Combinatorial Efficacy and Toxicity of an Engineered Toxin Body MT-3724 with Gemcitabine and Oxaliplatin in Relapsed or Refractory Diffuse Large B Cell Lymphoma

MT-3724 is an engineered direct-kill immunotoxin comprised of a CD20-specific scFv fused to a Shiga-like toxin subunit. In this phase IIa study, eight patients with relapsed diffuse large B-cell lymphoma were treated with MT-3724 combined with gemcitabine and oxaliplatin (GEMOX). The objective response rate was 85.7%, with a median duration of response of 2.2 months. The 12-month overall survival and progression-free survival were 71.4% and 28.6%, respectively. Two patients experienced grade 2 capillary leak syndrome (CLS). Combination therapy with MT-3724 and GEMOX demonstrated an early efficacy signal but was limited by the incidence of CLS.

A phase 1 study of the novel immunotoxin MT-5111 in patients with HER2+ tumors: Interim results

2583

Background: MT-5111 is a 55kD engineered toxin body (ETB) targeting HER2 in solid tumors that binds to an epitope distinct from trastuzumab and pertuzumab, offering potential combination strategies with other HER2-targeting agents. MT-5111 may demonstrate efficacy in patients (pts) resistant to other HER2-targeting agents, as its mechanism of action induces direct cell kill via enzymatic and permanent ribosome destruction. Methods: This is a phase 1 study in adults with advanced HER2+ solid tumors. The dose-escalation portion (Part A) enrolls pts into sequential dose cohorts, followed by Part B expansion cohorts for HER2+ breast cancer (BC), gastroesophageal adenocarcinoma (GEA), and any other HER2+ cancer (CA). MT-5111 is dosed weekly IV over 30 min in each 21-day treatment (tx) cycle until disease progression, unacceptable toxicity, death or withdrawn consent. Results: As of Jan 2022, 27 pts had enrolled in Part A cohorts (0.5 to 10 µg/kg/dose) with completed DLT assessments: 9 (33%) pts were male and 18 (67%) female, median age 67 and a median of 4 prior systemic and 2 prior HER2-targeting tx. Common tissue types were BC (9/30%), biliary CA (6/22%), GEA (4/15%). The following safety data reflect 33 treated pts to date including ongoing 13 µg/kg/dose Part A and 10 µg/kg/dose BC expansion cohorts. No Grade (G) 4/5 tx-emergent adverse events (AEs) or DLTs occurred. Tx-related AEs occurred in 17 (52%) pts, most commonly G1/2 fatigue (8/24%). 3 pts had G1 troponin elevations without clinical signs or symptoms of cardiac distress: 1 at 6.75 µg/kg/dose, 2 at 10 µg/kg/dose. 2 pts (3 and 4.5 µg/kg/dose) had reversible G2 and G1, respectively, infusion-related reactions (IRR)s. A comparison of cytokines from baseline to on-treatment timepoints reveals no evidence of significant changes, even in pts with IRR. Best response per RECIST thus far was stable disease (SD) in 7 pts or non-CR/non-PD in 2 pts: 1 pt had SD for 12 weeks (wks) (4.5 μg/kg, pancreatic CA); 1 pt (1 μg/kg/dose, BC) had non-CR/non-PD for 30 wks; 1 pt (10 μg/kg/dose, GEA) has ongoing SD for 18 wks. AUClast data match PK simulations in non-human primate studies. Cmax at 10 µg/kg/dose is ≥5 times the IC50 values of high HER2 expressing gastric CA and BC cell lines while approaching the IC50 of a moderately HER2 expressing liver CA cell line. Conclusions: MT-5111 is well tolerated to-date with no clinically significant immuno/cardiotoxicity. Dose escalation is ongoing at a dose of 13µg/kg, expected to be required for efficacious exposure. Clinical trial information: NCT04029922.

Safety and Efficacy of Engineered Toxin Body MT-3724 in Relapsed or Refractory B-cell Non-Hodgkin's Lymphomas and Diffuse Large B-cell Lymphoma

MT-3724, a novel engineered toxin body comprised of an anti-CD20 single-chain variable fragment genetically fused to Shiga-like Toxin A subunit, is capable of binding to and internalizing against CD20, inducing cell killing via permanent ribosomal inactivation. This study evaluated MT-3724 in patients with relapsed/refractory B-cell non-Hodgkin lymphoma (r/rNHL). This open-label, multiple-dose phase Ia/b trial included a dose escalation in patients with r/rNHL according to a standard 3+3 design. Primary objectives were to determine the MTD and pharmacokinetics/pharmacodynamics. In a dose expansion study at MTD in serum rituximab-negative patients with diffuse large B-cell lymphoma (DLBCL), primary objectives were safety, tolerability, and pharmacokinetics/pharmacodynamics. Twenty-seven patients enrolled. MTD was 50 μg/kg/dose with 6,000 μg/dose cap. Thirteen patients experienced at least one grade ≥3 treatment-related adverse events; the most common grade ≥3 event was myalgia (11.1%). Two patients (75 μg/kg/dose) experienced grade 2 treatment-related capillary leak syndrome. Overall objective response rate was 21.7%. In serum rituximab-negative patients with DLBCL or composite DLBCL (n = 12), overall response rate was 41.7% (complete response, n = 2; partial response, n = 3). In patients with detectable baseline peripheral B cells, treatment resulted in dose-dependent B-cell depletion. The proportion of patients with anti-drug antibodies (ADA) increased during treatment and the majority appeared to be neutralizing based on an in vitro assay; nevertheless, tumor regression and responses were observed. MT-3724 demonstrated efficacy at the MTD in this population of previously treated patients with r/rDLBCL, with mild-to-moderate immunogenic safety events.

Significance

This work describes the safety and efficacy of a new pharmaceutical pathway that could provide a treatment option for a subset of patients with a critical unmet therapeutic need. The study drug, MT-3724, is capable of targeting B-cell lymphomas via a unique, potent cell-killing mechanism that appears to be promising.

Abstract P2-13-45: Interim results of a phase 1 study of the novel immunotoxin MT-5111 in patients with HER2+tumors

Background: Engineered toxin bodies (ETBs) are composed of a de-immunized Shiga-like Toxin A subunit genetically fused to an antibody-like binding domain. ETBs can force receptor internalization, induce potent cell-kill via enzymatic and permanent inactivation of ribosomes, and may not be subject to resistance mechanisms of other therapeutics. MT-5111 is a 55 kD ETB targeting HER2 in solid tumors that binds to an epitope distinct from trastuzumab and pertuzumab, offering potential combination strategies with other HER2-targeting agents. MT-5111 may demonstrate efficacy in patients (pts) resistant to other HER2-targeting agents, as its mechanism of action does not rely on inhibition of kinase signaling or cytoskeletal or DNA damage. Methods: The primary objective is to determine the maximum tolerated dose (MTD) of MT-5111 monotherapy in adult pts with advanced HER2+ solid tumors. Secondary objectives are pharmacokinetics (PK), efficacy, and immunogenicity. Using a modified 3+3 design, the dose-escalation part of the study enrolls pts with HER2+ tumors into 7 cohorts: 0.5, 1, 2, 3, 4.5, 6.75, and 10 µg/kg/dose. Three dose-expansion cohorts will follow for HER2+ breast cancer, gastro-esophageal cancer, and other HER2+ tumors. All pts receive MT-5111 weekly as 30-min IV infusions in each 21-day treatment (tx) cycle (C) until disease progression (PD), unacceptable toxicity, death, or withdrawn consent (NCT04029922). Results: Per data cut in June 2021, 21 pts (mean age 64 years, range 34-78; 38% male) in cohorts 1-6 with breast (n=7), biliary (n=6), gastric (n=3), pancreatic (n=2), lung (n=2), and colon (n=1) cancer were treated (Table 1). Pts had a median of 4 prior lines of systemic therapies (range, 1-8) and 2 prior lines of HER2-targeting treatments (range, 0-6). No Grade (G)4 or 5 tx-emergent (TE) adverse events (AEs) occurred. Tx-related AEs occurred in 11 (52%) pts; the most common was fatigue (n=7, 33%). One pt (4.5 µg/kg) had a possibly (per PI) related G3 serious AE (SAE) of dyspnea and hypoxia, but also lymphangitic carcinomatosis and H. influenzae infection. The other related SAE occurred in a pt (6.75 µg/kg) who had a G1 transient troponin increase without concomitant cardiac symptoms or ECG/ECHO changes. All other related AEs were ≤G2. There were no clinically significant changes in cardiac biomarkers (troponin, ECG, left ventricular ejection fraction) nor were there cases of capillary leak syndrome. Two pts (3 µg/kg and 4.5 µg/kg) had reversible G2 infusion-related reactions. Best response to date has been stable disease. AUClast data matched PK simulations based on non-human primate studies, and Cmax data at 6.75 µg/kg indicated that current in-human exposure was between the IC50 values of high and medium HER2-expressing cell lines (approximately 10-89 ng/mL). Thus, a dose of at least 10 µg/kg may be required to achieve effective exposure. To date, no dose-limiting toxicities have been observed and the 10 µg/kg/dose cohort is now accruing. Conclusions: MT-5111 was well tolerated with no clinically significant immuno- or cardiotoxicity. Dose escalation is ongoing and nearing levels expected to be required for efficacious exposure.

