Durvalumab as monotherapy and in combination therapy in patients with lymphoma or chronic lymphocytic leukemia: The FUSION NHL 001 trial

BACKGROUND

Studies suggest that immune checkpoint inhibitors may represent a promising strategy for boosting immune responses and improving the antitumor activity of standard therapies in patients with relapsed/refractory hematologic malignancies.

AIMS

Phase 1/2 FUSION NHL 001 was designed to determine the safety and efficacy of durvalumab, an anti-programmed death ligand 1 (PD-L1) antibody, combined with standard-of-care therapies for lymphoma or chronic lymphocytic leukemia (CLL).

METHODS AND RESULTS

The primary endpoints were to determine the recommended phase 2 dose of the drugs used in combination with durvalumab (durvalumab was administered at the previously recommended dose of 1500 mg every 4 weeks) and to assess safety and tolerability. Patients were enrolled into one of four arms: durvalumab monotherapy (Arm D) or durvalumab in combination with lenalidomide ± rituximab (Arm A), ibrutinib (Arm B), or rituximab ± bendamustine (Arm C). A total of 106 patients with relapsed/refractory lymphoma were enrolled. All but two patients experienced at least one treatment-emergent adverse event (TEAE); those not experiencing a TEAE were in Arm C (diffuse large B-cell lymphoma [DLBCL]) and Arm D (DLBCL during the durvalumab monotherapy treatment period). No new safety signals were identified, and TEAEs were consistent with the respective safety profiles for each study treatment. Across the study, patients with follicular lymphoma (FL; n = 23) had an overall response rate (ORR) of 59%; ORR among DLBCL patients (n = 37) was 18%. Exploratory biomarker analysis showed that response to durvalumab monotherapy or combination therapy was associated with higher interferon-γ signature scores in patients with FL (p = .02).

CONCLUSION

Durvalumab as monotherapy or in combination is tolerable but requires close monitoring. The high rate of TEAEs during this study may reflect on the difficulty in combining durvalumab with full doses of other agents. Durvalumab alone or in combination appeared to add limited benefit to therapy.

Oral azacitidine plus venetoclax in patients with relapsed/refractory or newly diagnosed acute myeloid leukemia: The phase 1b OMNIVERSE trial

TPS7068

Background: For patients (pts) with acute myeloid leukemia (AML) who cannot undergo intensive chemotherapy (IC), lower-intensity treatment (Tx) regimens, including low-dose cytarabine (LDAC) and hypomethylating agents (HMAs; azacitidine [AZA], decitabine), are generally well tolerated but are associated with lower response rates than IC [Vey 2020]. Similarly, the BCL2 inhibitor, venetoclax (VEN), has shown antileukemic activity, although only modest clinical benefit as monotherapy [Konopleva 2016]. VEN + AZA shows synergistic activity in preclinical models, enhancing leukemic cell apoptosis in vitro and anti-tumor activity in vivo [Jin 2020]. In IC-ineligible pts with ND AML, VEN + injectable AZA significantly increased complete remission (CR)/CR with incomplete hematologic recovery (CRi) rates ( P < 0.001) and prolonged overall survival (OS; P < 0.001) vs AZA only [DiNardo 2020]. VEN, in combination with an HMA or LDAC, is approved in the US for Tx of pts with ND AML ≥ 75 years (y) of age or who cannot undergo IC due to comorbidities. Oral-AZA (CC-486) is approved for Tx of pts with newly diagnosed (ND) AML in first CR or CRi after IC who cannot receive curative therapy (eg, HSCT). In the phase 3 QUAZAR AML-001 trial, maintenance Tx with Oral-AZA 300 mg QD for 14 days (d)/28-d Tx cycle improved OS and relapse-free survival vs placebo in older pts in CR/CRi after IC [Wei 2020]. Incorporation of AZA into DNA is S-phase-restricted; thus, extending AZA exposure over a longer duration by using an oral formulation increases the opportunity for cycling tumor cells to incorporate the drug to sustain therapeutic activity [Laille 2015]. Additionally, an all-oral combination regimen allows for outpatient administration to optimize pt convenience and reduce resource utilization. Methods: OMNIVERSE (NCT04887857) is an open-label, multicenter, 2-part phase 1b trial. The main goals are to evaluate safety and establish the maximum tolerated dose of Oral-AZA + VEN in pts ≥ 18 y of age with relapsed/refractory AML who are ineligible for further IC ( part 1), and subsequently, in pts with ND AML ≥ 75 y of age, or pts 18–74 y of age with comorbidities that prevent use of IC or HSCT ( part 2). Key eligibility criteria include ECOG performance status of 0–2 (ECOG 3 is allowed for pts 18–74 y of age with comorbidities) and unfavorable-risk cytogenetics for pts with ND AML. The Oral-AZA starting dose is 300 mg QD × 14 d/28-d cycle, which can be de-escalated to 200 mg QD × 14 d depending on dose-limiting toxicities; oral VEN 400 mg QD is taken continuously (or 21 d/cycle for dose level −2). A modified toxicity probability interval-2 design is used to evaluate dose levels. Sample size depends on the dose levels utilized (≤ 18 pts/part). Enrollment began in 2021. The trial is ongoing at clinical sites in the United States and Australia. Clinical trial information: NCT04887857.

