What SiteOne Therapeutics does

SiteOne Therapeutics was a privately-held clinical-stage biotechnology company founded in 2010 and headquartered in South San Francisco, California. The company focused exclusively on developing non-opioid therapeutics for acute, neuropathic, visceral, and musculoskeletal pain through selective inhibition of the NaV1.8 sodium ion channel, a validated target in pain signal transmission. Its lead investigational candidate, STC-004, is a small molecule designed to interrupt pain signaling without engaging opioid receptors, offering a non-addictive alternative to conventional opioid analgesics in a market context shaped by roughly 80,000 US opioid overdose deaths annually and 51.6 million US adults living with chronic pain.

As a pre-commercial entity, SiteOne generated no product revenue. Its operating model relied on equity financings from biotech-focused investors — including Amgen, Mission BioCapital, Novo Holdings, OrbiMed, and Wellington Management — supplemented by up to $15 million in non-dilutive grant funding from the National Institute on Drug Abuse through the NIH HEAL Initiative in May 2023. The company operated with 11-50 employees and advanced STC-004 through clinical development without an independent commercial infrastructure. In May 2025, Eli Lilly and Company acquired SiteOne Therapeutics for up to $1 billion to expand its pain management portfolio beyond its core cardiometabolic franchise, integrating the NaV1.8 program alongside its broader non-opioid pain strategy that was catalyzed by Vertex's FDA approval of Journavx.

Name

SiteOne Therapeutics

Legal name

SiteOne Therapeutics Inc.

Website

https://siteonetherapeutics.com

Company type

Private

Founded year

2010

Operating status

Acquired

Headcount range

11–50 employees

Short description

SiteOne Therapeutics was a clinical-stage biotech developing non-opioid pain therapeutics via selective NaV1.8 ion channel inhibition, with lead candidate STC-004 targeting acute and chronic pain, acquired by Eli Lilly in May 2025 for up to $1 billion.

Ownership category

akta.pro rank

Product category

Non-opioid Pain Therapeutics

akta.pro primary industry

Pain Management & Anesthesiology Pharmaceuticals (HLAIAAAN)

Keywords

• Non-opioid pain therapeutics
• NaV1.8 ion channel inhibitors
• Clinical-stage biotechnology
• Pain management therapeutics
• Selective sodium channel modulators

Headquarters

HQ city

South San Francisco

HQ country

United States

HQ region

North America

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Core offering

SiteOne Therapeutics develops investigational non-opioid pain therapeutics using selective NaV1.8 ion channel inhibition. The company's lead candidate, STC-004, is being advanced as a non-addictive alternative to opioids for the treatment of acute, neuropathic, visceral, and musculoskeletal pain. The platform is built around peripherally restricted NaV1.8 inhibition to deliver pain relief while avoiding central nervous system side effects and opioid-associated addiction and abuse liabilities.

Product overview

SiteOne Therapeutics is a biotechnology company developing non-opioid pain therapeutics. The company's primary product candidates include STC-004 and the NaV1.8 inhibitor, both targeting pain through selective NaV1.8 ion channel inhibition. These investigational treatments aim to provide non-addictive alternatives to opioids for pain management. The company was acquired by Eli Lilly in May 2025 for up to $1 billion.

Differentiator

Problem solved

Functional benefit

Products and services

• STC-004

Quantifiable outcome

• First novel non-opioid pain drug approved in decades (Vertex's Journavx) validates the non-opioid pain market opportunity

Segments1 record

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature1 record

Partnerships

One partnership is on record.

• Eli Lilly and CompanyflagshipStrategic or Co-development Partner · 1 May 2025Eli Lilly acquired SiteOne Therapeutics in May 2025 for up to $1 billion to expand its pain management portfolio with non-addictive chronic pain therapies. The acquisition is part of Lilly's broader strategy to build its non-opioid pain pipeline beyond its core cardiometabolic business, leveraging the commercial success of GLP-1 franchise products.

Scale indicators3 records

Recent moves5 records

Expansion highlights5 records

Direct peers

• Cara Therapeutics: Cara Therapeutics is a clinical-stage biotech developing difelikefalin, a peripheral KOR agonist approved for chronic kidney disease-associated pruritus and explored in pain indications. Cara is a direct peer as a focused pain and pruritus therapeutic developer, addressing similar unmet needs in non-opioid alternatives.
• Trevena Inc. Trevena developed OLINVYK (oliceridine), an FDA-approved opioid for moderate-to-severe acute pain in hospital settings, focused on providing differentiated pain management. Trevena is a direct peer as a pain-focused biopharmaceutical company developing novel pain therapeutics.
• Collegium Pharmaceutical: Collegium Pharmaceutical is a specialty pharmaceutical company focused on responsible pain management, with a portfolio including abuse-deterrent opioids (Xtampza) and non-opioid pain therapies. Collegium is a direct peer as a commercial-stage pain management specialist addressing both opioid and non-opioid pain markets.
• Vertex Pharmaceuticals: Vertex developed and gained FDA approval for Journavx (suzetrigine), the first-in-class selective NaV1.8 inhibitor for moderate-to-severe acute pain. It is the most directly comparable peer to SiteOne, pursuing the identical mechanism of action in pain and establishing the regulatory and commercial benchmark for NaV1.8 selective inhibition.

Emerging players

• Centrexion Therapeutics: Centrexion is a clinical-stage biotech focused on developing non-opioid therapeutics for chronic pain conditions, including CNTX-4971 (capsaicin-based injection) for knee osteoarthritis pain. Centrexion is an emerging player addressing the same non-opioid pain thesis as SiteOne through a distinct delivery mechanism.
• Tonix Pharmaceuticals: Tonix Pharmaceuticals is a clinical-stage company developing CNS-focused therapeutics including TNX-102 SL for chronic pain conditions such as fibromyalgia. Tonix is an emerging player in the non-opioid pain space, addressing overlapping chronic pain indications with SiteOne's programs.

Broad incumbents

• Amgen: Amgen led SiteOne's $15 million Series 2 financing in 2017, signaling strategic interest in SiteOne's NaV1.8 program. As a major biotech with broad inflammation and pain franchises, Amgen is a relevant incumbent peer in non-opioid pain therapeutics development.
• Pfizer: Pfizer has pursued non-opioid pain therapeutics, including the NGF inhibitor tanezumab (co-developed with Eli Lilly) for chronic pain conditions. Pfizer competes in the same non-opioid pain strategic category as SiteOne, although through a different mechanism of action (NGF inhibition versus NaV1.8 inhibition).
• Eli Lilly and Company: Eli Lilly acquired SiteOne in May 2025 for up to $1 billion to expand its non-opioid pain portfolio. As a global top-tier pharmaceutical developer with established commercial infrastructure, Lilly is both the acquirer/parent and a broader incumbent developing pain therapeutics alongside its cardiometabolic franchise.
• Regeneron Pharmaceuticals: Regeneron has been a major developer of NGF inhibitor pain therapies, including fasinumab for chronic pain conditions (osteoarthritis and chronic low back pain). Regeneron competes in the non-opioid pain category through a distinct mechanism (NGF) but addresses the same patient population and prescriber base as SiteOne.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat3 records

Key risks5 records

Key highlights6 records

Customer concentration

Revenue estimate

Valuation estimate

Number of profiles

Profiles6 records

Funding overview

Funding rounds6 records

Investors14 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 SiteOne Therapeutics