An open-label, single-arm phase 2 trial of valemetostat for relapsed or refractory adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATL) is an aggressive non-Hodgkin lymphoma with poor prognosis and few treatment options for patients with relapsed, recurrent, or refractory disease. We evaluated the efficacy and safety of valemetostat, a potent enhancer of zeste homolog 2 (EZH2) and EZH1 inhibitor, in treating relapsed or refractory (R/R) ATL. This multicenter phase 2 trial enrolled patients with R/R aggressive ATL (acute, lymphoma, unfavorable chronic type). Patients received valemetostat 200 mg/day orally until progressive disease or unacceptable toxicity. The primary end point was overall response rate (ORR) centrally assessed by an independent efficacy assessment committee (IEAC). Secondary end points included best response in disease compartments, duration of response (DOR), pharmacokinetics, and safety. Twenty-five patients (median age, 69.0 years) with a median of 3 prior lines of therapy were enrolled; 24 had prior mogamulizumab treatment. The primary end point was met with a centrally reviewed ORR of 48.0% (90% confidence interval [CI], 30.5-65.9), including 5 complete and 7 partial remissions. Patients pretreated with mogamulizumab had an ORR of 45.8% (4 complete and 7 partial remissions). IEAC-assessed median DOR was not reached (NR) (95% CI, 1.87 to NR; months). Treatment-emergent adverse events (TEAEs) were manageable. TEAEs that occurred in ≥20% of patients included thrombocytopenia, anemia, alopecia, dysgeusia, neutropenia, lymphopenia, leukopenia, decreased appetite, and pyrexia. Grade ≥3 TEAEs included thrombocytopenia, anemia, lymphopenia, leukopenia, and neutropenia. Valemetostat demonstrated promising efficacy and tolerability in heavily pretreated patients, warranting further investigation in treating R/R ATL. This trial was registered at www.clinicaltrials.gov as #NCT04102150.

A phase 2 study of axicabtagene ciloleucel in relapsed or refractory large B-cell lymphoma in Japan: 1-year follow-up and biomarker analysis

Axicabtagene ciloleucel (axi-cel) is an autologous, CD19-targeting chimeric antigen receptor T‑cell therapy. We recently reported the 3-month follow-up results of a phase 2, multicenter, open‑label, single-arm study of axi-cel in Japanese patients with relapsed or refractory (R/R) large B-cell lymphoma (LBCL) (JapicCTI-183914). Here, we present 1-year efficacy and safety data and biomarker analysis data regarding mechanisms of resistance to axi-cel. Primary and secondary endpoints included investigator-assessed objective response rate (ORR), serious adverse events, and treatment-emergent adverse events. Axi-cel pharmacokinetics were also examined. Biomarker analysis was performed by cytokine measurement, immunohistochemistry, RNA sequencing, and whole-exome sequencing. At a median follow-up of 13.4 months, ORR was 86.7% (13/15 patients), and the complete response (CR) rate improved to 53.3% (8/15 patients) due to response conversion. Seven patients experienced disease progression, and one achieved CR after re-treatment with axi-cel. No new safety concerns were detected. Plausible resistance mechanisms to axi-cel varied among patients but included CD19 downregulation, programmed death-ligand 1 upregulation, and increased macrophage and angiogenesis signatures. The 1-year efficacy and safety of axi-cel were confirmed in Japanese patients with R/R LBCL. Resistance to treatment may involve multiple factors, including target antigen loss and an unfavorable tumor environment.Clinical trial registration: Japan Clinical Trials Information; JapicCTI-183914.

