SNV-4818 is an investigational, orally administered, small molecule therapeutic agent currently under development by Synnovation Therapeutics. It is engineered as a pan-mutant-selective Phosphoinositide 3-kinase alpha (PI3Kα) inhibitor, a classification that underscores its targeted mechanism of action against common oncogenic mutations within the PI3Kα enzyme. Specifically, SNV-4818 is designed to address mutations in both the kinase (H1047X) and helical (E545/542X) domains of PI3Kα, while critically sparing the wild-type (non-mutated) form of the enzyme.[1] This selectivity forms the basis of its potential best-in-class profile, aiming to provide an improved therapeutic window by enhancing anti-tumor efficacy and mitigating toxicities—such as stomatitis, hyperglycemia, and rash—that have often limited the clinical utility of first-generation PI3Kα inhibitors.[1]
The rapid progression of SNV-4818 into clinical trials, as Synnovation Therapeutics' second oncology program to reach this stage within approximately three years of the company's establishment, highlights a focused and potentially efficient drug development strategy.[1] This accelerated timeline may be indicative of the company's leveraging of an experienced leadership team, some with prior associations with Incyte, and a robust medicinal chemistry platform.[3] SNV-4818 is currently being evaluated in a Phase I clinical trial (NCT06736704 / SNV4818-101) involving patients with advanced solid tumors that harbor activating PI3Kα mutations. The trial design includes cohorts for SNV-4818 as a monotherapy and in combination with fulvestrant, specifically for patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer.[1] Dosing of the first patient in this study was announced in February 2025, signifying a key milestone in its clinical development pathway.[1] The "best-in-class" positioning of SNV-4818 is not merely a strategic label but is scientifically rooted in its differentiated mechanism of wild-type PI3Kα sparing, which directly addresses the known tolerability challenges of earlier PI3Kα inhibitors. This suggests a clear, targeted approach to improving upon existing therapeutic strategies for PI3Kα-driven malignancies.
SNV-4818 is a novel, investigational small molecule drug.[1] In the context of oncological therapeutics, it is classified as a targeted therapy, more specifically as a Phosphoinositide 3-kinase alpha (PI3Kα) inhibitor.[1] Small molecule inhibitors like SNV-4818 typically offer the advantage of oral bioavailability, facilitating patient administration, and are designed to penetrate cells to modulate intracellular signaling pathways critical for cancer cell growth and survival. The oral administration of SNV-4818 is confirmed in its clinical trial design.[4]
SNV-4818 was discovered and is being developed internally by Synnovation Therapeutics.[1] Launched in January 2024 with a substantial Series A financing of $102 million, led by Third Rock Ventures, Synnovation Therapeutics is a precision medicine company.[3] The company is dedicated to the discovery and development of potentially best-in-class targeted small molecule therapies, leveraging its deep expertise in cancer biology and a world-class medicinal chemistry team.[1] Synnovation's stated mission is to efficiently advance these novel agents into clinical trials, aiming to transform patient care through precision medicine.[1] The leadership team includes seasoned professionals, with CEO Wenqing Yao having a significant prior tenure at Incyte.[3] SNV-4818 is the second clinical-stage asset in Synnovation's pipeline; their lead program, SNV1521, a PARP1 selective inhibitor, entered Phase I clinical trials in January 2024.[1] The company is headquartered in Wilmington, Delaware.[8]
Synnovation's strategic focus on developing "best-in-class" molecules, such as SNV-4818 and SNV1521, rather than exclusively pursuing "first-in-class" agents, indicates a deliberate approach to drug development.[1] This strategy appears centered on identifying well-validated oncogenic targets and engineering novel chemical entities with optimized pharmacological properties designed to overcome the known limitations (e.g., toxicity, selectivity, CNS penetration) of earlier drugs in those classes. This pragmatic methodology suggests a market-aware and scientifically driven philosophy aimed at delivering tangible improvements in therapeutic outcomes. The significant Series A funding secured by Synnovation, particularly for a company concentrating on enhancing therapies for validated targets, signals robust investor confidence. This confidence is likely rooted in the perceived strength of the company's medicinal chemistry capabilities and the extensive experience of its leadership team, notably their prior contributions to successful drug development programs at Incyte.[3] Such backing suggests a belief in the substantial clinical and commercial value that can be generated by meticulously addressing the shortcomings of previous generations of targeted therapies.
