What Halda Therapeutics does

Halda Therapeutics was a clinical-stage biotechnology company founded in 2018 in New Haven, Connecticut, by Yale professor Craig Crews, to develop a new class of precision oncology medicines called RIPTAC (Regulated Induced Proximity Targeting Chimeras). RIPTACs are heterobifunctional small molecules that operate via a novel "hold and kill" mechanism: one end binds a tumor-specific protein while the other binds a protein performing an essential cellular function, and bringing the two together causes loss of an essential cell function, triggering selective cancer cell death. The platform was explicitly designed to bypass the resistance mechanisms that commonly defeat precision oncology drugs that target oncogenic driver proteins. Halda's lead clinical-stage candidate, HLD-0915, is an oral RIPTAC therapeutic for metastatic castration-resistant prostate cancer (mCRPC) targeting androgen receptor (AR) and BRD4; it received FDA Fast Track designation and entered Phase 1/2 clinical trials in February 2025, with first-in-human data reported in October 2025 showing a 59% PSA50 response rate in patients completing at least two cycles and 100% partial response in RECIST-measurable disease (5/5 patients).

The company's pipeline also included a RIPTAC program for hormone receptor-positive metastatic breast cancer in IND-enabling studies, plus discovery-stage candidates for lung and other solid tumors. In August 2025, Halda entered a strategic research collaboration with VantAI valued at over $1 billion in potential total value, leveraging VantAI's Neo-1 foundation model and NeoLink structural proteomics platform to identify novel target-effector pairs for next-generation RIPTAC medicines in oncology and immunology. As a pre-commercial company, Halda generated no product revenue; its business model relied on advancing RIPTAC candidates through clinical development toward future regulatory approval and commercialization, supported by approximately $202 million in total venture funding from Canaan Partners, RA Capital Management, Frazier Life Sciences, Deep Track Capital, Vida Ventures, Boxer Capital, Taiho Ventures, Access Biotechnology, Elm Street Ventures, and Connecticut Innovations. On December 29, 2025, Johnson & Johnson completed its acquisition of Halda for $3.05 billion in cash, ending the company's independent operations.

Name

Halda Therapeutics

Legal name

Halda Therapeutics Inc.

Website

https://haldatx.com

Company type

Private

Founded year

2018

Operating status

Acquired

Headcount range

11–50 employees

Short description

Halda Therapeutics is a clinical-stage biotechnology company developing RIPTAC therapeutics — oral heterobifunctional small molecules using a "hold and kill" mechanism to selectively destroy cancer cells in metastatic castration-resistant prostate cancer and other solid tumors. Acquired by J&J for $3.05 billion.

Ownership category

akta.pro rank

Product category

Precision Oncology Therapeutics

NAICS

Biological Product (except Diagnostic) Manufacturing (325414)

SIC

Pharmaceutical Preparations (2834)

akta.pro primary industry

mRNA Therapeutics (vaccines, protein replacement, immuno-oncology) (HLAAADAA)

akta.pro secondary industries

Oncology Gene Therapies (incl. oncolytic vectors & gene-modified approaches) (HLAAACAF), Gene Therapy CMC/Process Development Platforms (capsid engineering, producer cell lines, plasmids, upstream/downstream) (HLAAACAN)

Keywords

• Precision oncology therapeutics
• Cancer drug discovery
• Bifunctional small molecules
• Protein proximity therapeutics
• Clinical stage biopharmaceutical

Headquarters

HQ city

New Haven

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Technology or R&D, Operations, Marketing or Sales, Infrastructure

Revenue model

1. Drug Development and Commercialization: Pre-commercial clinical stage biotechnology company developing novel RIPTAC therapeutics for cancer treatment. Revenue will be generated through future drug sales upon regulatory approval

Go-to-market motion1 record

Distribution channels1 record

Marketing channels4 records

Core offering

Halda Therapeutics develops RIPTAC (Regulated Induced Proximity Targeting Chimeras) therapeutics, a novel class of heterobifunctional small molecule drugs that use a 'hold and kill' mechanism to selectively kill cancer cells by holding together a tumor-specific protein and a protein with an essential cellular function. The lead clinical-stage candidate HLD-0915 targets metastatic castration-resistant prostate cancer (mCRPC) and has received FDA Fast Track designation; additional programs target hormone receptor positive metastatic breast cancer and other solid tumors.

