HSD3B1 and Response to a Nonsteroidal CYP17A1 Inhibitor in Castration-Resistant Prostate Cancer

Research

JAMA Oncology | Brief Report HSD3B1 and Response to a Nonsteroidal CYP17A1 Inhibitor in Castration-Resistant Prostate Cancer

Nima Almassi, MD; Chad Reichard, MD; Jianbo Li, PhD; Carly Russell, MS; Jaselle Perry, MS; Charles J. Ryan, MD; Terence Friedlander, MD; Nima Sharifi, MD

Invited Commentary page 562

IMPORTANCE The HSD3B1 (1245C) germline variant encodes for a gain-of-function missense Related article page 558 in 3β-hydroxysteroid dehydrogenase isoenzyme 1 (3βHSD1) that results in increased dihydrotestosterone synthesis from extragonadal precursors and is predictive of more rapid progression to castration-resistant prostate cancer (CRPC).

OBJECTIVE To determine whether the HSD3B1 (1245C) genotype is predictive of clinical response to extragonadal androgen ablation with nonsteroidal 17α-hydroxylase/17,20-lyase (CYP17A1) inhibition in men with metastatic CRPC.

DESIGN, SETTING, AND PARTICIPANTS An observational study of men with metastatic CRPC treated with ketoconazole between June 1998 and December 2012 was conducted at the University of California, San Francisco.

EXPOSURES Extragonadal androgen ablation with the nonsteroidal CYP17A1 inhibitor ketoconazole among men with metastatic CRPC.

MAIN OUTCOMES AND MEASURES The primary end points of analysis were duration of ketoconazole therapy and time to disease progression stratified by HSD3B1 genotype. Disease progression was defined as either biochemical or radiographic progression, using the Prostate Cancer Working Group 3 and Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 definitions, respectively. Kaplan-Meier analysis was used to estimate time on therapy and time to disease progression. A log-rank test for trend was used to compare outcomes by HSD3B1 genotype.

RESULTS A total of 90 men (median [interquartile range] age, 61.5 [55.3-67.0] years) with metastatic CRPC were included in the analysis, with sufficient data to determine duration of ketoconazole therapy and time to disease progression in 88 and 81 patients, respectively. The median duration of therapy increased with the number of inherited HSD3B1 (1245C) variant alleles: 5.0 months (95% CI, 3.4-10.4) for 0 variant alleles; 7.5 months (95% CI, 4.9-19.2) for 1; and 12.3 months (95% CI, 1.8-not reached) for 2 (overall comparison for trend, Author Affiliations: Glickman P = .01). Median progression-free survival also increased with number of HSD3B1 (1245C) Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio variant alleles inherited: 5.4 months (95% CI, 3.7-7.5) for 0 variant alleles; 9.7 months (95% CI, (Almassi, Reichard, Sharifi); 5.6-32.9) for 1; and 15.2 months (95% CI, 7.8-not reached) for 2 (overall comparison for trend, Department of Quantitative Health P = .03). Sciences, Cleveland Clinic, Cleveland, Ohio (Li); Division of Hematology/ Oncology, Department of Medicine, CONCLUSIONS AND RELEVANCE Inheritance of the HSD3B1 (1245C) variant allele, which is a University of California, San predictive biomarker of resistance to castration, is also a predictive biomarker of sensitivity to Francisco, Helen Diller Family extragonadal androgen ablation with a nonsteroidal CYP17A1 inhibitor. These findings signal Comprehensive Cancer Center, San Francisco (Russell, Perry, Ryan, a possible pathway of treatment stratification for patients with prostate cancer. Friedlander); Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio (Sharifi); Department of Hematology and Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (Sharifi). Corresponding Author: Nima Sharifi, MD, Department of Cancer Biology, Lerner Research Institute, Cleveland JAMA Oncol. 2018;4(4):554-557. doi:10.1001/jamaoncol.2017.3159 Clinic, Cleveland, OH 44195 Published online October 12, 2017. ([email protected]).

