Abstract CT216: A Phase 1/2 Study of INCB000928 as Monotherapy or in Combination with Ruxolitinib in Patients with Anemia Due to Myelofibrosis (INCB 00928-104)

Background: Anemia represents a therapeutic challenge in patients with myelofibrosis (MF). ALK2 activation is associated with elevated hepcidin, which may contribute to anemia of chronic disease and anemia due to hematologic malignancies, and is associated with increased transfusion rate and reduced overall survival. This phase 1/2, open-label, multicenter, dose-escalation/dose-expansion study will evaluate the safety and tolerability of INCB000928, a potent, highly selective, ALK2 inhibitor, as monotherapy or combined with ruxolitinib in patients with anemia due to MF (INCB 00928-104; NCT04455841). Methods: Patients with histologically confirmed primary/secondary MF presenting with transfusion-dependent or symptomatic anemia will receive oral INCB000928 either alone (treatment group [TG] A) or combined with ruxolitinib (TGB). In TGA, patients must have intermediate (INT)-2 or high-risk (per Dynamic International Prognostic Scoring System [DIPSS]) disease that is intolerant, resistant, refractory, or has lost response to prior JAK inhibitor therapy (≥12 weeks). In TGB, patients must have received stable ruxolitinib therapy for ≥12 consecutive weeks before first dose and have INT-1/INT-2, or high-risk disease. Eligibility also requires age ≥18 y, ECOG PS 0-1 (dose-escalation) or 0-2 (dose-expansion), life expectancy >6 months, no other hematologic malignancy, no prior stem cell transplantation, no major surgery within 28 days, and no prior disease-directed therapy within 5 half-lives or 28 days of first dose. In Part 1 (dose escalation), TGA will receive INCB000928 monotherapy starting at 50 mg/day (28-day cycles). Dose-escalation will follow a Bayesian optimal-interval design to determine the maximum tolerated dose (MTD) and/or recommended dose for expansion (RDE). Dose increases not exceeding 2-fold will continue until Grade ≥2 treatment-related toxicity occurs. TGB will receive INCB000928 plus ruxolitinib; INCB000928 dose escalation will start 2 dose levels below the highest dose determined to be safe and tolerable in TGA. In Part 2 (dose expansion), the RDE in TGB will be evaluated in combination with ruxolitinib in ~25 patients; treatment will continue for ≤12 months, and may continue if clinically beneficial and no progression occurs. Primary objective is to determine the safety and tolerability of INCB000928 as monotherapy or combined with ruxolitinib. Secondary objectives are to determine the efficacy of INCB000928 as monotherapy or combined with ruxolitinib (anemia response, duration of anemia response, mean change from baseline in hemoglobin, and RBC transfusion rate through weeks 24 and 48); evaluate INCB000928 pharmacokinetics; and evaluate effects of INCB000928 as monotherapy or combined with ruxolitinib on hepcidin levels and other measures of iron homeostasis and erythropoiesis.

Citation Format: Stephen T. Oh, Jean-Jacques Kiladjian, Francesca Palandri, Jason R. Gotlib, Sanjay Mohan, Haris Ali, Ekatherine Asatiani, Francis Seguy, Feng Zhou, Srdan Verstovsek. A Phase 1/2 Study of INCB000928 as Monotherapy or in Combination with Ruxolitinib in Patients with Anemia Due to Myelofibrosis (INCB 00928-104) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT216.

A phase 3 study to evaluate the efficacy and safety of tafasitamab plus lenalidomide and rituximab versus placebo plus lenalidomide and rituximab in patients with relapsed/refractory (R/R) follicular lymphoma (FL) or marginal zone lymphoma (MZL)