Phase I dose-escalation study of milademetan in patients with relapsed or refractory acute myeloid leukemia

Long-term survival in patients with acute myeloid leukemia (AML) remains low, and current treatment modalities are inadequate. Milademetan (DS-3032, RAIN-32), a small-molecule specific murine double minute 2 inhibitor, has shown a p53 status-dependent antitumor effect in vitro studies. This is the first phase I study report of milademetan monotherapy in relapsed/refractory (R/R) AML patients evaluating the safety, tolerability, pharmacokinetics, and preliminary tumor response for further clinical development. Fourteen patients received 90 (starting dose, n = 4), 120 (n = 6), or 160 mg (n = 4) of oral milademetan once daily in a 14/28 treatment cycle. The median total treatment duration was 1.5 cycles. Dose-limiting toxicity did not occur, and the maximum tolerated dose was not reached. Thus, the recommended dose was defined as 160 mg. The most common adverse events (AEs) were decreased appetite (64.3%), febrile neutropenia (50%), nausea (42.9%), and anemia (35.7%). No deaths or AEs leading to treatment discontinuation occurred. Five serious treatment-emergent AEs occurred in 4 patients. Plasma concentration increased linearly with milademetan dose. However, trends in the safety and efficacy of oral milademetan in patients with R/R AML warrant further clinical investigation. This study can inform future milademetan studies in hematologic malignancies.

The first-in-human phase I study of a brain-penetrant mutant IDH1 inhibitor DS-1001 in patients with recurrent or progressive IDH1-mutant gliomas

BACKGROUND

Approximately 70% of lower-grade gliomas harbor isocitrate dehydrogenase 1 (IDH1) mutations, resulting in the accumulation of oncometabolite D-2-hydroxyglutarate (D-2-HG); this leads to epigenetic dysregulation, oncogenesis, and subsequent clonal expansion. DS-1001 is an oral brain-penetrant mutant IDH1 selective inhibitor. This first-in-human study investigated the safety, pharmacokinetics, pharmacodynamics, and efficacy of DS-1001.

METHODS

This was a multicenter, open-label, dose-escalation, phase I study of DS-1001 for recurrent/progressive IDH1-mutant (R132) glioma (N = 47) (NCT03030066). DS-1001 was administered orally at 125-1400 mg twice daily. Dose-escalation used a modified continual reassessment method.

RESULTS

The maximum tolerated dose was not reached. Eight patients were continuing treatment at the data cutoff. Most adverse events (AEs) were grade 1-2. Twenty patients (42.6%) experienced at least 1 grade 3 AE. No grade 4 or 5 AEs or serious drug-related AEs were reported. Common AEs (>20%) were skin hyperpigmentation, diarrhea, pruritus, alopecia, arthralgia, nausea, headache, rash, and dry skin. The objective response rates were 17.1% for enhancing tumors and 33.3% for non-enhancing tumors. Median progression-free survival was 10.4 months (95% confidence interval [CI], 6.1 to 17.7 months) and not reached (95% CI, 24.1 to not reached) for the enhancing and non-enhancing glioma cohorts, respectively. Seven on-treatment brain tumor samples showed a significantly lower amount of D-2-HG compared with pre-study archived samples.

CONCLUSIONS

DS-1001 was well tolerated with a favorable brain distribution. Recurrent/progressive IDH1-mutant glioma patients responded to treatment. A study of DS-1001 in patients with chemotherapy- and radiotherapy-naïve IDH1-mutated WHO grade 2 glioma is ongoing (NCT04458272).

Sapropterin for phenylketonuria: A Japanese post-marketing surveillance study

BACKGROUND

The aim of this study was to assess the long-term safety and efficacy of sapropterin in a real-world setting in Japanese patients with tetrahydrobiopterin (BH4)-responsive phenylketonuria.

METHODS

This post-marketing surveillance study enrolled all of the patients in Japan with confirmed BH4-responsive PKU who were administrated sapropterin between July 2008 and October 2017. Patients were observed at least every 3 months during follow up, with key data collected on treatment exposure/duration, effectiveness according to physician's judgement, serum phenylalanine levels, and adverse events.