Table 1.Metastatic HER2 status and MT-5111 treatment by cohortDose0.5 µg/kg1.0 µg/kg2.0 µg/kg3.0 µg/kg4.5 µg/kg6.75 µg/kgCohort123456Number of patients treated with MT-5111433335Metastatic HER2 2+ by IHC: ALL/BC1/11/11/01/10/04/0Metastatic HER2 3+ by IHC: ALL/BC3/12/02/12/13/01/1BC, breast cancer.

Citation Format: Brian A. Van Tine, Monica Mita, Minal A. Barve, Erika P. Hamilton, Andrew J. Brenner, Frances Valdes, Daniel Ahn, Joleen Hubbard, Jason Starr, Angela Georgy, Joshua Pelham, Banmeet S. Anand, Thomas Strack, Andrés Machado Sandri, Zev A. Wainberg. Interim results of a phase 1 study of the novel immunotoxin MT-5111 in patients with HER2+tumors [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-13-45.

A phase 1 study of the novel immunotoxin MT-5111 in patients with HER2+tumors: Interim results

297

Background: MT-5111 is a 55 kD engineered toxin body (ETB) targeting HER2 in solid tumors that binds to an epitope distinct from trastuzumab and pertuzumab, offering potential combination strategies with other HER2-targeting agents. MT-5111 may demonstrate efficacy in patients (pts) resistant to other HER2-targeting agents, as its mechanism of action induces direct cell kill via enzymatic and permanent ribosome destruction and does not rely on inhibition of kinase signaling or cytoskeletal or DNA damage. Methods: This is a phase 1 study in adult pts with advanced HER2+ solid tumors. The dose-escalation portion (modified 3+3 design) enrolls pts into sequential cohorts followed by expansion cohorts for HER2+ breast cancer (BC), gastric or gastroesophageal junction adenocarcinoma (GEA), and other HER2+ tumors. MT-5111 is dosed weekly IV over 30 min in each 21-day treatment (tx) cycle until disease progression, unacceptable toxicity, death, or withdrawn consent. Results: As of Sep 2021 (contains preliminary data), 24 pts (mean age 64 yrs) were treated, 13 (54%) of whom had gastrointestinal (GI) tumors (6 biliary, 3 GEA, 2 pancreatic, 2 colo/rectal) (Table). Pts with GI tumors had a median of 3 prior systemic tx and 1 prior HER2-targeting tx. No Grade (G) 4/5 tx-emergent adverse events (AEs) occurred. Tx-related AEs occurred in 13 (54%) pts, most commonly fatigue (n=7, 29%). One pt with biliary cancer and concurrent lymphangitic carcinomatosis and H. influenzae infection (4.5 µg/kg) had a possibly related G3 serious AE (SAE) of dyspnea, which resolved 9 days later. Another related SAE occurred in a pt with GEA (6.75 µg/kg) who had a G1 transient troponin increase that resolved during hospitalization, with no clinical symptoms or ECG/ECHO changes; the pt withdrew from study before further dosing. All other related AEs were ≤G2. No other clinically significant changes in cardiac biomarkers (troponin, ECG, LVEF) or cases of capillary leak syndrome occurred. Two pts (3 and 4.5 µg/kg) had reversible G2 infusion-related reactions. Best response to date has been stable disease. AUClast data matched PK simulations based on non-human primate studies. Cmax data at 10 µg/kg indicate that current in-pt exposure was between IC50 values of high and medium HER2-expressing cell lines (approx 10-89 ng/mL). Thus, at least 10 µg/kg may be required to achieve effective exposure. No dose-limiting toxicities have been observed. The 10 µg/kg cohort is now accruing. Following this cohort, an expansion cohort for pts with BC will open. Conclusions: MT-5111 was well tolerated with no clinically significant immuno/cardiotoxicity. Dose escalation is ongoing and is nearing levels expected to be required for efficacious exposure. Clinical trial information: NCT04029922. [Table: see text]

Abstract CT130: Phase 1 study of the novel immunotoxin MT-5111 in patients with HER-2+tumors

Background: Engineered toxin bodies (ETBs), composed of an engineered Shiga-like Toxin A subunit genetically fused to an antibody-binding domain, can force receptor internalization, induce potent cell-kill via enzymatic and permanent inactivation of ribosomes, and may not be subject to resistance mechanisms of other targeted agents. MT-5111, a de-immunized 55 kD ETB targeting HER2 in solid tumors, also binds to an epitope distinct from trastuzumab and pertuzumab, which may permit combination strategies with other HER2 targeting agents. Methods: The primary objective is to determine maximum tolerated dose (MTD) of MT-5111 monotherapy in adult patients (pts) with advanced HER2+ solid tumors. Secondary objectives are PK, efficacy, and immunogenicity. Using a modified 3+3 design, the dose-escalation part of the study includes the following 7 cohorts: 0.5, 1, 2, 3, 4.5, 6.75, and 10 µg/kg. Three dose-expansion cohorts will follow for HER2+ breast cancer, gastro-esophageal cancer, and any other HER2+ tumors. All pts will receive MT-5111 weekly as a 30-min IV infusion in each 21-d treatment (tx) cycle (C) until disease progression (PD), unacceptable toxicity, death, or withdrawn consent (NCT04029922). Results: As of the data cut in December 2020, 16 pts were treated; cancer types included breast (n=6), gastric (n=1), colon (n=1), gallbladder (n=5), and other solid tumors (n=3). Mean age was 64 years (range, 34-78); 37.5% were male. Pts received a median of 4 prior lines of systemic therapies (range, 1-8). No G4 or G5 TEAEs occurred. Six pts had 11 G3 TEAEs; the most common were increased AST and dyspnea (both n=2). Three pts had tx-emergent serious adverse events (abdominal distension [n=1]; dyspnea [n=2]). Tx-related TEAEs occurred in 8 (50%) pts; the most common was fatigue (n=5, 31.3%) and all were ≤ grade 2 in nature, except for one grade 3 event of dyspnea. No cardiac TEAEs, clinically significant changes in cardiac biomarkers (troponin, electrocardiogram, left ventricular ejection fraction), or cases of capillary leak syndrome were observed. Fifteen pts discontinued with PD; 1 pt in cohort 5 (4.5 µg/kg) is on tx with stable disease. To date, no DLTs have been observed and the MTD has not been reached. One pt in cohort 2 (1 µg/kg) had resolution of all hepatic lesions (sub-centimeter lesions pre-tx) at the end of C8; however, the pt came off study due to clinical progression at the end of C10. PK data for the first 5 cohorts matched simulations based on non-human primate studies. Conclusions: MT-5111 was well tolerated with no clinically significant cardiotoxicity. Continued dose escalations are ongoing.

