Faeth Therapeutics: Preliminary response rate is 33%
At the October 30 data cutoff, 16 of 42 treated patients remained on treatment, while six were not efficacy-evaluable.
Sentiment and the balance of points
Rhea-AI Sentiment reads the wording of the document, how positive or negative its language is on a 1 to 5 scale. The balance of points shown with the takes weighs what the document actually discloses, so the two can disagree, for example when a trial that missed its main goal is described in upbeat language.
Rhea-AI Filing Summary
Faeth Therapeutics, Inc. reported preliminary Phase 2 results for PIKTOR (serabelisib and sapanisertib) plus paclitaxel in patients with advanced endometrioid endometrial cancer after platinum and an immune checkpoint inhibitor. Confirmed ORR was 33% (12 of 36) in efficacy-evaluable patients, with a disease control rate of 83%. Among patients with PIK3CA mutations, confirmed ORR was 44% and disease control rate was 81%. Across all 42 treated patients, estimated median PFS was 7.4 months (95% CI: 5.3 months to not reached) and preliminary six-month PFS was 62% (95% CI: 43% to 75%), at the October 30, 2026 data cutoff.
At the October 23, 2026 safety cutoff, 27 of 42 patients (64%) had a grade 3 or higher treatment-related adverse event; 2 of 42 discontinued because of such events, and no drug-related deaths were reported. Treatment-related hyperglycemia occurred in 12% (2% grade 3), and stomatitis in 21% (2% grade 3).
PIK-201 is a single-arm study and does not establish the contribution of each drug or comparative safety or efficacy. Results are preliminary and may change with follow-up, response confirmation and data verification. PIKTOR is investigational and has not been approved by any regulatory authority. Pivotal trial design is expected by 1H 2027, subject to regulatory alignment.
How this balance works
Rhea-AI gives every point it takes from this document a weight. Minor counts 1, Moderate 3 and Major 9, so one Major point outweighs several Minor ones. The bar adds up the weights on each side, and when neither side holds more than 65% of the total the balance reads Mixed.
It reads the document as published, with the same rules for every company, and it does not look at what the market expected or at how the stock traded, so a point can be objectively good on a day the stock falls.
Rhea-AI Sentiment measures something else, the tone of the wording.
Positive
- Moderate pointConfirmed objective response rate: 33% (12 of 36) efficacy-evaluable patients.
Negative
- Moderate pointGrade 3 or higher treatment-related adverse events occurred in 27 of 42 patients (64%).
8-K Event Classification
Key Figures
Key Terms
objective response rate medical
disease control rate medical
progression-free survival medical
efficacy-evaluable patients medical
single-arm study medical
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What efficacy results did FTH report for PIK-201?
When does Faeth expect to disclose the PIK-201 pivotal-trial design?
AI-generated analysis. How Rhea-AI works. Not financial advice.
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM
CURRENT REPORT
Pursuant to Section 13 or 15(d)
of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported):
(Exact Name of Registrant as Specified in its Charter)
| (State or Other Jurisdiction of Incorporation) |
(Commission File Number) |
(IRS Employer Identification No.) |
| (Address of Principal Executive Offices) | (Zip Code) |
Registrant’s telephone number, including area code:
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:
| Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) |
| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) |
| Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) |
| Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) |
Securities registered pursuant to Section 12(b) of the Securities Exchange Act of 1934:
| Title of each class |
Trading symbol |
Name of each exchange on which registered | ||
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).
Emerging growth company
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
| Item 8.01 | Other Events. |
On November 9, 2026, Faeth Therapeutics, Inc. (the “Company”) made available a presentation to be used to discuss, among other things, the topline clinical data from the Company’s Phase 2 PIK-201 trial evaluating PIKTOR in patients with advanced endometrial cancer. A copy of the presentation is attached as Exhibit 99.1 to this Current Report on Form 8-K.
