# Theseus Pharmaceuticals Inc. (THRX)

Source: https://www.quantisnow.com/company/THRX
Generated: 2026-11-13T06:34:18.780Z

- Ticker: THRX
- Exchange: NASDAQ
- Sector: Health Care
- Industry: Biotechnology: Pharmaceutical Preparations
- IPO year: 2004
- Website: theseusrx.com

## About

Theseus Pharmaceuticals, Inc., a biopharmaceutical company, engages in the discovery, development, and commercialization of targeted therapies for the treatment of cancer patients. Its lead product candidate is THE-630, a pan-variant inhibitor for activating and resistance mutations of the KIT kinase or a pan-KIT inhibitor for the treatment of gastrointestinal stromal tumors (GIST), a type of cancer characterized by oncogenic activation of KIT. The company also develops fourth-generation EGFR inhibitor that is active against C797S, an EGFR mutation that causes resistance to first- or later-line osimertinib treatment in patients with non-small cell lung cancer. Its development programs address drug resistance mutations in key driver oncogenes, which are mutated genes that cause cancer. The company was incorporated in 2017 and is based in Cambridge, Massachusetts.

## Latest THRX news and filings

- 2024-02-26 14:00 UTC [SEC Form 15-12G filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-15-12g-filed-by-theseus-pharmaceuticals-inc-5290724)
- 2024-02-16 21:00 UTC [SEC Schedule 13D] [SEC Form SC 13D/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-13da-filed-by-theseus-pharmaceuticals-inc-amendment-5270686)
- 2024-02-16 05:15 UTC [SEC Form EFFECT] [SEC Form EFFECT filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-effect-filed-by-theseus-pharmaceuticals-inc-5269444)
- 2024-02-14 21:03 UTC [SEC Form 4] [SEC Form 4 filed by Yi Kathy](https://www.quantisnow.com/insight/sec-form-4-filed-by-yi-kathy-5262916)
- 2024-02-14 21:03 UTC [SEC Form 4] [SEC Form 4 filed by Stein Steven H](https://www.quantisnow.com/insight/sec-form-4-filed-by-stein-steven-h-5262910)
- 2024-02-14 21:02 UTC [SEC Form 4] [SEC Form 4 filed by Orbimed Advisors Llc](https://www.quantisnow.com/insight/sec-form-4-filed-by-orbimed-advisors-llc-5262838)
- 2024-02-14 21:01 UTC [SEC Form 4] [Hayden Donald J Jr closing all direct ownership in the company (SEC Form 4)](https://www.quantisnow.com/insight/hayden-donald-j-jr-closing-all-direct-ownership-in-the-5262814)
- 2024-02-14 21:00 UTC [SEC Form 4] [Dukes Iain D. closing all direct ownership in the company (SEC Form 4)](https://www.quantisnow.com/insight/dukes-iain-d-closing-all-direct-ownership-in-the-company-5262800)
- 2024-02-14 21:01 UTC [SEC Form 4] [SEC Form 4 filed by Gordon Carl L](https://www.quantisnow.com/insight/sec-form-4-filed-by-gordon-carl-l-5262798)
- 2024-02-14 21:00 UTC [SEC Form 4] [Dahms Bradford D. closing all direct ownership in the company (SEC Form 4)](https://www.quantisnow.com/insight/dahms-bradford-d-closing-all-direct-ownership-in-the-company-5262758)
- 2024-02-14 19:26 UTC [SEC Form S-8 POS] [SEC Form S-8 POS filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-s-8-pos-filed-by-theseus-pharmaceuticals-inc-5262058)
- 2024-02-14 19:24 UTC [SEC Form S-8 POS] [SEC Form S-8 POS filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-s-8-pos-filed-by-theseus-pharmaceuticals-inc-5262054)
- 2024-02-14 19:22 UTC [SEC Form POS AM filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-pos-am-filed-by-theseus-pharmaceuticals-inc-5262042)