Overall survival by IDH2 mutant allele (R140 or R172) in patients with late-stage mutant-IDH2 relapsed or refractory acute myeloid leukemia treated with enasidenib or conventional care regimens in the phase 3 IDHENTIFY trial

7005

Background: IDH2 gene mutations (m IDH2) occur in up to ̃20% of patients (pts) with acute myeloid leukemia (AML), most commonly as R140Q (in ̃75% of cases) or R172K (̃25%) point mutations. The functional effects and prognostic relevance of m IDH2-R140 and m IDH2-R172 can vary (Papaemmanuil 2016). In the randomized, phase 3 IDHENTIFY trial, enasidenib (ENA), an oral mIDH2 inhibitor, did not significantly improve overall survival (OS) vs conventional care regimens (CCR) as salvage treatment (Tx) for older pts with m IDH2 relapsed/refractory (R/R) AML in ITT analysis, but a trend for improved OS with ENA was detected in pts with IDH2-R172 mutations. We further investigated OS and correlative biomarkers in IDHENTIFY pt subgroups defined by m IDH2 variant (R140/R172). Methods: This open-label trial (NCT02577406) enrolled pts ≥ 60 years of age who had received 2 or 3 prior AML Tx. Pts were preselected to a CCR (azacitidine, intermediate- or low-dose Ara-C, or supportive care), and were then randomized 1:1 to ENA 100 mg/d or CCR in 28d cycles. Co-occurring gene mutations were identified by targeted next-generation sequencing (37-gene panel) of bone marrow mononuclear cell (BMMC) DNA. Total 2-HG levels were determined by LC/MS. Results: Of 319 pts enrolled, 88 pts (28%; 43 ENA, 45 CCR) had m IDH2-R172 and 229 (72%; 115 ENA, 114 CCR) had m IDH2-R140. Median baseline (BL) 2-HG levels were similar between Tx arms and m IDH2 variant subgroups, as were IDH2 variant allele frequencies. Pts with m IDH2-R172 had fewer median BL co-mutations (4 [range 2–8]) than did pts with m IDH2-R140 (5 [1–11]) ( P < 0.0001). The most frequently co-occurring mutations were SRSF2 and RUNX1 in the R140 cohort (59% each) and DNMT3A in the R172 cohort (57%). Compared with the R172 cohort, the R140 group was enriched with SRSF2, FLT3 (-ITD/-TKD), NPM1, RUNX1, and JAK2 mutations, whereas DNMT3A and TP53 mutations were more common in the R172 group. In Cox multivariate analysis including m IDH2 variant (R140/R172), DNMT3A mutation status, and number of gene mutations at BL, m IDH2-R172 was significantly ( P = 0.04) correlated with improved OS (vs. R140) in the ENA arm, whereas the number of BL gene mutations was significantly ( P < 0.01) associated with OS in the CCR arm. Median OS in the R172 subgroup was 14.6 mo with ENA vs 7.8 mo with CCR (HR, 0.59 [95%CI 0.35-0.98]; P = 0.039) and 1-yr survival rates were 62% and 30%, respectively. In m IDH2-R140 pts, median OS was 5.7 mo in both Tx arms (0.93 [0.70-1.24]; P = 0.61), and 1-year survival rates were 29% and 25% with ENA and CCR, respectively. Conclusions: Mutational burden and co-mutational profiles differed between pts with m IDH2-R140 and m IDH2-R172 R/R AML. ENA improved survival outcomes for pts with IDH2-R172 mutations, with median OS and 1-year survival rate approximately double those in the CCR arm. Clinical trial information: NCT02577406.

