Abstract P4-13-05: Evolving treatment patterns in hormone receptor-positive, HER2-negative metastatic breast cancer
Authors: Lankford ML , Britton SL , Buettner AD , Scharf M , Tiscione B , Willey JP , Mahtani RL 
Published: May 2019

Background: The last several years have seen the approval of multiple targeted agents for use alone or combined with standard endocrine therapies (ET) in the 1st, 2nd, and 3rd line hormone receptor positive (HR+), HER2 negative (HER2-) metastatic breast cancer (MBC) settings. Due to these new approvals, standards of care for treatment are evolving.

Methods: Prescribing preferences (PPrefs) of 592 U.S.-based medical oncologists were studied using a validated, proprietary, case-based market research tool (Challenging Cases®). Data were acquired using blinded, audience-response iPad technology at 8 live and virtual events during 2016-2018.

Two core hypothetical cases were presented: 1st line MBC and recurrent (REC) MBC. For each core case the following variables were introduced: time from completion of adjuvant (adj) therapy (Tx) to REC disease, site of metastases [visceral (VIS) vs non-visceral (N-VIS)], and age for the 1st line case, and type of metastases and line of Tx for the recurrent case. Rx choices for which there are published phase 3 data were offered, as well as a category for “other.”

Results:

Table 1.Preferred Rx for recurrent disease during or after 5 yrs of adjuvant non-steroidal aromatase inhibitor (NSAI)*ScenarioExemestane (EXE) + Everolimus (EVE)NSAI + CDK inhibitor (CDKi)Fulvestrant (FUL) + CDKiChemotherapy (CT)Endocrine therapy (ET)OtherREC 18 months (mos) into adj AI Tx, VIS) and N-VIS mets, Age 635%25%63%3%4%0%REC post 5 yrs adj AI and 2 yr treatment free interval (TFI), N-VIS mets, Age 674%49%34%1%12%1%REC post 5 yrs adj AI and 2 yr TFI, N-VIS mets, Age 853%34%19%0%42%1%* May not equal 100% due to rounding.

Table 2.Preferred Rx for 2nd or 3rd recurrence*ScenarioEXE + EVENSAI + CDKiFUL + CDKiCTETAbemaciclibOtherREC post 5 yrs adj AI and 2 yr TFI, N-VIS mets, age 67 --&gt; 12 mos 1st line Tx --&gt; N-VIS mets31%12%38%6%12%1%1%REC post 5 yrs adj AI and 2 yr TFI, N-VIS mets, age 67 --&gt; 12 mos 1st line NSAI + palbociclib Tx --&gt; N-VIS mets38%1%33%9%15%0%3%REC 12 mos into adj AI, age 61,N-VIS mets --&gt;12 mos Tx 1st line --&gt;N-VIS mets21%9%53%9%6%0%1%REC post 5 yrs adj AI and 2 yr TFI, N-VIS mets, age 67 --&gt;12 mos 1st line Tx, N-VIS mets --&gt; 6 mos 2nd line Tx --&gt; VIS and N-VIS mets23%1%9%59%5%2%1%* May not equal 100% due to rounding.

In the setting of a patient (pt), age 63 with early REC on an adj AI, the most preferred strategy was FUL + a CDKi. In a pt, age 67, who completed 5 years of an adj AI with a TFI of 2 years, the most common preference was NSAI + a CDKi. In an older pt (age 85) who completed 5 years of an adj AI and TFI of 2 years, the most common choice of TX was single agent ET. For a pt with N-VIS mets treated in the 2nd line setting, FUL + a CDKi was the most preferred strategy. In a 2nd line pt with REC at 12 mos on adj Tx and after 12 mos of 1st line Tx, FUL + a CDKi and EXE + EVE were the most preferred therapies. In a 3rd line pt, with VIS mets CT was the preferred choice.

Conclusion: Treatment patterns in HR+ HER2- MBC are evolving with the approval of several new agents and emerging data. Age, time to relapse, line of Tx, and type of mets may be some of the key factors that determine PPrefs in HR+, HER2- MBC.

Citation Format: Lankford ML, Britton SL, Buettner AD, Scharf M, Tiscione B, Willey JP, Mahtani RL. Evolving treatment patterns in hormone receptor-positive, HER2-negative metastatic breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-13-05.