TPS7568

Background: Most patients with the indolent non-Hodgkin lymphoma (NHL) subtypes FL or MZL respond to first-line treatment but relapse is common, and there is no single standard treatment for patients with R/R FL or MZL. Tafasitamab is an Fc-engineered humanized monoclonal antibody (mAb) against CD19 which is broadly expressed in FL and MZL, and regulates B-cell proliferation via B-cell receptor signaling. In preclinical studies, tafasitamab has shown activity against NHL cell lines in combination with rituximab (anti-CD20 mAb) and lenalidomide (LEN). Tafasitamab monotherapy has shown promising clinical activity in a phase 2a study in patients with R/R NHL (NCT01685008), with an ORR of 29% (n/N = 10/34) in patients with FL and 33% (n/N = 3/9) in patients with MZL. In an ongoing phase 2, single-arm study (L-MIND, NCT02399085), tafasitamab plus LEN followed by tafasitamab alone demonstrated an ORR of 57.5% (n/N = 46/80) in patients with R/R diffuse large B-cell lymphoma (FDA approved indication). These preclinical and clinical observations from phase 2 trials suggest a potential clinical benefit of tafasitamab plus LEN and rituximab for patients with R/R FL or MZL. Methods: This phase 3 double-blind, placebo-controlled, randomized study is designed to investigate whether tafasitamab plus LEN and rituximab provides improved clinical benefit compared with LEN and rituximab in patients with R/R FL or R/R MZL. Patients will be randomized 1:1 to receive tafasitamab (12 mg/kg IV on days 1, 8, 15, and 22 of a 28-day cycle [cycles 1–3], then days 1 and 15 [cycles 4–12]) plus LEN (20 mg PO QD, days 1–21/ cycle for 12 cycles) and rituximab (375 mg/m2 IV on days 1, 8, 15, and 22 of cycle 1, then day 1 of cycles 2–5), or placebo (0.9% saline solution IV) plus LEN and rituximab. The primary study endpoint is PFS (investigator assessed [INV] by Lugano 2014 criteria) for patients with FL. Key secondary endpoints are PFS (INV) in overall population (FL and MZL), PET-CR rate (INV) at end of treatment (4–8 weeks after last treatment) and OS in patients with FL. Inclusion criteria include age ≥18 y, histologically confirmed FL (grade 1, 2, or 3a) or MZL (nodal, splenic, or extranodal), documented R/R disease, ≥1 prior systemic anti-CD20 therapy (including anti-CD20 refractory disease), ECOG PS ≤2, adequate systemic organ function, and high tumor burden (per GELF criteria). Exclusion criteria include prior rituximab plus LEN treatment, history of radiotherapy for other diseases (≥25% of bone marrow), nonhematologic malignancy, congestive heart failure (LVEF < 50%), active systemic infection, known CNS lymphoma, or severe immunocompromised state. inMIND (NCT04680052, EudraCT2020-004407-13) is currently enrolling patients; planned enrollment is 528 patients with R/R FL and 60–90 patients with R/R MZL. Clinical trial information: NCT04680052.

Phase I pharmacological and bioavailability study of oral diflomotecan (BN80915), a novel E-ring-modified camptothecin analogue in adults with solid tumors

PURPOSE

Diflomotecan (BN80915) is an E-ring modified camptothecin analogue that possesses greater lactone stability in plasma compared with other topoisomerase I inhibitors, a potential advantage for antitumor activity. As with other camptothecins, oral administration has pharmacological and clinical advantages. This Phase I study was performed to assess the feasibility of the administration of oral diflomotecan, to determine the maximum-tolerated, dose its bioavailability, and to explore the pharmacokinetics.

EXPERIMENTAL DESIGN

An initial i.v. bolus was administered to assess the bioavailability of diflomotecan. Fourteen days later, diflomotecan was administered p.o. once daily for 5 days to adult patients with solid malignant tumors and repeated every 3 weeks. BN80915 and its open lactone form BN80942 were measured.

RESULTS

Twenty-two patients entered the study and received a total of 57 cycles of oral diflomotecan at flat dose levels of 0.10, 0.20, 0.27, and 0.35 mg. The main toxicity was hematological, but some patients experienced alopecia, mild gastrointestinal toxicity, and fatigue. At the 0.35-mg dose level, 2 of 4 patients experienced dose-limiting toxicity comprising grade 3 thrombocytopenia with epistaxis and febrile neutropenia in 1 patient and uncomplicated grade 4 neutropenia lasting for >7 days in another. Toxicity was acceptable at the 0.27-mg dose level at which dose-limiting toxicities were observed in 3 of 12 patients (grade 4 neutropenia > 7 days, complicated by fever in 1 patient but without other signs of infection). After two cycles of diflomotecan, 6 patients had disease stabilization, which was maintained in 2 patients for 9 months and >1 year, respectively. Diflomotecan pharmacokinetics were linear over the dose range studied. Systemic exposure correlated with the fall in WBC counts. The mean oral bioavailability (+/-SD) was 72.24 +/- 59.2% across all dose levels. Urinary excretion of BN80915 was very low.

CONCLUSIONS

The recommended oral diflomotecan dose for Phase II studies is 0.27 mg/day x 5 every 3 weeks. This regimen is convenient and generally well tolerated with a favorable pharmacokinetic profile and high but variable bioavailability.

Behavioural effects of peripherally injected interleukin-1: role of prostaglandins

To investigate the possible mediation by prostaglandins of changes in behaviour induced by peripheral injection of interleukin-1 (IL-1), two types of behavioural tests were chosen, social exploration in mice and schedule-controlled behaviour in rats. Mice treated with 1 and 2.5 micrograms recombinant human IL-1 beta showed a time- and dose-dependent decrease in exploration of a juvenile conspecific. This effect was completely blocked by pretreatment with 10 mg/kg indomethacin or 10 mg/kg piroxicam, but not with 50 mg/kg aspirin. The disruption of operant responding induced by 5 micrograms IL-1 in rats was also suppressed by pretreatment with 5 mg/kg indomethacin or 10 mg/kg piroxicam. These results indicate that prostaglandins mediate the behavioural effects of peripherally injected IL-1.