PartnerFacts
Data last updated: Oct 23, 2026, 5:45 PM ETLatest filing: Oct 22, 2026Now: Oct 24, 2026, 7:57 AM ET

Sponsor Check › Person

JS
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Joseph Schlessinger

Named as an officer, director or promoter on SEC Form D filings · CT, MA · Aug 12, 2009 → Feb 9, 2021

4deals (issuers)
$127.4Mreported sold
68investors
14Form D filings
2009–2021years on file
Follow this personLook further ↓PDF

Data last updated Oct 23, 2026, 5:45 PM ET · Courts (RECAP) last checked: Oct 24, 2026, 2:19 AM ET · SEC enforcement last checked: Oct 24, 2026, 2:24 AM ET

The short version

Joseph Schlessinger is listed as an executive officer, director, and promoter on 14 SEC Form D filings by 4 issuers between Aug 2009 and Feb 2021: Inozyme Pharma, Inc. (Boston, MA — pharmaceuticals — 2017–2020; $67.4M reported sold to 14 investors), KOLLTAN PHARMACEUTICALS INC (New Haven, CT — biotechnology — 2009–2014; $60M reported sold to 54 investors), Opna Immuno-Oncology SA (St Sulpice, Switzerland (as filed: V8) — biotechnology — 2021) and Opna-IO, LLC (New York, NY — biotechnology — 2020).

What this means A repeat sponsor — 4 separate companies raised money with this person listed as executive officer, director, and promoter, over about 12 years. Across those companies the filings report $127.4M sold in total.

Listed alongside Axel Bolte (11 shared filings), Arthur G. Altschul, Jr. (6 shared filings), E. Jonathan Soderstrom (6 shared filings), Stanley Choy (6 shared filings), Thomas B. Neff (6 shared filings) and 19 others.

What this means These are the other officers, directors or promoters the companies named on the same forms — the team around Joseph. Each name links to their own page.

The issuers belong to 2 sponsor groups: Opna (2 issuers, $0 reported sold, 2020–2021) and Overbrook (8 issuers, $662.5M reported sold, 2009–2026).

What this means This person is listed across more than one sponsor team; each group page shows that team's full track record.

Public records searched: federal courts (CourtListener / RECAP), SEC enforcement releases, state securities regulators (AK, AL, AR, AZ, CA, CT, DE, FINRA, GA, HI, ID, IL, KS, KY, LA, MA, MD, ME, MI, MO, MS, MT, NASAA, NC, ND, NH, NM, NV, OK, OR, PA, RI, SC, SD, TN, TX, VT, WA, WI, WV, WY) — 9 court cases matching the name, 4 bankruptcy cases matching the name listed in Key records below.

What this means 13 records came back, including 2 court cases still open — open cases can take years and cost money. Each one is listed below with a link to the original document and a line saying why it matched. A name match is not proof it is the same person or company — read the why line and the document. Being sued or named in a release is an accusation, not a finding.

We compared 14 public filings for Joseph Schlessinger and found 12 differences, 4 worth asking the sponsor about: Amount sold went down between filings; Investor count went down between filings; and more below.

What this means These are differences between the sponsor's own SEC filings — both values, dates and sources are listed in Key records, section 4. Most have ordinary explanations; ask the sponsor.

What the community is saying

Community search for Joseph Schlessinger has not run yet — it is joining a line of 29,245 names; searches run around the clock at the hosts' allowed rate. Searched so far: 638 names.

Community comments are quoted as written by their authors. Sources searched: BiggerPockets forums (via DuckDuckGo, Brave, Bing and BiggerPockets search) and Reddit (search feed + public archive).

Key records

Five things investors ask first. Items still in human review are counted, not shown.

1. Lawsuits

9 cases: 2 open, 3 closed (disposition not in docket feed), 2 dismissed, 2 judgment

