Clinical characteristics and overall survival among acute myeloid leukemia patients with TP53 gene mutation or chromosome 17p deletion.

Approximately 5% to 15% of acute myeloid leukemia (AML) patients have TP53 gene mutations (TP53m), which are associated with very poor outcomes. Adults (≥18 years) with a new AML diagnosis were included from a nationwide, de-identified, real-world database. Patients receiving first-line therapy were divided into three cohorts: venetoclax (VEN) + hypomethylating agents (HMAs; Cohort A), intensive chemotherapy (Cohort B), or HMA without VEN (Cohort C). A total of 370 newly diagnosed AML patients with TP53m (n = 124), chromosome 17p deletion (n = 166), or both (n = 80) were included. The median age was 72 years (range, 24-84); most were male (59%) and White (69%). Baseline bone marrow (BM) blasts were ≤30%, 31%-50%, and >50% in 41%, 24%, and 29% of patients in Cohorts A, B, and C, respectively. BM remission (<5% blasts) with first-line therapy was reported in 54% of patients (115/215) overall, and 67% (38/57), 62% (68/110), and 19% (9/48) for respective cohorts (median BM remission duration: 6.3, 6.9, and 5.4 months). Median overall survival (95% CI) was 7.4 months (6.0-8.8) for Cohort A, 9.4 months (7.2-10.4) for Cohort B, and 5.9 months (4.3-7.5) for Cohort C. There were no differences in survival by treatment type after adjusting for the effects of relevant covariates (Cohort A vs. C adjusted hazard ratio [aHR] = 0.9; 95% CI, 0.7-1.3; Cohort A vs. B aHR = 1.0; 95% CI, 0.7-1.5; and Cohort C vs. B aHR = 1.1; 95% CI, 0.8-1.6). Patients with TP53m AML have dismal outcomes with current therapies, demonstrating the high unmet need for improved treatments.

Magrolimab Plus Rituximab in Relapsed/Refractory Indolent Non-Hodgkin Lymphoma: Phase 1/2 Trial 3-Year Follow-up.

Relapsed/refractory (R/R) indolent non-Hodgkin lymphoma (iNHL) is generally considered incurable with current treatment options. Previous phase 1b/2 results showed combining the anti-cluster-of-differentiation (CD) 47 activity of magrolimab with the anti-CD20 activity of rituximab (M+R) has antitumor activity against R/R iNHL. Here, we report 3-year follow-up data from this phase 1b/2 study (NCT02953509) assessing long-term safety and efficacy of M+R in R/R iNHL. After magrolimab priming, 4 groups of phase 1b M+R patients received 10-45 mg/kg magrolimab maintenance doses with 375 mg/m2 rituximab. Phase 2 explored 30 and 45 mg/kg magrolimab. Primary endpoints were treatment-emergent adverse events (TEAEs) and objective response rate (ORR). Secondary endpoints included duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Exploratory analysis included assessment of circulating tumor DNA, biomarkers of magrolimab tumor penetration, and drug target expression. Of 46 patients treated in phase 1b/2, 42 had follicular lymphoma and 4 had marginal zone lymphoma. All patients experienced ≥1 any-grade TEAE, and 44 reported ≥1 treatment-related TEAE. No additional toxicities were reported during long-term follow-up, and there were no treatment-related deaths. Median follow-up was 36.7 (range, 1.2-62.3) months. The ORR was 52.2%, with 30.4% achieving a complete response. The median DOR was 15.9 (95% CI, 5.6-not estimable) months. The median time-to-response was 1.8 (range, 1.6-5.5) months; median PFS and OS were 7.4 (95% CI, 4.8-13.0) months and not reached, respectively. These results demonstrate the long-term safety and efficacy of M+R in patients with iNHL and support further exploration of CD47-based treatment combinations.

Magrolimab Plus Rituximab with/without Chemotherapy in Patients with Relapsed/Refractory Diffuse Large B-Cell Lymphoma.

Patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) ineligible for available salvage therapies have limited options for long-term disease control, necessitating novel treatments. Previously, magrolimab (anti-cluster-of-differentiation-47 antibody) plus rituximab (M+R) demonstrated ability to induce complete responses (CR) in R/R DLBCL. Here we report 3-year follow-up data from this phase 1b/2 study (NCT02953509) assessing long-term safety and efficacy of M+R, and initial safety and efficacy of M+R plus gemcitabine-oxaliplatin (M+R-GemOx), in R/R DLBCL. After magrolimab priming, 4 M+R patient groups received 10-45 mg/kg magrolimab with 375 mg/m2 rituximab; M+R-GemOx patients received 30 or 45 mg/kg magrolimab with 375 mg/m2 rituximab, 1000 mg/m2 gemcitabine, and 100 mg/m2 oxaliplatin. Primary endpoints were treatment-emergent adverse events (TEAEs) and objective response rate (ORR). Secondary endpoints included duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Of 132 patients treated, 99 received M+R and 33 received M+R-GemOx. Most common any-grade TEAEs were fatigue (M+R, 40%; M+R-GemOx, 70%), infusion-related reactions (M+R, 39%), or anemia (M+R-GemOx, 70%). Treatment-related TEAEs led to magrolimab discontinuation in 7% (M+R) and 6% (M+R-GemOx). One death was considered treatment related (M+R-GemOx, colitis). M+R ORR was 24% (CR, 12%), and median DOR was 9.3 months. Median PFS and OS were 1.8 and 9.2 months, respectively. M+R-GemOx ORR was 52% (CR, 39%); 12-month DOR rate was 66.6% (95% CI, 33.1-86.1%). Median PFS and OS were 3.9 months and not reached, respectively. These results demonstrate that M+R with/without GemOx is well tolerated, and M+R-GemOx has clinical activity in patients with R/R DLBCL.