RESULTS

Of 87 enrolled patients, 85 patients (male, 42.4%; outpatients, 96.5%) were included in the safety and efficacy analysis sets. Treatment started at age <4 years in 43 (50.6%) patients and the most common starting daily dose was 5-10 mg/kg (n = 41, 48.2%) with the overall duration of treatment between 0.2 and 17.2 years. Serum phenylalanine levels, according to loading tests, reduced from a baseline level of 9.66 mg/dL (range 0.48-36.80 mg/dL) by >30% in 84 patients. Treatment was deemed effective in 79 of 85 patients (92.9%, 95% confidence interval: 85.3-97.4). One patient (1.2%) experienced an adverse drug reaction (alanine aminotransferase increased) 50 days after the start of administration, which resolved without complications with continued treatment.

CONCLUSIONS

Sapropterin appears well tolerated and highly effective in Japanese patients treated in a real-world setting, including those who start treatment at age <4 years and pregnant women.

Safety and pharmacokinetics of milademetan, a MDM2 inhibitor, in Japanese patients with solid tumors: A phase I study

Milademetan (DS‐3032, RAIN‐32) is an orally available mouse double minute 2 (MDM2) antagonist with potential antineoplastic activity owing to increase in p53 activity through interruption of the MDM2‐p53 interaction. This phase I, dose‐escalating study assessed the safety, tolerability, efficacy, and pharmacokinetics of milademetan in 18 Japanese patients with solid tumors who relapsed after or were refractory to standard therapy. Patients aged ≥ 20 years received oral milademetan once daily (60 mg, n = 3; 90 mg, n = 11; or 120 mg, n = 4) on days 1 to 21 in a 28‐day cycle. Dose‐limiting toxicities, safety, tolerability, maximum tolerated dose, pharmacokinetics, and recommended dose for phase II were determined. The most frequent treatment‐emergent adverse events included nausea (72.2%), decreased appetite (61.1%), platelet count decreased (61.1%), white blood cell count decreased (50.0%), fatigue (50.0%), and anemia (50.0%). Dose‐limiting toxicities (three events of platelet count decreased and one nausea) were observed in the 120‐mg cohort. The plasma concentrations of milademetan increased in a dose‐dependent manner. Stable disease was observed in seven out of 16 patients (43.8%). Milademetan was well tolerated and showed modest antitumor activity in Japanese patients with solid tumors. The recommended dose for phase II was considered to be 90 mg in the once‐daily 21/28‐day schedule. Future studies would be needed to further evaluate the potential safety, tolerability, and clinical activity of milademetan in patients with solid tumors and lymphomas. The trial was registered with Clinicaltrials.jp: JapicCTI‐142693.

A dose-finding approach for genomic patterns in phase I trials

Precision medicine is an emerging approach for disease treatment and prevention that accounts for individual variability in genes, environment, and lifestyle. Cancer is a genomic disease; therefore, the dose-efficacy and dose-toxicity relationships for molecularly targeted agents in cancer most likely differ, based on the genomic mutation pattern. The individualized optimal dose - the maximal efficacious dose with a clinically acceptable safety profile - may vary depending on the genomic mutation patterns and should be determined prior to the use of these agents in precision medicine. In addition, genes that influence the individualized optimal doses should be identified in early-phase development. In this study, we propose a novel dose-finding approach to identify the individualized optimal dose for molecularly targeted agents in phase I cancer trials. Individualized optimal dose determination and gene selection were conducted simultaneously based on L ₁ and L ₂ penalized regression. Similar to most reported dose-finding approaches, this study considers non-monotonic patterns for dose-efficacy and dose-toxicity relationships, as well as correlations between efficacy and toxicity outcomes based on multinomial distribution. Our dose-finding algorithm is based on the predictive probability calculated with an estimated penalized regression model. We compare the operating characteristics between the proposed and existing methods by simulation studies under various scenarios.

ACT-14 A FIRST-IN-HUMAN STUDY OF MUTANT IDH1 INHIBITOR DS-1001B IN PATIENTS WITH RECURRENT GLIOMAS

BACKGROUND

WHO grade II/III gliomas frequently harbor isocitrate dehydrogenase 1 (IDH1) mutations, resulting in intratumoral accumulation of oncometabolite D-2-hydroxyglutarate (D-2-HG) and subsequent clonal expansion. DS-1001b is an oral selective inhibitor of mutant IDH1 R132X that was designed to penetrate the blood-brain barrier.

