Neratinib Plus Capecitabine Shows Activity in HER2-Positive Metastatic Breast Cancer

The gist: A recent clinical trial tested a new breast cancer treatment in volunteer patients. The treatment combines a new drug called neratinib with the chemotherapy drug capecitabine. The trial found promising results for patients who had HER2-positive metastatic breast cancer and who had already been treated with trastuzumab (Herceptin) and taxanes. Some of the patients had also had prior treatment with the drug lapatinib (Tykerb). Patients interested in this treatment can now enroll in a new phase III clinical trial.

“Neratinib is an irreversible pan-tyrosine kinase inhibitor with activity against HER1, HER2, and HER4. In a phase I/II trial reported in the Journal of Clinical Oncology, Saura et al found that the combination of neratinib and capecitabine exhibited high activity in patients with trastuzumab (Herceptin)- and taxane-pretreated HER2-positive metastatic breast cancer, including those with prior treatment with the dual HER1/HER2 kinase inhibitor lapatinib (Tykerb)…

“In the phase I dose-escalation phase in 33 patients, the maximum tolerated dose of the combined regimen was found to be neratinib at 240 mg once a day continuously and capecitabine at 1,500 mg/m2 twice a day on days 1 and 14 every 21 days. No dose-limiting toxicity was observed at this level; dose-limiting toxicities at higher doses of neratinib or capecitabine included diarrhea, increased liver enzymes, and asthenia…

“In the phase II portion, 72 patients, including 7 with prior lapatinib treatment, received the maximum tolerated dose of the combination. The overall response rate in 65 patients with no prior lapatinib was 64% (95% confidence interval [CI] = 51%–76%), including complete response in 12%. In the 7 patients with prior lapatinib treatment, the response rate was 57% (95% CI = 18%–90%), including complete response in 1 patient (14%).

“Stable disease ≥ 24 weeks was achieved in an additional 8% and 14% of patients. Median progression-free survival was 40.3 weeks (95% CI = 30.3–66.0 weeks) and 35.9 weeks (95% CI = 18.9–60.1 weeks).”


Trial Shows Trastuzumab Should Remain as Standard of Care for HER2-Positive Breast Cancer

“Analysis of more than 8,000 women who participated in the world’s largest study of two treatments for HER2-positive breast cancer reinforces other findings from the clinical trial showing that trastuzumab (Herceptin) should remain the standard of care for this cancer, says a Mayo Clinic researcher.

“This study, being presented at the European Society for Medical Oncology (ESMO) 2014 Congress in Madrid, reveals that when used as a single HER2-targeted therapy in addition to standard chemotherapy, trastuzumab offers a better outcome than does lapatinib (Tykerb), says Edith A. Perez, M.D., deputy director at large, Mayo Clinic Cancer Center and director of the Breast Cancer Translational Genomics Program at Mayo Clinic in Florida.

“Dr. Perez is co-chair of ALTTO (Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization study). The phase III clinical trial, which tested combinations of the two drugs or use of the drugs by themselves—in addition to standard chemotherapy—enrolled 8,381 participants at 946 medical centers in 44 countries.

“A key finding from ALTTO, released in June, showed that lapatinib, when used in addition to trastuzumab as part of dual therapy, did not offer any statistically significant benefit to patients, such as disease-free survival or overall survival. Dual blockade using two anti-HER2 drugs only increased toxicity, said Dr. Perez.”


NeoALTTO Trial Shows No Benefit of Lapatinib Plus Trastuzumab in Secondary Survival Endpoints in HER2-Positive Early Breast Cancer

Editor’s note: This story is about a clinical trial—a research study with volunteer patients. The goal of the trial was to test a post-surgery breast cancer treatment that combines the drugs lapatinib (Tykerb) and trastuzumab (Herceptin), and compare the combination to either drug on its own. All patients involved had early stage breast cancer that tested positive for HER2. The study found good tumor shrinkage rates for the combination treatment, but found no difference in overall survival time between patients who took the combo versus patients treated with a single drug.

“The phase III NeoALTTO trial showed a significantly improved pathologic complete response rate with lapatinib (Tykerb) plus trastuzumab (Herceptin) vs either alone in women with HER2-positive early breast cancer. As reported in The Lancet Oncology by de Azambuja et al, the combination was not associated with any benefit in the secondary endpoints of event-free survival or overall survival, although the investigators noted that the trial was not powered to detect survival differences. Significantly better event-free survival and overall survival were observed in patients with pathologic complete response, with the association in event-free survival being significant in the combination group…

“In this open-label trial, 455 patients were randomly assigned between January 2008 and May 2010 to receive oral lapatinib at 1,500 mg (n = 154), intravenous (IV) trastuzumab at a 4 mg/kg loading dose followed by 2 mg/kg (n = 149), or lapatinib at 1,000 mg plus trastuzumab (n = 152) for 6 weeks, followed by an additional 12 weeks of the assigned anti-HER2 therapy in combination with weekly paclitaxel 80 mg/m². Definitive surgery was performed at 4 weeks after the last dose of paclitaxel. After surgery, patients received three cycles of FEC (fluorouracil at 500 mg/m², epirubicin at 100 mg/m², cyclophosphamide at 500 mg/m²) given IV every 3 weeks followed by 34 weeks of the same assigned neoadjuvant anti-HER2 therapy.

