Drug-drug interactions associated with kinase inhibitors: highlighting a new resource for oncologists and clinical pharmacists

Experimentele farmacotherapi

The effect of stretching during warming-up on the flexibility of junior handball players

BACKGROUND: The OPUS study demonstrated that addition of cetuximab to 5-fluorouracil, folinic acid and oxaliplatin (FOLFOX4) significantly improved objective response and progression-free survival (PFS) in the first-line treatment of patients with KRAS exon 2 wild-type metastatic colorectal cancer (mCRC). In patients with KRAS exon 2 mutations, a detrimental effect was seen upon addition of cetuximab to FOLFOX4. The current study reports outcomes in subgroups defined by extended RAS testing. PATIENTS AND METHODS: Samples from OPUS study KRAS exon 2 wild-type tumours were reanalysed for other RAS mutations in four additional KRAS codons (exons 3-4) and six NRAS codons (exons 2-4) using BEAMing. A cutoff of 5% mutant/wild-type sequences was selected to define RAS status; we also report an analysis using a cutoff based on the technical lower limit for mutation identification (0.1%). RESULTS: Other RAS mutations were detected in 31/118 (26%) evaluable patients. In the extended analysis of RAS wild-type tumours (n=87), objective response was significantly improved by addition of cetuximab to FOLFOX4 (58% versus 29%; odds ratio 3.33 [95% confidence interval 1.36-8.17]; P=0.0084); although limited by population size, there also appeared to be trends favouring the cetuximab arm in terms of PFS and overall survival in the RAS wild-type group compared with the RAS evaluable group. There was no evidence that patients with other RAS mutations benefited from cetuximab, but small numbers precluded precise estimations of treatment effects. In the combined population of patients with any RAS mutation (KRAS exon 2 or other RAS), a clear detrimental effect was associated with addition of cetuximab to FOLFOX4. CONCLUSION: Patients with RAS-mutant mCRC, as defined by mutations in KRAS and NRAS exons 2-4, derive no benefit and may be harmed by the addition of cetuximab to FOLFOX4. Restricting cetuximab administration to patients with RAS wild-type tumours will further tailor therapy to maximise benefit

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PURPOSE: The phase III CRYSTAL study demonstrated that addition of cetuximab to fluorouracil, leucovorin, and irinotecan (FOLFIRI) significantly improved overall survival, progression-free survival, and objective response in the first-line treatment of patients with KRAS codon 12/13 (exon 2) wild-type metastatic colorectal cancer (mCRC). Outcome was reassessed in subgroups defined by extended RAS mutation testing. PATIENTS AND METHODS: Existing DNA samples from KRAS exon 2 wild-type tumors from CRYSTAL study patients were reanalyzed for other RAS mutations in four additional KRAS codons (exons 3 and 4) and six NRAS codons (exons 2, 3, and 4) using beads, emulsion, amplification, and magnetics technology. No tissue microdissection was performed. A >/= 5% mutant allele cutoff was used to call mutations. RESULTS: Mutation status was evaluable in 430 (64.6%) of 666 patients with KRAS exon 2 wild-type tumors. Other RAS mutations were detected in 63 (14.7%) of 430 patients. In those with RAS wild-type tumors, a significant benefit across all efficacy end points was associated with the addition of cetuximab to FOLFIRI. In patients with other RAS tumor mutations, no difference in efficacy outcomes between treatment groups was seen. The safety profile in RAS subgroups was similar and in line with expectations. CONCLUSION: In the first-line treatment of mCRC, patients with RAS wild-type tumors derived a significant benefit from the addition of cetuximab to FOLFIRI; patients with RAS tumor mutations did not. Molecular testing of tumors for all activating RAS mutations is essential before considering anti-epidermal growth factor receptor therapy, thereby allowing the further tailoring of cetuximab administration to maximize patient benefit

Medical treatment of advanced colorectal cancer in 2009

The treatment options currently available in the medical therapy of advanced colorectal cancer (CRC) appear to be an abundance of riches. The integration of oxaliplatin and irinotecan as conventional cytotoxic agents as well as bevacizumab and the epidermal growth factor receptor (EGFR) antibodies, cetuximab and panitumumab, as novel targeted agents into standard medical therapy have improved median overall survival in metastatic CRC beyond 2 years. It cannot be overemphasized that these significant improvements in outcome of patients with CRC are closely linked to the number of active drugs available to treat this disease. The abundance of treatment options, however, comes with specific challenges for the practical management of palliative medical therapy in advanced CRC, in particular with regard to the utilization of targeted agents. In this context, bevacizumab has established itself as the standard component of first-line chemotherapy. It is of interest for clinical practice that so far no predictive marker for the activity of bevacizumab in metastatic CRC has been identified. The key questions surrounding the use of bevacizumab in the palliative setting are whether its continuation beyond tumor progression provides clinical benefit, and which patient group is at higher risk for bevacizumab-related toxicities. Cetuximab and panitumumab have demonstrated efficacy both in combination with chemotherapy or – in contrast to bevacizumab – as single agent. In unselected patients, the effect of both EGFR antibodies on time-related parameters, progression free survival and overall survival, is moderate at best with emphasis more on the induction of tumor responses in a select group of patients. Therefore, until recently, EGFR antibodies were mainly regarded as salvage therapy options, in particular, since there did not appear to be a loss of activity when used in later lines of therapy. The finding that CRC harboring KRAS (and BRAF) mutations are resistant to EGFR antibodies, has allowed us to enrich the patient population with CRC that have a chance to benefit from cetuximab or panitumumab therapy. Biomarker-based treatment decisions are therefore now an integral part of clinical practice and trial design in CRC. In conclusion, targeted agents have become an integral part of medical therapy for advanced CRC. The challenge for current oncologic practice is to develop a rationale and biomarker-based treatment algorithm utilizing all potentially active agents as individualized therapy