Pazopanib in Patients with Osteosarcoma Metastatic to the Lung: Phase 2 Study Results and the Lessons for Tumor Measurement

Background. This single-arm, multicenter, phase 2 study evaluated the safety and antitumor activity of pazopanib in patients with unresectable, pulmonary metastatic osteosarcoma. Patients and Methods. Patients with pulmonary metastatic osteosarcoma unresponsive to chemotherapy were eligible. Patients who received prior tyrosine kinase inhibitor therapy were excluded. Pazopanib at 800 mg once daily was administered for 28-day cycles. Tumor responses were evaluated by local radiology assessment 1 month prior to and after initiation of treatment to calculate tumor doubling time and after every even numbered cycle. The primary endpoints were progression-free survival at 4 months, concomitant with a demonstrated 30% increase in tumor doubling time relative to the pretreatment growth rate. Results. 12 patients (7 female) were enrolled. The study was terminated prematurely due to withdrawal of financial support by the sponsor. 8 subjects were eligible for the primary analysis, whereas 4 patients were in a predefined exploratory “slow-growing” cohort. In the “fast-growing” cohort, 3 of the 8 patients (37.5%) eligible for first-stage analysis were deemed “success” by the preplanned criteria, adequate to proceed to second-stage accrual. In addition, 1 of the 4 patients in the “slow-growing” cohort experienced a partial remission. Grade 1-2 diarrhea was the most common adverse event, and grade 3 events were infrequent. Conclusion. This study illustrates a novel method of demonstrating positive drug activity in osteosarcoma by increasing tumor doubling time, and this is further supported by a partial response in a patient with “slow-growing” disease. This trial is registered with NCT01759303.

A Randomized Phase 2 Trial of Azacitidine ± Durvalumab as First-line Therapy for Higher-Risk Myelodysplastic Syndromes

Azacitidine-mediated hypomethylation promotes tumor cell immune recognition but may increase inhibitory immune checkpoint (ICP) molecule expression. We conducted the first randomized phase 2 study of azacitidine plus the ICP inhibitor durvalumab versus azacitidine monotherapy as first-line treatment of higher-risk myelodysplastic syndromes (HR-MDS). Patients (N=84) received azacitidine 75 mg/m2 subcutaneously (days 1-7) with (Arm A) or without (Arm B) durvalumab 1500 mg intravenously on day 1 every 4 weeks. After a median follow-up of 15.25 months, 8 patients in Arm A and 6 in Arm B remained on treatment. Patients in Arms A and B received a median of 7.9 and 7.0 treatment cycles, respectively, with 73.7% and 65.9% completing ≥4 cycles. The overall response rate (primary endpoint) was 61.9% in Arm A (26/42) and 47.6% in Arm B (20/42; P=0.18), and median overall survival was 11.6 months (95% CI: 9.5, nonevaluable) versus 16.7 months (95% CI: 9.8, 23.5) (P=0.74). Durvalumab-related adverse events (AEs) were reported by 71.1% of patients; azacitidine-related AEs were reported by 82% (A) and 81% (B). Grade 3 or 4 hematologic AEs were reported in (Arm A vs B) 89.5% vs 68.3% of patients. Patients with TP53 mutations tended to have a worse response than patients without these mutations. Azacitidine increased PD-L1 (CD274) surface expression on bone marrow granulocytes and monocytes, but not blasts, in both arms. In summary, combining durvalumab and azacitidine in patients with HR-MDS was feasible, but with more toxicities and without significant improvement in clinical outcomes over azacitidine alone. ClinicalTrials.gov: NCT02775903

Effective GH replacement with once-weekly somapacitan vs daily GH in children with GHD: 3-year results from REAL 3

Context Current GH therapy requires daily injections, which can be burdensome. Somapacitan is a long-acting GH derivative in development for treatment of GH deficiency (GHD). Objective Evaluate the efficacy, safety, and tolerability of once-weekly somapacitan after 3 years of treatment. Design A multicenter, randomized, controlled, phase 2 study comparing somapacitan and once-daily GH for 156 weeks (NCT02616562). Setting Twenty-nine sites in 11 countries. Patients Fifty-nine children with GHD randomized (1:1:1:1) and exposed to treatment. Fifty-three children completed the 3-year period. Interventions Patients received somapacitan (0.04 [n=14], 0.08 [n=15] or 0.16 [n=14] mg/kg/week) or daily GH (n=14) (0.034 mg/kg/day, equivalent to 0.238 mg/kg/week) subcutaneously during the first year, after which all patients on somapacitan received 0.16 mg/kg/week. Main Outcome Measures Height velocity (HV) at year 3; changes from baseline in height standard deviation score (HSDS), HVSDS and IGF-I SDS. Results The estimated treatment difference (95% CI) in HV for somapacitan 0.16/0.16 mg/kg/week versus daily GH at year 3 was 0.8 cm/year (−0.4; 2.1). Change in HVSDS from baseline to year 3 was comparable between somapacitan 0.16/0.16 mg/kg/week, the pooled somapacitan groups, and daily GH. A gradual increase in HSDS from baseline was observed for all groups. At year 3, mean HSDS was similar for the pooled somapacitan groups and daily GH. Change from baseline to year 3 in mean IGF-I SDS was similar across treatments. Conclusions Once-weekly somapacitan in children with GHD showed sustained efficacy over 3 years in all assessed height-based outcomes with similar safety and tolerability to daily GH.

