhibitor. Alternate antiretroviral agents without predicted interactions should be used when possible for concurrent administration with sorafenib. The Oncologist 2017;22:505-e49.

Inefficiencies and Patient Burdens in the Development of the Targeted Cancer Drug Sorafenib: A Systematic Review

Failure in cancer drug development exacts heavy burdens on patients and research systems. To investigate inefficiencies and burdens in targeted drug development in cancer, we conducted a systematic review of all prelicensure trials for the anticancer drug, sorafenib (Bayer/Onyx Pharmaceuticals). We searched Embase and MEDLINE databases on October 14, 2014, for prelicensure clinical trials testing sorafenib against cancers. We measured risk by serious adverse event rates, benefit by objective response rates and survival, and trial success by prespecified primary endpoint attainment with acceptable toxicity. The first two clinically useful applications of sorafenib were discovered in the first 2 efficacy trials, after five drug-related deaths (4.6% of 108 total) and 93 total patient-years of involvement (2.4% of 3,928 total). Thereafter, sorafenib was tested in 26 indications and 67 drug combinations, leading to one additional licensure. Drug developers tested 5 indications in over 5 trials each, comprising 56 drug-related deaths (51.8% of 108 total) and 1,155 patient-years (29.4% of 3,928 total) of burden in unsuccessful attempts to discover utility against these malignancies. Overall, 32 Phase II trials (26% of Phase II activity) were duplicative, lacked appropriate follow-up, or were uninformative because of accrual failure, constituting 1,773 patients (15.6% of 11,355 total) participating in prelicensure sorafenib trials. The clinical utility of sorafenib was established early in development, with low burden on patients and resources. However, these early successes were followed by rapid and exhaustive testing against various malignancies and combination regimens, leading to excess patient burden. Our evaluation of sorafenib development suggests many opportunities for reducing costs and unnecessary patient burden in cancer drug development.

Clinical Response to Sorafenib in a Patient with Metastatic Colorectal Cancer and FLT3 Amplification

Background

A considerable number of patients with metastatic colorectal cancer progress after exhausting all approved standard therapies but maintain an adequate performance status and could be candidates for further treatment. We aim at reviewing our experience with sorafenib treatment of a patient with FLT3 mutation in refractory metastatic colorectal cancer.

Methods

Treatment with sorafenib of a patient with metastatic colorectal cancer and FLT3 translocation who had previously been heavily treated.

Results

The patient with metastatic colorectal cancer, aged 51 years, showed significant symptomatic and laboratory improvement with sorafenib treatment (400 mg twice daily).

Conclusion

The presented case illustrates how an aggressive and refractory colorectal tumor may respond well to targeted therapy.

Sorafenib and irinotecan (NEXIRI) as second- or later-line treatment for patients with metastatic colorectal cancer and KRAS-mutated tumours: a multicentre Phase I/II trial

Background:

This trial evaluated the feasibility and efficacy of combined sorafenib and irinotecan (NEXIRI) as second- or later-line treatment of patients with KRAS-mutated metastatic colorectal cancer (mCRC), who had progressed after irinotecan-based chemotherapy.

Methods:

In Phase I, in a 3+3 dose escalation schedule, patients received irinotecan (125, 150 or 180 mg m⁻² every 2 weeks), in combination with 400 mg sorafenib b.d. The primary end point was the maximum-tolerated dose of irinotecan. In Phase II, the primary end point was disease control rate (DCR). Secondary end points were progression-free survival (PFS), overall survival (OS) and toxicity.

Results:

Phase I included 10 patients (median age 63 (49–73)); no dose-limiting toxicity was seen. In Phase II, 54 patients (median age 60 (43–80) years) received irinotecan 180 mg m⁻² every 2 weeks with sorafenib 400 mg b.d. Nine patients (17%) remained on full-dose sorafenib. The DCR was 64.9% (95% CI, 51–77). Median PFS and OS were 3.7 (95% CI, 3.2–4.7) and 8.0 (95% CI, 4.8–9.7) months, respectively. Toxicities included Grade 3 diarrhoea (37%), neutropenia (18%), hand-foot syndrome (13%) and Grade 4 neutropenia (17%).

Conclusion:

The NEXIRI regimen showed promising activity as second- or later-line treatment in this heavily pretreated mCRC population (ClinicalTrials.gov NCT00989469).

Regorafenib: from bench to bedside in colorectal cancer

Colorectal cancer (CRC) remains the third cause of cancer-related mortality in the USA. Despite the advances in screening, many patients present with incurable metastatic disease. Chemotherapy forms the basis of treatment for patients with advanced disease. Angiogenesis is an important step in developing metastases and, therefore, blocking the VEGF pathway seems promising. The development of bevacizumab as a monoclonal antibody targeting the VEGF pathway improved progression-free survival and overall survival in the metastatic settings, with no improvement in disease-free or overall survival in the adjuvant settings. Small molecules such as tyrosine-kinase inhibitors have been long evaluated in metastatic CRC with disappointing results in improving outcome. Most recently, the CORRECT study has resulted in improved outcome in patients with metastatic CRC who were heavily pretreated when they received regorafenib.

Personalizing colon cancer therapeutics: targeting old and new mechanisms of action

The use of pharmaceuticals for colon cancer treatment has been increasingly personalized, in part due to the development of new molecular tools. In this review, we discuss the old and new colon cancer chemotherapeutics, and the parameters that have been shown to be predictive of efficacy and safety of these chemotherapeutics. In addition, we discuss how alternate pharmaceuticals have been developed in light of a potential lack of response or resistance to a particular chemotherapeutic.

Sorafenib overcomes irinotecan resistance in colorectal cancer by inhibiting the ABCG2 drug-efflux pump

Despite recent advances in the treatment of colorectal cancer (CRC), tumor resistance is a frequent cause of chemotherapy failure. Therefore, new treatment options are needed to improve survival of patients with irinotecan-refractory CRCs, particularly those bearing KRAS mutations that preclude the use of anti-EGFR therapies. In this study, we investigated whether sorafenib could reverse irinotecan resistance, thereby enhancing the therapeutic efficacy of routinely used irinotecan-based chemotherapy. We used both in vitro (the HCT116, SW48, SW620, and HT29 colon adenocarcinoma cell lines and four SN-38-resistant HCT-116 and SW48 clones) and in vivo models (nude mice xenografted with SN-38-resistant HCT116 cells) to test the efficacy of sorafenib alone or in combination with irinotecan or its active metabolite, SN-38. We have shown that sorafenib improved the antitumoral activity of irinotecan in vitro, in both parental and SN-38-resistant colon adenocarcinoma cell lines independently of their KRAS status, as well as in vivo, in xenografted mice. By inhibiting the drug-efflux pump ABCG2, sorafenib favors irinotecan intracellular accumulation and enhances its toxicity. Moreover, we found that sorafenib improved the efficacy of irinotecan by inhibiting the irinotecan-mediated p38 and ERK activation. In conclusion, our results show that sorafenib can suppress resistance to irinotecan and suggest that sorafenib could be used to overcome resistance to irinotecan-based chemotherapies in CRC, particularly in KRAS-mutated tumors.