Table 1: SNV-4818 - Key Characteristics
Feature | Description | Reference(s) |
---|---|---|
Drug Name | SNV-4818 | 1 |
Synonyms | None explicitly provided (SNV4818 is the primary identifier) | - |
Developer | Synnovation Therapeutics | 1 |
Drug Class | Small molecule, PI3Kα inhibitor | 1 |
Mechanism of Action | Pan-mutant-selective inhibitor of PI3Kα, sparing wild-type PI3Kα | 1 |
Key Target Mutations | Kinase (H1047X) and helical domain (E545/542X) PI3Kα mutations | 1 |
Route of Administration | Oral | 4 |
Current Development Phase | Phase I Clinical Trial | 1 |
The Phosphoinositide 3-kinase (PI3K) pathway, and specifically its alpha (α) isoform, plays a pivotal role in normal cellular function and is frequently dysregulated in cancer. PI3Kα is a key enzyme in the PI3K/AKT/mTOR signaling cascade, a central regulatory network that governs essential cellular processes such as cell growth, proliferation, survival, differentiation, and metabolism. Activating mutations in the PIK3CA gene, which encodes the p110α catalytic subunit of PI3Kα, are among the most common oncogenic alterations found in human cancers. These mutations are particularly prevalent in breast cancer but are also observed across a wide range of other solid tumor types.[1] Such mutations typically lead to constitutive (unregulated) activation of PI3Kα kinase activity, resulting in persistent downstream signaling that promotes uncontrolled cell division, resistance to apoptosis, and ultimately, tumor development and progression. This well-established role in driving cancer makes PI3Kα a highly validated and attractive target for therapeutic intervention.
SNV-4818 is characterized as a highly potent, pan-mutant-selective PI3Kα inhibitor.[1] The designation "pan-mutant-selective" implies that the compound is designed to effectively inhibit a broad spectrum of common activating mutations within the PI3Kα enzyme, rather than being limited to a single, specific mutational variant. The fundamental mechanism of action of SNV-4818 involves the direct inhibition of the kinase activity of these aberrantly activated mutant forms of PI3Kα. By binding to and blocking the catalytic function of mutant PI3Kα, SNV-4818 aims to interrupt the oncogenic signaling pathways that are essential for the growth and survival of cancer cells harboring these specific PIK3CA mutations.
A critical aspect of SNV-4818's design is its ability to effectively target key classes of PIK3CA mutations that are clinically prevalent. These include mutations occurring in the kinase domain, most notably at the H1047 hotspot (e.g., H1047R), and mutations within the helical domain, such as those at positions E545 (e.g., E545K) and E542 (e.g., E542K).[1] These distinct classes of mutations, while both leading to pathway activation, can confer different biochemical properties to the enzyme. The ability of SNV-4818 to cover this spectrum of mutations is significant for its potential clinical applicability. Press releases from Synnovation Therapeutics state that SNV-4818 "may effectively cover kinase (H), helical domain (E), and other PI3Kα mutations clinically" and allows for "broad spectrum PI3Kα mutation coverage including targeting both H1047X and E545/542X classes".[1] Other information suggests SNV4818 "can hinder the H1047X mutant and moderate selectivity for E545/542X mutants".[6] This nuanced profile suggests a high degree of potency against H1047X mutations and substantial, clinically relevant activity against the E545/542X class, all while maintaining its crucial wild-type sparing characteristic. The capacity to address such mutational heterogeneity is a key element of its therapeutic strategy.
The defining feature of SNV-4818, and the primary basis for its "best-in-class" potential, is its "excellent selectivity against wild type PI3Kα".[1] This "wild-type-sparing" capability is of paramount importance. First-generation PI3Kα inhibitors often lacked sufficient discrimination between the mutant oncogenic forms of the enzyme and the wild-type PI3Kα that is essential for normal cellular functions in healthy tissues. Consequently, their clinical use was frequently hampered by significant on-target, off-tumor toxicities, including hyperglycemia (due to PI3Kα's role in insulin signaling), rash, and stomatitis.[1] These adverse events often became dose-limiting, preventing the achievement of optimal therapeutic concentrations in the tumor. By selectively targeting the mutant forms of PI3Kα while largely avoiding inhibition of the wild-type enzyme, SNV-4818 is designed to decouple anti-tumor efficacy from these common mechanism-based toxicities. This improved selectivity is anticipated to result in a wider therapeutic index.
