Corvus Pharmaceuticals, Inc. (NASDAQ: CRVS), a clinical-stage biopharmaceutical company pioneering interleukin-2-inducible T-cell kinase (ITK) inhibition as a novel immunotherapy platform, announced today positive results from Cohort 4 of its randomized, double-blind, placebo-controlled Phase 1 clinical trial evaluating soquelitinib in patients with moderate to severe atopic dermatitis (AD). The data, confirming and extending findings from earlier cohorts, demonstrated clinically meaningful efficacy with an acceptable safety profile and provide the scientific foundation for advancing soquelitinib into Phase 2 development for this indication in the first quarter of 2026.​

This represents a significant milestone for Corvus’s strategic expansion beyond oncology into inflammatory and autoimmune disease indications, leveraging a differentiated mechanism of action that targets upstream T cell signaling pathways implicated in multiple immune-mediated conditions.

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Cohort 4 Demonstrates Robust Efficacy with Extended Treatment Duration

As of January 15, 2026, enrollment in Cohort 4 was completed, with all 12 patients receiving soquelitinib completing the full 56-day (8-week) treatment regimen. Among 12 patients assigned to placebo, 10 were evaluable at day 56, as two patients experienced disease flares requiring rescue therapy during the treatment period—an outcome not observed in any soquelitinib-treated patient.​

Primary Efficacy Endpoints: At day 56, soquelitinib-treated patients achieved a mean percent reduction in Eczema Area and Severity Index (EASI) score of 72% compared to 40% for placebo patients—a statistically significant and clinically meaningful differential. The kinetics of response demonstrated continuous improvement from day 28 to day 56, with progressive widening of the response curve separation compared to placebo. This temporal response pattern suggests that extended treatment duration beyond four weeks may be necessary to achieve maximal therapeutic benefit with ITK inhibition—a finding that will inform future dosing strategy in Phase 2 development.​

EASI Response Benchmarks: Using standardized dermatology efficacy benchmarks, 75% of soquelitinib-treated patients achieved EASI 75 (≥75% reduction in EASI from baseline), 25% achieved EASI 90 (≥90% reduction), and 33% achieved Investigator’s Global Assessment (IGA) score of 0 or 1 (clear or almost clear skin). By contrast, placebo-treated patients achieved EASI 75, EASI 90, and IGA 0/1 in only 20%, 0%, and 0% of patients, respectively.​

These response rates compare favorably to those observed with approved JAK inhibitors and biologic therapies in moderate to severe atopic dermatitis, particularly considering that 50% of Cohort 4 patients had previously received systemic therapies—a population enriched for treatment-refractory disease.​

Consistency Across All Phase 1 Cohorts: Dose-Response Validation

Corvus conducted a comprehensive dose-escalation Phase 1 program comprising four cohorts evaluating soquelitinib at doses ranging from 50 mg twice daily (Cohort 1) to 200 mg twice daily (Cohorts 3 and 4), with Cohort 4 extending the treatment duration from 28 days to 56 days to assess durability of response.​

Aggregated data across Cohorts 1 through 4 (n=72 total patients, with 35% having received prior systemic therapies) demonstrated dose-dependent efficacy, with the 200 mg twice-daily dose exhibiting optimal balance between efficacy and tolerability. Cohort 3 and Cohort 4—both evaluating the 200 mg twice-daily dose—showed similar efficacy profiles, with Cohort 4 exhibiting higher frequencies of EASI 75 and EASI 90, likely attributable to the extended 56-day treatment duration allowing additional time for therapeutic effect to manifest.​

Importantly, the favorable efficacy profile was observed across a heterogeneous patient population, including individuals with baseline EASI scores reflecting severe disease (mean EASI score of 25.7 in Cohort 4 soquelitinib group vs. 21.9 in placebo group) and prior systemic therapy exposure—population characteristics that typically predict diminished therapeutic response in clinical trials.​

Biomarker Data Support Soquelitinib Novel Mechanism of Action

Corvus measured circulating levels of key inflammatory cytokines to assess the immunological mechanism underlying soquelitinib’s clinical efficacy. Reductions in serum interleukin-4 (IL-4) and interleukin-5 (IL-5)—cytokines centrally implicated in the pathophysiology of atopic dermatitis and type 2 inflammatory responses—were observed in soquelitinib-treated patients across Cohorts 3 and 4.​