| Item 9.01 | Financial Statements and Exhibits. |
(d) Exhibits
| Exhibit |
Exhibit Description | |
| 99.1 | Faeth Therapeutics, Inc. Corporate Presentation, dated November 9, 2026. | |
| 101.SCH | Inline XBRL Taxonomy Extension Schema Document. | |
| 101.LAB | Inline XBRL Taxonomy Extension Label Linkbase Document. | |
| 101.PRE | Inline XBRL Taxonomy Extension Presentation Linkbase Document. | |
| 104 | The cover page from this Current Report on Form 8-K, formatted in Inline XBRL. | |
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
| Faeth Therapeutics, Inc. | ||||||
| Date: November 9, 2026 | /s/ Christopher W. Gerry | |||||
| Christopher W. Gerry | ||||||
| General Counsel and Secretary | ||||||
FAETH THERAPEUTICS PIKTOR Phase 2 Endometrial Cancer Topline Results NOVEMBER 9, 2026 Exhibit 99.1
This Presentation contains forward-looking statements of Faeth Therapeutics, Inc. (the “Company”) within the meaning of the federal securities laws. Words such as “may,” “will,” “should,” “could,” “believe,” “expect,” “anticipate,” “intend,” “plan,” “estimate,” “potential” and similar terms identify forward-looking statements. These include statements about: the potential benefits of its product candidates and of multi-node inhibition relative to other agents; the design, timing and results of ongoing and planned preclinical and clinical studies, including the data from the Phase 2 trial of PIKTOR in combination with paclitaxel (PIK-201) in advanced endometrial cancer, which may change as scans are confirmed and patients remain on study; its regulatory strategy, including the potential design and timing of any registrational trial and the outcome of interactions with the U.S. Food and Drug Administration; potential development in additional indications and in combination with other agents; the evolution of the treatment landscape and competitive environment, including third-party product candidates; estimated addressable markets and patient populations; and benchmarks the Company considers relevant to its clinical data. These statements reflect management’s current views and are not guarantees of future performance. Actual results could differ materially from those expressed or implied, as a result of risks including: the Company’s ability to obtain additional capital; whether its clinical trials demonstrate acceptable safety and efficacy, and the risk that interim, preliminary or preclinical data will not be predictive of final or clinical results; delays in the commencement, enrollment or completion of clinical trials; the outcome of interactions with regulatory authorities; reliance on third parties to conduct and supply clinical trials; the size of market opportunities, which are estimates based on assumptions that may prove incorrect; competition; changes in law or regulation; and the other risks described under “Risk Factors” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, as amended, its subsequent Quarterly Reports on Form 10-Q and its other filings with the U.S. Securities and Exchange Commission. The Company undertakes no obligation to update forward-looking statements except as required by law. PIKTOR (serabelisib and sapanisertib) is investigational; its safety and efficacy have not been established and it has not been approved by any regulatory authority. The PIK-201 results presented are preliminary and reflect the specified data cutoffs and analysis populations. Results may change with additional follow-up, response confirmation, data verification and analysis. Efficacy-evaluable analyses exclude certain treated patients, as described in this Presentation, and results may differ from analyses of all treated patients. PIK-201 is a single-arm study of PIKTOR in combination with paclitaxel and does not establish the contribution of individual components or comparative safety or efficacy. This Presentation includes information from third-party studies, publications and other sources and the Company’s own estimates. The Company believes these sources are reliable but has not independently verified them. Data from different clinical trials are presented for context only: no head-to-head trials have been conducted, trials differ in design, populations and endpoints, cross-trial comparisons must be interpreted with caution, and no conclusions about comparative safety or efficacy should be drawn. Views expressed by the Company’s non-employee speakers are their own. Trademarks, service marks and trade names of other companies appearing in this Presentation are the property of their respective owners and may appear without the ® or TM symbols; their use is not intended to imply any relationship with, or endorsement by, their owners. IMPORTANT INFORMATION Forward-Looking Statements
