{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,18]],"date-time":"2025-11-18T13:27:32Z","timestamp":1763472452012,"version":"3.45.0"},"reference-count":17,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2025,11,17]],"date-time":"2025-11-17T00:00:00Z","timestamp":1763337600000},"content-version":"vor","delay-in-days":16,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Pharmaceutical Statistics"],"published-print":{"date-parts":[[2025,11]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>Duration of response (DOR) has been increasingly used as a useful measure of response to treatments in randomized clinical trials (RCT). Some estimands for DOR, such as the restricted mean DOR, although simple to use, may be sensitive to outliers and may not correctly measure treatment effects on the quantiles of DOR, such as the proportion of patients with DOR of at least 3\u2009months. Quantile regression for survival data has been well developed. However, it is not directly applicable to DOR data in RCTs, due to the presence of non\u2010responders for whom DOR is not defined. Although they can be treated as having zero DOR in a standard quantile regression, such an approach may not be flexible to model these subset of patients. To mitigate this issue, we propose an approach similar to the two\u2010parts zero\u2010inflated models, for example, for count data, so that the nonresponders are modeled as a part of the model, while DOR is modeled using quantile regression. A simulation study is conducted to examine the performance of the proposed approach. For illustration, we apply our approach to a simulated dataset of an acute myeloid leukemia trial, since the true dataset cannot be used due to confidentiality. The asymptotic properties of the proposed approach are also derived.<\/jats:p>","DOI":"10.1002\/pst.70053","type":"journal-article","created":{"date-parts":[[2025,11,18]],"date-time":"2025-11-18T04:21:32Z","timestamp":1763439692000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Quantile Effect on Duration of Response: A Zero\u2010Inflated Censored Regression Approach"],"prefix":"10.1002","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0278-5254","authenticated-orcid":false,"given":"Nan","family":"Sun","sequence":"first","affiliation":[{"name":"BeOne Medicines  Shanghai China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jixian","family":"Wang","sequence":"additional","affiliation":[{"name":"Bristol Myers Squibb  Boudry Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ram","family":"Tiwari","sequence":"additional","affiliation":[{"name":"Global StatSolutions  Reston Virginia USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2025,11,17]]},"reference":[{"key":"e_1_2_12_2_1","unstructured":"US Department of Health and Human Services \u201cGuidance for industry clinical trial endpoints for the approval of cancer drugs and biologics \u201d2018."},{"issue":"5","key":"e_1_2_12_3_1","doi-asserted-by":"crossref","DOI":"10.1001\/jamanetworkopen.2021.8175","article-title":"Comparison of Duration of Response vs Conventional Response Rates and Progression\u2010Free Survival as Efficacy End Points in Simulated Immuno\u2010Oncology Clinical Trials","volume":"4","author":"Hu C.","year":"2021","journal-title":"JAMA Network Open"},{"issue":"6","key":"e_1_2_12_4_1","doi-asserted-by":"crossref","first-page":"874","DOI":"10.1001\/jamaoncol.2018.0275","article-title":"Evaluating Treatment Effect Based on Duration of Response for a Comparative Oncology Study","volume":"4","author":"Huang B.","year":"2018","journal-title":"JAMA Oncology"},{"issue":"5","key":"e_1_2_12_5_1","doi-asserted-by":"crossref","first-page":"865","DOI":"10.1002\/pst.2198","article-title":"Utilizing Restricted Mean Duration of Response for Efficacy Evaluation of Cancer Treatments","volume":"21","author":"Huang B.","year":"2022","journal-title":"Pharmaceutical Statistics"},{"key":"e_1_2_12_6_1","doi-asserted-by":"crossref","DOI":"10.1017\/CBO9780511754098","volume-title":"Quantile regression","author":"Koenker R.","year":"2005"},{"key":"e_1_2_12_7_1","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1146\/annurev-economics-063016-103651","article-title":"Quantile