Schlessinger v. Safe Step Walk In Tub, LLC open
District Court, M.D. Tennessee · No. 3:25-cv-01251 · Filed Oct 30, 2025 · Nature of suit: P.I.: Other · Cause: 28:1332 Diversity-Fraud
Role of Schlessinger: Plaintiff · Outcome: Open — no termination date on the docket (bulk snapshot 2026-09-30) Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); surname only in the caption; court in TN (not a filing state)
Schlessinger v. Safe Step Walk In Tub, LLC open
District Court, S.D. Florida · No. 1:25-cv-24355 · Filed Sep 23, 2025
Role of Schlessinger: Plaintiff · Outcome: Open — no termination date on the docket (bulk snapshot 2026-09-30) Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); surname only in the caption; court in FL (not a filing state)
Schlessinger v. Leaf Home Enhancements, LLC closed
District Court, S.D. Florida · No. 1:24-cv-20582 · Filed Feb 14, 2024 · Closed Aug 12, 2024
Role of Schlessinger: Plaintiff · Outcome: Terminated 2024-08-12 (disposition not included in the bulk docket feed — see docket) Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); surname only in the caption; court in FL (not a filing state)
Schlessinger v. Star Nissan Inc. closed
District Court, N.D. Illinois · No. 1:20-cv-05106 · Filed Aug 31, 2020 · Closed Mar 31, 2021
Role of Schlessinger: Plaintiff · Outcome: Terminated 2021-03-31 (disposition not included in the bulk docket feed — see docket) Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); surname only in the caption; court in IL (not a filing state)
SOL SCHLESSINGER & POLYMERIC RESOURCES CORP. dismissed
District Court, D. New Jersey · No. 2:19-cv-13474 · Filed Jun 6, 2019 · Closed Jul 26, 2019 · Nature of suit: 190 Contract: Other · Cause: 28:1332 Diversity-Notice of Removal
Role of SOL SCHLESSINGER & POLYMERIC RESOURCES CORP.: Party · Outcome: Terminated 2019-07-26 — FJC Integrated Database disposition: Dismissed: settled Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); different first name (sol); court in NJ (not a filing state)
Schlessinger v. Valspar Corporation judgment
District Court, E.D. New York · No. 2:10-cv-02694 · Filed Jun 14, 2010 · Closed Sep 28, 2011 · Nature of suit: Contract: Other · Cause: 28:1332 Diversity-Other Contract
Role of Schlessinger: Plaintiff · Outcome: Terminated 2011-09-28 — FJC Integrated Database disposition: Judgment on motion before trial; judgment for defendant Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); surname only in the caption; court in the person's filing state (NY)
Schlessinger v. Cabletron Systems closed
District Court, D. New Hampshire · No. 1:98-cv-00037 · Filed Jan 20, 1998 · Closed Mar 3, 1998 · Nature of suit: 850 Securities, Commodities, Exchange
Role of Schlessinger: Plaintiff · Outcome: Terminated 1998-03-03 — FJC Integrated Database disposition: Statistical closing Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); surname only in the caption; court in NH (not a filing state)
MERIDIAN LEASING v. SCHLESSINGER judgment
District Court, E.D. Pennsylvania · No. 2:92-cv-00340 · Filed Jan 17, 1992 · Closed Apr 9, 1992 · Nature of suit: 190 Other contract actions
Role of SCHLESSINGER: Defendant · Outcome: Terminated 1992-04-09 — FJC Integrated Database disposition: Judgment on default; judgment for plaintiff Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); surname only in the caption; court in PA (not a filing state)
DAVID SCHLESSINGER v. BRUCE MCDONNELL, AND dismissed
District Court, D. New Jersey · No. · Filed Oct 5, 1988 · Closed Oct 13, 1989 · Nature of suit: 190 Other contract actions
Role of DAVID SCHLESSINGER: Plaintiff · Outcome: Terminated 1989-10-13 — FJC Integrated Database disposition: Dismissed: settled Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); different first name (david); court in NJ (not a filing state)
What was searched

Sources searched: CourtListener bulk data (RECAP dockets as of 2026-09-30; recall-first rule 10-24) — federal district + bankruptcy courts State courts: not covered (one-tap state court links under Look further). PACER: not searched. · Last checked Oct 24, 2026, 2:19 AM ET.

Court records show docket facts only; we never restate allegations as facts. Outcome wording comes from the docket feed; where it does not state a disposition we say so.

State courts: not covered (one-tap state court links under Look further). No state offers a lawful automated statewide source PartnerFacts can use today. Texas (re:SearchTX) terms prohibit storing results in a database open to third parties; New York (WebCivil) and Massachusetts (MassCourts) require a browser check that blocks scripted queries; California has no statewide index (58 county portals; Rule of Court 2.503 grants name-based access case by case); Florida, Utah and Illinois offer paid or partial access whose terms for automated use are unverified. Washington (dw.courts.wa.gov; bulk index reports under a JISC data-dissemination agreement), Delaware (CourtConnect; Court of Chancery not included) and Arizona (apps.azcourts.gov/publicaccess, which has an official channel to request high-volume access) are the candidates; PartnerFacts will request written permission before any automated search. Federal courts are searched through CourtListener / RECAP.

2. Regulatory actions

None found in sources searched — SEC enforcement releases (checked Oct 24, 2026) · state securities regulators: VA (crawled Oct 23, 2026)

What was searched

SEC enforcement searched: SEC litigation releases + SEC administrative proceedings (sec.gov index, 1995-09-19 → 2026-10-23) — last checked Oct 24, 2026, 2:24 AM ET.