Monday, November 9, 2026 INTRODUCTION 1 2 3 4 5 Introduction Anand Parikh, Chair, CEO and Co-Founder PIK-201 Phase 2 data: disease, design, efficacy, and safety Dr. Debbie Chirnomas, Chief Medical Officer Clinical perspective on endometrial cancer David Starks, MD, MPH, Gynecologic Oncologist, Avera Cancer Institute, Sioux Falls, South Dakota; treating physician and Phase 2 principal investigator Closing remarks and next steps Anand Parikh, Chair, CEO and Co-Founder Q&A Questions and Answers Faeth management and Dr. Starks Agenda
1 Potentially first-in-class activity We believe PIKTOR is the first oral multinode PAM inhibitor to show potentially durable activity in endometrial cancer 2 Encouraging preliminary PFS in post-I/O, post-platinum setting Confirmed ORR of 33%1, DCR of 83%, with KM estimated mPFS of 7.4 months Confirmed ORR of 44%, DCR of 81% among patients with PIK3CA mutation 3 Low discontinuation and low PAM-class toxicity Low rates of PAM-related toxicities, including all-grade hyperglycemia (12%, 2% gr. 3) and stomatitis (21%, 2% gr. 3) 4 Pivotal planning underway Pivotal trial design expected by 1H 20272 INTRODUCTION 1Confirmed ORR of 33% (12 of 36 efficacy-evaluable patients) with PIKTOR plus paclitaxel; one additional patient had an unconfirmed partial response and died before a confirmatory scan, leading to an unconfirmed ORR of 36% (13 of 36 efficacy-evaluable patients). 2Subject to regulatory alignment. PAM: PI3K/AKT/mTOR. ORR: objective response rate. DCR: disease control rate. PFS: progression-free survival. mPFS: median PFS. I/O: immunotherapy. KM: Kaplan-Meier. Data cuts: efficacy 10.30.26, safety 10.23.26. PIK-201: Encouraging efficacy with differentiated PAM-class tolerability
Targeting the PI3K/AKT/mTOR pathway to address one of the most frequent genomic drivers in solid tumors1 1 cBioPortal References: Cerami et al., Cancer Discov. 2012, and Gao et al., Sci. Signal, 2013. Source: cBioPortal, TCGA PanCancer Atlas uterine corpus endometrial carcinoma (n=509); split by PIK3CA status calculated by Faeth ~50% of endometrial cancers carry a PIK3CA mutation, but only a small percentage are isolated to PIK3CA alone PIK3CA mutation only PAM Pathway (- PIK3CA) PIK3CA mutation only INTRODUCTION PIKTOR combines PI3Kα and mTORC1/2 selective drugs PAM pathway mutation + PIK3CA mutation PAM Pathway (+ PIK3CA)
TODAY'S DATA PIKTOR - Potential to address several large markets INTRODUCTION Ongoing Development Future Potential Expansion U.S. TAM 2L Endometrioid Endometrial Cancer ~$2.5B ~9,000 pts × ~9.7 cycles U.S. TAM 2L HR+/HER2- Breast Cancer ~$10B ~32,000 pts × ~10 cycles U.S. TAM 1L HR+/HER2- Breast Cancer ~$62B ~93,000 pts × 11-40 cycles U.S. TAM KEAP1/NFE2L2- mutated NSCLC ~$1.5B ~10,000 pts × ~4.9 cycles U.S. TAM Platinum-resistant Ovarian Cancer ~$2.5B ~11,600 pts × ~7.3 cycles U.S. total addressable market (TAM) = estimated U.S. patients per year × number of 28-day cycles × $30,000 per cycle (reported list price of gedatolisib (REVTORPYK); PIKTOR’s price has not been set): 2L endometrioid endometrial cancer: ~9,000 patients a year whose disease progresses after first-line platinum chemotherapy and an immune checkpoint inhibitor, whether or not they receive further treatment (incidence; company estimate: ~12,300 advanced or recurrent × ~95% receiving 1L IO + chemo × ~77% progressing) × ~9.7 cycles (8.9 months, mean time on lenvatinib plus pembrolizumab, KEYNOTE-775), assuming all are treated; 2L HR+/HER2− advanced breast cancer: ~32,000 patients/yr progressing on 1L CDK4/6i + endocrine therapy (incidence; company estimate: ~38,000 starting 1L CDK4/6i + ET × ~85% lifetime progression) × ~10 cycles (~9 months; mean gedatolisib treatment duration 9.0–11.3 months, VIKTORIA-1; Celcuity 10-Q, Nov. 2026). 1L HR+/HER2− advanced breast cancer: ~93,000 1L patients (prevalence; company estimates: endocrine-sensitive ~60,000 + endocrine-resistant ~33,000) × ~22 cycles (weighted average reflecting ~36-month and ~15-month durations of therapy in ETS and ETR). 2L+ KEAP1/NFE2L2-mutated NSCLC: ~10,000 patients/yr (incidence; ~46,000 receiving second-line therapy × ~22% with a KEAP1 or NFE2L2 mutation, TCGA) × ~4.9 cycles (4.5 months, median PFS of docetaxel, CodeBreaK 200); Platinum-resistant ovarian cancer: ~11,600 patients/yr (incidence; company estimate) × ~7.3 cycles (6.7 months, median PFS of bevacizumab plus chemotherapy, AURELIA), assuming all are treated. PIKTOR has not been studied in the three future settings. Sources: ACS Cancer Facts & Figures 2026; SEER; NCI PDQ; Howlader, JNCI 2014; Malmgren, 2018; Pan, NEJM 2017; Parikh, 2024; Finn, NEJM 2016; Hortobagyi, NEJM 2016; Clarke, JCO 2019; Åkesson, Gynecol Oncol 2023; Eskander, NEJM 2023; Mirza, NEJM 2023; Makker, NEJM 2022; EMA Lenvima report, 2021; Celcuity 10-Q, Nov. 2026; Roche epidemiology, 2025; TCGA; Ganti, JAMA Oncol 2021; Gallicchio, JNCI 2022; Chen, Innov Pharm 2025; Richardson, JAMA Oncol 2023; de Langen, Lancet 2023; Pujade-Lauraine, JCO 2014. Estimates describe the size of each treatment setting; they are not forecasts of PIKTOR revenue or market share. PIKTOR is investigational and has not been approved by any regulatory authority.