“Pathologic complete response was observed in 51.3% of the combination recipients vs 29.5% of the trastuzumab recipients (P = .0001), and there was no difference in pathologic complete response between the trastuzumab group and the lapatinib group (24.7%, P = .34).”


Drugs to Avoid in Patients on Tyrosine Kinase Inhibitors

Editor’s note: More and more people with cancer are being treated with drugs known as tyrosine kinase inhibitors (TKIs). As with any other drug, oncologists who prescribe TKIs must be aware of other drugs a patient is taking to ensure there will not be a dangerous drug-drug interaction. Researchers recently published a report outlining known and potential drug-drug interactions between TKIs and other drugs. Oncologists and patients may wish to take these into account when considering cancer treatment with TKIs.

“With the rapid and widespread uptake of tyrosine kinase inhibitors (TKIs) in oncology over the past several years, serious drug–drug interactions are an “increasing risk,” according a new report.

“To guarantee the safe use of TKIs, ‘a drugs review for each patient is needed,’ write Frank G.A. Jansman, PharmD, PhD, from Deventer Hospital in the Netherlands, and colleagues in a review published in the July issue of the Lancet Oncology.

“The review provides a comprehensive overview of known and suspected interactions between TKIs and conventional prescribed drugs, over-the-counter drugs, and herbal medicines.

“All 15 TKIs approved to date by the US Food and Drug Administration or the European Medicines Agency are evaluated.

“They are axitinib (Inlyta, Pfizer), crizotinib (Xalkori, Pfizer), dasatinib (Sprycel, Bristol-Myers Squibb and Otsuka America), erlotinib (Tarceva, Osi Pharmaceuticals), gefitinib (Iressa, AstraZeneca), imatinib (Gleevec, Novartis), lapatinib (Tykerb, GlaxoSmithKline), nilotinib (Tasigna, Novartis), pazopanib (Votrient, GlaxoSmithKline), regorafenib (Stivarga, Bayer), ruxolitinib (Jakafi, Incyte), sorafenib (Nexavar, Bayer), sunitinib (Sutent, Pfizer), vandetanib (Caprelsa, AstraZeneca), and vemurafenib (Zelboraf, Roche).”


Disturbing Discovery: New Generation of Targeted Cancer Drugs Cause Tumors To Become Drug Resistant and More Aggressive

Breast-cancer-cell

“In a modest-sized lab at the Moores Cancer Center at the University of California, San Diego, scientists investigating how cancer cells develop resistance to drug treatments recently discovered something that surprised even the most seasoned members of the research team: A new generation of drugs that are currently among the most popular treatments for lung, breast and pancreatic cancers actually induce drug resistance and spur tumor growth.

“These popular cancer drugs, known as receptor tyrosine kinase inhibitors (RTKs), are actually making cancers stronger. That’s the bad news. The good news is that researchers believe they have found a way to eliminate that threat.

“Researchers found that two of the drugs — Erlotinib for lung cancer and Lapatinib for breast cancer — are effective for a while, but eventually stop killing cancer cells and begin prompting them to resist the drug and become more aggressive.

“ ‘We knew that cancer typically builds up a resistance to these and other drugs. But we did not know that these drugs actually induce tumor progression,’ said David Cheresh, Moores’ vice chair of pathology and the lead researcher on this study.”

Image: A breast cancer cell. London Research Institute EM Unit/Cancer Research UK


Clinical Response to a Lapatinib-Based Therapy of a Li-Fraumeni Syndrome Patient with a Novel HER2-V659E Mutation

“Genomic characterization of recurrent breast and lung tumors developed over the course of 10 years in a 29-year-old patient with a germline p53 mutation (Li-Fraumeni Syndrome) identified oncogenic alterations in the HER2 and EGFR genes across all tumors, including HER2 amplifications, an EGFR-exon 20 insertion, and the first-in-human HER2-V659E mutation showing a phenotypic convergent evolution towards HER2 and EGFR alterations. Following the identification of HER2-activating events in the most recent lung carcinoma and in circulating tumor cells, we treated the reminiscent metastatic lesions with a lapatinib-based therapy. A clinical response both symptomatic and radiologic was achieved. HER2-V659E sensitivity to lapatinib was confirmed in the laboratory.”