IL-4 Suppression: Cohort 4 patients demonstrated the largest reductions in circulating IL-4 levels, with suppression observed both during the 56-day treatment period and extending into the post-treatment observation period through day 86. The magnitude of IL-4 suppression exhibited dose-dependent characteristics, with higher doses producing greater cytokine reduction.​

IL-5 Suppression: Similar patterns were observed for IL-5, with soquelitinib-treated patients in Cohorts 1 through 3 showing reductions in serum IL-5 compared to placebo. Cohort 3 patients (receiving 200 mg twice daily for 28 days) exhibited the largest IL-5 reductions compared to placebo among the shorter-duration cohorts.​

These biomarker findings provide mechanistic validation of soquelitinib’s proposed mode of action: selective ITK inhibition modulates T helper cell differentiation, shifting the balance away from pro-inflammatory Th2 and Th17 phenotypes toward regulatory T cell (Treg) phenotypes, thereby suppressing the production of type 2 inflammatory cytokines (IL-4, IL-5, IL-13) that drive atopic dermatitis pathology.​

Soquelitinib Safety Profile: No Serious Adverse Events Observed

Across all four Phase 1 cohorts, soquelitinib demonstrated a favorable safety and tolerability profile. Notably, no serious adverse events were reported in soquelitinib-treated patients. Treatment-emergent adverse events were predominantly mild to moderate in severity and consistent with the underlying atopic dermatitis disease state rather than drug-related toxicity.​

The absence of significant safety signals is particularly noteworthy given that soquelitinib selectively inhibits ITK—a kinase critical to T cell receptor signaling and T cell development. While ITK knockout mice exhibit reduced numbers of mature thymocytes and altered CD4+:CD8+ ratios, pharmacological ITK inhibition in adult humans appears well-tolerated, likely because mature T cells retain sufficient residual ITK-independent signaling capacity to maintain essential immune surveillance functions.​

Importantly, no opportunistic infections, laboratory abnormalities, or immunosuppression-related complications were observed—a safety profile contrasting favorably with broad-spectrum immunosuppressive therapies and suggesting that selective ITK inhibition provides a more targeted immunomodulatory effect without global immune suppression.

Soquelitinib Mechanism of Action: ITK Inhibition and T Cell Differentiation Reprogramming

Soquelitinib’s therapeutic potential derives from a mechanistically rational approach targeting ITK—a non-receptor tyrosine kinase expressed predominantly in T cells and natural killer cells that plays a pivotal role in integrating T cell receptor (TCR) and cytokine signaling pathways.​

T Cell Receptor Signaling Integration: Following TCR engagement by antigen-presenting cells, ITK becomes activated downstream of lymphocyte-specific protein tyrosine kinase (Lck) and zeta-chain-associated protein kinase 70 (ZAP-70). Activated ITK phosphorylates phospholipase C-γ1 (PLCγ1), triggering calcium mobilization and downstream activation of nuclear factor of activated T cells (NFAT) and nuclear factor kappa B (NF-κB)—transcription factors that drive inflammatory gene expression.​

Th17/Treg Balance Regulation: Recent mechanistic studies have revealed that ITK plays a critical role in determining the balance between pro-inflammatory T helper 17 (Th17) cells and immunosuppressive regulatory T cells (Tregs). ITK deficiency or pharmacological inhibition shifts T cell differentiation toward the Treg phenotype while impairing Th17 differentiation. This shift occurs through multiple mechanisms:​

• Enhanced IL-2 Sensitivity: ITK-deficient T cells exhibit increased sensitivity to interleukin-2 (IL-2) signaling, promoting STAT5 activation and FoxP3 expression—the master transcriptional regulator of Treg cells.​
• Impaired mTOR Activation: ITK inhibition reduces mammalian target of rapamycin (mTOR) pathway activation, suppressing the glycolytic metabolism and c-Myc expression required for Th17 differentiation while permitting the oxidative metabolism favored by Tregs.​
• Suppressed Pro-inflammatory Cytokine Production: By impairing TCR-mediated activation of NFAT and NF-κB, ITK inhibition reduces production of IL-4, IL-5, IL-13, IL-17, and interferon-gamma—cytokines centrally implicated in atopic dermatitis, psoriasis, inflammatory bowel disease, and other immune-mediated conditions.​