State securities regulators: Securities regulators searched (3,318 actions): AZ Corporation Commission Securities Division (411 actions, 2017–2026), CA DFPI (25 actions, 2007–2024; listing starts 2002 — 16 of 12,159 DFPI respondent pages read so far; sponsor-name matches are read first), DE DOJ Investor Protection Unit (257 actions, 1987–2026), TX State Securities Board (586 actions, 2006–2026), WA DFI (2,039 actions, 2001–2026) — last crawled Oct 23, 2026, 9:57 PM ET. No machine-readable public listing today for CO, FL, IA, IN, MN, NE, NJ, NY, OH, UT, VA (see docs/state-regulators.md).

3. Bankruptcies

4 cases: 4 closed (disposition not in docket feed)

David E. Schlessinger closed
United States Bankruptcy Court, W.D. Pennsylvania · No. 15-21557 · Filed Apr 30, 2015 · Closed Jan 25, 2016
Role of David E. Schlessinger: Debtor · Outcome: Case closed 2016-01-25 (disposition not included in the bulk docket feed — see docket) Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); different first name (david); court in PA (not a filing state)
David Schlessinger closed
United States Bankruptcy Court, W.D. Pennsylvania · No. 03-30882 · Filed Sep 3, 2003 · Closed May 21, 2007
Role of David Schlessinger: Debtor · Outcome: Case closed 2007-05-21 (disposition not included in the bulk docket feed — see docket) Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); different first name (david); court in PA (not a filing state)
David M Schlessinger closed
United States Bankruptcy Court, N.D. Illinois · No. 00-28879 · Filed Oct 3, 2000 · Closed Jan 10, 2001
Role of David M Schlessinger: Debtor · Outcome: Case closed 2001-01-10 (disposition not included in the bulk docket feed — see docket) Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); different first name (david); court in IL (not a filing state)
David Schlessinger closed
United States Bankruptcy Court, W.D. Pennsylvania · No. 87-22606 · Filed Sep 23, 1987 · Closed Apr 8, 1992
Role of David Schlessinger: Debtor · Outcome: Case closed 1992-04-08 (disposition not included in the bulk docket feed — see docket) Docket on CourtListener ↗
same rare surname (3 people in Form D filings, 17 federal dockets); different first name (david); court in PA (not a filing state)
What was searched

Sources searched: Federal bankruptcy courts via CourtListener / RECAP archive (federal district courts, federal bankruptcy courts). State courts: not covered (one-tap state court links under Look further). PACER: not searched (RECAP only). · Last checked Oct 24, 2026, 2:19 AM ET.

Court records show docket facts only; we never restate allegations as facts. Outcome wording comes from the docket feed; where it does not state a disposition we say so.

State courts: not covered (one-tap state court links under Look further). No state offers a lawful automated statewide source PartnerFacts can use today. Texas (re:SearchTX) terms prohibit storing results in a database open to third parties; New York (WebCivil) and Massachusetts (MassCourts) require a browser check that blocks scripted queries; California has no statewide index (58 county portals; Rule of Court 2.503 grants name-based access case by case); Florida, Utah and Illinois offer paid or partial access whose terms for automated use are unverified. Washington (dw.courts.wa.gov; bulk index reports under a JISC data-dissemination agreement), Delaware (CourtConnect; Court of Chancery not included) and Arizona (apps.azcourts.gov/publicaccess, which has an official channel to request high-volume access) are the candidates; PartnerFacts will request written permission before any automated search. Federal courts are searched through CourtListener / RECAP.

4. Differences between public sources

Comparisons cover issuers and sponsor groups — see the issuer pages under Deals

12 differences found between the filings for Joseph Schlessinger — 4 worth asking about (compared 14 filings on Oct 24, 2026)

Worth asking · Sep 8, 2009 – Jan 4, 2010

Amount sold went down between filings — KOLLTAN PHARMACEUTICALS INC

The Sep 8, 2009 filing says $3,500,000 sold; the Jan 4, 2010 Form D says $2,500,000 sold — $1,000,000 less.

What this means Amounts sold normally only go up as a raise continues. A drop can mean investors were refunded, a figure was corrected, or an earlier number was wrong. Ask the sponsor which it was.