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wo major sources of androgens supply prostate cancer: (1) gonadal testosterone and (2) extragonadal an- Key Points drogens that mainly originate from the human adrenal T Question Is inheritance of the HSD3B1 (1245C) genotype that reticularis but may also arise in part from de novo steroido- encodes for a gain-of-function in 3β-hydroxysteroid genesis from cholesterol within tumors.1 The requirement for dehydrogenase isoenzyme 1 (3βHSD1) and an increase in potent gonadal androgens and efficacy of androgen deprivation androgen synthesis from extragonadal precursor steroids therapy (ADT) by medical or surgical castration in men with associated with more favorable treatment outcomes with metastatic prostate cancer has been well established since the nonsteroidal 17α-hydroxylase/17,20-lyase (CYP17A1) inhibition among men with metastatic castration-resistant prostate cancer initial description by Huggins and Hodges.2 Androgen depri- (CRPC)? vation therapy remains a cornerstone treatment for men with metastatic disease and has demonstrated benefit in earlier- Findings In this study of 90 men with metastatic CRPC, the stage disease, such as when used concurrently with radio- presence of the HSD3B1 (1245C) variant allele was associated with increased duration of therapy and increased progression-free therapy for select men with localized prostate cancer.3 survival with ketoconazole treatment. Despite the initial efficacy of ADT, men with advanced disease invariably develop castration-resistant prostate cancer Meaning HSD3B1 (1245C) inheritance, which is a known predictive (CRPC), which is driven by synthesis of the potent andro- biomarker of resistance to castration, is also predictive of response to nonsteroidal CYP17A1 inhibition, identifying a subset of tumors gens, testosterone and/or dihydrotestosterone, and stimula- that are clinically more dependent on extragonadal precursor tion of the androgen receptor (AR) by extragonadal precursor steroids. steroids.4,5 The enzyme 3β-hydroxysteroid dehydrogenase isoenzyme 1 (3βHSD1, encoded by the gene HSD3B1)isre- quired for intratumoral synthesis of potent androgens from peripheral blood mononuclear cells using a polymerase chain 8 extragonadal precursors.6 The common germline variant reaction–based melting curve assay, described previously. The HSD3B1 (1245C) encodes for a gain-of-function in 3βHSD1, in- primary end points of analysis were duration of ketoconazole creasing what is otherwise the rate-limiting step for intratu- therapy and time to disease progression stratified by HSD3B1 moral androgen synthesis from extragonadal precursor genotype. Clinical progression was defined as the time of first steroids.7 In 3 cohorts of patients with advanced prostate can- occurrence of either biochemical progression, using the 12 cer, HSD3B1 (1245C) inheritance is associated with more rapid Prostate Cancer Working Group 3 definition, or radio- progression from initiation of ADT to development of CRPC.8 graphic progression, using Response Evaluation Criteria in Solid 13 These findings have been independently validated in a fourth Tumors (RECIST) version 1.1 criteria. Kaplan-Meier analysis cohort9 and further support variant HSD3B1 (1245C) inheri- was used to estimate time on ketoconazole therapy and time tance as a predictive biomarker of ADT resistance. to disease progression. A log-rank test for trend was used to We hypothesized that patients with variant HSD3B1 (1245C) compare outcomes among HSD3B1 homozygous wild type, inheritance develop CRPC because they have tumors that are heterozygous, and homozygous variant genotypes. The Cox more dependent on extragonadal precursor steroids and thus proportional hazards model was used to estimate hazard would have more durable responses to pharmacologic inhibi- ratio of the primary outcomes between genotypes. tion of 17α-hydroxylase/17,20-lyase (CYP17A1), which is re- quired for extragonadal androgen synthesis. Testing this hy- pothesis with abiraterone is problematic, because this steroidal Results CYP17A1 inhibitor is also converted by 3βHSD1 to multiple downstream steroidal metabolites, including an AR agonist that Ninety men met inclusion criteria and were included in the may oppose its effects downstream of blocking endogenous study. Forty-four patients (49%) were HSD3B1 homozygous androgen synthesis.10,11 Therefore, we chose to study the as- wild type; 34 (38%), heterozygous; and 12 (13%), homozy- sociation between HSD3B1 inheritance and duration of CRPC gous variant (Table), for a total variant allelic frequency of 32%, response to ketoconazole, a nonsteroidal CYP17A1 inhibitor that which is consistent with prior cohorts.8,9 Sufficient data were is not clouded by the same issues. available to determine duration of therapy and time to progression for 88 and 81 patients, respectively. Median duration of therapy increased with the number of Methods variant HSD3B1 (1245C) alleles inherited: 5.0 months (95% CI, 3.4-10.4) for 0 variant alleles; 7.5 months (95% CI, 4.9-19.2) for Men with metastatic CRPC who were treated with ketocon- 1; and 12.3 months (95% CI, 1.8-not reached) for 2 (overall com- azole and did not receive abiraterone before or during keto- parison for trend, P = .01; pairwise comparison of 0 and 1 vari- conazole treatment were identified from a prospectively main- ant alleles, P = .01; pairwise comparison of 0 and 2 variant tained database at the University of California, San Francisco, alleles, P = .03) (Figure 1). Compared with homozygous wild and made up the cohort of this observational study. Clinical type, the hazard ratio for remaining on treatment was 1.8 (95% data and biological samples were obtained using informed con- CI, 1.1-2.9; P = .01) for the heterozygous group and 2.2 (95% sent with a protocol approved by the institutional review board CI, 1.1-4.4; P = .02) for the homozygous variant group. of the University of California, San Francisco. HSD3B1 germ- Median time to disease progression similarly increased line genotype was determined from DNA extracted from with the number of variant HSD3B1 (1245C) alleles inherited:

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Table. Patient Characteristics Figure 2. Progression-Free Survival Stratified by HSD3B1 Genotype

Characteristic No. (%) 100 Age at diagnosis in years, 61.5 (55.3-67.0) median (IQR), y Homozygous variant 80 Heterozygous Grade group at diagnosis Homozygous wild type

I 10 (11.1) 60 II 13 (14.4) III 10 (11.1) 40 IV 17 (18.9) 20

V 27 (30.1) Survival,Progression-Free % Unknown 13 (14.4) 0 PSA at diagnosis, median (IQR) 15.2 (7.0-84.1) 0 12 24 36 48 60 72 Time, mo Primary local therapy No. at risk Radical prostatectomy 24 (26.7) Homozygous wild type 41 10 5 3 2 1 0 Heterozygous 29 12 8 7 4 1 1 External beam radiation therapy 24 (26.7) Homozygous variant 11643111 Brachytherapy 10 (11.1) Sufficient data were available to determine time to progression for 81 patients. None 32 (35.5) Forty-one patients were HSD3B1 homozygous wild type; 29, heterozygous; and Ketoconazole dose 11 homozygous. Median time to disease progression increased with the number 400 mg every 8 h 75 (83.3) of variant HSD3B1 alleles inherited. 200 mg every 8 h 8 (8.9) Unknown 7 (7.8) ratio for disease progression was 0.6 (95% CI, 0.4-1.0; P = .06) HSD3B1 Genotype for the heterozygous group and 0.5 (95% CI, 0.3-1.1; P = .08) Homozygous wild type 44 (49.0) for the homozygous variant group. Heterozygous 34 (38.0) Homozygous variant 12 (13.0) Abbreviations: IQR, interquartile range; PSA, prostate-specific antigen. Discussion

Inheritance of the HSD3B1 (1245C) germline variant that en- Figure 1. Duration of Ketoconazole Therapy Stratified codes a missense in 3βHSD1 and increases synthesis7 of po- by HSD3B1 Genotype tent androgens from extragonadal precursor steroids enables