Arvinas VP, Oncology Clinical Development Gamida Cell VP, Clinical Development Pfizer Medical Director / Medical Strategy Head Yale School of Medicine Assistant Professor, Director of Pediatric Stem Cell Transplant Dr. Debbie Chirnomas, MD MPH Chief Medical Officer CLINICAL Background Dr. Debbie Chirnomas MD, MPH, Faeth Chief Medical Officer
FAETH THERAPEUTICS Clinical NOVEMBER 9, 2026
Metabolic in nature Associated with metabolic syndrome and obesity5 The most common gynecological cancer (~68k new U.S. cases annually)1 Unlike many cancers, both new cases and mortality are increasing2 High unmet need Chemotherapy remains the backbone, with very limited 2L treatment options3 Dominated by PAM-pathway mutations Found in ~85% of tumors with no approved pathway targeting agent for EC4 ACS estimates, 2015 vs. 20252 ACS Cancer Facts and Figures, 2015 and 2025 ↑26% Incidence ↑36% Mortality ~68k New U.S. cases/yr CLINICAL 1American Cancer Society. Key Statistics for Endometrial Cancer, rev. Jan 14, 2026; Cancer Facts & Figures 2026, Table 1 (68,270 uterine corpus cases estimated for 2026, including uterine sarcomas). 2American Cancer Society. Cancer Facts & Figures 2015, p. 4, and 2025, Table 1 (54,870 to 69,120 estimated new cases; 10,170 to 13,860 estimated deaths). Projected counts reflect population growth and aging. 3Oaknin A, et al. Ann Oncol. 2022;33(9):860-877. 4Cancer Genome Atlas Research Network. Nature. 2013;497(7447):67-73. 5 Lauby-Secretan B, et al. N Engl J Med. 2016;375(8):794-798; Esposito K, et al. Endocrine. 2014;45(1):28-36. Endometrial Cancer (EC) is a rising and underserved indication
Estrogen driven — unopposed estrogen from obesity, anovulation, PCOS, and other causes ER/PR high PAM alterations in >90% of cases Endometrioid ~80% of cases1 | hormone-dependent Less estrogen-driven: arises in atrophic endometrium, older patients, less strongly linked to obesity ER/PR low or absent PAM alterations less common (PIK3CA mutated in ~40% of serous). TP53 mutated ~90%. HER2 amplified ~25–30% of serous. Non-endometrioid (serous, clear cell, undifferentiated) ~10-20% of cases2 | largely hormone-independent CLINICAL Endometrioid endometrial cancers are driven by the overlap in estrogen and PAM signaling Sources: Mahdy H et al., Endometrial Cancer, StatPearls 2024; Zhang L et al., Cancers (Basel) 2020;12:686; NCI PDQ® Endometrial Cancer Treatment (Health Professional Version); Bokhman JV, Gynecol Oncol 1983;15:10–17; Barry JA et al., Hum Reprod Update 2014;20:748–58; Setiawan VW et al., J Clin Oncol 2013;31:2607–18; Cheung LWT et al., Cancer Discov 2011;1:170–85; Cancer Genome Atlas Research Network, Nature 2013;497:67–73; Fader AN et al., J Clin Oncol 2018;36:2044–51. Endometrioid / non-endometrioid shares reflect Type I / Type II classification. TP53, HER2 and PIK3CA figures for non-endometrioid refer to serous carcinomas. PAM: PI3K/AKT/mTOR. ¹ Zhang L et al., Cancers (Basel) 2020;12:686. ² Setiawan VW et al., J Clin Oncol 2013;31:2607–18.
Selected options for advanced endometrial cancer after 1L report median PFS of 3.8 to 7.3 months PIK-201 population: second line or later, post immune checkpoint inhibitor and platinum Median PFS for the options shown, from separate trials with different populations and eras; other options (e.g., trastuzumab deruxtecan in HER2-expressing disease) are not shown. Cross-trial comparison; no head-to-head trials, and patient populations and study designs differ. PIK-201 eligibility: endometrioid endometrial cancer, second line or later, post immune checkpoint inhibitor and platinum, with a PI3K/AKT/mTOR pathway mutation. Sources: first line, Faeth company materials, October 2026; TroFuse-005 control arm, patients assigned paclitaxel (n=119; Lorusso et al., Lancet 2026, supplement Table S15); KEYNOTE-775 final analysis, all-comers; patients had not received prior anti-PD-1 therapy. Makker V, et al. J Clin Oncol. 2023;41(16):2904-2910; Lorusso et al., Lancet 2026 (TroFuse-005; PFS by BICR). aEC: advanced endometrial cancer. 1L: first-line therapy. PFS: progression-free survival. ADC: antibody-drug conjugate. *investigational agent. Paclitaxel ORR 17% median PFS, mo 3.8 TroFuse-005 Phase 3; ESMO 2026 LBA011 Pembrolizumab plus lenvatinib ORR 34% median PFS, mo 7.3 KEYNOTE-775, Phase 3 Sacituzumab tirumotecan* ORR 35% median PFS, mo 7.2 TROP2 ADC; TroFuse-005, Phase 3 Reported outcomes after prior therapy Immunotherapy plus chemotherapy Pembrolizumab plus lenvatinib (pMMR); single-agent chemotherapy (paclitaxel or doxorubicin); trastuzumab deruxtecan (HER2 IHC 3+) No preferred regimen FIRST LINE THIRD LINE AND LATER SECOND LINE CLINICAL