Citation Format: Zev A. Wainberg, Monica M. Mita, Minal A. Barve, Erika P. Hamilton, Andrew J. Brenner, Frances Valdes, Daniel Ahn, Joleen Hubbard, Jason Starr, Christine Burnett, Joshua Pelham, Eric T. Williams, Banmeet S. Anand, Thomas Strack, Andrés Machado Sandri, Brian A. Van Tine. Phase 1 study of the novel immunotoxin MT-5111 in patients with HER-2+tumors [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 CT130.

A phase I open-label study to investigate safety and tolerability, efficacy, pharmacokinetics, pharmacodynamics, and immunogenicity of MT-5111 in patients with HER2-positive tumors

TPS258

Background: Engineered toxin bodies (ETBs) are comprised of a proprietarily engineered form of Shiga-like Toxin A subunit genetically fused to antibody-like binding domains. ETBs work through novel mechanisms of action & are capable of forcing internalization, self-routing through intracellular compartments to the cytosol & inducing potent cell-kill via the enzymatic & permanent inactivation of ribosomes. MT-5111 is a de-immunized ETB targeting HER2+ solid tumors. Its novel mechanism of action, via enzymatic ribosome inactivation, may not be subject to resistance mechanisms that exist for tyrosine kinase inhibitors, antibody-drug conjugates, or antibody modalities. MT-5111 binds an epitope on HER2, distinct from trastuzumab or pertuzumab, that may provide for combination potential with other HER2-targeting agents. MT-5111 is a 55 kilodalton protein & may have improved tumor penetration capability. The objective of this trial will be to determine the safety, tolerability, & maximum tolerated dose (MTD) of MT-5111 in patients (pts) with advanced HER2+ solid tumors. Methods: This Phase 1, first-in-human, open-label, dose escalation & expansion study will evaluate MT-5111 monotherapy in pts with HER2-positive solid tumors. The primary objective is to determine the MTD; secondary objectives include pharmacokinetics, tumor response & immunogenicity. Part 1 consists of MT-5111 dose escalation (0.5, 1.0, 2.0, 3.0, 4.5, 6.75, 10µg/kg/dose) based on a modified 3+3 design (n≤42 pts); Part 2 (dose expansion) will evaluate MT-5111 at the MTD in ≤98 pts. All pts will be administered MT-5111 over 30 min via IV infusion on Days 1, 8, & 15 of each 21-day cycle until disease progression, unacceptable toxicity, death, withdrawal of consent, or another reason for withdrawal. Part 1 will include pts with any HER2+ solid cancers. Part 2 will enroll 3 expansion cohorts: HER2+ breast (BC), HER2+ gastric or gastroesophageal junction adenocarcinomas (collectively referred as gastroesophageal adenocarcinomas [GEA]) & other HER2+ solid cancers. Immunohistochemistry (IHC) status must be 2+ or 3+, regardless of in situ hybridization (ISH) results; if no IHC is available for pts with BC or GEA, ISH criteria per the American Society of Clinical Oncology College of American Pathologists guidelines will be used. In metastatic cases, HER2 positivity must be demonstrated on metastatic lesions. Pts with HER2+ BC should have had ≥2 lines of HER2-directed therapy; pts with HER2+ GEA should have received or been intolerant to trastuzumab. Pts with evaluable disease may be included in Part 1; in Part 2, all pts must have ≥1 measurable lesion per Response Evaluation Criteria in Solid Tumors v1.1. Further details can be found on clinicaltrials.gov (NCT04029922). Enrollment, which began in September 2019, is ongoing. Clinical trial information: NCT04029922.

Abstract PO-63: A phase 2a open-label study of MT-3724, a novel CD20-targeting engineered toxin body, in combination with lenalidomide (LEN) in subjects with relapsed or refractory B-cell non-Hodgkin lymphoma (NHL)

Background: Engineered toxin bodies (ETBs) are a distinct class of targeted immunotoxins in development by Molecular Templates as anticancer therapeutics. ETBs have a novel mechanism of action that drives a potent and targeted response mediated by antibody-like binding, cellular internalization, and enzymatic ribosomal inhibition via the delivery of a Shiga-like toxin subunit A (SLTA). MT-3724 comprises an anti-CD20 single chain variable fragment genetically fused to SLTA with an approximate molecular weight of 55 kDa and is being developed for the treatment of relapsed or refractory diffuse large B-cell lymphoma (r/rDLBCL). MT-3724 is currently being studied in three ongoing phase 1/2 studies for r/rDLBCL.

Methods: MT-3724 is being evaluated in this phase 2a study (NCT03645395) in combination with LEN in adult patients with histologically confirmed, relapsed, or refractory CD20+ B-cell NHL. The primary objectives of this study are to determine the safety and tolerability, including the maximum tolerated dose (MTD), of MT-3724+LEN. Secondary objectives include pharmacokinetics, pharmacodynamics, immunogenicity, and tumor response. The study is being conducted in two parts. Part 1 includes MT-3724 dose escalation over 5 dose cohorts according to the modified 3+3 design and will include up to 24 subjects with CD20+ NHL. Part 2 is designed to assess the safety and tolerability of MT-3724+LEN in the MTD Expansion Cohort, where the dose declared as MTD of MT-3724 in Part 1 will be given in combination with LEN in up to 40 subjects with CD20+ r/rDLBCL. Eligible subjects must have received at least one approved therapy for NHL and must have measurable disease by Lugano criteria. Subjects who have progressed following CAR T-cell therapy, autologous or allogeneic stem cell transplant are also eligible. Serum rituximab level must be negative (<500 ng/mL) at screening because it competes with MT-3724 for binding to CD20. In the first 2 dose cohorts (10 and 25 ug/kg/dose) of Part 1, subjects received MT-3724 IV infusions over 1 hour three times weekly for 2 weeks and LEN (20 mg daily) on Days 1-21 of each 28-day treatment cycle for Cycles 1 and 2. In subsequent cycles, MT-3724 was administered once weekly with continued LEN dosing on Days 1-21. Because of 2 dose-limiting toxicities (grade 2 capillary leak syndrome) in Cohort 2, the dose in Cohort 3 was reduced to 20 ug/kg/dose. The protocol was amended so that in future Cohorts 4 and 5 (25 and 50 ug/kg/dose), MT-3724 will be dosed biweekly for 2 weeks for Cycles 1 and 2 and then once weekly for subsequent cycles. The study is recruiting subjects at multiple study centers.

Citation Format: Jason Tache, Deborah A. Katz, Amitabha Mazumder, David Peace, Christine Burnett, Thomas Strack, Elizabeth Bay, Roger Waltzman, Seung Lee. A phase 2a open-label study of MT-3724, a novel CD20-targeting engineered toxin body, in combination with lenalidomide (LEN) in subjects with relapsed or refractory B-cell non-Hodgkin lymphoma (NHL) [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-63.

