An innovative, multi-arm, complete phase 1b study of the novel anti-cancer agent tasisulam in patients with advanced solid tumors.

BACKGROUND: This phase Ib study used a parallel, multi-arm design to examine tasisulam-sodium (hereafter tasisulam), a drug with complex pharmacology, combined with standard chemotherapies in patients with advanced solid tumors, with the ultimate goal of accelerating drug development. METHODS: Patients received escalating doses of tasisulam (3 + 3 schema; target Cmax 300-400 µg/mL) every 28 days plus 1,000 mg/m(2) gemcitabine HCl (days 1 and 15), 60 mg/m(2) docetaxel, 200 mg/m(2)/day temozolomide, 75 mg/m(2) cisplatin, or 150 mg/day erlotinib. Following dose-escalation, patients were enrolled into specific tumor subtype arms, chosen based on the established activity of the standard agent. Because tasisulam is highly albumin-bound, patients in the tumor-specific confirmation arms were dosed targeting specific albumin-corrected exposure ranges (AUCalb) identified during dose-escalation (3,500 h*µg/mL [75th percentile] for docetaxel, temozolomide, and cisplatin; 4,000 h*µg/mL for gemcitabine and erlotinib). RESULTS: A total of 234 patients were enrolled. The safety profile of tasisulam with standard chemotherapies was sufficient to allow enrollment into the dose-confirmation phase in all arms. The primary dose-limiting toxicities were hematologic (thrombocytopenia and neutropenia). The most common grade ≥3 drug-related treatment-emergent adverse event was neutropenia, with the highest incidence in the docetaxel arm. CONCLUSIONS: The multi-arm design allowed the efficient determination of the maximum tolerated dose of tasisulam across multiple combinations, and a preliminary characterization of pharmacokinetics, safety, and potential efficacy. Although enrollment into all planned groups was not completed due to termination of compound development, these data support the feasibility of this approach for accelerated cancer drug development, even for drugs with complex pharmacology.

Real-World Outcomes of Trilaciclib Among Patients with Extensive-Stage Small Cell Lung Cancer Receiving Chemotherapy.

INTRODUCTION: Trilaciclib was recently approved in the USA for reducing chemotherapy-induced myelosuppression (CIM) among adults with extensive-stage small cell lung cancer (ES-SCLC) when administered prior to chemotherapy. There is limited understanding of real-world outcomes of trilaciclib. METHODS: A comprehensive literature review was conducted using a keyword search in the MEDLINE, Embase, and conference abstracts. Additional studies were identified through communications with the authors of relevant studies. Published and unpublished real-world studies of trilaciclib- and comparable non-trilaciclib-treated patients with ES-SCLC were included. Evidence on myelosuppressive hematologic adverse events (HAEs), cytopenia-related healthcare utilization, and other reported outcomes (e.g., hospitalizations, dose reduction, and treatment delay) were synthesized. If feasible, outcomes were compared qualitatively between the trilaciclib and historical reference groups, and between first-line trilaciclib initiators and the overall trilaciclib population. Weighted averages were estimated for selected outcomes using sample size as the weight. RESULTS: The literature search identified five unique studies based on eight records-two included trilaciclib only, two non-trilaciclib only, and one both. In trilaciclib cohorts, the weighted average prevalence of grade ≥ 3 myelosuppressive HAEs in ≥ 1 lineage, ≥ 2 lineages, and all three lineages was 40.5%, 14.5%, and 7.5%, respectively. All rates were numerically lower compared to the historical non-trilaciclib cohorts (58.8%, 28.0%, 13.0% respectively). Cytopenia-related healthcare utilization was also lower in the trilaciclib cohorts. In general, first-line trilaciclib initiators had numerically lower myelosuppressive HAEs and cytopenia-related healthcare utilization than the overall trilaciclib patients. CONCLUSIONS: The existing evidence suggests that trilaciclib may reduce single and multilineage grade ≥ 3 myelosuppressive HAEs and cytopenia-related healthcare utilization among patients with ES-SCLC in the real world. It is a promising new treatment for CIM prevention in ES-SCLC and may bring greater benefits to first-line trilaciclib initiators. Future studies are recommended to further evaluate the real-world effectiveness of trilaciclib.