This mechanistic framework positions soquelitinib as a fundamentally differentiated therapeutic approach compared to JAK inhibitors—which block cytokine signaling downstream of cytokine receptors—and biologic antibodies—which neutralize individual cytokines or cytokine receptors. By acting upstream at the level of T cell differentiation and activation, ITK inhibition offers the potential for broader immunomodulatory effects across multiple inflammatory pathways.

Clinical Context: Addressing Unmet Need in Treatment-Refractory Atopic Dermatitis

Atopic dermatitis affects approximately 10-20% of children and 1-3% of adults worldwide, with moderate to severe disease affecting an estimated 30-40% of AD patients. The condition imposes substantial burden on quality of life, with intense pruritus (itching), sleep disturbance, psychological distress, and social stigma representing major morbidity drivers.​

The therapeutic landscape for moderate to severe atopic dermatitis has undergone dramatic transformation over the past five years, driven by the approvals of:

• Biologic Therapies: Dupixent (dupilumab, Sanofi/Regeneron)—an IL-4 receptor alpha antagonist—and Adbry (tralokinumab, LEO Pharma)—an IL-13 antagonist
• Oral JAK Inhibitors: Rinvoq (upadacitinib, AbbVie) and Olumiant (baricitinib, Eli Lilly)
• Topical JAK Inhibitors: Opzelura (ruxolitinib, Incyte) and Correctim (delgocitinib, LEO Pharma)​

Despite these advances, significant unmet need persists. Approximately 30-40% of patients treated with biologic therapies fail to achieve adequate disease control, and 15-25% of patients discontinue JAK inhibitors due to incomplete efficacy or tolerability concerns. Additionally, biologics require subcutaneous injection and carry high cost burdens (often exceeding $40,000 annually), while JAK inhibitors face safety concerns including increased infection risk, cardiovascular events, and malignancy warnings mandated by FDA black box labeling.​

Soquelitinib’s differentiated mechanism—targeting upstream T cell signaling rather than downstream cytokine pathways—offers theoretical advantages including broader immunomodulatory effects, potential efficacy in biologic-refractory patients, and a favorable safety profile avoiding the broad immunosuppression associated with pan-JAK inhibition.

Strategic Implications: Dual Indication Development and Platform Potential

Corvus is advancing soquelitinib across two parallel clinical development programs:

Oncology (Peripheral T Cell Lymphoma): A registrational Phase 3 clinical trial (NCT06561048) is evaluating soquelitinib in patients with relapsed or refractory peripheral T-cell lymphoma (PTCL) following up to three prior lines of therapy. Interim Phase 1/1b data demonstrated tumor responses in heavily pretreated PTCL patients, including one complete response, one nodal complete response, and two partial responses among 11 evaluable patients treated at the 200 mg twice-daily dose. The FDA granted Fast Track designation to soquelitinib for this indication in July 2024, and the Phase 3 trial is actively enrolling 150 patients randomized 1:1 to soquelitinib vs. standard-of-care chemotherapy, with progression-free survival as the primary endpoint.​

Inflammatory/Autoimmune Disease (Atopic Dermatitis and Beyond): Based on the positive Phase 1 data, Corvus plans to initiate a Phase 2 trial in Q1 2026 evaluating soquelitinib in patients with moderate to severe atopic dermatitis who have failed at least one prior topical or systemic therapy. The trial design has not been disclosed but is expected to enroll approximately 200 patients and provide proof-of-concept efficacy data to support Phase 3 advancement.​

Beyond atopic dermatitis, Corvus has articulated a broader strategic vision positioning ITK inhibition as a platform technology applicable to multiple T cell-mediated inflammatory and autoimmune diseases, including psoriasis, inflammatory bowel disease (Crohn’s disease and ulcerative colitis), rheumatoid arthritis, and systemic lupus erythematosus. The mechanistic rationale for these indications derives from the central role of dysregulated Th17/Treg balance in their pathophysiology.​

This dual-indication strategy—simultaneously advancing soquelitinib in both oncology and inflammatory disease—reflects growing recognition within the biopharmaceutical industry that immunomodulatory agents often exhibit therapeutic utility across both immune-mediated diseases and cancer immunotherapy.