A phase II study of MT-3724, a novel CD20-targeting engineered toxin body, to evaluate safety, pharmacodynamics, and efficacy in subjects with relapsed or refractory diffuse large B-cell lymphoma

TPS8074

Background: Engineered toxin bodies (ETBs) are comprised of a proprietarily engineered form of Shiga-like Toxin A subunit (SLT-A) genetically fused to antibody-like binding domains. ETBs work through novel mechanisms of action and are capable of forcing internalization, self-routing through intracellular compartments to the cytosol, and inducing potent cell-kill via the enzymatic and permanent inactivation of ribosomes. MT-3724 represents a novel ETB modality comprised of an anti-CD20 single-chain variable fragment genetically fused to SLT-A. It is capable of efficient internalization once bound to CD20 and can induce potent direct cell-kill via enzymatic ribosome inactivation. MT-3724 is currently being studied in three ongoing Phase 2 studies for relapsed or refractory diffuse large B-cell lymphoma (r/rDLBCL). Methods: The primary objective of this single-arm, Phase 2 study (NCT02361346) is to determine the efficacy of MT-3724 monotherapy in r/rDLBCL based on overall response rate (ORR), defined as the proportion of subjects with a complete/partial response according to the Lugano criteria, as assessed by independent, central review. Key secondary objectives include safety, progression-free survival, investigator‐assessed ORR, duration of response, overall survival, and pharmacodynamics. Adverse events will be assessed and documented according to Common Terminology Criteria for Adverse Events version 5.0. Key eligibility criteria include adult subjects with histologically confirmed, r/rDLBCL, with ≥2 prior standard of care systemic NHL treatment regimens, and ≥1 measurable lesion. As rituximab and other CD20-targeting antibodies compete with MT-3724 for the same CD20 domain, minimum washout periods from these agents must be observed. Subjects remain eligible post stem cell transplant or chimeric antigen receptor T-cell therapy. Subjects will receive 50 µg/kg MT-3724 IV over 1 hour on Days 1, 3, 5, 8, 10 and 12 of a 21-day treatment cycle. The anticipated sample size is N = 100. Interim analyses will be performed to confirm minimum efficacy thresholds based on the encouraging data observed in the completed phase 1 portion of the study [Hamlin et al. Blood 2019;134(Suppl 1):4098]. Multiple global sites are enrolling subjects. Clinical trial information: NCT02361346 .

A phase I study of the novel immunotoxin, MT-5111, in subjects (subj) with HER-2 positive tumors: Interim results

e15567

Background: Engineered toxin bodies (ETBs), composed of a Shiga-like Toxin A subunit genetically fused to antibody-like binding domains, can force receptor internalization, self-route through intracellular compartments to the cytosol, and induce potent cell-kill via the enzymatic and permanent inactivation of ribosomes. MT-5111, a de-immunized 55 kD ETB targeting HER2 in solid tumors, binds to an epitope distinct from and non-competitive with trastuzumab and pertuzumab. Methods: The primary objective is to determine the maximum tolerated dose (MTD) of MT-5111 monotherapy in adults with advanced HER2+ solid tumors. Secondary objectives are pharmacokinetics, efficacy, and immunogenicity. Part 1 will identify the MTD via MT-5111 dose escalation (0.5, 1.0, 2.0, 3.0, 4.5, 6.75, 10 µg/kg/dose) according to a modified 3+3 design. Part 2 will further evaluate the safety of MT-5111 at the recommended phase 2 dose (RP2D) in 3 separate cohorts of subjs with a HER2 immunohistochemistry score ≥2 in a metastatic lesion of primary breast, gastroesophageal, or other cancers. All subjs receive MT-5111 as a 30-minute IV infusion on Days 1, 8, and 15 of each 21-day treatment (tx) cycle (C) until disease progression, unacceptable toxicity, death, or withdrawn consent. Details can be found on clinicaltrials.gov (NCT04029922). Results: The first cohort (0.5 µg/kg/dose) enrolled 4 subjs (metastatic breast cancer, n = 2; metastatic cholangiocarcinoma, n = 2). Three subjs were female and the mean age was 69 years (median 65, range 64-78). Subjs received a mean of 5 prior lines of therapy (median 4.5, range 3-8). Three subjs completed C1 of tx without dose-limiting toxicities; 1 subj was inevaluable. Two subjs had progressive disease in C2. A total of 23 AEs occurred in 4 subjs; all were grade (G) 1-2 except one G3 event of hypertension in a subj with a history of hypertension. There were 2 tx-related AEs (G1 chills; G2 aspartate aminotransferase increased in the setting of progressive liver metastases). There was 1 serious, non-tx-related AE (G2 dyspnea) that occurred in the inevaluable subj. No cardiac AEs were noted, nor clinically significant changes in cardiac biomarkers, an important safety parameter given non-human primate toxicity. Conclusions: MT-5111 appears to be well tolerated at the lowest dose with no apparent cardiotoxicity to date. Drug concentrations are expected to be below the level required for in vitro tumor cell killing. Safety and efficacy data from subsequent dose escalation cohorts are expected by May 2020. Clinical trial information: NCT04029922.

A phase I open-label study to investigate safety and tolerability, efficacy, pharmacokinetics, pharmacodynamics, and immunogenicity of MT-5111 in subjects with HER-2 positive tumors

TPS465

Background: Engineered toxin bodies (ETBs) are proprietarily engineered from a Shiga-like Toxin A subunit fused to antibody-like binding domains. ETBs can force receptor internalization, self-route to the cytosol, and induce cell-kill via inactivation of ribosomes. MT-5111 is a 55 kDa de-immunized ETB targeting HER2, and may not be subject to resistance mechanisms that exist for TKI, ADC, or antibodies. It binds a HER2 epitope distinct from trastuzumab or pertuzumab, could be combined with other HER2 targeting agents, and may have improved tumor penetration. Methods: MT-5111 is evaluated as monotherapy in subj with confirmed HER2+ locally advanced or metastatic cancers. The primary objective is to determine the maximum tolerated dose in subjects (subj) with advanced HER2-positive tumors. Secondary endpoints are PK, tumor response and immunogenicity. Part 1 will escalate doses to identify MTD in up to 42 subj. Part 2 will further evaluate MT-5111 at the MTD in up to 98 subj. All subj will receive MT-5111 on Days 1, 8, and 15 of each 21-day cycle until disease progression, unacceptable toxicity, death, withdrawal of consent or another reason for withdrawal. Part 1 will include subj with any HER2+ solid cancers. Part 2 will enroll 3 expansion cohorts: HER2+ breast (BC), HER2+ gastroesophageal cancer (GEA), and other HER2+ solid cancers. HER2+ must be demonstrated on metastatic lesions in case of metastases. Tumors tested by immunohistochemistry (IHC) must have IHC status of 2+ or 3+, regardless of in-situ hybridization (ISH) results; for BC and GEA, if no IHC is available, ISH per ASCO-CAP guidelines is used. Subj with HER2+ BC should have had at least 2 lines of HER2-directed therapy; subj with HER2+ gastric cancer should have received trastuzumab or have been intolerant to trastuzumab. Subj with evaluable disease may be included in Part 1; in Part 2, all subj must have at least 1 measurable lesion per RECIST 1.1. ECOG should be 0-1, and bone marrow, hepatic, renal, cardiac function should be adequate. Further details can be found on clinicaltrials.gov (NCT04029922). Enrollment has begun in September 2019. Clinical trial information: NCT04029922.

Phase 1 Study of High-Specific-Activity I-131 MIBG for Metastatic and/or Recurrent Pheochromocytoma or Paraganglioma

CONTEXT

No therapies are approved for the treatment of metastatic and/or recurrent pheochromocytoma or paraganglioma (PPGL) in the United States.

OBJECTIVE

To determine the maximum tolerated dose (MTD) of high-specific-activity I-131 meta-iodobenzylguanidine (MIBG) for the treatment of metastatic and/or recurrent PPGL.

DESIGN

Phase 1, dose-escalating study to determine the MTD via a standard 3 + 3 design, escalating by 37 MBq/kg starting at 222 MBq/kg.

SETTING

Three centers.

PATIENTS

Twenty-one patients were eligible, received study drug, and were evaluable for MTD, response, and toxicity.

INTERVENTION

Open-label use of high-specific-activity I-131 MIBG therapy.

MAIN OUTCOME MEASURES

Dose-limiting toxicities, adverse events, radiation absorbed dose estimates, radiographic tumor response, biochemical response, and survival.

