What Isosceles Pharmaceuticals does

Isosceles Pharmaceuticals is a privately held, clinical-stage immuno-oncology company founded in 2019 in Wilmington, North Carolina, developing synthetic small-molecule immunotherapy adjuvants designed to convert immunologically cold, PD-L1-negative tumors into checkpoint-sensitive and cellular-therapy-sensitive targets. Its lead clinical candidate, IPI201, is a patented synthetic resorcinyl isoprenyl benzene derivative formulated for intravenous administration; the molecule acts through four convergent pathways (cGAS–STING/IRF3 PD-L1 upregulation, A2A/CB2-mediated M1→M2 macrophage repolarization, TNF-α/ROS anti-inflammatory reduction, and GPR18/GPR55/5-HT1A tissue reperfusion) and was advanced into a Phase I first-in-human trial in healthy volunteers in April 2026, with a planned Phase I/II basket trial in PD-1 refractory triple-negative breast cancer. A second asset, IPI301, extends the IPI201 molecule into a dissolving microneedle patch for rapid intradermal delivery into adjacent inflammatory indications, and a CytoImmune collaboration has established a patented dual role for IPI201 in NK cell-based immunotherapy.

The company is pre-revenue and operates a partnership-and-licensing-oriented business model: there are no approved or commercial products, pricing is not publicly disclosed, and forward economics are expected to flow through enterprise partnerships with checkpoint inhibitor manufacturers, cellular immunotherapy developers, and clinical research organizations. Go-to-market is enterprise-field-sales driven, with materials (executive summary, mechanism of action deck, preclinical data package, IP portfolio overview, partnership economics) provided on request to qualified partners and investors via [email protected]. Capital structure is anchored by a $4.996 million Equifund round from October 2022, and the leadership and advisory bench (Caligiuri, Stein, Giuliani, Neuman, Lanier, Mannebach) carries substantial prior pharma experience at Merck, Roche, Incyte, City of Hope, and other large organizations.

Name

Isosceles Pharmaceuticals

Legal name

Isosceles Pharmaceuticals, Inc.

Website

https://isoscelespharma.com

Company type

Private

Founded year

2019

Operating status

Operating

Headcount range

11–50 employees

Short description

Isosceles Pharmaceuticals is a privately held, clinical-stage immuno-oncology company developing IPI201, a patented IV synthetic small-molecule immunotherapy adjuvant designed to convert cold, PD-L1-negative tumors into checkpoint-sensitive targets, currently in a Phase I trial with a planned basket trial in PD-1 refractory triple-negative breast cancer.

Ownership category

akta.pro rank

Product category

Immuno-Oncology Biopharmaceuticals

NAICS

Pharmaceutical Preparation Manufacturing (325412)

SIC

Pharmaceutical Preparations (2834)

akta.pro primary industry

Immunology & Inflammation Pharmaceuticals (HLAIAAAD)

akta.pro secondary industries

Immunology & Autoimmune Specialty Pharmaceuticals (HLAIACAB), Clinical Development (Phase I–III Trial Design & Execution) (HLAIALAE), Therapeutic Vaccines (e.g., Cancer/Chronic Infection) (HLAIAEAG)

Keywords

• Immuno-oncology therapeutics
• Small-molecule immunotherapy
• Checkpoint inhibitor adjuvants
• Clinical-stage biotechnology
• Pharmaceutical drug development

Headquarters

HQ city

Wilmington

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Pre-revenue Clinical Stage: Isosceles is a pre-revenue clinical-stage pharmaceutical company. IPI201 is in Phase I (initiated April 2026) and IPI301 is preclinical. No products are approved or commercially sold. Specific partnership economics, formulation advantages, and IP defensibility are available on request to qualified partners and investors, indicating a forward model centered on licensing/partnering economics rather than direct commercialization.

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels5 records

Core offering

Isosceles Pharmaceuticals develops synthetic small-molecule immunotherapy adjuvants designed to be combined with existing PD-1/PD-L1 checkpoint inhibitors and NK cell-based cellular immunotherapies. The lead candidate IPI201, a patented resorcinyl isoprenyl benzene derivative formulated for IV administration, entered Phase I first-in-human dosing in April 2026 with a planned Phase I/II basket trial targeting PD-1 refractory triple-negative breast cancer. A second pipeline asset, IPI301, extends the same molecule into a dissolving microneedle patch for rapid intradermal delivery in adjacent inflammatory indications.

Product overview

Isosceles Pharmaceuticals operates a two-asset immuno-modulatory platform built around a single small-molecule mechanism rather than a unified software product. The lead clinical asset, IPI201, is a patented IV-formulated synthetic resorcinyl isoprenyl benzene derivative (immunotherapy adjuvant) currently in a Phase I trial (initiated April 2026) with a planned Phase I/II basket trial in PD-1 refractory triple-negative breast cancer; it acts through four convergent pathways (cGAS-STING/IRF3, A2A/CB2 macrophage repolarization, anti-inflammatory TNF-α/ROS reduction, and GPR18/GPR55/5-HT1A hypoxia reversal) to convert cold tumors into checkpoint-sensitive targets. The second asset, IPI301, extends the same IPI201 molecule into a dissolving microneedle patch for rapid intradermal delivery in adjacent inflammatory indications and is currently preclinical. Together IPI201 and IPI301 form Isosceles' adjuvant platform intended to expand, rather than replace, existing checkpoint inhibitors such as Keytruda and Tecentriq and to enhance cellular immunotherapies including NK and CAR-NK approaches.

