What is cAMPfield Therapeutics?

cAMPfield Therapeutics is a clinical-stage biopharmaceutical company focused on developing well-tolerated and highly effective oral medicines for immune-mediated inflammatory diseases, including inflammatory bowel disease (IBD). The company is founded and led by industry veterans with success developing Entyvio®, Humira®, Otezla®, and Zeposia®.

Prifemilast is a potentially best-in-class, once-daily oral PDE4B-selective inhibitor in clinical development for inflammatory bowel disease (IBD). It has been well-tolerated in more than 700 clinical trial participants and has demonstrated robust efficacy in a Phase 3 trial for plaque psoriasis.

How does prifemilast differ from other PDE4 inhibitors?

Prifemilast demonstrates 3-fold greater inhibition of the PDE4B subtype versus PDE4D, making it 5-fold more selective for PDE4B than earlier generations of PDE4 inhibitors. It also shows limited central nervous system penetration and a prolonged absorption profile that produces a slower rise in cAMP, which may improve tolerability relative to earlier PDE4 inhibitors.

Who founded cAMPfield Therapeutics?

cAMPfield Therapeutics was co-founded by Mountainfield Venture Partners together with Mark Stenhouse (former COO of Prometheus Biosciences and VP US Immunology at AbbVie, leading US sales of Humira®), Asit Parikh, MD, PhD (former SVP and Head of GI at Takeda, leading development of Entyvio®), Keith Usiskin, MD (former VP, Head of GI at BMS/Celgene and Sanofi, leading development of Otezla® and Zeposia® for IBD), David Socks, MBA (Chief Operating Officer), and Christian Fougner, MD, PhD (VP, Program Leader).

How much funding has cAMPfield Therapeutics raised?

cAMPfield Therapeutics launched with $180 million in Series A financing, backed by Mountainfield Venture Partners, Frazier Life Sciences, Deep Track Capital, Forbion, Abingworth, Venrock, Longitude Capital, Novo Holdings, and RA Capital.

cAMPfield Therapeutics | Redefining the Treatment of Inflammatory Diseases

Q: What diseases is cAMPfield developing prifemilast for?

cAMPfield is initiating a global Phase 2b study of prifemilast in moderate-to-severe ulcerative colitis and a global Phase 2 study in moderate-to-severe Crohn's disease. Prifemilast is also being developed in plaque psoriasis in Greater China by cAMPfield's partner, Newsoara Biopharma Co., Ltd. (Newsoara).

Q: What is the genetic rationale for targeting PDE4B in IBD?

A 2017 genetic analysis of more than 35,000 individuals found that loss-of-function variants in the ADCY7 gene were associated with approximately a two-fold increased risk of ulcerative colitis (Luo et al., Nature Genetics 2017). ADCY7 encodes an enzyme that generates intracellular cAMP. Because PDE4 inhibition increases cAMP by preventing its breakdown, these findings suggest that enhanced cAMP signaling through PDE4 inhibition may help protect against the inflammatory processes that drive ulcerative colitis.

About us

The architects of today's standard of care

Founders

Executives who played key roles in the development or commercialization of Entyvio®, Humira®, Otezla® and Zeposia®

Mark Stenhouse

Chair, Board of Directors

Board Member — Phathom Pharmaceuticals

Prior experience

COO — Prometheus Biosciences (acquired by Merck for $11B)
VP US Immunology — AbbVie / Abbott
Led US sales and marketing for Humira®

Asit Parikh, MD, PhD

Independent Board Member

CEO — MOMA Therapeutics

Board Member — Phathom Pharmaceuticals

Prior experience

SVP and Head of GI — Takeda
Led development of Entyvio® for IBD
Staff Gastroenterologist — Newton-Wellesley Hospital

Keith Usiskin, MD

Interim Chief Medical Officer

Prior experience

VP, Head of GI — BMS / Celgene, Sanofi
Senior Director, Clinical Lead — Janssen
Led development of Otezla® and Zeposia® for IBD

Mountainfield Venture Partners

Founder

A biopharma company creation firm building transformative companies around in-licensed drug candidates, world-class leadership teams, and syndicated capital raises from top-tier life science institutional investors.

Visit mountainfieldvp.com →

All third-party product names, company names, and logos are trademarks™ or registered® trademarks of their respective holders. Use of them does not imply any affiliation with or endorsement by them.