1.0 prostate cancer to use this alternative androgen supply in the absence of gonadal testosterone, thus facilitating more rapid Homozygous variant 8,9 0.8 Heterozygous development of CRPC. Our data indicate that the same Homozygous wild type mechanism that enables earlier CRPC by engaging extrago- 0.6 nadal steroids more effectively may make them more dependent on these steroids. Therefore, this tumor resistance mecha- 0.4 nism may also be exploited clinically as a tumor vulnerability to drugs that block the synthesis of potent androgens from ex- 0.2 tragonadal steroids, or possibly to AR antagonists that pre- vent these potent androgens from activating downstream path- Probability on Treatment of Remaining 0 0 12 24 36 48 60 72 84 96 ways. As only a proportion of patients treated with potent Time, mo CYP17A1 inhibitors or AR antagonists respond clinically, a pre- No. at risk Homozygous wild type 43 12 4 2 1 0 0 0 0 dictive biomarker for the identification of patients who ben- Heterozygous 33 14 8 8 5 3 1 1 1 efit would undoubtedly have clinical value.14,15 Although this Homozygous variant 12 6 5 4 3 2 2 1 1 study specifically addressed HSD3B1 (1245C) as a biomarker Sufficient data were available to determine the duration of therapy for 88 of response to a nonsteroidal CYP17A1 inhibitor, it is possible patients. Forty-three patients were HSD3B1 homozygous wild type; it may also identify responders to steroidal inhibitors; how- 33, heterozygous; and 12, homozygous. Median duration of therapy increased ever, steroidal metabolites of the latter agents make evalua- with the number of variant HSD3B1 alleles inherited. tion more complex.10,11

5.4 months (95% CI, 3.7-7.5) for 0 variant alleles; 9.7 months Limitations (95% CI, 5.6-32.9) for 1; and 15.2 months (95% CI, 7.8-not The present study has limitations that warrant consider- reached) for 2 (overall comparison for trend, P = .03; pair- ation. This observational study is subject to selection biases wise comparison of 0 and 1 variant alleles, P = .07; pairwise inherent to its retrospective design. Importantly, we comparison of 0 and 2 variant alleles, P =.07)(Figure 2). Com- excluded patients who were administered abiraterone before pared with the homozygous wild-type group, the hazard ketoconazole therapy to eliminate prior exposure to CYP17A1

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inhibition as a possible confounder on our end points of analysis. Finally, the clinical utility of a biomarker predictive Conclusions of response to ketoconazole is limited as this agent is no longer routinely used for men with metastatic CRPC in the The HSD3B1 (1245C) variant allele is associated with pro- United States and Europe. The study was specifically longed time to disease progression among men with meta- designed to study nonsteroidal CYP17A1 inhibition because static CRPC treated with nonsteroidal CYP17A1 inhibition. These 3βHSD mediates conversion of the steroidal CYP17A1 inhibi- findings suggest that the variant allele, which increases the tor abiraterone acetate to several steroidal metabolites, synthesis of potent androgens from extragonadal precursor including an AR agonist, which would be expected to par- steroids and hastens the development of CRPC, may be a pre- tially or wholly obscure the hypothesized impact of HSD3B1 dictive biomarker of tumor vulnerability to pharmacologic genotype on treatment outcomes.11 CYP17A1 inhibition with a nonsteroidal drug.