Regression: 40\u2009Years on","volume":"9","author":"Koenker R.","year":"2017","journal-title":"Annual Review of Economics"},{"key":"e_1_2_12_8_1","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1146\/annurev-statistics-042720-020233","article-title":"Quantile regression for survival data","volume":"8","author":"Peng L.","year":"2021","journal-title":"Annual Review of Statistics and Its Application"},{"key":"e_1_2_12_9_1","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1093\/jnci\/djk024","article-title":"Response Rate as an Endpoint in Clinical Trials","volume":"99","author":"George S. L.","year":"2007","journal-title":"JNCI Journal of the National Cancer Institute"},{"issue":"9","key":"e_1_2_12_10_1","doi-asserted-by":"crossref","first-page":"1008","DOI":"10.1200\/JCO.2014.59.0489","article-title":"Overall Response Rate, Progression\u2010Free Survival, and Overall Survival With Targeted and Standard Therapies in Advanced Non\u2013Small\u2010Cell Lung Cancer: US Food and Drug Administration Trial\u2010Level and Patient\u2010Level Analyses","volume":"33","author":"Blumenthal G. M.","year":"2015","journal-title":"Journal of Clinical Oncology"},{"issue":"1","key":"e_1_2_12_11_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.2307\/1269547","article-title":"Zero\u2010Inflated Poisson Regression, With an Application to Defects in Manufacturing","volume":"34","author":"Lambert D.","year":"1992","journal-title":"Technometrics"},{"issue":"3","key":"e_1_2_12_12_1","first-page":"1411","article-title":"Statistical Inference in Quantile Regression for Zero\u2010Inflated Outcomes","volume":"32","author":"Ling W.","year":"2022","journal-title":"Statistica Sinica"},{"issue":"504","key":"e_1_2_12_13_1","doi-asserted-by":"crossref","first-page":"1517","DOI":"10.1080\/01621459.2013.837368","article-title":"Cure Rate Quantile Regression for Censored Data With a Survival Fraction","volume":"108","author":"Wu Y.","year":"2013","journal-title":"Journal of the American Statistical Association"},{"key":"e_1_2_12_14_1","doi-asserted-by":"crossref","DOI":"10.1201\/9780203753736","volume-title":"Generalized Linear Models","author":"McCullagh P.","year":"2019"},{"issue":"464","key":"e_1_2_12_15_1","doi-asserted-by":"crossref","first-page":"1001","DOI":"10.1198\/016214503000000954","article-title":"Censored regression quantiles","volume":"98","author":"Portnoy S.","year":"2003","journal-title":"Journal of the American Statistical Association"},{"issue":"487","key":"e_1_2_12_16_1","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1198\/jasa.2009.tm08230","article-title":"Locally Weighted Censored Quantile Regression","volume":"104","author":"Wang H. J.","year":"2009","journal-title":"Journal of the American Statistical Association"},{"key":"e_1_2_12_17_1","first-page":"831","volume-title":"Proceedings of the Fifth Berkeley Symposium on Mathematical Statistics and Probability","author":"Efron B.","year":"1967"},{"issue":"4","key":"e_1_2_12_18_1","doi-asserted-by":"crossref","first-page":"456","DOI":"10.1016\/j.cct.2007.10.008","article-title":"Analysis of Duration of Response in Oncology Trials","volume":"29","author":"Ellis S.","year":"2008","journal-title":"Contemporary Clinical Trials"}],"container-title":["Pharmaceutical Statistics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/pst.70053","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,18]],"date-time":"2025-11-18T13:23:32Z","timestamp":1763472212000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/pst.70053"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11]]},"references-count":17,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2025,11]]}},"alternative-id":["10.1002\/pst.70053"],"URL":"https:\/\/doi.org\/10.1002\/pst.70053","archive":["Portico"],"relation":{},"ISSN":["1539-1604","1539-1612"],"issn-type":[{"type":"print","value":"1539-1604"},{"type":"electronic","value":"1539-1612"}],"subject":[],"published":{"date-parts":[[2025,11]]},"assertion":[{"value":"2025-01-30","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-11-03","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-11-17","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e70053"}}