Results of a phase II study of pemetrexed as first-line chemotherapy in patients with advanced or metastatic breast cancer.

Palliation is the primary goal in metastatic breast cancer (MBC), and safe, efficacious, new single-agent options are needed. Pemetrexed, an antifolate, inhibits several folate-dependent enzymes involved in purine biosynthesis. The primary goal of this study was to determine the objective response rate in patients with advanced or MBC given pemetrexed as a first-line, dose-dense, every 2-week chemotherapy. Women with HER2-negative advanced or MBC, without prior cytotoxic treatment for this stage of disease, were treated with intravenous pemetrexed 600 mg/m² on Day 1 of each 14-day cycle. Standard dexamethasone, folic acid, and vitamin B(12) premedications were given. 37 patients enrolled; 36 received ≥ 1 dose of pemetrexed and 35 were evaluable for response. Median age of patients was 61.4 years, 76% were hormone receptor positive (ER+ and/or PR+). Prior treatment included adjuvant chemotherapy (57%) and/or endocrine (65%). Patients received a median of 6 cycles of pemetrexed (range, 1-21). Based on 35 evaluable patients, the overall response rate (ORR) was 26% (1 CR and 8 PR), and the clinical benefit rate (CR+ PR+ stable disease [SD] ≥ 6 months) was 40%. Median progression-free survival (PFS) was 4.1 months (range, <1-22.4). Median overall survival (OS) was 18.9 months (range, <1-27.7). Grades 3-4 treatment-related toxicities included: neutropenia (36%), leukopenia (17%), fatigue (14%), and anemia (14%). Grade 1/2 alopecia was seen in 8% of patients. This phase II study of dose-dense, single-agent pemetrexed showed moderate activity in the first-line setting with acceptable toxicity and no significant alopecia.

Trilaciclib dose selection: an integrated pharmacokinetic and pharmacodynamic analysis of preclinical data and Phase Ib/IIa studies in patients with extensive-stage small cell lung cancer.

PURPOSE: Trilaciclib is a first-in-class CDK4/6 inhibitor that transiently arrests hematopoietic stem and progenitor cells (HSPCs) in the G1 phase of the cell cycle to preserve them from chemotherapy-induced damage (myelopreservation). We report integrated analyses of preclinical and clinical data that informed selection of the recommended Phase II dose (RP2D) used in trilaciclib trials in extensive-stage small cell lung cancer (ES-SCLC). METHODS: A semi-mechanistic pharmacokinetic/pharmacodynamic (PK/PD) model developed from preclinical data guided selection of an optimal dose for G1 bone marrow arrest in a first-in-human Phase I study (G1T28-1-01). PK, PD, safety, and efficacy data from G1T28-1-01 and two Phase Ib/IIa studies (G1T28-02/-03) in ES-SCLC were analyzed to support RP2D selection. RESULTS: Model simulation of bone marrow arrest based on preclinical data predicted that a ≥ 192 mg/m2 dose would induce a 40-50% decrease in total bone marrow proliferation in humans and almost 100% cell cycle arrest of cycling HSPCs. Consistent with this model, analysis of bone marrow aspirates in healthy volunteers after trilaciclib 192 mg/m2 administration demonstrated almost 100% G1 arrest in HSPCs and 40% decrease in total bone marrow proliferation, with minimal toxicity. G1T28-02/-03 reported similar PK parameters with trilaciclib 200 mg/m2 but slightly lower exposures than expected compared with healthy volunteers; consequently, 240 and 280 mg/m2 doses were also tested to match healthy volunteer exposures. Based on PK and relevant safety data, 240 mg/m2 was selected as the RP2D, which was also favored by myelopreservation endpoints in G1T28-02/-03. CONCLUSION: Integrated PK/PD, safety, and efficacy data support 240 mg/m2 as the RP2D for trilaciclib. CLINICALTRIALS. GOV IDENTIFIERS: NCT02243150; NCT02499770; NCT02514447.