RESULTS

The MTD was determined to be 296 MBq/kg on the basis of two observed dose-limiting toxicities at the next dose level. The highest mean radiation absorbed dose estimates were in the thyroid and lower large intestinal wall (each 1.2 mGy/MBq). Response was evaluated by total administered activity: four patients (19%), all of whom received >18.5 GBq of study drug, had radiographic tumor responses of partial response by Response Evaluation Criteria in Solid Tumors. Best biochemical responses (complete or partial response) for serum chromogranin A and total metanephrines were observed in 80% and 64% of patients, respectively. Overall survival was 85.7% at 1 year and 61.9% at 2 years after treatment. The majority (84%) of adverse events were considered mild or moderate in severity.

CONCLUSIONS

These findings support further development of high-specific-activity I-131 MIBG for the treatment of metastatic and/or recurrent PPGL at an MTD of 296 MBq/kg.

The pharmacokinetics of alternative insulin delivery systems

Limited progress has been made toward developing safer and more acceptable methods for the administration of insulin treatment, despite several attempts to replace subcutaneous injection with alternate routes of administration. Attempts to develop methods for pulmonary administration have demonstrated promise, but have been met with little patient acceptance thus far, while potentially more attractive routes, such as nasal, oral or transdermal administration, have been mainly unsuccessful in providing sufficiently favorable pharmacokinetics and bioavailability for clinical use. The use of enhancers and/or enzyme inhibitors transiently increases absorption across the epithelia of the oral and nasal cavities and the mucosa of the gastrointestinal tract; however, absorption appears to be highly variable, overall bioavailability remains low, causing the cost of goods to be high, and the long-term safety of additives and insulin as a potential local growth factor is not well characterized. While research in some areas of alternative insulin delivery is ongoing, the continued refinement of subcutaneous injection devices and new pharmacological strategies for patients with type 2 diabetes may reduce the need for delivering exogenous insulin and, thus, for alternate administration routes.

Glycemic control with preprandial versus basal insulin in patients with type 2 diabetes mellitus poorly controlled by oral antidiabetes agents

OBJECTIVE

This study was designed to compare glycemic control (glycated hemoglobin [A1C] level) with either once-daily basal insulin (BI) (insulin glargine) or preprandial insulin (PPI) (Exubera) [insulin human (recombinant DNA origin)] inhalation powder, Pfizer Inc., New York, NY) in patients with type 2 diabetes mellitus (T2DM) poorly controlled on at least two oral antidiabetes agents (OADs).

METHODS

This was a 26-week, open-label, parallel-group, randomized study where 257 patients (mean A1C 8.6%) on OAD treatment for > or = 3 months were treated with either BI (n = 122) or PPI (n = 135). Based on self-monitored blood glucose levels, PPI dose was adjusted before each major meal, whereas BI dose was titrated in the morning or before bedtime. Prestudy OADs were continued, but doses could be modified.

RESULTS

At 26 weeks, change from baseline in A1C was greater with PPI (-1.7 vs. -1.4%, P = 0.0389). Numerically, more patients achieved A1C <6.5% (28% vs. 19%) and A1C <7.0% (63% vs. 55%) with PPI compared with BI. PPI had lower postmeal glucose increments, but higher prebreakfast glucose and weight gain (1.1kg), than BI. Mild or moderate hypoglycemic events were more frequent with PPI (6.2 vs. 2.9 events/months), but nocturnal hypoglycemic events were less frequent (22% vs. 30%).

CONCLUSIONS

PPI improved postprandial glucose and A1C levels significantly more than BI. More patients achieved A1C targets with PPI, at the expense of more hypoglycemia and body weight gain. These results illustrate the potential benefits and detriments of prandial insulin supplementation in patients with T2DM poorly controlled on OADs alone.

Real-world effectiveness of new medicines should be evaluated by appropriately designed clinical trials

OBJECTIVES

Health care providers, policy makers, and importantly patients themselves are increasingly interested in the outcomes of clinical trials yet often expect different questions to be addressed than those commonly asked in conventional phase 3 trials.

STUDY DESIGN AND SETTING

Review of methodological articles.

RESULTS

Conventional randomized controlled trials (RCTs) emphasize internal validity through standardization and control but by design reduce external validity, that is, generalizability of results and conclusions. Ongoing uncertainty about effectiveness or safety of medical interventions in the real world is the major driver for developing improved phase 3b and phase 4 study designs. Factors that should improve the relevance of these real-world trials (RWTs) include choice of endpoints; investigator specialty, appropriate patient selection criteria; emphasis on patient-physician interaction; admittance of relevant interventions in all study groups; and more flexible, simple, and possibly event-driven study visits and procedures, while maintaining randomization as a critical element to address confounders.

CONCLUSION

Although we do not believe that RWTs will supplant conventional RCTs, properly designed RWTs will enrich our understanding of the effectiveness of new health care interventions and better inform patients and health care providers alike.

Glycemic exposure is affected favorably by inhaled human insulin (Exubera) as compared with subcutaneous insulin glargine (Lantus) in patients with type 2 diabetes

BACKGROUND

The objective was to compare the effects on glycemia of adding either inhaled human insulin (Exubera [EXU] [insulin human (recombinant DNA origin) inhalational powder]) or subcutaneous insulin glargine (GLA) to the treatment regimens of patients with type 2 diabetes uncontrolled with oral antidiabetic drugs.

METHODS

Forty patients were randomized to receive either EXU three times daily prior to meals or subcutaneous GLA once daily in a crossover design. Interstitial glucose concentrations were monitored using a continuous glucose monitoring system (CGMS) for the final 72-h period of 8 treatment days.

RESULTS

Total insulin dosage on the last treatment day was approximately 40.1+/-18.1 units/day EXU compared with 16.4+/-4.8 units/day GLA. Serum insulin levels over the 72-h CGMS period were higher for EXU than for GLA (1,091+/-589 pmol/mL/h vs. 737+/-386 pmol/mL/h; ratio, 148; 95% confidence interval [CI], 130-169). The glucose exposure over this period was lower with EXU than with GLA (380+/-45 mmol/Lh vs. 426+/-89 mmol/Lh; ratio, 88.57; 95% CI, 84-93). The overall hypoglycemic event rate was 8.7 events per subject-month for EXU and 2.4 for GLA.

CONCLUSIONS

Prandial insulin therapy with EXU, using a higher daily insulin dose, reduces total daily glucose exposure--in particular postmeal glycemia--more effectively than a basal insulin analog.

Assessing the impact of a new delivery method of insulin on glycemic control using a novel trial design

OBJECTIVE

The purpose of the trial was to examine the impact of inhaled human insulin (INH) on patient or physician willingness to adopt insulin after oral diabetes agent failure.

RESEARCH DESIGN AND METHODS

The EXPERIENCE trial was a one-year randomized controlled trial conducted at primary, secondary and tertiary care facilities in Europe and North America. The primary study endpoint was difference in glycated hemoglobin (A(1c)) between randomized groups at 26 weeks, and results from that phase have been reported previously. The present report concerns results from the second 26-week extension phase. We also consider the applicability of the design. The trial recruited 727 patients with type 2 diabetes mellitus who, prior to randomization, were using two or more oral diabetes agents and whose A(1c) was ≥ 8.0%. Patients were randomized to two treatment settings: Group 1 (usual care with the option of INH) or Group 2 (usual care only). Usual care included adjusting oral therapy (optimizing current regimen or adding/deleting agents) and/or initiating subcutaneous (SC) insulin.