Leadership team

Significant experience successfully executing global clinical development programs

Bill Gerhart, MBA

Chief Executive Officer

Senior Advisor — Mountainfield Venture Partners

Board Member — Pulmovant

Prior experience

CEO — Kinevant, Respivant, Patara, Elevation, and Mpex Pharma

David Socks, MBA

Chief Operating Officer, Co-founder

Managing Partner — Mountainfield Venture Partners

Prior experience

Venture Partner — Frazier Life Sciences
Co-founder of >15 biopharma companies, including 6 IPOs
4-time CEO, including Phathom Pharmaceuticals

Patricia Turney, MBA

Chief Technical Officer

Prior experience

CTO — Acelyrin
SVP, Operations — Arcutis Biotherapeutics
VP, External Supply — Amgen

John Kempen, MS

SVP, Clinical Development Operations

Prior experience

SVP, Head of Global Clinical Operations — Gossamer Bio
Director, Clinical Operations — Receptos / Celgene and Ardea Biosciences / AstraZeneca
Clinical Operations — Allergan, PPD, ICON

Rita Shah, PharmD

VP, Regulatory Affairs

Prior experience

Sr. Director, Global Regulatory Strategy — Vertex Pharmaceuticals
VP, Global Regulatory Affairs — MBX Biosciences
Regulatory Affairs — AstraZeneca, Johnson & Johnson

Christian Fougner, MD, PhD

VP, Program Leader, Co-founder

Prior experience

VP — Mountainfield Venture Partners
Management Consultant — McKinsey & Company

Rayne Rodgers, MPH

Executive Director, Chief of Staff

Prior experience

Head of Patient Advocacy / Recruitment — Roivant, Kinevant, and miRagen Therapeutics
VP — Muscular Dystrophy Association
Program Manager — Takeda

Board of directors

Mark Stenhouse · ChaircAMPfield

Bill Gerhart, MBAcAMPfield

Aditya Kohli, PhDFrazier Life Sciences

Nanna Lüneborg, PhD, MBAForbion

Rebecca LuseDeep Track Capital

Asit Parikh, MD, PhDIndependent

David Socks, MBAcAMPfield / Mountainfield

Our science

Validated mechanism + validated drug

Mechanism of Action

PDE4 inhibition in inflammatory bowel disease

cAMPfield is advancing prifemilast, a selective, once-daily oral inhibitor of phosphodiesterase 4B (PDE4B) for the treatment of IBD. PDE4 inhibition is a clinically validated mechanism in ulcerative colitis, and prifemilast has demonstrated best-in-class potential across more than 700 participants treated in clinical trials.

PDE4B inhibition mechanism of action in inflammatory bowel disease — adapted with permission from Silvio Danese. In IBD, low cAMP and active PDE4 drive immune infiltrate, pro-inflammatory cytokines, leukocyte recruitment, neutrophil chemotaxis and epithelial barrier disruption. PDE4B inhibition raises cAMP via PKA-CREB / Epac-Rap1, increasing anti-inflammatory cytokines, reducing leukocyte trafficking and neutrophil recruitment, and preserving epithelial barrier integrity — restoring mucosal homeostasis. — Adapted with permission from Silvio Danese.

Three lines of evidence that PDE4 inhibition works in IBD

01 · Mechanism

Inhibiting PDE4 helps restore balance to an overactive immune system by reducing multiple inflammatory signals that are known to drive IBD

Cyclic adenosine monophosphate (cAMP) is a key regulator of immune cell function and helps control inflammatory responses. PDE4 enzymes break down cAMP, reducing its anti-inflammatory effects. PDE4B, a PDE4 isoform predominantly expressed in immune cells, plays an important role in regulating inflammatory signaling. Therefore, selectively inhibiting PDE4B promotes cAMP signaling and helps reduce inflammation.¹

Inhibiting PDE4B in IBD leads to an increase of intracellular cAMP, which in turn leads to:

Reduced production of pro-inflammatory cytokines (e.g., TNFα, IL-23)
Increased production of anti-inflammatory cytokines (e.g., IL-10)
Limited recruitment of immune cells to inflamed gut tissue and epithelial barrier improvement
Suppression of pro-fibrotic pathways

TNF ↓ IL-23 ↓ IL-10 ↑ Mucosal lymphocytes ↓

02 · Human genetics

Supported by human genetic evidence

When humans carry genetic variants that alter the same molecular pathway targeted by a drug, they represent a “natural experiment” that can provide valuable insight into the therapeutic and safety effects of modulating that pathway. In 2017, a genetic analysis of more than 35,000 individuals found that loss-of-function variants in the ADCY7 gene were associated with approximately a two-fold increased risk of ulcerative colitis.²

ADCY7 encodes an enzyme that generates intracellular cAMP, a key signaling molecule that helps regulate immune responses. PDE4 inhibition similarly increases cAMP levels, but by preventing its breakdown. Taken together, these findings suggest that reduced cAMP signaling increases susceptibility to ulcerative colitis, while enhancing cAMP signaling through PDE4 inhibition has the opposite effect and helps protect against the inflammatory processes that drive disease.

03 · Clinical trials

Validated in clinical trials

PDE4 inhibitors have been safe and efficacious in numerous clinical trials, leading to regulatory approvals in multiple immune-mediated inflammatory diseases, including plaque psoriasis, psoriatic arthritis, Behçet's disease, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and progressive pulmonary fibrosis.