Form D (earlier) · Sep 8, 2009 ↗Form D (later) · Jan 4, 2010 ↗KOLLTAN PHARMACEUTICALS INC — PartnerFacts page ↗
Sources
Worth asking · Aug 12, 2009 – Sep 8, 2009

Amount sold went down between filings — KOLLTAN PHARMACEUTICALS INC

The Aug 12, 2009 filing says $40,000,000 sold; the Sep 8, 2009 Form D says $3,500,000 sold — $36,500,000 less.

What this means Amounts sold normally only go up as a raise continues. A drop can mean investors were refunded, a figure was corrected, or an earlier number was wrong. Ask the sponsor which it was.

Form D/A (earlier) · Aug 12, 2009 ↗Form D (later) · Sep 8, 2009 ↗KOLLTAN PHARMACEUTICALS INC — PartnerFacts page ↗
Sources
Worth asking · Aug 12, 2009 – Sep 8, 2009

Investor count went down between filings — KOLLTAN PHARMACEUTICALS INC

The Aug 12, 2009 filing reports 54 investors; the Sep 8, 2009 Form D reports 1 investor.

What this means Investor counts normally only grow. A smaller number can mean investors left or were refunded, or a count was corrected. Ask the sponsor what happened.

Form D/A (earlier) · Aug 12, 2009 ↗Form D (later) · Sep 8, 2009 ↗KOLLTAN PHARMACEUTICALS INC — PartnerFacts page ↗
Sources
Note · Aug 12, 2009

16% of the money raised went to insiders — KOLLTAN PHARMACEUTICALS INC

The Aug 12, 2009 Form D/A reports $40,000,000 sold and $6,261,900 of the proceeds used for payments to officers, directors or promoters (marked as an estimate).

What this means The filing reports how much of the money raised was paid to insiders. Over 10% is high for most deals. Ask what it paid for.

Form D/A · Aug 12, 2009 ↗KOLLTAN PHARMACEUTICALS INC — PartnerFacts page ↗
Sources
Note · Jul 24, 2008 – Sep 16, 2010

No amendment in the last 12 months on an offering that may still be open — KOLLTAN PHARMACEUTICALS INC (latest filing Sep 16, 2010)

The latest filing for this offering is dated Sep 16, 2010 (first sale Jul 24, 2008). It reports $6,000,000 sold of $7,500,000 offered. No later amendment is in our index as of Oct 24, 2026.

What this means SEC rules expect a yearly amendment while an offering is still going. The raise may simply have ended — a Form D does not say when it closed. Ask the sponsor whether the offering closed, when, and at what amount.

Form D/A · Sep 16, 2010 ↗KOLLTAN PHARMACEUTICALS INC — PartnerFacts page ↗
Sources
Worth asking · Mar 27, 2020 – Jun 8, 2020

Joseph Schlessinger is no longer listed on the Jun 8, 2020 amendment — Inozyme Pharma, Inc.

Joseph Schlessinger appears on the Mar 27, 2020 Form D/A (director) but not on the Jun 8, 2020 Form D/A for the same offering.

What this means People leave, and the issuer must list only current officers, directors and promoters. It is still worth asking why this person left and who replaced them.

Form D/A · Mar 27, 2020 ↗Form D/A · Jun 8, 2020 ↗Joseph Schlessinger — PartnerFacts page ↗Inozyme Pharma, Inc. — PartnerFacts page ↗
Sources
Note · Aug 12, 2009 – Mar 29, 2019

4 role changes for the same people across filings

Joseph Schlessinger's role changed at Inozyme Pharma, Inc.: executive officer, director → director · Joseph Schlessinger's role changed at Inozyme Pharma, Inc.: executive officer, director → director · Joseph Schlessinger's role changed at Inozyme Pharma, Inc.: director → executive officer, director · Joseph Schlessinger's role changed at KOLLTAN PHARMACEUTICALS INC: director, promoter → director

What this means Roles on Form D are self-reported. Ask who runs the company today.

Form D/A · Nov 21, 2018 ↗Form D/A · Mar 29, 2019 ↗Joseph Schlessinger — PartnerFacts page ↗Inozyme Pharma, Inc. — PartnerFacts page ↗
Sources
Note · Aug 12, 2009 – Jun 8, 2020

6 offerings changed their target amount between filings

Offering amount changed between filings — Inozyme Pharma, Inc. · Offering amount changed between filings — Inozyme Pharma, Inc. · Offering amount changed between filings — Inozyme Pharma, Inc. · Offering amount changed between filings — KOLLTAN PHARMACEUTICALS INC · Offering amount lowered between filings — KOLLTAN PHARMACEUTICALS INC · and 1 more

What this means Targets change as deals grow or shrink. Ask whether later money has the same terms.