RESULTS

At baseline, insulin was initiated by more (odds ratio [OR] 6.0;95% confidence interval [CI] 4.2 to 8.8; P < 0.0001) patients in Group 1 (86.2%; 76.7% INH plus 9.5% SC) than in Group 2 (50.7%; SC insulin only). The largest reduction from baseline in A(1c) was in Group 1 (-2.0 ± 1.2%) at Week 12 and in Group 2 (-1.8 ± 1.3%) at Week 26 (P = 0.003). At 52 weeks, 79.8% were on insulin in Group 1 (67.4% INH; 12.4% SC) vs 58.1% (SC only) in Group 2, and mean (SD) changes in A(1c) from baseline were -1.9% (1.2%) and -1.8% (1.3%) in Groups 1 and 2, respectively (P = 0.05). Hypoglycemic event rates per patient month were 0.3 and 0.1 in Groups 1 and 2, respectively (P < 0.0001).

CONCLUSION

The EXPERIENCE trial showed that novel delivery technology can accelerate the adoption of insulin although some attenuation of differences is observed over time. And further, that this was achieved in a population of patients who appeared more ready to move to insulin therapy than observed in standard clinical practice, and a group of physicians who appeared more ready to adopt INH than the majority of physicians.

The effect of the availability of inhaled insulin on glycaemic control in patients with Type 2 diabetes failing on oral therapy: the evaluation of Exubera as a therapeutic option on insulin initiation and improvement in glycaemic control in clinical practice (EXPERIENCE) trial

AIM

To examine the impact of inhaled human insulin (Exubera, EXU) on patient or physician willingness to adopt insulin after oral glucose-lowering agent failure.

METHODS

During a randomized controlled trial in primary, secondary and tertiary care in Europe and North America, 739 patients using >or= 2 oral glucose-lowering agents with glycated haemoglobin (HbA(1c)) >or= 8.0% were assigned to two treatment groups: Group 1 (standard care with the option of EXU) or Group 2 (standard care only). Standard care included adjusting oral therapy (optimizing current regimen or adding/omitting agents) and/or initiating subcutaneous (s.c.) insulin. The primary endpoint was difference in HbA(1c) between randomized groups at 26 weeks. Secondary outcomes included differences in the rate of uptake of insulin therapy, proportion achieving satisfactory glycaemic control, treatment satisfaction and safety outcomes.

RESULTS

At baseline, insulin was initiated by more [odds ratio 6.0; 95% confidence interval (CI) 4.2 to 8.8; P < 0.0001] patients in Group 1 (86.2%; 76.7% EXU plus 9.5% s.c.) than Group 2 (50.7%; s.c. insulin only). At 26 weeks, mean (sd) changes in HbA(1c) from baseline were -2.0% (1.2%) and -1.7% (1.3%) in Groups 1 and 2, respectively, a difference of -0.2% (95% CI: -0.1% to -0.4%; P = 0.004). In Group 1, 45% of patients achieved an HbA(1c)<or= 7.0% by 26 weeks compared with 39% in Group 2 (P = 0.02).

CONCLUSION

The availability of EXU may increase initiation of insulin, thereby contributing to improved overall glycaemic control in patients with Type 2 diabetes inadequately controlled on two or more oral glucose-lowering agents.

Synthesis and in Vitro Evaluation of 18F- and 19F-Labeled Insulin: A New Radiotracer for PET-based Molecular Imaging Studies

A new and regioselective strategy was developed for the preparation of fluorine-18-labeled insulin as a novel positron emission tomography (PET) tracer. [18F]-4-Fluorobenzoic acid (4-18FBA), which was produced in 83 +/- 8% yield (n = 10), through the use of succinimidyl [18F]-4-fluorobenzoate (4-(18)FSB), was conjugated through a short spacer (6-aminohexanoic acid, AHx) to the PheB1 residue of a protected form of insulin. 18FB-AHx-insulin (8b) was repeatedly prepared in practical quantities (10-20 mCi, 370-740 MBq) in good radiochemical yield (9 +/- 5%, n = 9) and in a specific activity of 7.8 mCi/micromol. The final product was characterized by comparing the radioHPLC and radioTLC of 8b with that of the 19F-analogue (19FB-AHx-insulin, 8a) and by analyzing a carrier-added synthesis by mass spectrometry. Dithiothreitol and endoproteinase Glu-C digestion experiments on 8a confirmed that the prosthetic group was in fact conjugated to the PheB1 residue. An insulin receptor (IR) phosphorylation assay using CHO-hIR cells overexpressing recombinant human insulin receptors indicated no statistical difference in the extent of autophosphorylation stimulated by 8a as compared to that for human insulin (EC50 values of 0.82 nM and 1.0 nM, respectively). The stimulation of 2-deoxyglucose uptake in 3T3-L1 mouse adipocytes utilizing 8a versus unmodified human insulin gave similar EC50 values of 0.68 nM and 0.41 nM, respectively. The IC50 values for 8a versus native insulin for the displacement of 125I-insulin from HEK-293 cells were also the same within experimental error (2.6 nM for 8a versus 2.4 nM for unmodified human insulin). These results support the use of the 18F-insulin analogue as a PET tracer for imaging the distribution of insulin in vivo.

A comparative study of insulin lispro and human regular insulin in patients with type 2 diabetes mellitus and secondary failure of oral hypoglycemic agents

OBJECTIVE

To compare the effects of insulin lispro (LP) and human regular insulin (HR) when given twice daily with NPH insulin on glycemic control (HbA1c), daily blood glucose profiles and rates of hypoglycemia in patients with type 2 diabetes mellitus after failure to respond to sulfonylurea drugs.

RESEARCH DESIGN AND METHODS

A 5.5-month randomized, open-label, parallel study of 148 patients receiving either LP (n = 70) or HR (n = 78). Eight-point blood glucose profiles and HbA1c measurements were collected at baseline, 1.5, 3.5 and 5.5 months.

RESULTS

Two-hour post-breakfast and 2-hour post-supper blood glucose levels (means [and standard errors]) were significantly lower for LP than for HR at the end point (9.5 [0.4] mmol/L v. 10.9 [0.4] mmol/L and 8.4 [0.4] mmol/L v. 9.7 [0.4] mmol/L, respectively, p = 0.02 in both cases). HbA1c improved from 10.5% (0.2%) (LP) and 10.3% (0.2%) (HR) to 8.0% (0.1%). Hypoglycemia rates were similar during the day; however, there was an overnight trend to reduced rates with LP (0.08 [0.03] episodes/30 d v. 0.16 [0.04] episodes/30 d, p = 0.057). Quality-of life assessment showed significant improvement (p < 0.05) in the diabetes-related worry scale for LP subjects whereas HR subjects slightly worsened.

CONCLUSIONS

With traditional twice-daily insulin administration algorithms, LP improves 2-hour postprandial glucose levels, quality of life and overnight hypoglycemia rates while delivering an equivalent level of glycemic control (HbA1c) compared with HR to insulin-naïve patients with type 2 diabetes who require insulin.

Improved glycaemic control with the use of self-prepared mixtures of insulin lispro and insulin lispro protamine suspension in patients with types 1 and 2 diabetes

A total of 166 patients (102 type 1, 64 type 2) were randomised to insulin lispro (LP) combined with insulin lispro protamine suspension (NPL), an intermediate-acting formulation of LP, or to regular human insulin (HR) combined with human NPH insulin (NPH) in this open-label, parallel study. Insulin doses were similar at endpoint. Blood glucose (BG) measurements (before and two hours after meals, bedtime, 3 a.m.)(mmol/l) were lower with LP/NPL two hours after breakfast (8.84 +/- 0.32 vs 10.29 +/- 0.41, p < 0.001), before lunch (6.21 +/- 0.20 vs 7.10 +/- 0.31, p = 0.016), two hours after the evening meal (10.18 +/- 0.36 vs 7.86 +/- 0.28, p < 0.0.001), and at bedtime (7.85 +/- 0.28 vs 9.43 +/- 0.40, p = 001). HbA1c was lower for LP/NPL at endpoint (7.54 +/- 0.11% vs 7.92 +/- 0.10%, p = 0.019). There was no difference in hypoglycaemia or insulin antibody levels. LP/NPL resulted in better glycaemic control than HR/NPH without increasing the risk of hypoglycaemia.

