Gilead Provides Update on Phase 3 TROPiCS-04 Study

Gilead Sciences, Inc. (Nasdaq: GILD) today announced topline results from the confirmatory Phase 3 TROPiCS-04 study in locally advanced or metastatic urothelial cancer (mUC). The TROPiCS-04 study evaluated Trodelvy^® (sacituzumab govitecan-hziy; SG) vs. single-agent chemotherapy (treatment of physicians’ choice, TPC) in patients with mUC who have previously received platinum-containing chemotherapy and anti-PD-(L)1 therapy.

The study did not meet the primary endpoint of overall survival (OS) in the intention-to-treat (ITT) population. A numerical improvement in OS favoring Trodelvy was observed, and trends in improvement for select pre-specified subgroups and secondary endpoints of progression-free survival (PFS) and overall response rate (ORR) were also shown. The pre-specified subgroup analyses were not alpha-controlled for formal statistical testing. These data will be presented at an upcoming medical meeting.

In the overall study population, there was a higher number of deaths due to adverse events with Trodelvy compared to TPC, which were primarily observed early in treatment and related to neutropenic complications, including infection. Gilead will further investigate these data, and is working to reiterate to treating physicians the importance of granulocyte-colony stimulating factor (G-CSF) use for the prevention of neutropenic complications. Trodelvy has a Boxed Warning for severe or life-threatening neutropenia; please see below for Important Safety Information.

There are no changes to the known safety profile of Trodelvy for the approved breast cancer indications or other investigational uses. To date, the Trodelvy safety profile is generally well-tolerated and consistent with use in over 40,000 patients across Trodelvy’s approved indications and in clinical trials.

Gilead is continuing to analyze the data and will discuss the results and next steps with the FDA. In the U.S., Trodelvy has an accelerated approval indication for patients with locally advanced or metastatic urothelial cancer (mUC) who have previously received a platinum-containing chemotherapy and anti-PD-(L)1 therapy. This indication is approved under accelerated approval based on tumor response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials, including the TROPiCS-04 study.

Metastatic UC is an aggressive disease which most commonly affects older patients with concurrent medical morbidities and additional changes related to the aging process. Despite recent advances, survival rates remain poor with only 8% of patients living beyond five years after diagnosis. These results may in part reflect the difficulty of treating patients with mUC who have previously received platinum-containing chemotherapy and checkpoint inhibitor therapy. There is an urgent need for new treatment options to help improve long-term outcomes.

Gilead would like to thank the patients, families, investigators, and advocates who contributed to this important research. We remain committed to advancing care to address the unmet needs for the bladder cancer community.

Trodelvy is the first approved Trop-2-directed antibody-drug conjugate (ADC), which has demonstrated meaningful survival advantages in two different types of metastatic breast cancers. There are more than 20 ongoing clinical trials for Trodelvy.

Please see below for the approved U.S. Indication and additional Important Safety Information.

About Metastatic Urothelial Cancer

Bladder cancer is one of the most common cancers worldwide, with more than 1.6 million people living with the disease and urothelial cancer (UC) accounting for 90% of these cases. Metastatic bladder cancer is an aggressive disease and survival rates remain poor, with only 8% of patients living beyond five years after diagnosis. Despite recent advances, less than 20% of patients with metastatic bladder cancer go on to receive second-line therapy. There is an urgent need for new treatment options for patients with mUC who have progressed on available therapies to help improve long-term outcomes.

About the TROPiCS-04 Study

The TROPiCS-04 study is an open-label, global, multi-center, randomized Phase 3 study that evaluated Trodelvy vs. single-agent chemotherapy (treatment of physicians’ choice, TPC) in patients with locally advanced or mUC who received platinum-containing chemotherapy and checkpoint inhibitor therapy. The study enrolled 711 patients randomized 1:1 to receive either Trodelvy or one of three TPC chemotherapeutic standard of care (SOC) options: paclitaxel, docetaxel, or vinflunine. The primary endpoint was OS. Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), clinical benefit rate (CBR) and duration of objective tumor response (DoR) as assessed by investigator per Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and blinded independent central review (BICR). Further study details are available on clinicaltrials.gov (NCT04527991).

