공지 • Mar 19
Pfizer Inc Announces Positive Topline Results From Phase 3 Talapro-3 Study Of Talzenna In Combination With Xtandi
Pfizer Inc. announced positive topline results from the Phase 3 TALAPRO-3 study of TALZENNA (talazoparib), an oral poly ADP-ribose polymerase (PARP) inhibitor, in combination with XTANDI (enzalutamide), an androgen receptor pathway inhibitor (ARPI), in people with homologous recombination repair (HRR) gene-mutated metastatic castration-sensitive prostate cancer (mCSPC), also known as metastatic hormone-sensitive prostate cancer (mHSPC). The study met its primary endpoint, with TALZENNA plus XTANDI demonstrating a statistically significant and clinically meaningful improvement in radiographic progression-free survival (rPFS), compared to placebo plus XTANDI. The results markedly exceeded the pre-specified target hazard ratio of 0.63, with the majority of patients remaining progression-free at the time of analysis. Consistent efficacy benefit was also observed in patients whose tumors harbored BRCA and non-BRCA HRR gene alterations. At the time of the interim analysis, results showed a strong trend toward improved overall survival (OS), a key secondary endpoint. Benefits were also observed in other secondary endpoints, including overall response rate, duration of response, and time to Prostate-Specific Antigen (PSA) progression. The safety of TALZENNA plus XTANDI was consistent with the known safety profile of each medicine, and no new safety signals were identified. TALZENNA plus XTANDI in HRR gene-mutated mCSPC is an investigational treatment regimen. The TALAPRO-3 results will be submitted for presentation at an upcoming medical congress and will be discussed with global health authorities for potential regulatory submissions. TALZENNA plus XTANDI is currently approved in 60 countries, including in the United States for adults with HRR gene-mutated mCRPC and in the European Union for adults with mCRPC in whom chemotherapy is not clinically indicated.WARNINGS and PRECAUTIONS: Myelodysplastic Syndrome/Acute Myeloid Leukemia (MDS/AML), including cases with a fatal outcome, has been reported in patients who received TALZENNA. Overall, MDS/AML has been reported in 0.4% (3 out of 788) of solid tumor patients treated with TALZENNA as a single agent in clinical studies. In TALAPRO-2, MDS/AML occurred in 2 out of 511 (0.4%) patients treated with TALZENNA and enzalutamide and in 0 out of 517 (0%) patients treated with placebo and enzalutamide. The durations of TALZENNA treatment in these 5 patients prior to developing MDS/AML were 0.3, 1, 2, 3, and 5 years. Most of these patients had received previous chemotherapy with platinum agents and/or other DNA damaging agents including radiotherapy. Do not start TALZENNA until patients have adequately recovered from hematological toxicity caused by previous chemotherapy. Monitor blood counts monthly during treatment with TALZENNA. For prolonged hematological toxicities, interrupt TALZENNA and monitor blood counts weekly until recovery. If counts do not recover within 4 weeks, refer the patient to a hematologist for further investigations including bone marrow analysis and blood sample for cytogenetics. If MDS/AML is confirmed, discontinue TALZENNA. Myelosuppression consisting of anemia, neutropenia, and/or thrombocytopenia, have been reported in patients treated with TALZENNA. In TALAPRO-2, Grade =3 anemia, neutropenia, and thrombocytopenia were reported, respectively, in 48%, 19%, and 9% of patients receiving TALZENNA and enzalutamide. Forty-two percent of patients (216/511) required a red blood cell transfusion, including 25% (127/511) who required more than one transfusion. Discontinuation due to anemia, neutropenia, and thrombocytopenia occurred, respectively, in 8%, 3%, and 0.4% of patients. Withhold TALZENNA until patients have adequately recovered from hematological toxicity caused by previous therapy. Monitor blood counts monthly during treatment with TALZENNA. If hematological toxicities do not resolve within 28 days, discontinue TALZENNA and refer the patient to a hematologist for further investigations including bone marrow analysis and blood sample for cytogenetics. Embryo-Fetal Toxicity TALZENNA can cause fetal harm when administered to pregnant women. Advise male patients with female partners of reproductive potential or who are pregnant to use effective contraception during treatment and for 4 months following the last dose of TALZENNA. ADVERSE REACTIONS Serious adverse reactions reported in >2% of patients included anemia (9%) and fracture (3%). Fatal adverse reactions occurred in 1.5% of patients, including pneumonia, COVID infection, and sepsis (1 patient each). The most common adverse reactions (= 10%, all Grades), including laboratory abnormalities, for patients in the TALAPRO-2 study who received TALZENNA with enzalutamide vs patients receiving placebo with enzalutamide were hemoglobin decreased (79% vs 34%), neutrophils decreased (60% vs 18%), lymphocytes decreased (58% vs 36%), fatigue (49% vs 40%), platelets decreased (45% vs 8%), calcium decreased (25% vs 11%), nausea (21% vs 17%), decreased appetite (20% vs 14%), sodium decreased (22% vs 20%), phosphate decreased (17% vs 13%), fractures (14% vs 10%), magnesium decreased (14% vs 12%), dizziness (13% vs 9%), bilirubin increased (11% vs 7%), potassium decreased (11% vs 7%), and dysgeusia (10% vs 4.5%). Clinically relevant adverse reactions in 2%) in the XTANDI arm compared to placebo in the pooled, randomized, placebo-controlled studies are hemoglobin decrease, neutrophil count decreased, white blood cell decreased, hyperglycemia, hypermagnesemia, hyponatremia, hypophosphatemia, and hypercalcemia. Hypertension: In the combined data from five randomized placebo-controlled clinical trials, hypertension was reported in 14.2% of XTANDI patients and 7.4% of placebo patients. Hypertension led to study discontinuation in < 1% of patients in each arm. Drug Interactions Effect of Other Drugs on XTANDI Avoid coadministration with strong CYP2C8 inhibitors. If coadministration cannot be avoided, reduce the dosage of XTANDI. Avoid coadministration with strong CYP3A4 inducers. If coadministration cannot be avoided, increase the dosage of XTANDI. Effect of XTANDI on Other Drugs Avoid coadministration with certain CYP3A4, CYP2C9, and CYP2C19 substrates for which minimal decrease in concentration may lead to therapeutic failure of the substrate. If coadministration cannot be avoided, increase the dosage of these substrates in accordance with their Prescribing Information. In cases where active metabolites are formed, there may be increased exposure to the active metabolites.