METHODS

In this first-in-human, multicenter, phase I study (NCT03030066), eligible patients (pts) with recurrent/progressive IDH1 mutant glioma received DS-1001b twice daily (bid), continuous. A modified continual reassessment method was used for dose escalation. RANO and RANO-LGG criteria were used to assess tumor response. Pts who planned to undergo salvage surgery after developing progressive disease (PD) and who provided informed consent received DS-1001b treatment until surgery. Tumor samples were also obtained from those pts to measure the free form of DS-1001b and D-2-HG levels.

RESULTS

Between Jan 2017 and May 2019, DS-1001b (125–1400 mg bid) had administered for 47 pts, and 15 pts were continuing treatment. Maximum tolerated dose (MTD) was not reached. Most AEs were Gr 1–2. Gr 3 AEs were observed in 40% of pts. No Gr 4 or 5 AEs or serious drug-related AEs were reported. One dose limiting toxicity was Gr 3 white blood cell count decreased (1000 mg bid). Of 35 evaluable pts with contrast enhancing gliomas, one, five and 11 achieved complete response, partial response and stable disease (SD), respectively. Of evaluable 12 pts with contrast non-enhancing gliomas, four achieved minor response and eight achieved SD. Peak plasma concentration (Cmax) and area under the curve (AUC) increased dose-dependently.

CONCLUSIONS

DS-1001b was well tolerated up to 1400 mg bid with favorable brain distribution, and MTD was not reached. Recurrent/progressive IDH1 mutant glioma pts responded to treatment. Investigation is ongoing to determine the recommended Phase II dose. The latest data will be updated. Funding source: This study was funded by Daiichi Sankyo Co., Ltd.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of the afucosylated, humanized anti-EPHA2 antibody DS-8895a: a first-in-human phase I dose escalation and dose expansion study in patients with advanced solid tumors

Background

Erythropoietin-producing hepatocellular receptor A2 (EPHA2) is overexpressed on the cell surface in many cancers and predicts poor prognosis. DS-8895a is a humanized anti-EPHA2 IgG1 monoclonal antibody afucosylated to enhance antibody-dependent cellular cytotoxicity activity. We conducted a two-step, phase I, multicenter, open-label study to determine the safety, tolerability, and pharmacokinetics of DS-8895a in patients with advanced solid tumors.

Methods

Step 1 was a dose escalation cohort in advanced solid tumor patients (six dose levels, 0.1–20 mg/kg) to determine Step 2 dosing. Step 2 was a dose expansion cohort in EPHA2-positive esophageal and gastric cancer patients. DS-8895a was intravenously administered every 2 weeks for the duration of the study, with a 28-day period to assess dose-limiting toxicity (DLT). Safety, pharmacokinetics, tumor response, and potential biomarkers were evaluated.

Results

Thirty-seven patients (Step 1: 22, Step 2: 15 [9: gastric cancer, 6: esophageal cancer]) were enrolled. Although one DLT (Grade 4 platelet count decreased) was observed in Step 1 (dose level 6, 20 mg/kg), the maximum tolerated dose was not reached; the highest dose (20 mg/kg) was used in Step 2. Of the 37 patients, 24 (64.9%) experienced drug-related adverse events (AEs) including three (8.1%) with Grade ≥ 3 AEs. Infusion-related reactions occurred in 19 patients (51.4%) but were manageable. All patients discontinued the study (evident disease progression, 33; AEs, 4). Maximum and trough serum DS-8895a concentrations increased dose-dependently. One gastric cancer patient achieved partial response and 13 patients achieved stable disease. Serum inflammatory cytokines transiently increased at completion of and 4 h after the start of DS-8895a administration. The proportion of CD16-positive natural killer (NK) cells (CD3⁻CD56⁺CD16⁺) decreased 4 h after the start of DS-8895a administration, and the ratio of CD3⁻CD56⁺CD137⁺ to CD3⁻CD56⁺CD16⁺ cells increased on day 3.