About Trodelvy

Trodelvy^® (sacituzumab govitecan-hziy) is a first-in-class Trop-2-directed antibody-drug conjugate. Trop-2 is a cell surface antigen highly expressed in multiple tumor types, including in more than 90% of breast, bladder and lung cancers. Trodelvy is intentionally designed with a proprietary hydrolyzable linker attached to SN-38, a topoisomerase I inhibitor payload. This unique combination delivers potent activity to both Trop-2 expressing cells and the tumor microenvironment through a bystander effect.

Trodelvy is approved in almost 50 countries, with multiple additional regulatory reviews underway worldwide, for the treatment of adult patients with unresectable locally advanced or metastatic triple-negative breast cancer (TNBC) who have received two or more prior systemic therapies, at least one of them for metastatic disease.

Trodelvy also has multiple global approvals for certain patients with pre-treated HR+/HER2- metastatic breast cancer, including in Australia, Brazil, Canada, the European Union, Israel, United Arab Emirates and the United States. In the U.S., Trodelvy has an accelerated approval for treatment of certain patients with second-line or later metastatic urothelial cancer; see below for full indication statements.

Trodelvy is being explored for potential investigational use in other TNBC, HR+/HER2- and metastatic UC populations, as well as a range of tumor types where Trop-2 is highly expressed, including metastatic non-small cell lung cancer (NSCLC), head and neck cancer, gynecological cancer, and gastrointestinal cancers.

U.S. Indications for Trodelvy

In the United States, Trodelvy is indicated for the treatment of adult patients with:

• Unresectable locally advanced or metastatic triple-negative breast cancer (mTNBC) who have received two or more prior systemic therapies, at least one of them for metastatic disease.
• Unresectable locally advanced or metastatic hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative (IHC 0, IHC 1+ or IHC 2+/ISH–) breast cancer who have received endocrine-based therapy and at least two additional systemic therapies in the metastatic setting.
• Locally advanced or metastatic urothelial cancer (mUC) who have previously received a platinum-containing chemotherapy and either programmed death receptor-1 (PD-1) or programmed death-ligand 1 (PD-L1) inhibitor. This indication is approved under accelerated approval based on tumor response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials.

U.S. Important Safety Information for Trodelvy

BOXED WARNING: NEUTROPENIA AND DIARRHEA

• Severe or life-threatening neutropenia may occur. Withhold Trodelvy for absolute neutrophil count below 1500/mm³ or neutropenic fever. Monitor blood cell counts periodically during treatment. Consider G-CSF for secondary prophylaxis. Initiate anti-infective treatment in patients with febrile neutropenia without delay.
• Severe diarrhea may occur. Monitor patients with diarrhea and give fluid and electrolytes as needed. At the onset of diarrhea, evaluate for infectious causes and, if negative, promptly initiate loperamide. If severe diarrhea occurs, withhold Trodelvy until resolved to ≤Grade 1 and reduce subsequent doses.

CONTRAINDICATIONS

• Severe hypersensitivity reaction to Trodelvy.

WARNINGS AND PRECAUTIONS

Neutropenia: Severe, life-threatening, or fatal neutropenia can occur and may require dose modification. Neutropenia occurred in 64% of patients treated with Trodelvy. Grade 3-4 neutropenia occurred in 49% of patients. Febrile neutropenia occurred in 6%. Neutropenic colitis occurred in 1.4%. Withhold Trodelvy for absolute neutrophil count below 1500/mm³ on Day 1 of any cycle or neutrophil count below 1000/mm³ on Day 8 of any cycle. Withhold Trodelvy for neutropenic fever. Administer G-CSF as clinically indicated or indicated in Table 1 of USPI.

Diarrhea: Diarrhea occurred in 64% of all patients treated with Trodelvy. Grade 3-4 diarrhea occurred in 11% of patients. One patient had intestinal perforation following diarrhea. Diarrhea that led to dehydration and subsequent acute kidney injury occurred in 0.7% of all patients. Withhold Trodelvy for Grade 3-4 diarrhea and resume when resolved to ≤Grade 1. At onset, evaluate for infectious causes and if negative, promptly initiate loperamide, 4 mg initially followed by 2 mg with every episode of diarrhea for a maximum of 16 mg daily. Discontinue loperamide 12 hours after diarrhea resolves. Additional supportive measures (e.g., fluid and electrolyte substitution) may also be employed as clinically indicated. Patients who exhibit an excessive cholinergic response to treatment can receive appropriate premedication (e.g., atropine) for subsequent treatments.

