People · Operator

Jonathan S. Leff

Named in public records as an officer, director or promoter · active 2008–2015 · Pharmaceuticals, Biotechnology

3
Companies
3
Filings
$250.5M
Combined raised · real
Serial
Operator type
Companies
CompanyRoleSectorStageRaised · realValue · estTied
Kempharm, IncPharmaceuticalsSeries C$205.3M$981.3M2015
Rib X Pharmaceuticals IncPharmaceuticalsSeries B$29.7M$635.4M2012
Zymogenetics IncBiotechnologySeries B$15.5M$615.6M2008
Operator network

Jonathan S. Leff at the center, the companies they're named on, and every other operator named alongside them — an interlock map of shared founding teams, boards and funds. Name-matched, so treat as a research lead.

Todd Johnson · 27 companies · 1 sharedTodd JohnsonAdam Claypool · 6 companies · 1 sharedAdam ClaypoolRobert Beardsley · 5 companies · 1 sharedRobert BeardsleyRichard W. Pascoe · 4 companies · 1 sharedRichard W. PascoeDavid S. Tierney · 3 companies · 1 sharedDavid S. TierneyJoseph B. Saluri · 2 companies · 1 sharedJoseph B. SaluriRobert Karr · 2 companies · 1 sharedRobert KarrAdam J. Claypool · 1 companies · 1 sharedAdam J. ClaypoolJonathan Leff · 11 companies · 1 sharedJonathan LeffHarry H Penner, Jr. · 6 companies · 1 sharedHarry H Penner, J…Mark Leuchtenberger · 3 companies · 1 sharedMark Leuchtenberg…Cecilia Gonzalo · 2 companies · 1 sharedCecilia GonzaloGeorge M. Milne, Jr. · 2 companies · 1 sharedGeorge M. Milne, …Robert Conerly · 2 companies · 1 sharedRobert ConerlyC. Boyd H. Clarke · 1 companies · 1 sharedC. Boyd H. ClarkeEdward E. Penhoet, Ph.D. · 3 companies · 1 sharedEdward E. Penhoet…JAMES A. HARPER · 3 companies · 1 sharedJAMES A. HARPERJames A. Johnson · 3 companies · 1 sharedJames A. JohnsonDAVID H MACCALLUM · 2 companies · 1 sharedDAVID H MACCALLUMHeather L. Franklin · 2 companies · 1 sharedHeather L. Frankl…Lars Rebien Sorensen · 2 companies · 1 sharedLars Rebien Soren…Bruce L.A. Carter, Ph.D. · 1 companies · 1 sharedBruce L.A. Carter…Kempharm, Inc · $205.3M raisedKempharm, IncRib X Pharmaceuticals Inc · $29.7M raisedRib X Pharmaceuticals…Zymogenetics Inc · $15.5M raisedZymogenetics IncJonathan S. LeffJL
Jonathan S. Leff Company Co-operator (ring = serial)Hover to isolate ties · click to open
Co-operators (shared boards)

People named alongside Jonathan S. Leff on the same companies — an interlock signal (shared founding team, board, or fund). Name-matched, so verify before acting.

OperatorSharedTheir companies
Todd Johnson127
Jonathan Leff111
Harry H Penner, Jr.16
Adam Claypool16
Robert Beardsley15
Richard W. Pascoe14
James A. Johnson13
Edward E. Penhoet, Ph.D.13
David S. Tierney13
Mark Leuchtenberger13
JAMES A. HARPER13
George M. Milne, Jr.12
Lars Rebien Sorensen12
Robert Karr12
Heather L. Franklin12
Cecilia Gonzalo12
Joseph B. Saluri12
DAVID H MACCALLUM12
Robert Conerly12
Robert J. Beardsley, Ph.D.11

People are matched by normalized name across records; a common name may merge distinct individuals. Treat as a research lead, the same way modeled valuations are directional, not quoted.