Eligibility Criteria Endometrioid endometrial cancer Second line or later Post immune checkpoint inhibitor and platinum Must have a PI3K/AKT/mTOR pathway mutation Study is being conducted in partnership with: ORR: objective response rate. PFS: progression-free survival. CBR: clinical benefit rate. DOR: duration of response. OS: overall survival. PK: pharmacokinetics. Source: Faeth company materials, September 2026; ClinicalTrials.gov NCT06463028 GOG-3111. Single arm Sapanisertib 3 mg Serabelisib 200 mg Paclitaxel 80 mg/m2 Optional sub-study: diet to suppress glucose and insulin Endpoints Primary ORR Exploratory PK, efficacy by specific mutations Secondary PFS, CBR, DOR, OS, safety/tolerability CLINICAL GOG-3111/FTH-PIK-201 is a single-arm Phase 2 study of PIKTOR plus paclitaxel in pathway-altered endometrioid endometrial cancer
Characteristic Overall (N=42) Median Prior Lines of Therapy 2 (range 1-4) 1 2 3 4 9 (21%) 18 (43%) 10 (24%) 5 (12%) Prior Taxane Prior IO Prior ADC 42 (100%) 41 (98%) 4 (10%) Distant metastases 32 (76%) including peritoneal spread Lung mets Liver mets 38 (90%) 15 (36%) 10 (24%) *Diabetes determination based on reported medical history, concomitant medication at baseline, and/or baseline HbA1c of 6.5% or higher. **Pre-diabetes determination based on baseline HbA1c of 5.6% to less than 6.5%. ECOG: Eastern Cooperative Oncology Group. BMI: body mass index. 10.23.26 data cut. Characteristic Overall (N=42) Median age 64.5 years (range 34 to 86) Sex 42 (100%) (F) ECOG performance status 0 (55%), 1 (45%) Race 34 (81%) White, 3 (7%) Black, 1 (2%) Asian, 4 (10%) multiracial / not reported Median BMI (kg/m2) 29 (range 19 to 47) Diabetes* 10 (24%) Pre-diabetes** 10 (24%) CLINICAL Baseline demographics of GOG-3111/FTH-PIK-201 reflect heavily pretreated and comorbid patient population
PIKTOR + Paclitaxel achieved confirmed ORR of 33% (12/36) in efficacy-evaluable patients Best percent change in target lesion sum from baseline, by patient (N=36) EFFICACY The data cut includes 42 treated patients, of whom 36 were efficacy-evaluable. The other six stopped study treatment before their first response scan: three because of rapid disease progression, and three for reasons other than a treatment-related adverse event. *Best overall response of PD due to a new lesion, despite a 50% reduction in target lesions. Objective responses among efficacy-evaluable patients. Bars show each patient's best change in target lesions, including post-treatment scans. CBR-16 (clinical benefit rate at 16 weeks): confirmed complete or partial response, or stable disease lasting at least 16 weeks from first dose. CBR-24: confirmed complete or partial response, or stable disease lasting at least 24 weeks from first dose. DCR: disease control rate, defined as patients who have SD, PR, or CR as a best response. 10.30.26 data cut.
Response by PIK3CA status EFFICACY *Best overall response of PD due to a new lesion, despite a 50% reduction in target lesions. 10.30.26 data cut. On treatment
PIKTOR + Paclitaxel showed potentially durable and clinically meaningful activity As of the 10.30.26 data cut. Green arrows denote a patient still on study treatment. Non-evaluable patients are denoted in purple. The data cut includes 42 treated patients, of whom 36 were efficacy-evaluable. The other six stopped study treatment before their first response scan: three because of rapid disease progression, and three for reasons other than a treatment-related adverse event. TP53 NR: not reported. *Best overall response of PD due to a new lesion, despite a 50% reduction in target lesions Duration of treatment and time to first response in individual patients (N=42) EFFICACY 6 patients were not efficacy evaluable 3 had rapidly progressive disease · 3 non-AE reasons (distance/logistics; unrelated toe amputation; consent withdrawal)
Efficacy-evaluable population. 36 patients with post-baseline measurement. Colored by confirmed best overall response. Each line is one patient; values capped at +/-100%. Dashed lines mark the +20% (progression) and -30% (partial response) thresholds. 10.30.26 data cut. *Best overall response of PD due to a new lesion, despite a 50% reduction in target lesions EFFICACY Tumor shrinkage observed with PIKTOR + Paclitaxel Change in target lesion size over time (N=36)