Form D/A (earlier) · Mar 27, 2020 ↗Form D/A (later) · Jun 8, 2020 ↗Inozyme Pharma, Inc. — PartnerFacts page ↗Form D (earlier) · Nov 21, 2018 ↗
Sources
Note · Jan 5, 2017 – Nov 21, 2018

Reported revenue range changed between filings — Inozyme Pharma, Inc.

"No Revenues" (Jan 5, 2017); then "Decline to Disclose" (Nov 21, 2018).

What this means This is the size band the issuer picks for itself on the form. A change can mean the business grew or shrank — or that it chose not to say. Ask for current numbers.

Form D · Jan 5, 2017 ↗Form D · Nov 21, 2018 ↗Inozyme Pharma, Inc. — PartnerFacts page ↗
Sources
Note · Aug 12, 2009 – Sep 8, 2009

Reported revenue range changed between filings — KOLLTAN PHARMACEUTICALS INC

"No Revenues" (Aug 12, 2009); then "Decline to Disclose" (Sep 8, 2009).

What this means This is the size band the issuer picks for itself on the form. A change can mean the business grew or shrank — or that it chose not to say. Ask for current numbers.

Form D/A · Aug 12, 2009 ↗Form D · Sep 8, 2009 ↗KOLLTAN PHARMACEUTICALS INC — PartnerFacts page ↗
Sources
Note · Jan 12, 2017 – Nov 21, 2018

Address moved from Herrliberg, Switzerland (as filed: V8) to Boston, MA — Inozyme Pharma, Inc.

The people listed on the Jan 12, 2017 filing give Herrliberg, Switzerland (as filed: V8); on the Nov 21, 2018 filing they give Boston, MA.

What this means Businesses move; this just shows the two places and dates. If you were told one city and the forms say another, ask which is current.

Form D/A · Jan 12, 2017 ↗Form D/A · Nov 21, 2018 ↗Inozyme Pharma, Inc. — PartnerFacts page ↗
Sources
Note · Aug 12, 2009 – Feb 9, 2021

Joseph Schlessinger is listed with 2 different address states: CT, MA

CT on 10 filings (Aug 12, 2009 to Feb 9, 2021); MA on 4 filings (Nov 21, 2018 to Mar 27, 2020).

What this means The address on a Form D is usually the company's, not the person's home, so this often just reflects different companies. It can also mean a move. Nothing wrong by itself.

Form D/A · Aug 12, 2009 ↗Form D · Nov 21, 2018 ↗
Sources
What is compared

What is compared: every Form D and D/A we hold for this subject, side by side — filing dates vs. first-sale dates (the 15-day rule), amendment timing on open offerings (the yearly-amendment expectation), amounts sold, investor counts, offering amounts and minimums across amendments, industry and size bands, addresses, how each person's name and role is written, paid sellers' CRD numbers, and (for groups) where the member companies were formed and sit. Everything is as filed by the issuer; the SEC does not check it. Differences are common and usually have ordinary explanations — we show both values, the dates, and the source so you can ask. As of Oct 24, 2026.

5. Money to insiders

0 of 7 offerings report sales commissions; 0 report finder's fees; 0 report proceeds to related persons.

Offering (latest filing)Sales commissionsFinder's feesTo insidersPaid to sell itSource
Feb 9, 2021 D
Opna Immuno-Oncology SA
File 021-388869
$0$0$0None listed on this filingEDGAR ↗
Jun 17, 2020 D
Opna-IO, LLC
File 021-369142
$0$0$0None no CRD number reportedEDGAR ↗
Mar 27, 2020 D/A
Inozyme Pharma, Inc.
File 021-326389
$0$0$0None listed on this filingEDGAR ↗
Nov 21, 2018 D/A
Inozyme Pharma, Inc.
File 021-277738
$0$0$0None listed on this filingEDGAR ↗
Mar 19, 2014 D
KOLLTAN PHARMACEUTICALS INC
File 021-213905
$0$0$0None listed on this filingEDGAR ↗
Mar 7, 2012 D
KOLLTAN PHARMACEUTICALS INC
File 021-174497
$0$0$0
The foregoing does not include compensation in the form of salaries and bonuses to be paid to such individuals in their capacities as officers of the company.
None listed on this filingEDGAR ↗
Sep 16, 2010 D/A
KOLLTAN PHARMACEUTICALS INC
File 021-121462
$0$0$0None listed on this filingEDGAR ↗
How this is counted

Counts come from Form D Items 12–15 on the filings in our index (latest filing per offering; one offering = one SEC file number; an amendment updates its offering rather than adding one). "To insiders" = gross proceeds used for payments to executive officers, directors or promoters. "—" = not reported on that filing. Amounts marked (est.) were reported as estimates. "Paid to sell it" = sales compensation recipients named on that filing (Item 12), each linked to FINRA BrokerCheck when a CRD number is reported.