ARTICLE INFORMATION Role of the Funder/Sponsor: The funders/ 8. Hearn JWD, AbuAli G, Reichard CA, et al. Accepted for Publication: June 13, 2017. sponsors had no role in the design and conduct of HSD3B1 and resistance to androgen-deprivation the study; collection, management, analysis, and therapy in prostate cancer: a retrospective, Published Online: October 12, 2017. interpretation of the data; preparation, review, or multicohort study. Lancet Oncol. 2016;17(10): doi:10.1001/jamaoncol.2017.3159 approval of the manuscript; and decision to submit 1435-1444. Author Contributions: Drs Sharifi and Almassi the manuscript for publication. 9. Agarwal N, Hahn AW, Gill DM, Farnham JM, had full access to all the data in the study and take Poole AI, Cannon-Albright L. Independent responsibility for the integrity of the data and the REFERENCES validation of effect of HSD3B1 genotype on accuracy of the data analysis. 1. Sharifi N. Minireview: androgen metabolism in response to androgen-deprivation therapy in Study concept and design: Almassi, Ryan, castration-resistant prostate cancer. Mol Endocrinol. prostate cancer. JAMA Oncol. 2017;3(6):856-857. Friedlander, Sharifi. 2013;27(5):708-714. Acquisition, analysis, or interpretation of data: All 10. Li Z, Bishop AC, Alyamani M, et al. Conversion authors. 2. Huggins C, Hodges CV. Studies on prostate of abiraterone to D4A drives anti-tumour activity in Drafting of the manuscript: Almassi, Russell, Sharifi. cancer: I, the effect of castration, of estrogen and prostate cancer. Nature. 2015;523(7560):347-351. Critical revision of the manuscript for important of androgen injection on serum phosphatases in 11. Li Z, Alyamani M, Li J, et al. Redirecting intellectual content: Reichard, Li, Perry, Ryan, metastatic carcinoma of the prostate. Cancer Res. abiraterone metabolism to fine-tune prostate Friedlander, Sharifi. 1941;1(4):293-297. cancer anti-androgen therapy. Nature. 2016;533 Statistical analysis: Almassi, Li. 3. Attard G, Parker C, Eeles RA, et al. Prostate (7604):547-551. Obtained funding: Sharifi. cancer. Lancet. 2016;387(10013):70-82. 12. Scher HI, Morris MJ, Stadler WM, et al; Prostate Administrative, technical, or material support: Perry, 4. Yuan X, Cai C, Chen S, Chen S, Yu Z, Balk SP. Cancer Clinical Trials Working Group 3. Trial design Ryan, Friedlander, Sharifi. Androgen receptor functions in castration-resistant and objectives for castration-resistant prostate Study supervision: Ryan, Friedlander, Sharifi. prostate cancer and mechanisms of resistance to cancer: updated recommendations from the Conflict of Interest Disclosures: A patent new agents targeting the androgen axis. Oncogene. Prostate Cancer Clinical Trials Working Group 3. application has been filed by Cleveland Clinic for 2014;33(22):2815-2825. J Clin Oncol. 2016;34(12):1402-1418. a method of steroid-dependent disease treatment 5. Scher HI, Sawyers CL. Biology of progressive, 13. Eisenhauer EA, Therasse P, Bogaerts J, et al. based on HSD3B1. Nima Sharifi is listed as a castration-resistant prostate cancer: directed New response evaluation criteria in solid tumours: co-inventor on this patent application. therapies targeting the androgen-receptor signaling revised RECIST guideline (version 1.1). Eur J Cancer. Funding/Support: This work was supported by axis. J Clin Oncol. 2005;23(32):8253-8261. 2009;45(2):228-247. a grant from a Howard Hughes Medical Institute 6. Evaul K, Li R, Papari-Zareei M, Auchus RJ, 14. Ryan CJ, Smith MR, de Bono JS, et al. Physician-Scientist Early Career Award (to Sharifi N. 3β-hydroxysteroid dehydrogenase is a Abiraterone in metastatic prostate cancer without Dr Sharifi), a grant from the Prostate Cancer possible pharmacological target in the treatment of previous chemotherapy. N Engl J Med. 2013;368(2): Foundation (to Dr Sharifi), an American Cancer castration-resistant prostate cancer. Endocrinology. 138-148. Society Research Scholar Award (to Dr Sharifi), 2010;151(8):3514-3520. a grant from the US Army Medical Research and 15. Beer TM, Armstrong AJ, Rathkopf DE, et al; Materiel Command (grant No. W81XWH-09-1-0301 7. Chang KH, Li R, Kuri B, et al. A gain-of-function PREVAIL Investigators. Enzalutamide in metastatic to Dr Sharifi), and additional grants from the mutation in DHT synthesis in castration-resistant prostate cancer before chemotherapy. N Engl J Med. National Cancer Institute (grant No. R01CA172382, prostate cancer. Cell. 2013;154(5):1074-1084. 2014;371(5):424-433. R01CA190289, and R01CA168899 to Dr Sharifi).

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