Dakhil, Christopher

Abstract Background Hot flashes (HFs) negatively affect quality of life among perimenopausal and postmenopausal women. This study investigated the efficacy of oxybutynin vs placebo in decreasing HFs. Methods In this randomized, multicenter, double-blind study, women with and without breast cancer with 28 or more HFs per week, lasting longer than 30 days, who were not candidates for estrogen-based therapy, were assigned to oral oxybutynin (2.5 mg twice a day or 5 mg twice a day) or placebo for 6 weeks. The primary endpoint was the intrapatient change from baseline in weekly HF score between each oxybutynin dose and placebo using a repeated-measures mixed model. Secondary endpoints included changes in weekly HF frequency, HF-related daily interference scale questionnaires, and self-reported symptoms. Results We enrolled 150 women. Baseline characteristics were well balanced. Mean (SD) age was 57 (8.2) years. Two-thirds (65%) were taking tamoxifen or an aromatase inhibitor. Patients on both oxybutynin doses reported greater reductions in the weekly HF score (5 mg twice a day: −16.9 [SD 15.6], 2.5 mg twice a day: −10.6 [SD 7.7]), placebo −5.7 (SD 10.2); P < .005 for both oxybutynin doses vs placebo), HF frequency (5 mg twice a day: −7.5 [SD 6.6], 2.5 mg twice a day: −4.8 [SD 3.2], placebo: −2.6 [SD 4.3]; P < .003 for both oxybutynin doses vs placebo), and improvement in most HF-related daily interference scale measures and in overall quality of life. Patients on both oxybutynin arms reported more side effects than patients on placebo, particularly dry mouth, difficulty urinating, and abdominal pain. Most side effects were grade 1 or 2. There were no differences in study discontinuation because of adverse effects. Conclusion Oxybutynin is an effective and relatively well-tolerated treatment option for women with HFs.

Abstract Background: HF occur in about 75% of midlife women and are associated with quality of life disruption and premature endocrine therapy discontinuation among breast cancer survivors. Estrogen therapy, effective for HF, is contraindicated in hormone receptor-positive breast cancer (BC). Previous studies have suggested that Oxy could be effective in managing HF. Methods: This randomized, placebo (P)-controlled trial enrolled women who had experienced HF ≥28 times per week over >30 days and of sufficient severity to seek treatment. Patients (pts) were randomized to receive oral Oxy at two doses: 2.5mg BID for 6 weeks (Oxy2.5), 2.5mg BID for a week with subsequent increase to 5mg BID (Oxy5), or matching P, in equal ratios. Baseline and monthly questionnaires were administered including a HF diary, the HF related daily interference scale (HFRDIS) and a symptom experience questionnaire. The primary endpoint was intra-patient change in weekly HF score and frequency from baseline to end of study compared using Kruskal-Wallis tests. Results: 150 pts were accrued between 2/23/2017-3/5/2018. 4 pts cancelled before starting treatment and were excluded from analyses. This interim report includes the first 104 pts for which at least one post-baseline evaluation was available. Baseline characteristics were well-balanced between the arms. Sixty-two percent were on tamoxifen or an aromatase inhibitor for the duration of the study. Pts on both Oxy doses had a significantly greater reduction in HF score and frequency compared to P. Pts on Oxy2.5 had a mean change in HF score of -10 (SD 7.4) vs -5.1 (SD 9.7) with P, p=0.003; and a mean change in average weekly number of HF of -4.6 (SD 3.1) vs -2.3 (SD 3.9), p=0.002. Pts on Oxy5 had a mean change in HF score of -16.2 (SD 5.1) vs -5.1 (SD 9.7) with P, p<0.001; and a mean change in average weekly number of HF of -7.0 (SD 4.0) vs -2.3 (SD 3.9), p<0.001. Repeated measures mixed models confirmed that, after adjusting for baseline values, both Oxy arms had significantly lower HF scores and frequency compared to P (p<0.001). HFRDIS revealed that pts in both Oxy arms experienced improvement in the following HF interference measures: work, social activities, leisure activities, sleep, relations, life enjoyment, and overall quality of life. Pts on Oxy5 also had improvement in HF interference with mood. Pts on Oxy2.5 experienced more stomach pain (p=0.031), diarrhea (p=0.007), nausea (p=0.04), headaches (0.032), episodes of confusion (0.012), dry mouth (p=0.003) and dry eyes (0.027) compared to P. Pts on Oxy5 experienced more constipation (0.004), dry mouth (0.001) and difficulty urinating (0.004) compared to P. There were no differences in study discontinuation due to adverse effects between either Oxy arm and P (Oxy2.5 vs P, p=0.653; Oxy5 vs P, p=0.483). Conclusions: Oxy is superior to P for management of HF. Oxy2.5 and 5 were both associated with significant improvements in HF scores and frequency as well as improvement in HF interference with several quality of life measures. While pts on Oxy experienced more side effects than pts on P, rates of discontinuation due to adverse events were low. This study was supported by the Breast Cancer Research Foundation. Citation Format: Leon-Ferre RA, Novotny PJ, Faubion SS, Ruddy KJ, Flora D, Dakhil C, Rowland KM, Graham ML, Le-Lindqwister N, Loprinzi CL. A randomized, double-blind, placebo-controlled trial of oxybutynin (Oxy) for hot flashes (HF): ACCRU study SC-1603 [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 GS6-02.

Background: Although 50% to 90% of patients who receive epidermal growth factor receptor (EGFR) inhibitors develop a rash, options for rash prevention or palliation remain limited. This issue is particularly important from a palliative care standpoint because these agents are prescribed only to patients with incurable cancer. Here, we report (1) gene expression profiling of skin biopsies from patients with an EGFR inhibitor–induced rash and (2) a randomized, placebo-controlled feasibility trial with the antiandrogen, spironolactone. Both investigations were undertaken to begin to explore the hypothesis that androgens mediate EGFR inhibitor–induced rash and that antiandrogens palliate it. Methods/Results: First, 4 skin biopsies from patients with EGFR inhibitor–induced rash (3 men and 1 woman) were subject to gene expression microarray profiling. A public data set of normal skin gene expression (Gene Expression Omnibus, GSE22998) served as a reference. Sixty percent of commonly interrogated androgen receptor genes (207 of 308 between the 2 data sets) were differentially expressed ( P < .05) in the rash samples. Second, in a 17-patient double-blinded, placebo-controlled trial with topical spironolactone applied to the face, although the primary feasibility end point was not achieved, patients in the spironolactone arm received more doses of EGFR inhibitor, and anecdotal photographic evidence suggested salutatory effects of spironolactone on rash. Conclusions: Epidermal growth factor receptor inhibitor–induced rash appears to be androgen-mediated; antiandrogen therapy merits further study for rash prevention/palliation.