A Phase Ib multicenter, dose-escalation study of the polyamine analogue PG-11047 in combination with gemcitabine, docetaxel, bevacizumab, erlotinib, cisplatin, 5-fluorouracil, or sunitinib in patients with advanced solid tumors or lymphoma.

PURPOSE: Polyamines are absolutely essential for maintaining tumor cell proliferation. PG-11047, a polyamine analogue, is a nonfunctional competitor of the natural polyamine spermine that has demonstrated anticancer activity in cells and animal models of multiple cancer types. Preclinical investigations into the effects of common chemotherapeutic agents have revealed overlap with components of the polyamine metabolic pathway also affected by PG-11047. This report describes a Phase Ib clinical trial investigating PG-11047 in combination with cytotoxic and anti-angiogenic chemotherapeutic agents in patients with advanced refractory metastatic solid tumors or lymphoma. METHODS: A total of 172 patients were assigned to treatment arms based on cancer type to receive the appropriate standard-of-care therapy (gemcitabine, docetaxel, bevacizumab, erlotinib, cisplatin, 5-fluorouracil (5-FU), or sunitinib as directed) along with once weekly intravenous infusions of PG-11047. PG-11047 dose escalation ranged from 50 to 590 mg. RESULTS: The maximum tolerated dose (MTD) of PG-11047 in combination with bevacizumab, erlotinib, cisplatin, and 5-FU was 590 mg. Dose-limiting toxicities (DLTs) in these groups were rare (5 of 148 patients). Overall partial responses (PR) were observed in 12% of patients treated with PG-11047 and bevacizumab, with stable disease documented in an additional 40%. Stable disease occurred in 71.4% of patients in the 5-FU arm, 54.1% in the cisplatin arm, and 33.3% in the erlotinib arm. Four of the patients receiving cisplatin + PG-11047 (20%) had unconfirmed PRs. MTDs for gemcitabine, docetaxel, and sunitinib could not be determined due to DLTs at low doses of PG-11047 and small sample size. CONCLUSIONS: Results of this Phase Ib trial indicate that PG-11047 can be safely administered to patients in combination with bevacizumab, erlotinib, cisplatin, and 5-FU on the once weekly dosing schedule described and may provide therapeutic benefit. The manageable toxicity profile and high MTD determination provide a safety profile for further clinical studies.

(90)Y-clivatuzumab tetraxetan with or without low-dose gemcitabine: A phase Ib study in patients with metastatic pancreatic cancer after two or more prior therapies.

BACKGROUND: For patients with metastatic pancreatic adenocarcinoma, there are no approved or established treatments beyond the 2nd line. A Phase Ib study of fractionated radioimmunotherapy was undertaken in this setting, administering (90)Y-clivatuzumab tetraxetan (yttrium-90-radiolabelled humanised antibody targeting pancreatic adenocarcinoma mucin) with or without low radiosensitising doses of gemcitabine. METHODS: Fifty-eight patients with three (2-7) median prior treatments were treated on Arm A (N=29, (90)Y-clivatuzumab tetraxetan, weekly 6.5 mCi/m(2)doses×3, plus gemcitabine, weekly 200 mg/m(2) doses×4 starting 1 week earlier) or Arm B (N=29, (90)Y-clivatuzumab tetraxetan alone, weekly 6.5 mCi/m(2)doses×3), repeating cycles after 4-week delays. Safety was the primary endpoint; efficacy was also evaluated. RESULTS: Cytopaenias (predominantly transient thrombocytopenia) were the only significant toxicities. Fifty-three patients (27 Arm A, 26 Arm B, 91% overall) completed ⩾1 full treatment cycles, with 23 (12 Arm A, 11 Arm B; 40%) receiving multiple cycles, including seven (6 Arm A, 1 Arm B; 12%) given 3-9 cycles. Two patients in Arm A had partial responses by RECIST criteria. Kaplan-Meier overall survival (OS) appeared improved in Arm A versus B (hazard ratio [HR] 0.55, 95% CI: 0.29-0.86; P=0.017, log-rank) and the median OS for Arm A versus Arm B increased to 7.9 versus 3.4 months with multiple cycles (HR 0.32, P=0.004), including three patients in Arm A surviving >1 year. CONCLUSIONS: Clinical studies of (90)Y-clivatuzumab tetraxetan combined with low-dose gemcitabine appear feasible in metastatic pancreatic cancer patients beyond 2nd line and a Phase III trial of this combination is now underway in this setting.