Counted across every filing this person is listed on (latest filing per offering, per issuer).

Deals 4

Every issuer that named Joseph Schlessinger on a Form D, newest first. A Form D is the notice a company files after it starts selling a private investment.

OI
Biotechnology · group: Opna

Opna Immuno-Oncology SA

St Sulpice, Switzerland (as filed: V8) · Feb 9, 2021
  • Feb 9, 2021 · D · $0 sold of Indefinite · 0 investors · min. No minimum reported · role: Director EDGAR ↗

No sales reported yet as of the latest filing. Joseph is listed as director.

Latest filing on EDGAR ↗
Sources

Every row is a Form D or D/A on which the issuer listed this name as a related person. Amount sold and investors are the maximum reported on any filing for this issuer. "Similar" = offerings in the same industry claiming the same exemption, filed in the last 5 years: Biotechnology / 506(b) (3,253 filings); ranges are the middle half (25th–75th percentile). Computed by PartnerFacts from SEC EDGAR Form D data as of Oct 23, 2026, 5:45 PM ET. Rows without a range: fewer than 30 comparable filings, or not a Rule 506 offering. No ranking or score.

OI
Biotechnology · group: Opna

Opna-IO, LLC

New York, NY · Jun 17, 2020
  • Jun 17, 2020 · D · $0 sold of Indefinite · 0 investors · min. No minimum reported · role: Executive Officer, Director EDGAR ↗

No sales reported yet as of the latest filing. Joseph is listed as executive officer, director.

Latest filing on EDGAR ↗
Sources

Every row is a Form D or D/A on which the issuer listed this name as a related person. Amount sold and investors are the maximum reported on any filing for this issuer. "Similar" = offerings in the same industry claiming the same exemption, filed in the last 5 years: Biotechnology / 506(b) (3,253 filings); ranges are the middle half (25th–75th percentile). Computed by PartnerFacts from SEC EDGAR Form D data as of Oct 23, 2026, 5:45 PM ET. Rows without a range: fewer than 30 comparable filings, or not a Rule 506 offering. No ranking or score.

IP
Pharmaceuticals

Inozyme Pharma, Inc.

Boston, MA · Jan 5, 2017 → Mar 27, 2020 · 6 filings
  • Mar 27, 2020 · D/A · $33,699,996 sold of $33,699,996 · 11 investors · min. No minimum reported · role: Director EDGAR ↗
  • Mar 29, 2019 · D/A · $33,699,996 sold of $33,699,996 · 11 investors · min. No minimum reported · role: Director EDGAR ↗
  • Nov 21, 2018 · D · $10,699,996 sold of $10,699,996 · 5 investors · min. No minimum reported · role: Director EDGAR ↗
  • Nov 21, 2018 · D/A · $48,850,000 sold of $48,850,000 · 14 investors · min. No minimum reported · role: Executive Officer, Director EDGAR ↗
  • Jan 12, 2017 · D/A · $0 sold of Indefinite · 0 investors · min. No minimum reported · role: Executive Officer, Director EDGAR ↗
  • Jan 5, 2017 · D · $0 sold of Indefinite · 0 investors · min. No minimum reported · role: Executive Officer, Director EDGAR ↗

Raised $67.4M from 14 investors (100% of the $33.7M target) as of the latest filing. Joseph is listed as director, executive officer on 6 filings for this deal.

Latest filing on EDGAR ↗
Sources

Every row is a Form D or D/A on which the issuer listed this name as a related person. Amount sold and investors are the maximum reported on any filing for this issuer. "Similar" = offerings in the same industry claiming the same exemption, filed in the last 5 years: Pharmaceuticals / 506(b) (800 filings); ranges are the middle half (25th–75th percentile). Computed by PartnerFacts from SEC EDGAR Form D data as of Oct 23, 2026, 5:45 PM ET. Rows without a range: fewer than 30 comparable filings, or not a Rule 506 offering. No ranking or score.