Effectiveness of human ultralente versus NPH insulin in providing basal insulin replacement for an insulin lispro multiple daily injection regimen. A double-blind randomized prospective trial. The Canadian Lispro Study Group

OBJECTIVE

To compare human ultralente (UL) insulin with human NPH insulin as basal insulin replacement in patients who use insulin lispro before meals.

RESEARCH DESIGN AND METHODS

There were 178 patients with type 1 diabetes who were randomized to receive either human NPH or UL insulin once daily at bedtime in a 1-year double-blind clinical study. Eight-point blood glucose profiles were collected once monthly in the first 4 months, then every 2 months for the remainder of the study. Patients were also asked to perform premeal blood glucose measurements every day throughout the study. If before-supper blood glucose levels consistently exceeded 8 mmol/l despite optimal postprandial control with the lunch dose of insulin lispro, a second dose of basal insulin before breakfast was administered.

RESULTS

For the group as a whole, insulin doses before meals and basal insulin doses were similar at baseline. At study's end, meal doses remained the same (30 +/- 1 U/day for UL., 29 +/- 1 U/day for NPH), while basal requirements were somewhat higher for the UL group than the NPH group: 30 +/- 1 U/day vs. 26 +/- 1 U/day, respectively (P < 0.05). The rates of severe hypoglycemia were similar for patients on NPH (0.05 +/- 0.03 per patient every 30 days) and for UL (0.07 +/- 0.04 per patient every 30 days) insulin. There was no significant difference for glycemic control between the NPH and UL groups overall (HbAlc at the end of the study: 7.6 +/- 0.1 vs. 7.7 +/- 0.1%, respectively), and by study's end a similar number of patients in the NPH and the UL groups needed to be switched to twice daily basal insulin (21 and 24%, respectively). Patients requiring twice-daily injections of basal insulin had a longer duration of diabetes (17.8 +/- 1.5 vs. 14.0 +/- 0.8 years, P < 0.05) and a highest baseline HbAlc (8.6 +/- 0.1 vs. 8.0 +/- 0.1%, P < 0.002) and were significantly older (38 +/- 2 vs. 34 +/- 1 years, P < 0.007). Patients who were switched to twice-daily NPH insulin had lower HbAlc levels at study's end compared with those switched to twice-daily UL insulin (7.7 +/- 0.2 vs. 8.2 +/- 0.3%), but this difference was not statistically significant. Distribution of hypoglycemia across the day was also similar in both groups.

CONCLUSIONS

UL or NPH insulin, when used as the basal insulin for multiple injection regimens, results in similar glycemic control in patients using insulin lispro before meals. However, in patients who require a second injection of basal insulin, NPH insulin appears to provide lower prebreakfast and prelunch glucose levels compared with UL insulin.

Effect of continuous subcutaneous insulin infusion with lispro on hepatic responsiveness to glucagon in type 1 diabetes

OBJECTIVE

People with type 1 diabetes frequently develop a blunted counterregulatory hormone response to hypoglycemia coupled with a decreased hepatic response to glucagon, and consequently, they have an increased risk of severe hypoglycemia. We have evaluated the effect of insulin lispro (Humalog) versus regular human insulin (Humulin R) on the hepatic glucose production (HGP) response to glucagon in type 1 diabetic patients on intensive insulin therapy with continuous subcutaneous insulin infusion (CSII).

RESEARCH DESIGN AND METHODS

Ten subjects on CSII were treated for 3 months with lispro and 3 months with regular insulin in a double-blind randomized crossover study After 3 months of treatment with each insulin, hepatic sensitivity to glucagon was measured in each subject. The test consisted of a 4-h simultaneous infusion of somatostatin (450 microg/h) to suppress endogenous glucagon, regular insulin (0.15 mU x kg(-1) x min(-1)), glucose at a variable rate to maintain plasma glucose near 5 mmol/l, and D-[6,6-2H2]glucose to measure HGP During the last 2 h, glucagon was infused at 1.5 ng x kg(-1) x min(-1). Eight nondiabetic people served as control subjects.

RESULTS

During the glucagon infusion period, free plasma insulin levels in the diabetic subjects were 71.7+/-1.6 vs. 74.8+/-0.5 pmol/l after lispro and regular insulin treatment, with plasma glucagon levels of 88.3+/-1.8 and 83.7+/-1.5 ng/l for insulin:glucagon ratios of 2.8 and 3.0. respectively (NS). However, plasma glucose increased to 9.2+/-1.1 mmo/l after lispro insulin compared with 7.1+/-0.9 mmol/l after regular insulin (P < 0.01), and the rise in HGP was 5.7 +/-2.8 micromol x kg(-1) x min(-1) after lispro insulin versus 3.1+/-2.9 micromol x kg(-1) x min(-1) after regular insulin treatment (P=0.02). In the control subjects, HGP increased by 10.7+/-4.2 micromol x kg(-1) x min(-1) under glucagon infusion.

CONCLUSIONS

Insulin lispro treatment by CSII was associated with a heightened response in HGP to glucagon compared with regular human insulin. This suggests that insulin lispro increases the sensitivity of the liver to glucagon and could potentially decrease the risk of severe hypoglycemia.

Counterregulatory hormone responses after long-term continuous subcutaneous insulin infusion with lispro insulin

OBJECTIVE

To determine whether the long-term use of insulin lispro (LP) affects the counterregulatory hormone response to hypoglycemia.

RESEARCH DESIGN AND METHODS

Ten patients (age range 26-51 years; ratio of men to women 9:1; BMI 24.9 +/- 0.48; mean HbA1c 7.84 +/- 0.25%) with IDDM, treated with continuous subcutaneous insulin infusion (CSII; Disetronic H-TRON V100) were studied using a double-blind, crossover design. Patients were randomized to LP or human regular insulin (HR) for 3 months and then crossed over to the other insulin for an additional 3 months. All meal boluses were given 0-5 min before breakfast, lunch, and dinner. Counterregulatory hormone responses to a stepped hypoglycemic clamp (consecutive glucose levels in mmol/l: 4.2; 3.5; 2.8, each for 1 h) were evaluated at the end of each treatment period.

RESULTS

HbA1c was significantly lower with LP versus HR (7.47 +/- 0.28% vs. 7.9 +/- 0.26%, P = 0.04). The incidence of hypoglycemia per 30 days (capillary blood glucose < 3.0 mmol/l and/or symptoms) during the last month of the study was significantly lower with LP versus HR (8.7 +/- 2.9 vs. 11.8 +/- 2.9, P = 0.03). The total daily insulin dosage was not different in the two treatment periods. There was no episode of severe hypoglycemia or diabetic ketoacidosis. The peak growth hormone, cortisol, glucagon, and epinephrine responses during the same period of hypoglycemia were not different for each treatment period.

CONCLUSIONS

The use of LP in CSII results in improved glycemic control and a decrease in the frequency of hypoglycemia without adversely affecting counterregulatory hormone response to hypoglycemia.

