HER 2 Targeted therapy and Elevated Pulmonary Artery systolic pressure: To continue or not to continue

Abstract Background HER 2 targeted therapy is a used in a large number of cancer patients with HER 2 receptors positivity. There are reports suggesting HER 2 targeted therapy can cause pulmonary hypertension (PH) and treatment discontinuation is recommended. Prematurely discontinuing HER2-targeted therapy carries a high risk of disease relapse and worse survival outcomes. Methods Thirty-three patients who received HER 2 targeted therapy and developed elevated pulmonary artery systolic pressure (PASP) with normal left ventricular ejection fraction were included in the study. Patients were divided into 2 groups based on normal or elevated baseline PASP prior to HER2 therapy initiation. The electronic medical record was manually reviewed to documents endpoints including mortality due to PH, new onset right sided heart failure (HF) and discontinuation of HER 2 targeted therapy due to PH. Results In 33 patients there were 16 with normal baseline PASP and 17 with elevated baseline PASP. The mean follow-up was 4.9 years (± SD 2.89). Among patients with normal baseline PASP, PASP elevation was seen after a mean of 15.9 ± 12.9 doses. PASP elevation was transient with a mean increase in PASP of 16.9 ± 6.3 mm Hg. Only one patient discontinued HER2 therapy due to PH with subsequent normalization of PASP. Among patients with elevated baseline PASP, the mean increase in PASP was 4.3 ± 13.7 mm Hg after 6.87 ± 7.86 doses. One patient with baseline elevated PASP developed right sided heart failure and subsequently died as a consequence of PH. Introduction of a different HER2 targeted agent in 5/6 patients for disease progression did not affect PASP. Conclusion Our data suggests that elevated PASP while receiving HER 2 targeted therapy is transient and well tolerated, with most patients able to safely complete treatment without interruption.