Nilotinib versus imatinib as first-line therapy for patients with unresectable or metastatic gastrointestinal stromal tumours (ENESTg1): a randomised phase 3 trial

BACKGROUND

Nilotinib inhibits the tyrosine kinase activity of ABL1/BCR-ABL1 and KIT, platelet-derived growth factor receptors (PDGFRs), and the discoidin domain receptor. Gain-of-function mutations in KIT or PDGFRα are key drivers in most gastrointestinal stromal tumours (GISTs). This trial was designed to test the efficacy and safety of nilotinib versus imatinib as first-line therapy for patients with advanced GISTs.

METHODS

In this randomised, open-label, multicentre, phase 3 trial (ENESTg1), participants from academic centres were aged 18 years or older and had previously untreated, histologically confirmed, metastatic or unresectable GISTs. Patients were stratified by previous adjuvant therapy and randomly assigned (1:1) via a randomisation list to receive oral imatinib 400 mg once daily or oral nilotinib 400 mg twice daily. The primary endpoint was centrally reviewed progression-free survival. Efficacy endpoints were assessed by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT00785785.

FINDINGS

Because the futility boundary was crossed at a preplanned interim analysis, trial accrual terminated in April, 2011. Between March 16, 2009, and April 21, 2011, 647 patients were enrolled; of whom 324 were allocated nilotinib and 320 were allocated imatinib. At final analysis of the core study (data cutoff, October, 2012), 2-year progression-free survival was higher in the imatinib group (59·2% [95% CI 50·9-66·5]) than in the nilotinib group (51·6% [43·0-59·5]; hazard ratio 1·47 [95% CI 1·10-1·95]). In the imatinib group, the most common grade 3-4 adverse events were hypophosphataemia (19 [6%]), anaemia (17 [5%]), abdominal pain (13; 4%), and elevated lipase level (15; 5%), and in the nilotinib group were anaemia (18; 6%), elevated lipase level (15; 5%), elevated alanine aminotransferase concentration (12; 4%), and abdominal pain (11; 3%). The most common serious adverse event in both groups was abdominal pain (11 [4%] in the imatinib group, 14 [4%] in the nilotinib group).

INTERPRETATION

Nilotinib cannot be recommended for broad use to treat first-line GIST. However, future studies might identify patient subsets for whom first-line nilotinib could be of clinical benefit.

FUNDING

Novartis Pharmaceuticals.

Phase III trial of nilotinib versus imatinib as first-line targeted therapy of advanced gastrointestinal stromal tumors (GIST)

10501^

Background: Nilotinib (N) is a Bcr-Abl, KIT, and PDGFR tyrosine kinase inhibitor. This Phase III trial compared N and imatinib (I) as first-line therapy of advanced GIST. Accrual was stopped when a futility boundary was crossed at interim analysis (IA). This final analysis of the core study examined the effect of mutation on outcomes. Methods: Patients (pts) with unresectable and/or metastatic GIST who had no prior antineoplastic therapy or had recurrence ≥6 months (mos) after adjuvant I were randomized 1:1 to open-label N 400 mg bid or I 400 mg qd (400 mg bid for KIT exon 9 mutants). The primary endpoint was progression-free survival (PFS) per adjudicated central review. Enrollment targeted 736 pts to observe 375 events, yielding 90% power to detect a hazard ratio (HR) of 0.71 (median, 28 [N] and 20 [I] mos) with two-sided 5% type I error. Prior to IA, crossover was allowed only for pts with progressive disease (PD); after IA, pts on N with or without PD were offered I. Results: At IA, the PFS HR for N vs I of >1.111 suggested a low probability of N superiority to I. Final analysis was performed in 644 pts; both PFS and OS favored I. In subgroup analysis of 401 pts who had mutational data, there was a large PFS difference favoring I in KIT exon 9 mutants, but similar PFS in KIT exon 11 mutants (Table). Based on immature data, OS favored I in all mutants. Conclusions: The IA showed N could not be superior to I for PFS in the overall population as first-line targeted therapy for pts with advanced GIST. PFS of N and I differed according to molecular subtypes, with PFSfavoring Iin KIT exon 9 mutants but roughly similar in exon 11 mutants. Clinical trial information: NCT00785785. [Table: see text]