Hypersensitivity and Infusion-Related Reactions: Serious hypersensitivity reactions including life-threatening anaphylactic reactions have occurred with Trodelvy. Severe signs and symptoms included cardiac arrest, hypotension, wheezing, angioedema, swelling, pneumonitis, and skin reactions. Hypersensitivity reactions within 24 hours of dosing occurred in 35% of patients. Grade 3-4 hypersensitivity occurred in 2% of patients. The incidence of hypersensitivity reactions leading to permanent discontinuation of Trodelvy was 0.2%. The incidence of anaphylactic reactions was 0.2%. Pre-infusion medication is recommended. Have medications and emergency equipment to treat such reactions available for immediate use. Observe patients closely for hypersensitivity and infusion-related reactions during each infusion and for at least 30 minutes after completion of each infusion. Permanently discontinue Trodelvy for Grade 4 infusion-related reactions.

Nausea and Vomiting: Nausea occurred in 64% of all patients treated with Trodelvy and Grade 3-4 nausea occurred in 3% of these patients. Vomiting occurred in 35% of patients and Grade 3-4 vomiting occurred in 2% of these patients. Premedicate with a two or three drug combination regimen (e.g., dexamethasone with either a 5-HT3 receptor antagonist or an NK₁ receptor antagonist as well as other drugs as indicated) for prevention of chemotherapy-induced nausea and vomiting (CINV). Withhold Trodelvy doses for Grade 3 nausea or Grade 3-4 vomiting and resume with additional supportive measures when resolved to Grade ≤1. Additional antiemetics and other supportive measures may also be employed as clinically indicated. All patients should be given take-home medications with clear instructions for prevention and treatment of nausea and vomiting.

Increased Risk of Adverse Reactions in Patients with Reduced UGT1A1 Activity: Patients homozygous for the uridine diphosphate-glucuronosyl transferase 1A1 (UGT1A1)*28 allele are at increased risk for neutropenia, febrile neutropenia, and anemia and may be at increased risk for other adverse reactions with Trodelvy. The incidence of Grade 3-4 neutropenia was 58% in patients homozygous for the UGT1A1*28, 49% in patients heterozygous for the UGT1A1*28 allele, and 43% in patients homozygous for the wild-type allele. The incidence of Grade 3-4 anemia was 21% in patients homozygous for the UGT1A1*28 allele, 10% in patients heterozygous for the UGT1A1*28 allele, and 9% in patients homozygous for the wild-type allele. Closely monitor patients with known reduced UGT1A1 activity for adverse reactions. Withhold or permanently discontinue Trodelvy based on clinical assessment of the onset, duration and severity of the observed adverse reactions in patients with evidence of acute early-onset or unusually severe adverse reactions, which may indicate reduced UGT1A1 function.

Embryo-Fetal Toxicity: Based on its mechanism of action, Trodelvy can cause teratogenicity and/or embryo-fetal lethality when administered to a pregnant woman. Trodelvy contains a genotoxic component, SN-38, and targets rapidly dividing cells. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with Trodelvy and for 6 months after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with Trodelvy and for 3 months after the last dose.

ADVERSE REACTIONS

In the pooled safety population, the most common (≥ 25%) adverse reactions including laboratory abnormalities were decreased leukocyte count (84%), decreased neutrophil count (75%), decreased hemoglobin (69%), diarrhea (64%), nausea (64%), decreased lymphocyte count (63%), fatigue (51%), alopecia (45%), constipation (37%), increased glucose (37%), decreased albumin (35%), vomiting (35%), decreased appetite (30%), decreased creatinine clearance (28%), increased alkaline phosphatase (28%), decreased magnesium (27%), decreased potassium (26%), and decreased sodium (26%).

In the ASCENT study (locally advanced or metastatic triple-negative breast cancer), the most common adverse reactions (incidence ≥25%) were fatigue, diarrhea, nausea, alopecia, constipation, vomiting, abdominal pain, and decreased appetite. The most frequent serious adverse reactions (SAR) (>1%) were neutropenia (7%), diarrhea (4%), and pneumonia (3%). SAR were reported in 27% of patients, and 5% discontinued therapy due to adverse reactions. The most common Grade 3-4 lab abnormalities (incidence ≥25%) in the ASCENT study were reduced neutrophils, leukocytes, and lymphocytes.