Thrombosis in acute promyelocytic leukemia.

INTRODUCTION: Compared to bleeding, major thromboses are a less commonly encountered problem in acute promyelocytic leukemia (APL), and our knowledge about the epidemiology of major thromboses in APL stems mainly from individual case reports. The purpose of this study was to provide a better understanding of the epidemiology of APL-related thrombosis as a first step towards developing preventive strategies. MATERIALS AND METHODS: We report a rare case of catastrophic acute myocardial infarction in a patient with APL while she developed the all-trans retinoic acid (ATRA) syndrome. We describe the pathogenesis of APL-related thrombosis and review all previously reported cases of major thromboses in APL. RESULTS: We found 94 cases of major thromboses in patients with APL. Both genders were almost equally affected. More than 80% of events occurred before or during induction therapy with deep vein thrombosis/pulmonary embolism (DVT/PE), cardiac events, and cerebrovascular accidents (CVA) constituting more than 75% of all cases. Arterial events were slightly more common than venous events. Only 2 arterial events occurred after completion of induction therapy. Thrombosis was associated with life-threatening hemorrhage in about 15%, significant coagulative defects in about 50%, and ATRA syndrome in about 13% of cases. Cardiac thrombotic events, DVT/PE, and CVA were associated with ATRA syndrome in 24%, 4.5%, and 5% of cases, respectively (p=0.09). None of the observed trends and associations reached statistical significance. CONCLUSIONS: This review advances our understanding of the epidemiology of major thromboses in APL. With accumulation of more cases in the literature, some of our results may become statistically significant.

Phase III trial of cetuximab, bevacizumab, and 5-fluorouracil/leucovorin vs. FOLFOX-bevacizumab in colorectal cancer.

BACKGROUND: Cetuximab (C), alone or with irinotecan, demonstrates activity in irinotecan-refractory colorectal cancer (CRC). Activity of 5-fluorouracil (5-FU), leucovorin (L), and bevacizumab (B), and preliminary data of cetuximab + bevacizumab, and toxicity profiles suggests that FOLF-CB (5-FU, L, C+B) may have activity with a favorable toxicity profile as first-line therapy. METHODS: Eligible patients were randomized at registration to either arm A (mFOLFOX6-B) (modified, 5-FU. L (folinic acid), oxaliplatin (O) + bevacizumab), administered days 1 and 15 of each 28-day cycle as bevacizumab 5 mg/kg, oxaliplatin 85 mg/m(2), leucovorin 400 mg/m(2), and 5-FU 400 mg/m(2) then 1200 mg/m(2)/day for 48 hours, or arm B (FOLF-CB), which included bevacizumab, leucovorin, and 5-FU as in arm A and cetuximab 400 mg/m(2) day 1 cycle 1; all other weekly cetuximab doses were 250 mg/m(2). RESULTS: Two hundred forty-seven patients (arm A/arm B 124/123) were enrolled, and 239 were treated (118/121). Twelve-month progression-free survival (PFS) was 45%/32%, objective response rates (ORR) (complete response [CR] + partial response [PR]) were 52%/41%, disease control rates (CR+PR+stable disease [SD]) were 87%/83%, and median overall survival (OS) was 21/19.5 months, respectively. Grade 3-4 neutropenia was higher in arm A (28%/7%), as was grade 3 fatigue (12%/3%), and grade 3 neuropathy (11%/< 1%), whereas acneiform rash was confined to arm B. Retrospective analysis of KRAS mutational status did not demonstrate KRAS as a meaningful determinant of activity, except in arm B patients with KRAS-mutated tumors, which resulted in inferior PFS. Patient satisfaction favored the control (mFOLFOX6-B). CONCLUSION: FOLF-CB was not superior to mFOLFOX6-B in terms of 12-month PFS and ORR, and was not more acceptable to patients. This trial supports the conclusion of other recently reported trials that concurrent cetuximab+bevacizumab should not be routinely used in metastatic CRC.