Colorectal Cancer Coverage from Every Angle

Is Pertuzumab Plus Trastuzumab Effective in HER2-Amplified Colorectal Cancer?

By: Kayci Reyer
Posted: Tuesday, April 30, 2019

According to the results of the phase IIa multiple basket study MyPathway, published in The Lancet Oncology, the combination treatment of pertuzumab plus trastuzumab may prove to be beneficial for patients with HER2-amplified colorectal cancer. The investigators sought to determine whether targeted therapies could improve clinical outcomes in HER2-positive metastatic cancer as they have done in HER2-positive breast and gastric cancers.

“Dual HER2-targeted therapy with pertuzumab plus trastuzumab is well tolerated and could represent a therapeutic opportunity for patients with heavily pretreated, HER2-amplified metastatic colorectal cancer,” concluded Funda Meric-Bernstam, MD, of MD Anderson Cancer Center, and colleagues.

Between October 2014, and June 2017, the ongoing study enrolled 57 patients with treatment-refractory HER2-amplified metastatic colorectal cancer. As of August 2017, 18 patients (32%) achieved an objective response, with 1 patient (2%) having a complete response and 17 patients (30%) reaching partial responses. All participants were treated with pertuzumab (840-mg loading dose followed by 420 mg intravenously every 3 weeks) and trastuzumab (8-mg/kg loading dose followed by 6 mg/kg intravenously every 3 weeks).

Diarrhea (33%), fatigue (32%), and nausea (30%) were the most common treatment-related adverse events. A total of 21 patients (37%) experienced grade 3 or 4 treatment-related adverse events, with hypokalemia and abdominal pain each affecting 3 patients (5%). Among the serious adverse events reported in 10 patients (18%), only 2 were found to be related to treatment (chills and an infusion-related reaction). No treatment-related deaths occurred in this study.

“Results from MyPathway and HERACLES show the potential for dual HER2-targeted treatment in patients with HER2-positive metastatic colorectal cancer and highlight the importance of molecular testing in this disease,” concluded the investigators.

Disclosure: The study authors’ disclosure information may be found at

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