Across multiple Phase 2 clinical trials, PDE4 inhibitors have also demonstrated the significant potential to effectively treat ulcerative colitis^3-6; however, none have yet been advanced to Phase 3 trials or approval.

Citations

Fanizzi F, Danese S. Article in press. 2026.
Luo Y, et al. Nat Genet. 2017;49(2):186-192.
Schreiber S, et al. Gastroenterology. 2007;132(1):76-86.
Danese S, et al. Clin Gastroenterol Hepatol. 2020;18(11):2526-2534.e9.
Jones C, et al. Presented at: UEGW. 2025 October 4.
Peyrin-Biroulet L, et al. Presented at: DDW. 2026 May 5.

Prifemilast

A once-daily oral drug, selective for PDE4B, with more than 700 participants exposed

Prifemilast is a once-daily, oral PDE4B-selective inhibitor. Prifemilast has an extensive development history, including a completed Phase 3 trial in plaque psoriasis, supporting its potential to become a best-in-class oral therapy for IBD.

Overcoming the limitations of previous PDE4 inhibitors

While PDE4 inhibitors have been demonstrated effective for treating multiple diseases, their use has historically been limited by undesirable side effects. The side effects associated with previous PDE4 inhibitors are caused by^1-4:

Inhibiting the PDE4D isoform as well as PDE4B
Penetration into the central nervous system
Extremely tight binding affinity and rapid absorption, causing an undesirably rapid increase of intracellular cAMP

Prifemilast more selectively inhibits the PDE4B subtype versus PDE4D. This selectivity is important because PDE4B is highly expressed in inflammatory immune cells and plays a central role in regulating the production of pro-inflammatory cytokines, whereas inhibition of other PDE4 subtypes, particularly PDE4D, has been associated with unwanted adverse effects.

In animal models, prifemilast has shown limited penetration into the brain. Additionally, prifemilast exhibits prolonged absorption, resulting in a slower rise in cAMP levels following dosing. Collectively, the enhanced selectivity, limited central nervous system penetration, and controlled absorption profile engineered into prifemilast are designed to improve tolerability relative to earlier PDE4 inhibitors. This may enable dosing that achieves optimal efficacy without the dose-limiting adverse events historically associated with the class.⁵

Best-in-class results in clinical trials

Prifemilast has an extensive development history, with more than 700 clinical trial participants exposed to date, including more than 250 participants with 52 weeks of exposure. Prifemilast was studied in a Phase 3 trial in plaque psoriasis, an immune-mediated inflammatory disease that shares overlapping pathobiology with IBD, including the IL-23/Th17 axis. The trial results demonstrate greater placebo-adjusted efficacy than has been reported to date for other PDE4 inhibitors. Prifemilast also demonstrated a compelling tolerability profile, with treatment discontinuation rates lower than those observed with placebo. Together, these findings provide clinical evidence that potent modulation of the PDE4/cAMP pathway can translate into meaningful therapeutic benefit in human inflammatory disease, supporting the potential for prifemilast to deliver differentiated efficacy in patients with IBD.⁵

700+ PARTICIPANTS EXPOSED 250+ PARTICIPANTS EXPOSED FOR >52 WEEKS PHASE 3 · PSORIASIS

Citations

Fanizzi F, Danese S. Article in press. 2026.
Spina D. British Journal of Pharmacology. 2008;155(3):308-315.
Schafer PH, et al. Cellular Signalling. 2014;26(9):2016-2029.
Peng T, et al. J Med Chem. 2020;63(19):10594-10617.
Data on file (Newsoara); To-be-published.

Pipeline

Anchored by prifemilast

Our pipeline is anchored by prifemilast (HY1999/HPP737), a once-daily oral PDE4B-selective inhibitor for which we are initiating a global Phase 2b study in moderate-to-severe ulcerative colitis and a global Phase 2 study in moderate-to-severe Crohn's disease. Prifemilast is also being developed in plaque psoriasis in Greater China by cAMPfield's partner, Newsoara Biopharma Co., Ltd. (Newsoara).

Prifemilast

once-daily oral
PDE4B-selective
inhibitor

Indication

Preclinical

Phase 1

Phase 2

Phase 3

Filing

Ulcerative colitis

Global

Phase 2b · initiating

Crohn's disease

Global

Phase 2 · initiating

Plaque psoriasis

Newsoara · Greater China

Phase 3 · completed

News

Latest from cAMPfield

Company news, financing milestones, and clinical program updates. Visit the full newsroom →

June 18, 2026 · Launch

cAMPfield Launches With $180 Million Series A to Advance Prifemilast, a Potential Best-in-Class Oral Therapy for IBD

cAMPfield Therapeutics launched with a $180 million Series A financing to advance prifemilast, a once-daily oral PDE4 inhibitor in-licensed from Newsoara Biopharma, into global Phase 2 trials in moderate-to-severe ulcerative colitis and Crohn's disease. The financing was led by Frazier Life Sciences.

Read the launch announcement →

Contact