Prospective evaluation of the cardiac safety of HER2-targeted therapies in patients with HER2-positive breast cancer and compromised heart function: the SAFE-HEaRt study

Purpose

HER2-targeted therapies have substantially improved the outcome of patients with breast cancer, however, they can be associated with cardiac toxicity. Guidelines recommend holding HER2-targeted therapies until resolution of cardiac dysfunction. SAFE-HEaRt is the first trial that prospectively tests whether these therapies can be safely administered without interruptions in patients with cardiac dysfunction.

Methods

Patients with stage I–IV HER2-positive breast cancer candidates for trastuzumab, pertuzumab or ado-trastuzumab emtansine (TDM-1), with left ventricular ejection fraction (LVEF) 40–49% and no symptoms of heart failure (HF) were enrolled. All patients underwent cardiology visits, serial echocardiograms and received beta blockers and ACE inhibitors unless contraindicated. The primary endpoint was completion of the planned HER2-targeted therapies without developing either a cardiac event (CE) defined as HF, myocardial infarction, arrhythmia or cardiac death or significant asymptomatic worsening of LVEF. The study was considered successful if planned oncology therapy completion rate was at least 30%.

Results

Of 31 enrolled patients, 30 were evaluable. Fifteen patients were treated with trastuzumab, 14 with trastuzumab and pertuzumab, and 2 with TDM-1. Mean LVEF was 45% at baseline and 46% at the end of treatment. Twenty-seven patients (90%) completed the planned HER2-targeted therapies. Two patients experienced a CE and 1 had an asymptomatic worsening of LVEF to ≤ 35%.

Conclusion

This study provides safety data of HER2-targeted therapies in patients with breast cancer and reduced LVEF while receiving cardioprotective medications and close cardiac monitoring. Our results demonstrate the importance of collaboration between cardiology and oncology providers to allow for delivery of optimal oncologic care to this unique population.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05191-2) contains supplementary material, which is available to authorized users.

Isolated left ventricular apical hypoplasia: a new congenital anomaly described with cardiac tomography

OBJECTIVE

To describe cardiac tomography findings of an apparently new, presumably congenital, left ventricular (LV) abnormality noted consistently in three patients.

PATIENTS

Three patients presenting with non-specific symptoms including fatigue, shortness of breath, or chest discomfort were evaluated with cardiac tomography for cardiac structure and function.

RESULTS

Findings from the three patients were very similar: a truncated and spherical LV with abnormal diastolic and systolic function, invagination of fatty material into the myocardium of the defective LV apex, origin of a complex papillary network in the anteroapical LV, and an elongated right ventricle wrapping around the deficient apex.

CONCLUSIONS

Isolated LV apical hypoplasia is a unique, presumably congenital, cardiac anomaly that is an important condition to recognise.

Merocyanine dyes: effect of structural modifications on photophysical properties and biological activity

Merocyanine derivatives were prepared by structural alterations at the barbituric acid or chalcogenazole moieties. The photophysical properties of the dyes were markedly influenced by the presence of selenium rather than sulfur as a substituent at position 2 of the barbiturate. In methanol, quantum yields of both triplet state (phi T) and singlet oxygen sensitization (phi delta) were increased by over an order of magnitude, with a concomitant decrease in fluorescence, when selenium was present in the molecule. Photoisomerization, one of the dominant deactivation pathways in the sulfur- or oxygen-containing analogues, was completely absent in the selenium-containing derivatives. Efficient triplet state formation was observed for selenium-containing derivatives incorporated into L1210 cells by diffuse reflectance laser flash photolysis. Cytotoxicity studies, carried out using clonogenic assays on L1210 leukemia cells, showed a good correlation with phi T and phi delta, measured in solution. Experimental evidence provided by this paper supports a triplet state-, and probably singlet oxygen-, mediated phototoxic mechanism. Photoisomerization or singlet state mechanisms can be discounted.

Effects of structural modifications on the photosensitizing properties of dialkylcarbocyanine dyes in homogeneous and heterogeneous solutions

The photophysical characterization of structurally modified symmetric dialkylthiacarbocyanine dyes in homogeneous and biomimetic media is reported. The aim of the two specific structural modifications was to increase singlet oxygen production, hence enhancing the photosensitizing properties of these cyanine dyes. Specifically, (1) the sulfur was exchanged with selenium in order to enhance intersystem crossing via an internal heavy atom effect and (2) substituents of differing size were introduced into the meso-position of the polymethine chain to reduce photoisomerization. The result of incorporation of an internal heavy atom (selenium) into the structure of the dye yields the expected effect: this modification results in a 22-fold increase in the rate of intersystem crossing, but does not change the remaining competing deactivation rates of the first excited singlet state. As a consequence, singlet oxygen quantum yields increase from 0.001 to 0.014 in ethanol and from 0.006 to 0.08 in unilamellar liposomes. In the case of the meso-substituted thiacarbocyanine dyes, a significant reduction in photoisomerization is indeed observed. However, this modification drastically enhances internal conversion which then becomes the main deactivation pathway of the first excited singlet state. As a result, very small fluorescence and singlet oxygen quantum yields are obtained, e.g. 0.006 and 0.001, respectively, in ethanol.

Photophysical properties of 3,3'-dialkylthiacarbocyanine dyes in organized media: unilamellar liposomes and thin polymer films

All symmetrical dialkylthiacarbocyanine dyes, with the exception of the diethyl derivatives, are incorporated into liposomes. Absorption and fluorescence data indicate a solubilization site close to the bilayer surface with the alkyl chains penetrating into the lipid bilayer. Incorporation into organized assemblies affects the photophysical parameters of these dyes. Photoisomerization occurring from the first excited state becomes more difficult as the restrictive effect of the solubilization site increases. As a consequence, competing deactivation processes, such as fluorescence and triplet formation, become more efficient with the result that fluorescence quantum yields, triplet yields and singlet oxygen quantum yields are larger in liposomes than in homogeneous solution. Dihexylthiacarbocyanine iodide has a fluorescence quantum yield of 0.27 and 0.10 (25 degrees C) in dimyristoylphosphatidyl-choline liposomes and ethanol, respectively, and the singlet oxygen yield increases by a factor three to 0.006 on going from ethanol to liposomes. The effect of a highly organized environment is even more pronounced in thin polymer films. In these systems, photoisomerization is completely inhibited and only triplet formation is observed in the transient absorption spectrum.