Conclusions

Twenty mg/kg DS-8895a infused intravenously every 2 weeks was generally safe and well tolerated in patients (n = 21) with advanced solid tumors. The exposure of DS-8895a seemed to increase dose-dependently and induce activated NK cells.

Trial registration

Phase 1 Study of DS-8895a in patients with advanced solid tumors (NCT02004717; 7 November 2013 to 2 February 2017); retrospectively registered on 9 December 2013.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0679-9) contains supplementary material, which is available to authorized users.

Phase I study of a brain penetrant mutant IDH1 inhibitor DS-1001b in patients with recurrent or progressive IDH1 mutant gliomas

2004

Background: WHO grade II/III gliomas frequently harbor isocitrate dehydrogenase 1 ( IDH1) mutations, resulting in intratumoral accumulation of oncometabolite 2-hydroxyglutarate (2-HG) and subsequent clonal expansion. DS-1001b is an oral selective inhibitor of mutant IDH1 R132X that was designed to penetrate the blood-brain barrier. Methods: In this first-in-human, multicenter, phase I study (NCT03030066), eligible patients (pts) with recurrent/progressive IDH1 mutant glioma received DS-1001b twice daily (bid), continuous. A modified continual reassessment method was used for dose escalation. RANO and RANO-LGG criteria were used to assess tumor response. Pts who planned to undergo salvage surgery after developing progressive disease (PD) and who provided informed consent received DS-1001b treatment until surgery. Tumor samples were also obtained from those pts to measure the free form of DS-1001b and 2-HG levels. Results: Between Jan 2017 and Oct 2018, DS-1001b (125-1400 mg bid) had administered for 45 pts (median age 44 yrs, prior radiation therapy 100%, prior chemotherapy 82%), and 17 pts were continuing treatment. Maximum tolerated dose (MTD) was not reached. Most AEs were Gr 1-2. Gr 3 AEs were observed in 42.2% of pts. No Gr 4 or 5 AEs or serious drug-related AEs were reported. One dose limiting toxicity was Gr 3 white blood cell count decreased (1000 mg bid). Common AEs ( > 20%) were skin hyperpigmentation, diarrhea, pruritus, nausea, rash, and headache. Of 29 evaluable pts with contrast enhancing gliomas, one, three and 10 achieved complete response, partial response and stable disease (SD), respectively. Of evaluable nine pts with contrast non-enhancing gliomas, two achieved minor response and seven achieved SD. Peak plasma concentration (Cmax) and area under the curve (AUC) increased dose-dependently. The brain/plasma ratio of free form of DS-1001b ranged 0.19‒0.77 in 3 pts. Conclusions: DS-1001b was well tolerated up to 1400 mg bid with favorable brain distribution, and MTD was not reached. Recurrent/progressive IDH1 mutant glioma pts responded to treatment. Investigation is ongoing to determine the recommended Phase II dose. Clinical trial information: NCT03030066.

Dose escalation and expansion cohort study for DS-8895a in patients with advanced solid tumors