- 2024-02-14 15:44 UTC [SEC Form 8-K] [Theseus Pharmaceuticals Inc. filed SEC Form 8-K: Completion of Acquisition or Disposition of Assets, Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Material Modification to Rights of Security Holders, Changes in Control of Registrant, Leadership Update, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Other Events, Financial Statements and Exhibits](https://www.quantisnow.com/insight/theseus-pharmaceuticals-inc-filed-sec-form-8-k-completion-of-acquisition-5260889)
- 2024-02-14 15:04 UTC [SEC Schedule 14D-9] [SEC Form SC 14D9/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-14d9a-filed-by-theseus-pharmaceuticals-inc-amendment-5260484)
- 2024-02-14 14:32 UTC [SEC Form 25-NSE filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-25-nse-filed-by-theseus-pharmaceuticals-inc-5260135)
- 2024-02-14 13:30 UTC [Public Offering] [Theseus Pharmaceuticals Announces Closing of Tender Offer](https://www.quantisnow.com/insight/theseus-pharmaceuticals-announces-closing-of-tender-offer-5259671)
- 2024-02-13 17:36 UTC [SEC Schedule 13G] [SEC Form SC 13G/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-13ga-filed-by-theseus-pharmaceuticals-inc-amendment-5253719)
- 2024-02-07 22:21 UTC [SEC Schedule 14D-9] [SEC Form SC 14D9/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-14d9a-filed-by-theseus-pharmaceuticals-inc-amendment-5238498)
- 2024-01-30 13:52 UTC [SEC Schedule 14D-9] [SEC Form SC 14D9/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-14d9a-filed-by-theseus-pharmaceuticals-inc-amendment-5216107)
- 2024-01-30 13:29 UTC [Market Chatter] [Pursuant To Merger Agreement Terms, Concentra Merger Sub II And Theseus Determine Additional Price Per Share Max Of $0.15/Share; Cash Amount Paid In Offer Is $4.05/Share](https://www.quantisnow.com/insight/pursuant-to-merger-agreement-terms-concentra-merger-sub-ii-and-5215988)
- 2024-01-30 13:00 UTC [Concentra Announces Calculation of Additional Price Per Share and Extension of Expiration Date for Tender Offer for Theseus Pharmaceuticals](https://www.quantisnow.com/insight/concentra-announces-calculation-of-additional-price-per-share-and-extension-5215872)
- 2024-01-12 11:02 UTC [SEC Schedule 13D] [SEC Form SC 13D/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-13da-filed-by-theseus-pharmaceuticals-inc-amendment-5184915)
- 2024-01-10 14:47 UTC [SEC Schedule 14D-9] [SEC Form SC 14D9 filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-sc-14d9-filed-by-theseus-pharmaceuticals-inc-5181094)
- 2023-12-28 11:00 UTC [SEC Schedule 13D] [SEC Form SC 13D/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-13da-filed-by-theseus-pharmaceuticals-inc-amendment-5156770)
- 2023-12-27 21:43 UTC [SEC Schedule 13D] [SEC Form SC 13D/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-13da-filed-by-theseus-pharmaceuticals-inc-amendment-5156402)
- 2023-12-22 13:58 UTC [Market Insight] [Small-Cap Cancer Focused Theseus Pharmaceuticals Goes Private For Over $3.90/Share In Cash](https://www.quantisnow.com/insight/small-cap-cancer-focused-theseus-pharmaceuticals-goes-private-for-over-390share-5152483)
- 2023-12-22 11:52 UTC [SEC Form SC14D9C filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-sc14d9c-filed-by-theseus-pharmaceuticals-inc-5152210)
- 2023-12-22 11:36 UTC [SEC Form 8-K] [Theseus Pharmaceuticals Inc. filed SEC Form 8-K: Entry into a Material Definitive Agreement, Termination of a Material Definitive Agreement, Leadership Update, Regulation FD Disclosure, Financial Statements and Exhibits](https://www.quantisnow.com/insight/theseus-pharmaceuticals-inc-filed-sec-form-8-k-entry-into-a-5152198)