Preliminary PFS of 7.4 mo and preliminary PFS6 of 62% in all 42 treated patients (safety population) EFFICACY All 42 treated patients (safety population), of whom 36 were in the efficacy population. The other six stopped study treatment before their first response scan: three because of rapid disease progression, and three for reasons other than a treatment-related adverse event. 10.30.26 data cut. Tick marks indicate censored patients. 18 of 42 patients had a PFS event and 24 were censored: 15 on treatment without progression, 5 at the last scan before subsequent therapy, 4 off treatment without a PFS event. Numbers at risk shown under the x-axis. 1Lorusso D, et al. Lancet 2026 (TroFuse-005), Figure 2A. NR: not reached. PFS: progression-free survival. PFS6: progression-free survival at 6 months. Cross-trial comparison; no head-to-head trials have been conducted. 62% Preliminary progression-free survival at 6 months (95% CI 43, 75) 7.4 Preliminary median PFS (95% CI 5.3, NR) 16 patients remain on treatment 16 of 42 patients remain on treatment at the data cut. 51% vs. Sac-TMT PFS61 8.5 Preliminary median PFS (95% CI 5.4, NR) in efficacy population
Exploratory analysis shows decrease in ctDNA tumor fraction after 1 treatment cycle in 13 of 17 efficacy-evaluable patients n=17 patients with paired baseline and C2D1 samples with ctDNA results reported at time of 10.30.26 data cut. Increases above 100% are shown at 100% (actual +1,539%, +300% and +187%). EFFICACY 13 of 17 patients' ctDNA tumor fraction decreased by cycle 2 day 1 12 decreased by ≥50%
TRAEs in more than 20% of patients (safety population) Other TRAE PIK-201 summary of treatment-related adverse events (TRAEs) SAFETY Chart shows TRAEs in more than 20% of patients (N=42), related to any study drug (serabelisib, sapanisertib or paclitaxel); hyperglycemia shown as a select event. Overall, 27 of 42 patients (64%) had a grade 3 or higher TRAE. Grading by CTCAE V5.0. ALT: alanine aminotransferase. AST: aspartate aminotransferase. Neutropenia represents a grouped term (neutropenia and neutrophil count decreased); rash represents a grouped term (rash and rash maculo-papular). 10.23.26 data cut. 26% neutropenia, the most frequent grade 3 or higher TRAE 7%/7% ALT (Gr.1+2/Gr.3+) 2%/7% AST (Gr.1+2/Gr.3+) elevations attributed to PIKTOR alone 67% Nausea 29% 33% 5% 57% Fatigue 19% 19% 19% 45% Diarrhea 26% 19% 43% Vomiting 31% 12% 31% Constipation 26% 5% 31% Rash 10% 10% 12% 29% AST increased 7% 5% 17% 26% Decreased appetite 14% 12% 24% Alopecia 17% 7% 36% Neutropenia 10% 26% 31% ALT increased 12% 19% Grade 3+ Grade 2 Grade 1 21% Anemia 14% 5% 2% 21% Stomatitis 14% 5% 2% 12% Hyperglycemia 5% 5% 2% Patients (%) Adverse events 2 of 42 patients discontinued due to TRAEs: headache, dizziness No drug-related deaths
All grade % (G3+ %)* PIKTOR with paclitaxel PIK-201 · n=42 Treatment-related Endometrial Breast Cancer Len-Pembro KEYNOTE-775 · n=342 US label Sac-TMT TroFuse-005 · n=384 Treatment-related Capivasertib with fulvestrant CAPItello-291 · n=155 US label Zovegalisib with fulvestrant ReDiscover · n=60a Treatment-related Gedatolisib with fulvestrant VIKTORIA-1 · n=260b US label PAM-related Hyperglycemia 12% (2%) NRc <10%d 19% (2%)e 43% (8%) 10% (2%)f Rash 31% (12%) 20% (2%) <10%d 56% (15%)g 8% (2%) 35% (6%) Stomatitis 21% (2%)h 35% (3%) 55% (10%)h 25% (2%) 8% (0%) 63% (16%)f h Other AEs Nausea 67% (5%) 49% (3%) 36% (1%) 35% (1%) 52% (2%) 47% (2%) Vomiting 43% (0%) 37% (2%) 18% (1%) 21% (2%) 23% (0%) 29% (1%) Diarrhea 45% (0%) 55% (8%) 17% (2%) 77% (12%) 57% (3%) 23% (2%) ALT increased 31% (19%) 55% (9%)i <10%d 23% (3%)i <15%d 30% (2%)i Discontinued for an AE (%)j 5% 26% 3% 10% 7% 10% PIKTOR + Paclitaxel safety profile against relevant comparators SAFETY * Treatment-related: events investigators linked to treatment (for PIKTOR, any study drug, including paclitaxel). US label: events in the US prescribing information (PI), related or not. a400 mg twice daily with food. bPIK3CA wild-type; label’s two arms, with and without palbociclib, combined. cLabel lists hyperglycemia only as a lab value. dNot listed; the source shows only events in at least 10% (TroFuse-005) or 15% (ReDiscover) of patients. e2023 label; newer labels list it only as a lab value. fTreatment-related rate from Hurvitz, J Clin Oncol 2026, shown for comparability with PIKTOR (for hyperglycemia, the label lists it only as a lab value). gLabel’s combined row for skin reactions. hSteroid mouthwash to prevent stomatitis: recommended in TroFuse-005 (64% used one), required in VIKTORIA-1, not required in PIK-201. iLab test results, which usually run higher than reported AEs. j Patients who stopped the drug because of an AE: treatment-related for PIKTOR, Sac-TMT and zovegalisib; related or not for the US label columns. Sources: PIK-201 (ongoing), 10.23.26 data cut; LENVIMA and KEYTRUDA PIs (rev. 10/2026); Lorusso et al., Lancet 2026 (TroFuse-005); TRUQAP PI (rev. 9/2026); Varkaris et al., ESMO TAT 2026 (ReDiscover, data as of 1/13/26); REVTORPYK PI (rev. 07/2026). Data are derived from different clinical trials at different points in time. No head-to-head trials of PIKTOR and any other drug have been conducted. As a result, cross-trial comparisons cannot be made.