Atopic Dermatitis Market Opportunity and Competitive Positioning

The global atopic dermatitis therapeutics market was valued at approximately $16.3 billion in 2024 and is projected to reach $36 billion by 2033, reflecting a compound annual growth rate exceeding 9%. The rapid market expansion is driven by increasing disease prevalence, improved diagnostic awareness, expanding treatment adoption beyond topical corticosteroids, and premium pricing for biologic and targeted synthetic therapies.​

Within this landscape, JAK inhibitors represent the fastest-growing segment, with oral JAK inhibitors (Rinvoq, Olumiant) and topical JAK inhibitors (Opzelura) capturing substantial market share since their approvals beginning in 2021-2022. However, the JAK inhibitor class faces ongoing safety scrutiny following FDA-mandated warnings regarding serious cardiovascular events, malignancy, and thrombotic events observed with JAK inhibitors in rheumatoid arthritis populations—warnings that have been extended to the atopic dermatitis indication despite limited evidence of similar risks in AD patients.​

Soquelitinib’s selective ITK inhibition mechanism offers potential differentiation from pan-JAK or dual-JAK inhibitors, which broadly suppress signaling downstream of multiple cytokine receptors and growth factor receptors. The more targeted mechanism may translate to a more favorable safety profile—a hypothesis that will be tested in larger Phase 2/3 trials with extended treatment duration and safety follow-up.

Path Forward: Phase 2 Trial and Regulatory Strategy

Corvus plans to host a conference call and webcast on January 20, 2026, to present the Cohort 4 data in detail and outline the Phase 2 clinical development plan. Key questions to be addressed include:

• Dose Selection: Will the Phase 2 trial evaluate the 200 mg twice-daily dose exclusively, or will multiple doses be tested to optimize efficacy and safety?
• Treatment Duration: Will the Phase 2 trial adopt the extended 56-day (8-week) treatment duration validated in Cohort 4, or explore even longer treatment courses (12-24 weeks) to assess maintenance of response?
• Patient Population: Will enrollment be restricted to biologic- or JAK inhibitor-refractory patients, or will the trial enroll a broader population of systemic therapy-eligible patients?
• Endpoints: Will the primary endpoint be EASI 75 at a specific timepoint (e.g., week 12 or week 16), or will the trial evaluate sustained response through extended follow-up?

If the Phase 2 trial recapitulates the Phase 1 efficacy and safety findings in a larger, controlled population, Corvus could advance soquelitinib into pivotal Phase 3 trials as early as 2027, with potential regulatory submissions in 2028-2029—positioning the agent for commercial launch by 2030.

Conclusion: A Novel Mechanism Addressing Atopic Dermatitis and Beyond

The positive Cohort 4 data from Corvus Pharmaceuticals’ Phase 1 trial of soquelitinib in atopic dermatitis validate ITK inhibition as a therapeutically relevant mechanism for inflammatory skin disease and provide a strong rationale for advancing this first-in-class oral therapy into Phase 2 development. The 72% mean EASI reduction, 75% EASI 75 response rate, and favorable safety profile position soquelitinib as a differentiated therapeutic option with potential applicability across multiple T cell-mediated inflammatory and autoimmune conditions.

As the atopic dermatitis therapeutic landscape continues to evolve with the proliferation of JAK inhibitors and biologics, the demand for mechanistically differentiated agents with favorable benefit-risk profiles remains high. Soquelitinib’s upstream targeting of T cell differentiation pathways—combined with its oral bioavailability and demonstrated efficacy in treatment-experienced patients—positions it as a compelling addition to the expanding armamentarium for moderate to severe atopic dermatitis and potentially a platform technology for broader inflammatory disease applications.