The therapeutic rationale for SNV-4818 is built upon its potential to overcome the limitations of earlier PI3Kα inhibitors, primarily through its pan-mutant selectivity coupled with wild-type PI3Kα sparing. The anticipated clinical advantages include:
The development of SNV-4818 reflects a sophisticated understanding of the PI3Kα target, incorporating lessons learned from the clinical experiences with previous agents in this class. This iterative approach to drug design, which focuses on refining selectivity and optimizing pharmacological characteristics for a well-validated oncogenic target, is indicative of an advanced drug discovery program.
Preclinical characterizations consistently describe SNV-4818 as a "highly potent pan-mutant PI3Kα inhibitor" that exhibits "excellent selectivity against wild type PI3Kα".[1] Further details indicate a specific targeting of the H1047X kinase domain mutations, with "moderate selectivity" for the E545/542X helical domain mutants.[6] This profile suggests robust inhibitory activity against the primary oncogenic forms of PI3Kα while minimizing interaction with the non-mutated enzyme, which is crucial for reducing potential on-target, off-tumor toxicities. Although specific quantitative data, such as IC50 values or precise fold-selectivity ratios against different PI3Kα isoforms or mutants versus wild-type, are not provided in the available documentation, the qualitative emphasis on high potency and mutant-selectivity is central to the drug's purported "best-in-class" therapeutic potential. This nuanced selectivity profile implies extensive structure-activity relationship (SAR) studies were undertaken to meticulously fine-tune the molecule's binding affinities, aiming for an optimal therapeutic window that maximizes on-target (mutant) inhibition while minimizing off-target (wild-type) effects. Such precision is a hallmark of advanced medicinal chemistry efforts.
According to information from Synapse by Patsnap, SNV4818 was reported as "currently progressing through IND-enabling studies".[7] This phase of development typically involves a comprehensive suite of in vitro and in vivo pharmacological assessments, pharmacokinetic profiling, toxicology studies, and Chemistry, Manufacturing, and Controls (CMC) development, all necessary to support an Investigational New Drug (IND) application. The successful completion of these IND-enabling studies is a critical regulatory prerequisite for initiating human clinical trials. The subsequent announcements regarding the commencement of the Phase I trial for SNV-4818 in February 2025 confirm that these preclinical hurdles were successfully navigated and regulatory approval to proceed to human testing was obtained.[1] This progression signifies that SNV-4818 met the rigorous preclinical safety and efficacy thresholds required by regulatory authorities, supported by a substantial body of, as yet, undisclosed preclinical data.
A review of the provided documentation did not yield specific preclinical data presentations or peer-reviewed publications detailing the efficacy, pharmacokinetics, or pharmacodynamics of SNV-4818 at major oncology conferences such as the American Association for Cancer Research (AACR), the American Society of Clinical Oncology (ASCO), or the European Society for Medical Oncology (ESMO).[1] Snippet [12], for instance, discusses patient-derived xenografts in a general context at an AACR meeting but makes no mention of SNV-4818 or Synnovation Therapeutics. Therefore, while the company has made claims regarding the drug's designed characteristics and potential, detailed public disclosure of the supporting preclinical results in academic forums was not found within the supplied materials.
The inaugural clinical study for SNV-4818 is a Phase I trial designated SNV4818-101, registered under the ClinicalTrials.gov identifier NCT06736704.[4] This study represents a critical step in evaluating the translation of SNV-4818's promising preclinical profile into a safe and effective therapeutic agent for cancer patients.
Official Title, Phase, and Objectives:
The official title of the study is "SNV4818 in Participants With Advanced Solid Tumors".4 It is a Phase I clinical trial designed with the primary purpose of treatment.1 The core objectives are to evaluate the safety and tolerability of SNV-4818, to determine its pharmacokinetic profile, to assess preliminary anti-tumor efficacy, and to establish the recommended Phase 2 dose (RP2D) and/or the maximum tolerated dose (MTD) when administered as a monotherapy and in combination with fulvestrant.1
Study Design:
The SNV4818-101 trial is structured as an open-label, non-randomized, multicenter study.4 It utilizes a parallel assignment interventional model and incorporates both dose escalation and dose expansion cohorts.4 This design allows for the initial assessment of safety across a range of doses in smaller groups of patients (dose escalation), followed by further evaluation of safety and preliminary efficacy at selected dose levels in larger, more specific patient populations (dose expansion). The trial evaluates SNV-4818 under two distinct regimens: as a monotherapy and in combination with fulvestrant.1
Sponsor:
SNV-4818 was discovered and is being developed by Synnovation Therapeutics, which has issued press releases detailing the initiation of this Phase I trial.1 While Synnovation Therapeutics is the primary entity driving the development of SNV-4818, clinical trial database aggregators such as Veeva 4 and DrugBank 13 list "Pikavation Therapeutics, Inc." as the lead sponsor for NCT06736704. The precise relationship between Synnovation Therapeutics and Pikavation Therapeutics, or the reason for this discrepancy in sponsorship listing, is not clarified within the provided documentation. However, based on direct communications from Synnovation Therapeutics regarding their proprietary asset SNV-4818 and its progression into this specific trial, Synnovation is considered the principal developer and sponsor for the purposes of this report. This discrepancy highlights a point of ambiguity that may warrant clarification from official trial registries or the companies involved, though Synnovation's primary role in the drug's discovery and advancement to clinic is evident from their announcements.