Hyperglycemia TRAEs occurred in 12% of patients despite 48% of patients having diabetes or prediabetes at baseline Hyperglycemia (% of patients), by agent Grade 1-2 Grade 3-4 Inavolisib n=20, HbA1c <7% 55% 15% 70% Alpelisib n=152, HbA1c ≤6.4% 43% 14% 58% Zovegalisib n=60, HbA1c <7% or FPG <140 35% 8% 43% STX-478 n=46, HbA1c <8% 37% 39% Gedatolisib n=260, HbA1c ≤6.4% 8% 10% Baseline glycemic status, PIK-201 (N=42) 48% diabetes or prediabetes Diabetes 10 (23.8%) Prediabetes 10 (23.8%) Neither 22 (52.4%) Data are derived from different clinical trials at different points in time. No head-to-head trials of PIKTOR and any other drug have been conducted. As a result, cross-trial comparisons cannot be made. Treatment-related adverse events, except STX-478 (all causes). HbA1c (hemoglobin A1c) under each drug is that trial's entry limit. PIKTOR: PIK-201, 10.23.26 data cut. Inavolisib: GO39374, inavolisib + palbociclib + fulvestrant arm (Jhaveri, J Clin Oncol 2024). Alpelisib: VIKTORIA-1 Study 2 (Hurvitz, ASCO 2026). Zovegalisib: 400 mg fed cohort (Varkaris, ESMO TAT 2026). STX-478 (tersolisib): PIKALO-1, tersolisib + fulvestrant arm, n=46 (Jhaveri, ASCO 2026). Gedatolisib: VIKTORIA-1 Study 1, two arms pooled (Hurvitz, J Clin Oncol 2026). Diabetes: medical history, diabetes medication or baseline HbA1c ≥6.5%. Prediabetes: baseline HbA1c 5.6% to <6.5%. FPG: fasting plasma glucose. Percentages may not sum due to rounding. PIKTOR n=42, HbA1c ≤8% 10% 12% SAFETY 2% 2% 2%
Gr. 3 stomatitis TRAEs occurred in 2% of patients, despite no prophylaxis Stomatitis (% of patients), by agent Grade 1-2 Grade 3-4 Alpelisib n=152 34% Zovegalisib n=60 8% Gedatolisib n=260 47% 16% 63% Data are derived from different clinical trials at different points in time. No head-to-head trials of PIKTOR and any other drug have been conducted. As a result, cross-trial comparisons cannot be made. Treatment-related adverse events, except STX-478 (all causes). Stomatitis includes grouped terms (e.g., mucosal inflammation, mouth ulceration) where so reported. Comparators are in HR+/HER2- advanced breast cancer except sac-TMT and its chemotherapy control arm (endometrial cancer). PIKTOR: PIK-201, 10.23.26 data cut. Inavolisib: GO39374, inavolisib + palbociclib + fulvestrant arm (Jhaveri, J Clin Oncol 2024). Alpelisib: VIKTORIA-1 Study 2, alpelisib + fulvestrant arm (Hurvitz, ASCO 2026). Zovegalisib: ReDiscover, 400 mg BID fed cohort (Varkaris, ESMO TAT 2026). STX-478 (tersolisib): PIKALO-1, tersolisib + fulvestrant arm, n=46 (Jhaveri, ASCO 2026). Gedatolisib: VIKTORIA-1 Study 1, two arms pooled (Hurvitz, J Clin Oncol 2026). Sac-TMT: TroFuse-005 (Lorusso, Lancet 2026). Percentages may not sum due to rounding. ¹Prophylaxis: required in VIKTORIA-1 (gedatolisib arms); in TroFuse-005, called for by the protocol from the start, with steroid mouthwash highly recommended and centrally supplied for routine use from a September 2024 amendment (64% of sac-TMT patients used one); not required in PIK-201. PIKTOR n=42 19% 21% SAFETY Sac-TMT n=384 45% 10% 55% 8% Inavolisib n=20 90% 80% 10% 29% STX-478 n=46 7% 7% No prophylaxis1 Prophylaxis1 14% all grade Chemo alone (TroFuse-005 control arm): 5% 2% Prophylaxis1 2% grade 3+
PIKTOR ORR (%) mPFS (months) CONCLUSION Preliminary ORR/PFS above salvage chemotherapy performance in a heavily pre-treated population Data are derived from different clinical trials at different points in time. No head-to-head trials of PIKTOR and any other drug have been conducted. As a result, cross-trial comparisons cannot be made. PIK-201 is a single-arm study, which is not directly comparable to PFS in randomized trials. PIKTOR values: Confirmed ORR 12 of 36 efficacy-evaluable patients, 33.3%, 10.30.26 data cut, estimated mPFS 7.4 mo. 1TroFuse-005 paclitaxel values are from Lorusso D, et al. Lancet 2026, Supplementary Appendix Table S15. They cover all patients assigned weekly paclitaxel as the physician's-choice control (n=119). This population includes all endometrial cancer histologies and is not limited to endometrioid. Patients were not randomized between paclitaxel and doxorubicin. Confirmed ORR is 17% (20/117; response-evaluable population). mPFS is 3.8 mo. 2Han SN, et al. Gynecol Oncol 2023;178:110–118 (NCT02725268), weekly paclitaxel 80 mg/m² monotherapy arm, endometrioid histology only. Confirmed ORR is 16.4% (9/55; patients who received ≥1 dose; Table 3). mPFS is 3.3 mo (all randomized endometrioid patients, n=57). Not a pooled analysis. One axis scaled so that 100% = 10 months
