In this prospective observational study, patients with HER2 positive, RAS wild type mCRC...ORR were 50.0% and 25.0%, respectively….Pyrotinib with or without trastuzumab showed promising anti-tumor activity and acceptable toxicities in treatment-refractory, HER2-positive mCRC.

...patients with HER2-positive recurrent / metastatic CRC were enrolled and received oral pyrotinib 400 mg once a day plus intravenous trastuzumab... All patients were BRAF wild-type. Four patients achieved partial response, with an ORR of 22.2% (4/18; 95% CI, 6.4 to 47.6) and DCR of 61.1% (11/18; 95% CI, 35.8 to 82.7). While the ORR and DCR were 33.3% (4/12; 95% CI, 13.8 to 60.9) and 83.3% (10/12; 95% CI, 51.6 to 97.9), respectively, in RAS wild-type patients.... Pyrotinib combined with trastuzumab showed promising antitumor activity and a manageable safety profile in patients with RAS/BRAF wild-type HER2-positive advanced CRC.

ORR was 50.0% in the overall population, and 57.1% in RAS wild-type patients. At a median follow-up of 11.2 months, median PFS and OS were 7.53 and 16.8 months, respectively. The RAS/BRAF wild-type patients had prolonged survival (PFS: 7.53 vs. 1.63 months, P = .02; OS: NR vs.4.13 months, P = .001)...Trastuzumab in combination with pyrotinib demonstrated encouraging antitumor activity that translated to prolonged survival benefit in HER2 positive refractory or mCRC patients who are RAS wild-type with acceptable tolerance.