- 2023-12-22 11:34 UTC [Market Chatter] [Theseus Pharmaceuticals Enters Into Agreement To Be Acquired By Concentra Biosciences For between $3.90 And $4.05 In Cash Per Share Plus A Contingent Value Right; Acquisition Is Expected To Close In February 2024](https://www.quantisnow.com/insight/theseus-pharmaceuticals-enters-into-agreement-to-be-acquired-by-concentra-5152193)
- 2023-12-22 11:30 UTC [Theseus Pharmaceuticals Enters into Agreement to Be Acquired by Concentra Biosciences for between $3.90 and $4.05 in Cash per Share Plus a Contingent Value Right](https://www.quantisnow.com/insight/theseus-pharmaceuticals-enters-into-agreement-to-be-acquired-by-concentra-5152185)
- 2023-12-04 11:35 UTC [Market Insight] [Theseus Pharmaceuticals Terminated Employment Of Timothy P. Clackson, CEO Effective  Dec 7; CFO Bradford D. Dahms Named President](https://www.quantisnow.com/insight/theseus-pharmaceuticals-terminated-employment-of-timothy-p-clackson-ceo-effective-5114990)
- 2023-12-04 11:30 UTC [SEC Form 8-K] [Theseus Pharmaceuticals Inc. filed SEC Form 8-K: Leadership Update, Financial Statements and Exhibits](https://www.quantisnow.com/insight/theseus-pharmaceuticals-inc-filed-sec-form-8-k-leadership-update-financial-5114982)
- 2023-11-27 11:37 UTC [SEC Form 8-K] [Theseus Pharmaceuticals Inc. filed SEC Form 8-K: Other Events](https://www.quantisnow.com/insight/theseus-pharmaceuticals-inc-filed-sec-form-8-k-other-events-5103223)
- 2023-11-27 11:34 UTC [Market Chatter] [Theseus Pharmaceuticals Confirms Receipt Of Unsolicited Expression Of Interest For Acquisition From Foresite Capital And OrbiMed Advisors](https://www.quantisnow.com/insight/theseus-pharmaceuticals-confirms-receipt-of-unsolicited-expression-of-interest-for-5103217)
- 2023-11-27 11:30 UTC [Theseus Pharmaceuticals Confirms Receipt of Unsolicited Expression of Interest from Foresite Capital, LLC and OrbiMed Advisors LLC and Unsolicited Proposal from Concentra Biosciences LLC](https://www.quantisnow.com/insight/theseus-pharmaceuticals-confirms-receipt-of-unsolicited-expression-of-interest-from-5103209)
- 2023-11-24 21:28 UTC [SEC Schedule 13D] [SEC Form SC 13D/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-13da-filed-by-theseus-pharmaceuticals-inc-amendment-5102877)
- 2023-11-24 21:23 UTC [SEC Schedule 13D] [SEC Form SC 13D/A filed by Theseus Pharmaceuticals Inc. (Amendment)](https://www.quantisnow.com/insight/sec-form-sc-13da-filed-by-theseus-pharmaceuticals-inc-amendment-5102872)
- 2023-11-24 18:49 UTC [SEC Schedule 13D] [SEC Form SC 13D filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-sc-13d-filed-by-theseus-pharmaceuticals-inc-5102699)
- 2023-11-17 21:01 UTC [SEC Form 10-Q] [SEC Form 10-Q filed by Theseus Pharmaceuticals Inc.](https://www.quantisnow.com/insight/sec-form-10-q-filed-by-theseus-pharmaceuticals-inc-5093028)

## More

- Live page with ratings, short volume, options and peers: https://www.quantisnow.com/company/THRX
- Earnings history: https://www.quantisnow.com/earnings/THRX
- Dividend history: https://www.quantisnow.com/dividends/THRX
- Insider transactions: https://www.quantisnow.com/insiders/THRX
- Options chain: https://www.quantisnow.com/options/THRX
- SEC 8-K filings only: https://www.quantisnow.com/company/THRX/8-k
- RSS and alerts for THRX: https://www.quantisnow.com/docs/rss-feeds.md