Target Indications:
The trial is designed to enroll patients with advanced or metastatic solid tumors that harbor a documented activating mutation in the PIK3CA gene. This constitutes a tumor-agnostic approach for the monotherapy arms, reflecting the broad presence of PIK3CA mutations across various cancer types.1 In addition, a specific cohort is dedicated to patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer, who will receive SNV-4818 in combination with fulvestrant.1
Key Eligibility Criteria:
The key inclusion and exclusion criteria for the SNV4818-101 trial are summarized in Table 2.
Table 2: Key Eligibility Criteria for NCT06736704 (SNV4818-101)
Category | Criteria | Reference(s) |
---|---|---|
Inclusion Criteria | Age ≥ 18 years | 4 |
Advanced or metastatic solid tumor with a documented activating PIK3CA mutation | 4 | |
Refractory to, or intolerant of, available standard therapies | 4 | |
Measurable disease by RECIST 1.1 criteria or evaluable by clinically relevant tumor biomarkers in blood | 4 | |
Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 | 4 | |
Exclusion Criteria | Diagnosis of a primary CNS malignancy | 4 |
Active brain metastases or carcinomatous meningitis | 4 | |
Type 1 diabetes mellitus or uncontrolled Type 2 diabetes mellitus | 4 | |
Inadequate organ function | 4 | |
Clinically significant ECG abnormalities, including QTcF ≥ 470 ms | 4 |
The inclusion of a tumor-agnostic cohort for PIK3CA-mutated solid tumors alongside a specific HR+/HER2- breast cancer cohort in a Phase I trial represents a contemporary and efficient clinical development strategy. This approach allows for broader signal-seeking in the early phase of development and aligns with the increasing trend of basket trials for molecularly targeted agents, potentially accelerating the identification of responsive tumor types beyond the initial focus. The exclusion of patients with uncontrolled diabetes is a critical safety measure, given that hyperglycemia is a known class effect of PI3Kα inhibitors.[1] Even with SNV-4818's design for wild-type sparing, this precaution is warranted to mitigate potential metabolic disturbances and to more clearly assess the intrinsic metabolic effects of the investigational drug.
SNV-4818:
SNV-4818 is administered orally on a daily basis.4 The dose escalation cohorts will involve administering ascending dose levels of SNV-4818 to small groups of participants to determine safety and tolerability across a dose range. Subsequently, dose expansion cohorts will further evaluate one or more selected dose levels deemed safe and potentially efficacious from the escalation phase.414
Combination Agent: Fulvestrant:
In the combination therapy arms of the trial, SNV-4818 is administered concomitantly with fulvestrant.1 Fulvestrant, an established selective estrogen receptor degrader (SERD), is administered at its standard dose and schedule. This combination is specifically for patients with HR+/HER2- advanced breast cancer.1 The choice of fulvestrant as a combination partner is scientifically rational, as endocrine therapy is a cornerstone of treatment in HR+ breast cancer, and activation of the PI3K pathway is a known mechanism contributing to endocrine resistance. Co-targeting both the estrogen receptor pathway with fulvestrant and the PI3Kα pathway with SNV-4818 is a strategy aimed at potentially overcoming or delaying the development of therapeutic resistance and enhancing anti-tumor activity.