Product overview

Halda Therapeutics is developing RIPTAC™ (Regulated Induced Proximity Targeting Chimeras) therapeutics, a new class of precision cancer medicines that work by a novel 'hold and kill' mechanism. The company's product portfolio centers on its proprietary RIPTAC platform, which enables the design of bifunctional small molecules that hold together a tumor-specific protein and an essential cellular protein to selectively kill cancer cells. The lead clinical-stage product is HLD-0915 for metastatic castration-resistant prostate cancer (mCRPC), currently in Phase 1/2 clinical trials. Additional pipeline candidates include a Breast Cancer RIPTAC in IND-enabling stage and undisclosed RIPTAC programs for other solid tumors. The company was acquired by Johnson & Johnson in December 2025 for $3.05 billion.

Differentiator

Problem solved

Functional benefit

Products and services

• HLD-0915 First-in-class oral RIPTAC therapeutic for metastatic castration-resistant prostate cancer (mCRPC) that uses a 'hold and kill' mechanism binding androgen receptor (AR) and bromodomain 4 (BRD4) to selectively kill prostate cancer cells; granted FDA Fast Track designation.
• Breast Cancer RIPTAC RIPTAC therapeutic designed to overcome resistance in hormone receptor positive (HR+) metastatic breast cancer; targets selective delivery to breast cancer tumors to drive cancer cell death.
• Additional RIPTAC Pipeline Candidates Additional RIPTAC therapeutic candidates in discovery stage for undisclosed cancer indications, including programs for solid tumors such as lung cancer and other tumor types.

Quantifiable outcome

• 59% PSA50 response rate in patients completing at least 2 cycles of therapy with HLD-0915
• +3 more outcomes

Named customers1 record

Segments2 records

Ideal customer profiles1 record

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

One partnership is on record.

• VantAIcoreTechnology or Integration · 19 August 2025Strategic research collaboration worth over $1 billion in total potential value including upfront and milestone payments. VantAI leverages its Neo-1 foundation model and NeoLink structural proteomics platform to identify novel target-effector pairs for next-generation RIPTAC medicines in oncology and immunology. The partnership combines VantAI's AI-driven rational drug design with Halda's clinically validated RIPTAC modality.

Scale indicators4 records

Recent moves7 records

Expansion highlights5 records

Direct peers

• C4 Therapeutics: C4 Therapeutics develops bifunctional small molecule degraders (TORPEDO platform) for oncology, with clinical-stage assets in multiple myeloma and other cancers. Directly comparable in mechanism and therapeutic area.
• Arvinas: Arvinas develops PROTAC-based targeted protein degraders for cancer, founded by Craig Crews (also Halda's founder). RIPTAC and PROTAC are both heterobifunctional induced-proximity modalities, making Arvinas the most direct technological comparable.
• Kymera Therapeutics: Kymera develops heterobifunctional small molecule degraders (Pegasus platform) for cancer and immunology, with multiple clinical-stage oncology assets. Closely comparable modality and target space to Halda's RIPTAC.
• Monte Rosa Therapeutics: Monte Rosa develops molecular glue degraders (QuEEN discovery engine) for cancer and immunology, with clinical-stage oncology assets. Comparable as a precision oncology small molecule induced-proximity company.
• Foghorn Therapeutics: Foghorn develops precision medicines targeting chromatin regulatory biology in cancer, with clinical-stage oncology assets. Comparable as a clinical-stage precision oncology small molecule platform company.

Emerging players

• Black Diamond Therapeutics: Black Diamond develops precision oncology small molecules targeting allosteric mutant oncogenes. Comparable as a clinical-stage precision oncology company, though focused on different mechanism.
• Revolution Medicines: Revolution Medicines develops precision oncology drugs targeting RAS(ON) inhibitors, with multiple clinical-stage assets. Comparable as a clinical-stage precision oncology company with novel mechanism and strong investor backing.
• Aprea Therapeutics: Aprea develops small molecule anti-cancer therapies targeting DNA damage response. Comparable through the leadership connection (Halda CEO Christian Schade was Aprea President/CEO) and as a clinical-stage oncology company.
• Vor Biopharma: Vor Biopharma is a clinical-stage cell therapy and oncology company. Comparable through the leadership connection (Halda CMO Eyal Attar was previously Vor Bio CMO) and as a clinical-stage oncology platform company.

Others

• Forma Therapeutics: Forma was a clinical-stage small molecule drug discovery company acquired by Novo Nordisk in 2022 for $1.1B. Comparable as a precedent for a venture-backed small molecule platform exit and through CSO Kayser-Bricker's prior leadership role.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/halda-therapeutics
• Xx.com/HaldaThera

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles11 records

Funding overview

Funding rounds4 records

Investors12 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Halda Therapeutics