Prosecution Insights
Last updated: October 25, 2026

USPTO Art Unit 1646: Examiners and Allowance Rates

39 examiners • 10 with pending office actions • Biotechnology & Pharmaceuticals (Tech Center 1600)

Art unit baseline (last 5 years, 4,155 dispositions): 41% allowance rate • 3.9 office actions per allowance • 1,281 days median pendency
ExaminerAllowance rateResolved casesPending apps
Julie Zhen Qin Wu100.0%20
Amy Marie Chattin100.0%10
Michail A Belyavskyi100.0%10
Sue Xu Liu100.0%10
Stephen L Rawlings95.8%1190
Janet L Epps-Smith85.5%690
Mark Halvorson84.3%20416
Hong Sang83.7%21531
Karl J Puttlitz82.3%21548
Peter J Reddig78.4%28332
Nada Ahmed Mahmou Elmansy72.7%110
Ashley Hartman Gao71.4%140
Katherine Ann Holtzman69.8%6324
Prema Maria Mertz64.1%5550
Gyan Chandra63.5%7060
Kathleen Mary Cunningchen62.5%5637
Elizabeth Kemmerer58.8%6500
Zachary C Howard57.1%7430
Claire M Kaufman56.2%4090
Bruce D Hissong55.4%5040
Sarah Abdoalatif Alsomairy54.9%8223
Andrea K Mccollum54.0%4740
Estella M Gustilo53.0%6636
Lea S O'Brien51.6%311
Ruixiang Li50.8%8010
Danaya L Middleton50.0%280
Gary B Nickol50.0%20
Jegatheesan Seharaseyon49.8%3010
Michael D Pak49.4%5280
Sandra Dillahunt Carter49.3%4060
Nirmal Singh Basi47.4%190
Brittney Erin Donoghue46.7%150
Xiaozhen Xie46.4%5260
Carol Ann Chase44.2%5217
Dong Jiang37.9%5120
Sandra L Wegert21.3%750
Vanessa L Ford7.9%380
Gregory S Emch0.0%40
Bridget E Bunner0.0%10

Frequently Asked Questions

What is the allowance rate in USPTO Art Unit 1646?

40.9% over the last five years, across 4,155 resolved applications.

Which examiners in Art Unit 1646 have the highest allowance rates?

Among examiners with at least 30 resolved applications: Stephen L Rawlings (95.8%, 119 resolved), Janet L Epps-Smith (85.5%, 69 resolved), Mark Halvorson (84.3%, 204 resolved).

Which examiners in Art Unit 1646 have the lowest allowance rates?

Among examiners with at least 30 resolved applications: Vanessa L Ford (7.9%, 38 resolved), Sandra L Wegert (21.3%, 75 resolved), Dong Jiang (37.9%, 512 resolved).

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