MDM2 antagonist idasanutlin in patients with polycythemia vera: results from a single-arm phase 2 study

Idasanutlin, an MDM2 antagonist, showed clinical activity and rapid reduction in JAK2 V617F allele burden in patients with polycythemia vera (PV) in a phase 1 study. This open-label, phase 2 study evaluated idasanutlin in patients with hydroxyurea (HU)-resistant/intolerant PV, per the European LeukemiaNet criteria, and phlebotomy dependence; prior ruxolitinib exposure was permitted. Idasanutlin was administered once daily, days 1-5 of each 28-day cycle. The primary endpoint was composite response (hematocrit control and spleen volume reduction >35%) in patients with splenomegaly, and hematocrit control in patients without splenomegaly at week 32. Key secondary endpoints included safety, complete hematologic response (CHR), patient-reported outcomes, and molecular responses. All patients (n=27) received idasanutlin; 16 had response assessment (week 32). Among responders with baseline splenomegaly (n=13), 9 (69%) attained any spleen volume reduction and 1 achieved composite response. Nine patients (56%) achieved hematocrit control, and 8 patients (50%) achieved CHR. Overall, 43% of evaluable patients (n=6/14) showed a ≥50% reduction in the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (week 32). Nausea (93%), diarrhea (78%), and vomiting (41%) were the most common adverse events, with grade ≥3 nausea and vomiting experienced in 3 patients (11%) and 1 patient (4%), respectively. Reduced JAK2 V617F allele burden occurred early (after 3 cycles), with a median reduction of 76%, and associated with achieving CHR and hematocrit control. Overall, the idasanutlin dosing regimen showed clinical activity and rapidly reduced JAK2 allele burden in patients with HU-resistant/intolerant PV but was associated with low-grade gastrointestinal toxicity, leading to poor long-term tolerability. Registration: NCT03287245.

ACT-1 Multicenter investigator-initiated registration-directed Phase 2 study of E7090 in subjects with advanced or recurrent solid tumors with fibroblast growth factor receptor (FGFR) gene alteration: FORTUNE trial

Background: Genetic alterations of FGFRs are known to play an important role in the proliferation, survival, and migration of cancer cells as well as tumor angiogenesis and drug resistance. E7090 is an orally available selective tyrosine kinase inhibitor for FGFR1-3. A global Phase 2 study of E7090 in subjects with unresectable advanced or metastatic cholangiocarcinoma harboring FGFR2 gene fusion is ongoing (NCT04238715). We recently reported FGFR alterations that are highly sensitive to E7090 using a high-throughput functional evaluation method called MANO method (Nakamura et al. npj Precision Oncology, 2021), narrowing down the most promising FGFR alteration targets. Here, we designed a single-arm, open-label, investigator-initiated multicenter Phase 2 basket study to evaluate the efficacy and safety of E7090 in subjects with advanced or recurrent solid tumors harboring FGFR gene alterations, focusing on alterations identified by MANO method, as a sub-study under the nationwide large registry for rare cancers in Japan (MASTER KEY Project). Methods: The key eligibility criteria are: 1) Histologically confirmed metastatic or locally advanced solid tumor; 2) Ineffective to or intolerant to first line treatment, or for which standard treatment is no longer available; and 3) Confirmed FGFR gene alterations via next-generation sequencing assays that are reimbursed by insurance. Subjects will receive E7090 140 mg orally once daily until disease progression or development of unacceptable toxicity. The primary endpoint is objective response rate (ORR) by independent central review (RECIST v1.1), and the secondary endpoints include ORR by investigator assessment, progression-free survival, overall survival, disease control rate, safety, duration of response, and time to response. For primary brain tumors, RANO criteria is also applied in assessment of response. The study enrolls approximately 45 subjects. (Clinical Trial Registry: jRCT2031210043, ClinicalTrials.gov: NCT04962867)