Preliminary ORR/PFS in line with investigational ADC therapies and prior PAM + chemotherapy data Confirmed ORR. Estimated mPFS. PIKTOR: PIK-201 topline, data cut 10.30.26. Sac-TMT: 4 mg/kg cohort, China Phase 1/2 study KL264-01 (Kelun-Biotech, CCHIO 2025; data cut 5.21.25). Puxi-Sam: 2.4 mg/kg, B7-H4-expressing endometrial cohort (ASCO 2026). Rina-S: 100 mg/m² Q3W, cohort B2 (ASCO 2025); mPFS not reported (N/A). Gedatolisib: Colombo et al., Clin Cancer Res 2021;27(18):5012–19; Phase 1 gedatolisib + carboplatin AUC5 + paclitaxel 80 mg/m², endometrial subgroup (n=4); investigator-assessed best overall response per RECIST 1.1, unconfirmed; endometrial mPFS not reported (N/A). Data are derived from different clinical trials at different points in time. No head-to-head trials of PIKTOR and any other drug have been conducted. As a result, cross-trial comparisons cannot be made. One axis scaled so that 100% = 10 months. ADC: antibody-drug conjugate. PIKTOR CONCLUSION ORR (%) mPFS (months)
Data are maturing: 16 of 42 patients remain on treatment; median duration of response not reached. ORR: objective response rate. DCR: disease control rate. PFS: progression-free survival. CI: confidence interval. NR: not reached. ADC: antibody-drug conjugate. TOPO1: topoisomerase 1. Cross-trial comparisons; no head-to-head trials. Data cuts: efficacy 10.30.26, safety 10.23.26. Efficacy Confirmed ORR 33% (12 of 36), DCR of 83% Confirmed ORR 44%, DCR of 81% among patients with PIK3CA mutation Median PFS 7.4 months, preliminary (95% CI 5.3, NR) Preliminary 6-month PFS 62% (95% CI 43, 75) Safety 2 of 42 (5%) discontinued for treatment-related adverse events Hyperglycemia 12% (2% grade 3) (treatment-related); 48% diabetic or prediabetic at baseline Stomatitis 21% (2% grade 3) (treatment-related), steroid mouthwash not required Differentiation Oral, intermittent; no approved PI3K-pathway agent in endometrial cancer Responses in PIK3CA mutant and wild-type tumors ORR and PFS in the range of ADCs, without a TOPO1 payload (cross-trial) CONCLUSION PIKTOR plus paclitaxel: 33% confirmed ORR and 7.4-month preliminary median PFS after platinum and immunotherapy
FAETH THERAPEUTICS Q&A with PIK-201 Principal Investigator Dr. Starks NOVEMBER 9, 2026
Dr. David Starks MD, MPH Starks et al., Gynecologic Oncology 2022 Lead author, Phase 1 dose escalation study of sapanisertib, serabelisib, and paclitaxel Gynecologic Oncologist, Avera Cancer Institute Sioux Falls, South Dakota David Starks, MD, MPH CLINICAL Background Training MD, University of Michigan. Residency, Case Western. Fellowship, Cleveland Clinic.
A patient with stable disease for 20 months converted to a partial response and remains on treatment at 21+ months Age, Diabetes Status, BMI 53 years, diabetic, BMI 46.4 kg/m2 Prior lines of therapy 2 Histology Pure Endometrioid PIK3CA and PTEN status PIK3CA and PTEN mutations Best response Partial response Start of treatment January 2025 Stable disease Partial response at 20 months Still on treatment at 21+ months Single-patient example; may not be representative of outcomes in other patients. ctDNA: circulating tumor DNA. 10.30.26 data cut. -100% change in ctDNA tumor fraction (PIK3CA and AKT1) at cycle 2 day 1 CLINICAL
A patient with complete response in target lesions remains on treatment at 14+ months Age, Diabetes status, BMI 60 years, no history of diabetes, BMI 27.7 kg/m2 Prior lines of therapy 3 Histology Mixed Endometrioid PIK3CA and PTEN status PTEN mutation Best response Partial response (complete response in target lesions) Single-patient example; may not be representative of outcomes in other patients. ctDNA results pending. 10.30.26 data cut. Baseline Complete Response Abdomen Chest CLINICAL
FAETH THERAPEUTICS Closing Remarks NOVEMBER 9, 2026
1. Lead sponsors of recruiting or active Phase 2/3 ADC trials in endometrial cancer, ClinicalTrials.gov, accessed 1 November 2026; Phase 3: AstraZeneca, Daiichi Sankyo, Genmab, Gilead, GSK, Merck. Logos illustrative. 2. To our knowledge, based on a ClinicalTrials.gov search as of November 2026. ADC: antibody-drug conjugate. PAM: PI3K/AKT/mTOR. ADC 6+ sponsors in Phase 2/3 trials1 PAM 1 enrolling oral multi-node program2 PIKTOR Oral dosing 2L+ endometrial market, rising unmet need, one oral multi-node PAM-pathway option in development CLOSING REMARKS
PIK-201 (EC) Phase 2 readout PIK-201 data update at a medical meeting (mid-2027) Phase 3 EC initiation activities Achieved in 2026 1H 2027 2H 2027 Registrational trial design disclosure 1 PIK-101 (BC) initiated PIK-101 (BC) data CLOSING REMARKS Anticipated milestones 1 Subject to regulatory alignment.
2025 BJC publication PIKTOR preclinical results published 2026 Phase 2 readout PIK-201 Endometrial cancer 2027 Prepare for Phase 3 endometrial trial; Disclosure of Phase 1b breast data expected 2028+ Potential indication expansion: Ovarian, NRF2-mutated lung cancer, rare disease CLOSING REMARKS We believe PIK-201 provides a foundation for Phase 3 development and for PIKTOR’s potential expansion into additional tumor types
FAETH THERAPEUTICS Questions and Answers NOVEMBER 9, 2026
Thank you