KP
Biotechnology · group: Overbrook

KOLLTAN PHARMACEUTICALS INC

New Haven, CT · Aug 12, 2009 → Mar 19, 2014 · 6 filings
  • Mar 19, 2014 · D · $60,000,000 sold of $60,000,000 · 34 investors · min. No minimum reported · role: Director EDGAR ↗
  • Mar 7, 2012 · D · $25,000,000 sold of $25,000,000 · 1 investors · min. No minimum reported · role: Director EDGAR ↗
  • Sep 16, 2010 · D/A · $6,000,000 sold of $7,500,000 · 1 investors · min. No minimum reported · role: Director EDGAR ↗
  • Jan 4, 2010 · D · $2,500,000 sold of $2,500,000 · 1 investors · min. No minimum reported · role: Director EDGAR ↗
  • Sep 8, 2009 · D · $3,500,000 sold of $7,500,000 · 1 investors · min. No minimum reported · role: Director EDGAR ↗
  • Aug 12, 2009 · D/A · $40,000,000 sold of $40,000,000 · 54 investors · min. No minimum reported · role: Director, Promoter EDGAR ↗

Raised $60M from 54 investors (100% of the $60M target) as of the latest filing. Joseph is listed as director, promoter on 6 filings for this deal.

Latest filing on EDGAR ↗
Sources

Every row is a Form D or D/A on which the issuer listed this name as a related person. Amount sold and investors are the maximum reported on any filing for this issuer. "Similar" = offerings in the same industry claiming the same exemption, filed in the last 5 years: Biotechnology / 506(b) (3,253 filings); ranges are the middle half (25th–75th percentile). Computed by PartnerFacts from SEC EDGAR Form D data as of Oct 23, 2026, 5:45 PM ET. Rows without a range: fewer than 30 comparable filings, or not a Rule 506 offering. No ranking or score.

People around Joseph 24

Officers, directors, promoters and management entities named on the same filings, as of Oct 23, 2026, 5:45 PM ET.

AB
No photo found yet (own website and image search run after this page is viewed)
Person

Axel Bolte

Director, Executive Officer · 11 shared filings (2 issuers) · also on 4 other issuers

Axel Bolte is on 6 issuers in total — a repeat sponsor. Their page lists every one.

ES
No photo found yet (own website and image search run after this page is viewed)
Person

E. Jonathan Soderstrom

Director · 6 shared filings (1 issuer) · also on 3 other issuers

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

TN
No photo found yet (own website and image search run after this page is viewed)
Person

Thomas B. Neff

Director · 6 shared filings (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

AA
No photo found yet (own website and image search run after this page is viewed)
Person

Arthur G. Altschul, Jr.

Executive Officer, Director, Promoter · 6 shared filings (1 issuer) · also on 1 other issuer

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

YH
No photo found yet (own website and image search run after this page is viewed)
Person

Yaron Hadari

Executive Officer · 6 shared filings (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

SC
No photo found yet (own website and image search run after this page is viewed)
Person

Stanley Choy

Executive Officer · 6 shared filings (1 issuer) · also on 1 other issuer

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

KH
No photo found yet (own website and image search run after this page is viewed)
Person

K. Peter Hirth

Director · 5 shared filings (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

WM
No photo found yet (own website and image search run after this page is viewed)
Person

W. Bradford Middlekauff

Executive Officer · 5 shared filings (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

MS
No photo found yet (own website and image search run after this page is viewed)
Person

Michael Schmertzler

Executive Officer, Director · 5 shared filings (1 issuer) · also on 2 other issuers

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

RH
No photo found yet (own website and image search run after this page is viewed)
Person

Rob Hopfner

Director · 4 shared filings (1 issuer) · also on 2 other issuers

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

ME
No photo found yet (own website and image search run after this page is viewed)
Person

Martin Edwards

Director · 4 shared filings (1 issuer) · also on 2 other issuers

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

RD
No photo found yet (own website and image search run after this page is viewed)
Person

Reinaldo Diaz

Director · 4 shared filings (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

EM
No photo found yet (own website and image search run after this page is viewed)
Person

Edward Mathers

Director · 4 shared filings (1 issuer) · also on 5 other issuers

Edward Mathers is on 6 issuers in total — a repeat sponsor. Their page lists every one.

BP
No photo found yet (own website and image search run after this page is viewed)
Person

Brian W. Pusch

Executive Officer, Director · 2 shared filings (2 issuers) · also on 4 other issuers

Brian W. Pusch is on 6 issuers in total — a repeat sponsor. Their page lists every one.

SB
No photo found yet (own website and image search run after this page is viewed)
Person

Sarah Bhagat

Director · 2 shared filings (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

DH
No photo found yet (own website and image search run after this page is viewed)
Person

Douglas Hanahan

Director · 2 shared filings (2 issuers)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

AB
No photo found yet (own website and image search run after this page is viewed)
Person

Alex Bolte

Director · 1 shared filing (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

PH
No photo found yet (own website and image search run after this page is viewed)
Person

Peter Hirth

Director · 1 shared filing (1 issuer) · also on 7 other issuers

Peter Hirth is on 8 issuers in total — a repeat sponsor. Their page lists every one.