Treatment outcomes for newly diagnosed, treatment-naïve TP53-mutated acute myeloid leukemia: a systematic review and meta-analysis.

BACKGROUND: TP53 mutations, which are present in 5% to 10% of patients with acute myeloid leukemia (AML), are associated with treatment resistance and poor outcomes. First-line therapies for TP53-mutated (TP53m) AML consist of intensive chemotherapy (IC), hypomethylating agents (HMA), or venetoclax combined with HMA (VEN + HMA). METHODS: We conducted a systematic review and meta-analysis to describe and compare treatment outcomes in newly diagnosed treatment-naïve patients with TP53m AML. Randomized controlled trials, single-arm trials, prospective observational studies, and retrospective studies were included that reported on complete remission (CR), CR with incomplete hematologic recovery (CRi), overall survival (OS), event-free survival (EFS), duration of response (DoR), and overall response rate (ORR) among patients with TP53m AML receiving first-line treatment with IC, HMA, or VEN + HMA. RESULTS: Searches of EMBASE and MEDLINE identified 3006 abstracts, and 17 publications describing 12 studies met the inclusion criteria. Random-effects models were used to pool response rates, and time-related outcomes were analyzed with the median of medians method. IC was associated with the greatest CR rate of 43%, and CR rates were 33% for VEN + HMA and 13% for HMA. Rates of CR/CRi were comparable for IC (46%) and VEN + HMA (49%) but were lower for HMA (13%). Median OS was uniformly poor across treatments: IC, 6.5 months; VEN + HMA, 6.2 months; and HMA, 6.1 months. For IC, the EFS estimate was 3.7 months; EFS was not reported for VEN + HMA or HMA. The ORR was 41% for IC, 65% for VEN + HMA, and 47% for HMA. DoR was 3.5 months for IC, 5.0 months for VEN + HMA, and was not reported for HMA. CONCLUSIONS: Despite improved responses seen with IC and VEN + HMA compared to HMA, survival was uniformly poor, and clinical benefits were limited across all treatments for patients with newly diagnosed, treatment-naïve TP53m AML, demonstrating a significant need for improved treatment for this difficult-to-treat population.

Tolerability and Efficacy of the Anticluster of Differentiation 47 Antibody Magrolimab Combined With Azacitidine in Patients With Previously Untreated AML: Phase Ib Results.

PURPOSE: Magrolimab is a first-in-class humanized monoclonal antibody against cluster of differentiation 47, an antiphagocytic signal used by cancer cells to evade phagocytosis. Azacitidine upregulates prophagocytic signals on AML cells, further increasing phagocytosis when combined with magrolimab. We report final phase Ib data for magrolimab with azacitidine in patients with untreated AML ineligible for intensive chemotherapy (ClinicalTrials.gov identifier: NCT03248479). PATIENTS AND METHODS: Patients with previously untreated AML, including TP53-mutant AML, received magrolimab intravenously as an initial dose (1 mg/kg, days 1 and 4), followed by 15 mg/kg once on day 8 and 30 mg/kg once weekly or every 2 weeks as maintenance. Azacitidine 75 mg/m2 was administered intravenously/subcutaneously once daily on days 1-7 of each 28-day cycle. Primary end points were safety/tolerability and proportion with complete remission (CR). RESULTS: Eighty-seven patients were enrolled and treated; 72 (82.8%) had TP53 mutations with a median variant allele frequency of 61% (range, 9.8-98.7). Fifty-seven (79.2%) of TP53-mutant patients had European LeukemiaNet 2017 adverse-risk cytogenetics. Patients received a median of 4 (range, 1-39) cycles of treatment. The most common treatment-emergent adverse events included constipation (49.4%), nausea (49.4%), and diarrhea (48.3%). Thirty (34.5%) experienced anemia, and the median hemoglobin change from baseline to first postdose assessment was -0.9 g/dL (range, -3.6 to 2.5 g/dL). Twenty-eight (32.2%) patients achieved CR, including 23 (31.9%) patients with TP53 mutations. The median overall survival in TP53-mutant and wild-type patients were 9.8 months and 18.9 months, respectively. CONCLUSION: Magrolimab with azacitidine was relatively well tolerated with promising efficacy in patients with AML ineligible for intensive induction chemotherapy, including those with TP53 mutations, warranting further evaluation of magrolimab with azacitidine in AML. The phase III randomized ENHANCE-2 (ClinicalTrials.gov identifier: NCT04778397) and ENHANCE-3 (ClinicalTrials.gov identifier: NCT05079230) studies are recruiting frontline patients with AML.