The specific primary and secondary outcome measures with detailed metrics and timeframes are not fully elucidated in the provided snippets, as direct access to the official ClinicalTrials.gov record (NCT06736704) was limited.[15] However, based on standard Phase I oncology trial design and the stated objectives, the following can be inferred:
Primary Outcome Measures:
The primary focus of a Phase I trial is safety and tolerability. Therefore, primary outcome measures are expected to include 1:
Secondary Outcome Measures:
Secondary objectives typically involve preliminary assessments of anti-tumor activity and pharmacokinetics.1 These may include:
Recruitment Status:
The SNV4818-101 trial is actively recruiting participants.4 The first patient was dosed in February 2025.1 The estimated enrollment for the trial is 140 patients.4 One source indicates an estimated study completion date of December 2026.14
Key Clinical Sites and Principal Investigator:
The Phase I trial is being led by Principal Investigator Dr. Timothy Yap, M.D., Ph.D., a Professor of Investigational Cancer Therapeutics at the University of Texas MD Anderson Cancer Center.1 Several other investigational sites are participating in this multicenter study, including 4:
Activating mutations in PIK3CA are prevalent across a variety of solid tumors, with a particularly high incidence in breast cancer. Despite this, patients with such mutations often face limited effective and well-tolerated therapeutic options, especially in advanced or metastatic settings.[1] Existing PI3Kα inhibitors have shown clinical activity, but their utility has been constrained by toxicities associated with the inhibition of wild-type PI3Kα. SNV-4818, with its pan-mutant selectivity and wild-type sparing design, has the potential to address this significant unmet medical need by offering a more targeted approach.[1]
The core therapeutic hypothesis for SNV-4818 centers on its potential to deliver an improved clinical profile compared to first-generation PI3Kα inhibitors. By selectively inhibiting mutant forms of PI3Kα while avoiding significant inhibition of the wild-type enzyme, SNV-4818 is anticipated to cause fewer on-target, off-tumor side effects such as stomatitis, hyperglycemia, and rash.[1] This improved tolerability could translate into a wider therapeutic index, potentially allowing for more consistent and optimal dosing. Such an advantage may lead to greater target inhibition within the tumor, which in turn could result in enhanced anti-tumor efficacy and more durable responses.[1] If SNV-4818 successfully demonstrates a superior therapeutic index in clinical trials, it could not only establish a new standard of care for certain PI3Kα-mutated cancers but also significantly enhance the potential for developing effective and tolerable combination strategies with other targeted agents or chemotherapies, thereby further expanding its clinical utility.
The development of highly selective kinase inhibitors like SNV-4818 exemplifies the ongoing advancement of precision oncology. This paradigm focuses on tailoring medical treatments to the individual characteristics of each patient's disease, particularly by targeting specific molecular alterations, such as PIK3CA mutations, that drive tumor growth.[1] The success of SNV-4818 could further validate this approach and encourage the development of other highly selective inhibitors for various oncogenic targets. The relatively rapid progression of Synnovation Therapeutics from its launch to advancing two distinct "best-in-class" candidates (SNV-4818 and SNV1521) into Phase I trials also reflects the current biopharmaceutical landscape's receptiveness to companies that possess strong scientific rationale and experienced teams, even when their strategy involves improving upon existing, validated targets rather than solely pursuing entirely novel mechanisms.[1]
SNV-4818 is an orally bioavailable, investigational small molecule developed by Synnovation Therapeutics. It is designed as a highly potent and pan-mutant-selective PI3Kα inhibitor, with a key differentiating feature of excellent selectivity against wild-type PI3Kα. This profile aims to provide efficacy against tumors harboring common activating PIK3CA mutations (including H1047X and E545/542X classes) while minimizing the toxicities associated with earlier-generation, less selective PI3Kα inhibitors. SNV-4818 is currently in Phase I clinical development (NCT06736704 / SNV4818-101), being evaluated as a monotherapy in patients with various advanced solid tumors carrying PIK3CA mutations, and in combination with fulvestrant for HR+/HER2- advanced breast cancer.[1]
Although SNV-4818 is in the early stages of clinical evaluation, its development is founded on a strong scientific rationale aimed at addressing the well-documented limitations of previous PI3Kα-targeted therapies. The ongoing Phase I trial will be crucial in establishing its safety, tolerability, pharmacokinetic profile, and preliminary anti-tumor activity in humans. The data generated from this study will be pivotal in determining the future trajectory of SNV-4818, including the selection of optimal doses for subsequent, potentially pivotal, clinical trials. The journey of SNV-4818 will be closely monitored by the oncology community, as its clinical performance will significantly influence the future landscape of therapeutic strategies targeting the critical PI3Kα oncogenic pathway. Successful demonstration of an improved therapeutic index could herald a new generation of PI3Kα inhibitors with broader applicability and better patient outcomes.
Published at: May 19, 2025
This report is continuously updated as new research emerges.