99

Background: Erythropoietin-producing hepatocellular receptor A2 (EPHA2) is overexpressed on the cell surface of many tumors and is associated with poor prognosis, suggesting EPHA2 as a target for cancer therapy. DS-8895a is an afucosylated, humanized anti-EPHA2 IgG1 monoclonal antibody with potent cytotoxicity. We report results from a phase I clinical trial to determine safety, tolerability, and pharmacokinetics (PK) of DS-8895a in Japanese patients with advanced solid tumors (NCT02004717). Methods: Step 1 (dose escalation cohort) had patients with advanced solid tumors and comprised of six dose levels (0.1–20 mg/mL, intravenous infusion, every 2 weeks [Q2W]) with a 28-day dose limiting toxicity (DLT) evaluation period. Step 2 (expansion cohort) patients had gastric or esophageal cancer confirmed to be EPHA2 positive by immunohistochemistry. Dose level in Step 2 was determined based on results obtained in Step 1. We evaluated safety, PK, potential biomarkers including circulating NK cells and cytokines, and tumor response. Results: Maximum tolerated dose was not reached in Step 1 (n = 22). DS-8895a was administered at 20 mg/kg Q2W in Step 2 (n = 15). Among 37 patients in the safety analysis set, adverse events (AEs) were reported in 97.3% (64.9% drug-related); 35.1% presented grade ≥ 3 AEs (8.1% drug-related). Dose delay and study discontinuation due to AEs (treatment related: grade 4 platelet decrease, hypoesthesia, hypotension, peripheral coldness, nausea, and vomiting) were observed in one and four patients (20 mg/kg), respectively. Infusion-related reactions occurred in 51.4% of patients resulting in 10 dose interruptions with one discontinuation. Serum inflammatory cytokines were transiently increased 4 h from the end of infusion drug administration. Serum DS-8895a maximum and trough concentrations increased dose-dependently. Biomarkers had no apparent relationship to best overall response. Seven patients in Step 1 achieved stable disease; in Step 2, six patients achieved stable disease and one patient achieved partial response. Conclusions: DS-8895a was safe and well tolerated up to 20 mg/kg. The PK of DS-8895a was dose-dependent as expected. Clinical trial information: NCT02004717.

A randomized, double-blind study of hydromorphone hydrochloride extended-release tablets versus oxycodone hydrochloride extended-release tablets for cancer pain: efficacy and safety in Japanese cancer patients (EXHEAL: a Phase III study of EXtended-release HydromorphonE for cAncer pain reLief)

BACKGROUND

In Japan, there are limited options for switching opioid analgesics. Hydromorphone is an opioid analgesic that is routinely used instead of morphine for cancer pain; however, it is not yet available in Japan. The aim of this study was to assess the efficacy and safety of hydromorphone (DS-7113b) extended-release tablets in opioid-naïve patients with cancer pain not relieved by non-opioid analgesics.

SUBJECTS AND METHODS

This was a multicenter, randomized, double-blind, parallel-group trial. A double-dummy method was used for blinding. Each randomized subject received either hydromorphone extended-release tablets plus placebo oxycodone hydrochloride extended-release tablets 4 mg/day (n=88) or placebo hydromorphone extended-release tablets plus oxycodone hydrochloride extended-release tablets 10 mg/day (n=93) orally for 7 days (once-daily dosing for hydromorphone and twice-daily dosing for oxycodone). The doses were adjusted as necessary. Efficacy was evaluated by change in visual analog scale (VAS) score from baseline to completion of treatment.

RESULTS

The between-group difference in least squares mean changes in VAS score from baseline to completion or discontinuation of treatment was -0.4 mm (95% CI -5.9 to 5 mm) by analysis of covariance where the baseline VAS score was used as a covariate. The upper limit of the 95% CI was below 10 mm, which was predefined as the noninferiority limit. This verified the noninferiority of hydromorphone tablets relative to oxycodone tablets. The incidence of adverse events was 80.7% (71 of 88) in the hydromorphone group and 83.7% (77 of 93) in the oxycodone group. The most common adverse events were nausea, vomiting, somnolence, diarrhea, and constipation, most of which are commonly observed with opioid analgesics.

CONCLUSION

The efficacy and safety of hydromorphone extended-release tablets were equivalent to those of the oxycodone extended-release formulation.

A Dose-Finding Method Based on Multiple Dosing in Two-Agent Combination Phase I Trials

Here, we developed a new dose-finding method that partitions a cohort of patients based on the number of dose combinations within a prespecified acceptable toxicity range in two-agent combination Phase I trials. In the proposed method, patients in the same cohort are partitioned according to several dose combinations, although most of the existing methods allocate patients in the same cohort according to a single-dose combination. We compared the operating characteristics of the proposed and existing methods through simulation studies.