In the TROPiCS-02 study (locally advanced or metastatic HR-positive, HER2-negative breast cancer), the most common adverse reactions (incidence ≥25%) were diarrhea, fatigue, nausea, alopecia, and constipation. The most frequent serious adverse reactions (SAR) (>1%) were diarrhea (5%), febrile neutropenia (4%), neutropenia (3%), abdominal pain, colitis, neutropenic colitis, pneumonia, and vomiting (each 2%). SAR were reported in 28% of patients, and 6% discontinued therapy due to adverse reactions. The most common Grade 3-4 lab abnormalities (incidence ≥25%) in the TROPiCS-02 study were reduced neutrophils and leukocytes.

In the TROPHY study (locally advanced or metastatic urothelial cancer), the most common adverse reactions (incidence ≥25%) were diarrhea, fatigue, nausea, any infection, alopecia, decreased appetite, constipation, vomiting, rash, and abdominal pain. The most frequent serious adverse reactions (SAR) (≥5%) were infection (18%), neutropenia (12%, including febrile neutropenia in 10%), acute kidney injury (6%), urinary tract infection (6%), and sepsis or bacteremia (5%). SAR were reported in 44% of patients, and 10% discontinued due to adverse reactions. The most common Grade 3-4 lab abnormalities (incidence ≥25%) in the TROPHY study were reduced neutrophils, leukocytes, and lymphocytes.

DRUG INTERACTIONS

UGT1A1 Inhibitors: Concomitant administration of Trodelvy with inhibitors of UGT1A1 may increase the incidence of adverse reactions due to potential increase in systemic exposure to SN-38. Avoid administering UGT1A1 inhibitors with Trodelvy.

UGT1A1 Inducers: Exposure to SN-38 may be reduced in patients concomitantly receiving UGT1A1 enzyme inducers. Avoid administering UGT1A1 inducers with Trodelvy.

Please see full Prescribing Information, including BOXED WARNING.

About Gilead Sciences

Gilead Sciences, Inc. is a biopharmaceutical company that has pursued and achieved breakthroughs in medicine for more than three decades, with the goal of creating a healthier world for all people. The company is committed to advancing innovative medicines to prevent and treat life-threatening diseases, including HIV, viral hepatitis, COVID-19, and cancer. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, California.

Forward-Looking Statements

This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks, uncertainties and other factors, including Gilead’s ability to initiate, progress or complete clinical trials within currently anticipated timelines or at all, and the possibility of unfavorable results from ongoing or additional clinical trials, including those involving Trodelvy; uncertainties relating to regulatory applications and related filing and approval timelines, including pending or potential applications for Trodelvy for the treatment of metastatic and other TNBC, HR+/HER2- metastatic breast cancer, mUC, metastatic NSCLC, head and neck cancer, gynecological cancer and gastrointestinal cancer; Gilead’s ability to receive regulatory approvals for programs and/or indications that are currently under evaluation in a timely manner or at all, including the risk that the FDA may not grant full approval or may withdraw its accelerated approval for Trodelvy for the treatment of locally advanced or metastatic urothelial cancer (mUC), and the risk that any such approvals may be subject to significant limitations on use and is subject to, withdrawal or other adverse actions by the applicable regulatory authority; the possibility that Gilead may make a strategic decision to discontinue development of programs for indications that are currently under evaluation, including Trodelvy for treatment of mUC, and as a result, these programs may never be or cease to be commercialized for such indications; and any assumptions underlying any of the foregoing. These and other risks, uncertainties and other factors are described in detail in Gilead’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2024, as filed with the U.S. Securities and Exchange Commission. These risks, uncertainties and other factors could cause actual results to differ materially from those referred to in the forward-looking statements. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. The reader is cautioned that any such forward-looking statements are not guarantees of future performance and involve risks and uncertainties, and is cautioned not to place undue reliance on these forward-looking statements. All forward-looking statements are based on information currently available to Gilead, and Gilead assumes no obligation and disclaims any intent to update any such forward-looking statements.

U.S. Prescribing Information for Trodelvy including BOXED WARNING, is available at www.gilead.com.

Trodelvy, Gilead and the Gilead logo are trademarks of Gilead Sciences, Inc., or its related companies.

For more information about Gilead, please visit the company’s website at www.gilead.com or call Gilead Public Affairs at 1-800-GILEAD-5 or 1-650-574-3000.

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