PM
No photo found yet (own website and image search run after this page is viewed)
Person

Paul Medeiros

Director · 1 shared filing (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

TL
No photo found yet (own website and image search run after this page is viewed)
Person

Theresa M. LaVallee

Executive Officer · 1 shared filing (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

CS
No photo found yet (own website and image search run after this page is viewed)
Person

Carolyn F. Sidor

Executive Officer · 1 shared filing (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

GM
No photo found yet (own website and image search run after this page is viewed)
Person

Gerald McMahon

Executive Officer, Director · 1 shared filing (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

JH
No photo found yet (own website and image search run after this page is viewed)
Person

Jane Pritchett Henderson

Executive Officer · 1 shared filing (1 issuer) · also on 1 other issuer

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

GB
No photo found yet (own website and image search run after this page is viewed)
Person

Gideon Bollag

Director · 1 shared filing (1 issuer)

Listed on the same filings as Joseph Schlessinger. Their page shows their other deals.

The team behind the deals

O
Sponsor group

Opna

2 issuers · 2 filings · $0 reported sold · 2020–2021

One team, 2 deal companies. Joseph Schlessinger is listed on 2 of them.

Sources

Issuers are grouped when their Form D filings share related persons, a management entity or a business address (automatic match from the filings). "Listed" marks the issuers that name Joseph Schlessinger.

O
Sponsor group

Overbrook

8 issuers · 42 filings · $662.5M reported sold · 2009–2026

One team, 8 deal companies. Joseph Schlessinger is listed on 1 of them.

Sources

Issuers are grouped when their Form D filings share related persons, a management entity or a business address (automatic match from the filings). "Listed" marks the issuers that name Joseph Schlessinger.

Same business address

11 other issuers file from the same address

A shared address can mean the same team, a shared office building or a registered agent. It is a lead, not a conclusion.

Registrations and other filings

Adviser registration (Form ADV)

None of the 4 issuers this person is listed on appears in Form ADV (searched 24,962 advisers as of Oct 2, 2026). A person is never an adviser firm; Form ADV is checked for the issuers and the management companies they are listed with.

Other offering types (Regulation A and Regulation Crowdfunding)

Searched SEC Regulation A Data Sets (Forms 1-A, 1-K, 1-Z; 2015 Q2 → 2026 Q3); SEC Crowdfunding Offerings Data Sets (Form C family; 2016 Q2 → 2026 Q3); EDGAR form index for 2026 Q3 → 2026 Q4 (51,358 records as of Oct 23, 2026, 8:41 PM ET) — nothing matched this name.

Property records none — individuals are not matched

Property records are matched to companies only, never to individuals, so none are matched to Joseph Schlessinger by design. Searched property records in Hillsborough County FL (Clerk recorded-document index Oct 14, 2026 to Oct 15, 2026 + FL DOR 2026 ownership roll), Miami-Dade County FL (FL DOR 2026 ownership roll), Harris County TX (HCAD 2026 ownership roll), Dallas County TX (DCAD 2026 ownership roll), New York City ACRIS documents and PLUTO ownership rows already retrieved for other issuers, Cook County IL sale and ownership rows already retrieved for other issuers (814,874 records as of Oct 23, 2026, 8:59 PM ET) for the 4 issuers this person is listed on — nothing matched.

Public profiles and social

Websites and social links of the issuers Joseph Schlessinger is listed on: none on file. No website or social profile named in KOLLTAN PHARMACEUTICALS INC's SEC filings (Form C, Reg A, Form ADV; checked Oct 24, 2026). Web search for this name: #319,292 of 374,652 in line (1,381 issuers searched so far). One-tap searches: Look further ↓

Look further

One-tap searches on sites we do not index ourselves, with the name pre-filled (New Haven, CT). Each opens in a new tab; what you find there is not verified by PartnerFacts.

Social and web

LinkedIn people search ↗Instagram ↗X (Twitter) ↗Facebook ↗YouTube ↗Google ↗Google Images ↗Google News ↗Meta Ad Library ↗

Courts

CourtListener / RECAP (federal) ↗PACER case locator (federal, login) ↗Connecticut Judicial Branch case look-up ↗Massachusetts MassCourts ↗New York WebCivil Supreme ↗

Securities regulators

SEC EDGAR full-text search ↗SEC action look-up ↗FINRA BrokerCheck ↗SEC IAPD adviser search ↗

Business registries

Connecticut Secretary of State business search ↗Massachusetts Secretary of State business search ↗New York Secretary of State business search ↗OpenCorporates ↗

Change history

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