Differentiator

Problem solved

Functional benefit

Brands

• IPI201: Lead clinical candidate: a patented synthetic resorcinyl isoprenyl benzene derivative formulated for intravenous administration as a small-molecule immunotherapy adjuvant; currently in Phase I clinical studies for PD-1 relapsed or refractory solid tumors.
• IPI301

Products and services

• IPI201 Patented synthetic resorcinyl isoprenyl benzene derivative formulated for intravenous administration as a small-molecule immunotherapy adjuvant. Designed to upregulate PD-L1 via cGAS-STING/IRF3, repolarize tumor-associated macrophages, reduce inflammatory mediators, and improve tissue perfusion, with the goal of converting immunologically cold, PD-L1-negative tumors into checkpoint-sensitive targets in combination with PD-1 inhibitors such as Keytruda. Currently in Phase I clinical studies with a planned Phase I/II basket trial in PD-1 refractory triple-negative breast cancer.
• IPI301 Dissolving microneedle patch that extends the IPI201 molecule into a rapid intradermal delivery platform, positioned for adjacent inflammatory indications requiring fast onset. Currently in preclinical development.

Quantifiable outcome

• 15–30% responder rate to checkpoint inhibitors across most solid tumors (the addressable cold-tumor population)
• +8 more outcomes

Segments5 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Partnerships

Three partnerships are on record, tiered flagship and core.

• CytoImmuneflagshipStrategic or Co-development PartnerIsosceles collaborates with CytoImmune on NK cell-based immunotherapy, generating the foundational NK-cell potentiation data underpinning IPI201's expanded use case. The collaboration produced the patented dual role of IPI201: a 625% increase in generic NK cytolysis and a 50% increase in CAR-NK cytolysis, plus the discovery that IPI201 is the third known molecule (alongside IL-2 and IL-15) sufficient to sustain NK cell survival in vitro.
• Checkpoint Inhibitor Manufacturers (unnamed)coreChannel Partner/ Reseller/ Distributor"We work with checkpoint inhibitor manufacturers, cellular immunotherapy partners, and clinical research organizations to bring IPI201 from the lab into patients." Named combination partners mentioned across the site include atezolizumab (Tecentriq) in preclinical validation and camrelizumab (Phase II NCT05076682) as independent human evidence.
• Oncology-Focused Clinical Partners (unnamed)coreImplementation/ SI/ Consulting PartnerPhase I development is being conducted in collaboration with experienced oncology-focused clinical partners. The Phase I/II basket trial with lead indication in PD-1 refractory TNBC was initiated in April 2026 in Wilmington, NC.

Scale indicators9 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Bolt Biotherapeutics: Clinical-stage immuno-oncology company developing immune-stimulating antibody conjugates (ISACs) designed to convert cold tumors to hot in combination with checkpoint inhibitors. Closely comparable mechanism and target indication (PD-1 refractory solid tumors) to IPI201's IPI201 + anti-PD-1 combination strategy.
• Arcus Biosciences: Clinical-stage immuno-oncology company developing small-molecule combinations with checkpoint inhibitors, including the A2A receptor antagonist AB928 — directly relevant because IPI201 also engages A2A signaling as part of its macrophage repolarization mechanism. Both companies pursue combination strategies to expand checkpoint inhibitor responder populations.
• CytoImmune: Clinical-stage NK cell therapy company and Isosceles' named R&D partner on the IPI201 + NK cell program, including the foundational 625% generic NK cytolysis and 50% CAR-NK cytolysis data. Closest direct peer in the NK/CAR-NK combination space.
• Tempest Therapeutics: Clinical-stage oncology company developing TPST-1495, a dual EP4/COX inhibitor designed to reverse immune exclusion in solid tumors as a combination partner for checkpoint inhibitors. Highly comparable to IPI201's tumor microenvironment reprogramming thesis and target patient population of checkpoint non-responders.

Emerging players

• Nimbus Therapeutics: Clinical-stage company using computational chemistry to develop small-molecule immuno-oncology and metabolic disease therapies. Comparable as a small-molecule platform company advancing targeted oncology assets through early clinical development.
• Werewolf Therapeutics: Clinical-stage immuno-oncology company developing INDUKINE conditionally activated cytokines designed to enhance tumor-selective immune activation in solid tumors. Comparable as a small-molecule/biological approach to expanding the reach of checkpoint and cellular immunotherapies.
• Surface Oncology: Clinical-stage immuno-oncology company developing antibody-based therapies targeting the tumor microenvironment, including IL-27 and CD39 programs. Comparable as a small-cap clinical-stage I/O company pursuing microenvironment-modulating strategies.
• Trishula Therapeutics: Emerging clinical-stage company developing TTX-030, a CD39 antibody, and STING-pathway-targeted therapies for combination with checkpoint inhibitors. Comparable to IPI201's STING-axis engagement and combination-IO positioning in cold tumors.

Broad incumbents

• Merck & Co. (Keytruda): Developer of Keytruda (pembrolizumab), the PD-1 inhibitor explicitly cited as IPI201's primary combination partner. The most important potential large-pharma acquirer or partner for IPI201 if cold-to-hot clinical data read out positively.
• Roche (Tecentriq): Developer of Tecentriq (atezolizumab), the anti-PD-L1 antibody used in IPI201's preclinical combination validation. A natural potential partner given the existing preclinical combination dataset and Roche's leadership in checkpoint inhibitor development.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights6 records

Customer concentration

• LinkedInlinkedin.com/company/isosceles-pharmaceuticals

Revenue estimate

Valuation estimate

Number of profiles

Profiles16 records

Funding overview

Funding rounds1 record

Investors1 record

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 Isosceles Pharmaceuticals