Insulin lispro in CSII: results of a double-blind crossover study

Insulin lispro is a human insulin analog that dissociates more rapidly than human regular insulin after subcutaneous injection, resulting in higher insulin levels at an earlier point in time and a shorter duration of action. The aim of the study was to evaluate if this pharmacokinetic difference would translate into better postprandial and overall control in 30 IDDM patients (age, 35.1 +/- 1.5 years; male-female ratio, 17:13; BMI, 24.8 +/- 0.5 kg/m2; HbA1c, 8.03 +/- 0.13% at baseline) treated with continuous subcutaneous insulin infusion (CSII; Disetronic H-TRON V100) in a double-blind crossover clinical study. Patients were randomized to insulin lispro or human regular insulin for 3 months before crossing over to the other insulin for another 3 months. All meal boluses were given immediately before breakfast, lunch, and supper. An eight-point blood glucose profile was measured once weekly, and HbA1c levels were measured monthly. At the end of the 3-month treatment period, HbA1c levels were significantly lower with insulin lispro, compared with human regular insulin: 7.66 +/- 0.13 vs. 8.00 +/- 0.16% (P = 0.0041). While preprandial, bedtime, and 2:00 A.M. values for blood glucose were not significantly different, 1-h postprandial blood glucose was significantly improved after breakfast, lunch, and dinner with insulin lispro, compared with human regular insulin: 8.35 vs. 9.79 mmol/l (P = 0.006), 7.58 vs. 8.74 mmol/l (P = 0.049), and 7.85 vs. 9.01 mmol/l (P = 0.03). The incidence of hypoglycemia per 30 days (blood glucose levels, <3.0 mmol/l) was 8.4 +/- 1.3 before randomization, decreasing to 6.0 +/- 0.9 for insulin lispro and to 7.6 +/- 1.3 for regular insulin during the last month of the study. Two patients in each group reported insulin precipitation. We conclude that insulin lispro improves glycemic control in CSII without increasing the risk of hypoglycemia.

Final results of the Canadian phase I dose escalation trial of gemcitabine and cisplatin for advanced non-small cell lung cancer

When given at doses of > or = 1,250 mg2 weekly x 3 with a 1-week break, single-agent gemcitabine induces responses in more than 20% of previously untreated patients with non-small cell lung cancer (NSCLC). This study was undertaken to determine the maximum tolerated doses for a 4-week cycle of gemcitabine and cisplatin given in combination weekly x 3 with a 1-week rest. Patients younger than 75 years were eligible if they had stage III/IV NSCLC, life expectancy > or = 12 weeks, hemoglobin > or = 10 g/dL, absolute granulocyte count > or = 2 x 10(9)/L, platelets > or = 100 x 10(9)/L, hepatic enzymes < or = 3 times the upper limit of normal, and serum creatinine < or = 130 mumol/L. The starting doses for gemcitabine and cisplatin were 1,000 mg/m2 and 25 mg/m2 per week x 3, respectively. At dose level 2 cisplatin was increased to 30 mg/m2/week x 3. Thereafter only the gemcitabine was increased, by 250 mg/m2/wk at each dose level, to a maximum of 2,250 mg/m2/wk at dose level 7. The median nadir granulocyte and platelet counts decreased with each dose level, but dose-limiting toxicity in two or more patients was not encountered in the first treatment cycle, even at dose level 7. Cumulative bone marrow toxicity was seen at all dose levels, and this resulted in frequent dose reductions or omissions. Dose delivery was well maintained over time only at dose level 1. Grade 3-4 nonhematologic toxicity was infrequent and rarely dose limiting. An assessment of all toxicities seen during the treatment cycles was undertaken using continual reassessment methodology. This model suggested that dose level 4 (cisplatin 30 mg/m2/wk and gemcitabine 1,500 mg/m2/wk) would be the maximum dose at which grade 4 toxicity would be expected in up to 33% of patients at any time over four treatment cycles. Of 47 patients evaluable for response, partial remission was seen in 14, with an overall response rate of 30% (confidence interval, 17% to 43%). The median duration of response was 16 weeks and the median survival time was 24 weeks (range, 3.5 to 64+ weeks). A phase II trial is planned in which dose level 4 will be evaluated in a larger cohort of patients with NSCLC.

Phase I dose-escalation trial of gemcitabine and cisplatin for advanced non-small-cell lung cancer: usefulness of mathematic modeling to determine maximum-tolerable dose

PURPOSE

This study was undertaken to determine the maximum-tolerated doses of gemcitabine and cisplatin, each given weekly for 3 weeks with a 1-week rest.

PATIENTS AND METHODS

Patients less than 75 years of age were eligible if they had stage III/IV non-small-cell lung cancer (NSCLC), life expectancy > or = 12 weeks, hemoglobin level > or = 10 g/dL, granulocyte count > or = 2 x 10(9)/L, platelet count > or = 100 x 10(9)/L, hepatic enzymes < or = three times the upper limit of normal, and creatinine concentration < or = 130 mumoles/L. The starting doses for gemcitabine and cisplatin were 1,000 mg/m2 and 25 mg/m2 per week for 3 weeks. At dose level 2, cisplatin was increased to 30 mg/m2/wk for 3 weeks, and thereafter only gemcitabine was increased by 250 mg/m2/wk at each dose level to a maximum of 2,250 mg/m2/wk.

RESULTS

There were 33 men and 17 women, with a median age of 62 years. Pathology included adenocarcinoma in 35 patients, squamous in eight, large cell in six, and mixed histology in one. Sixteen patients had stage III and 34 had stage IV tumors. The median nadir granulocyte and platelet counts decreased with each dose level, but cycle 1 dose-limiting toxicity (DLT) in > or = two patients was not encountered in cycle 1, even at the highest dose level. Cumulative marrow toxicity was seen at all levels, which resulted in frequent dose reductions or omissions. A mathematic model of all toxicities over time suggested that dose level 4 (cisplatin 30 mg/m2/wk and gemcitabine 1,500 mg/m2/wk) would be the maximum dose at which grade 4 toxicity would be expected in < or = 33% of patients over four cycles. Of 47 assessable patients, 14 achieved a partial response (30%; confidence interval, 17% to 43%). The median duration was 16 weeks and the median survival time was 24 weeks (range, 3.5-64+).

CONCLUSION

Weekly gemcitabine and cisplatin are active against NSCLC, and the recommended phase II doses are 30 and 1,500 mg/m2/wk for 3 weeks, respectively.

Phase I trial of gemcitabine and cisplatin in advanced non-small cell lung cancer: a preliminary report

A phase I trial was performed to investigate the tolerability and efficacy of the novel nucleoside analogue gemcitabine in combination with cisplatin in the treatment of advanced non-small cell lung cancer. Both cisplatin and gemcitabine were administered as 30 min infusions weekly x 3 with a week of rest. There was one dose escalation of cisplatin from 25 mg/m2 (dose level 1) to 30 mg/m2 (in subsequent dose levels 2-5), such that the mean dose intensity for the weekly x 3 q 4 week cycle was 22.5 mg/m2/week which is close to that achieved with 100 mg/m2 bolus monthly. Gemcitabine was initiated at 1000 mg/m2 (dose levels 1 and 2) then escalated by 250 mg/m2/week to 1750 mg/m2 (dose level 5). Of 32 chemotherapy-naive patients entered (22 males, 10 females; median age 61 years, range 29-74 years), 11 had localized tumours (2 stage IIIa, 9 IIIb) and 21 had stage IV tumours with haematogenous metastases and a poor prognosis. Twenty-one patients had adenocarcinoma, 4 squamous cell carcinoma, 6 large cell undifferentiated tumors, and one had mixed squamous and adenocarcinoma. Dose-limiting toxicity was not seen in more than one patient in cycle 1 at any dose level. Grade 4 granulocytopenia and thrombocytopenia occurred more frequently with repeated dosing, necessitating dose reductions except at the lowest dose level (cisplatin 25 mg/m2, gemcitabine 1000 mg/m2). Non-haematological toxicity was mild and rapidly reversible. Cisplatin administration led to a higher frequency of nausea and vomiting than that seen with gemcitabine alone, but this was easily controlled with antiemetics. In the 28 patients evaluable, to date responses have been seen at most dose levels, with an overall response rate 35.7%. This phase I trial is ongoing and further dose escalation is intended to determine the MTD of gemcitabine.

[Selective blood sampling from the sinus petrosus inferior: a comparison of CRF and TRH stimulation]

In 10 patients with hypophyseal Cushing microadenomas, selective bilateral sampling from the inferior petrosal sinuses was performed and the effect of stimulation by iv TRH and CRF was compared. On the side of the microadenoma. ACTH concentration rose from 650 +/- 242 pg/ml to 2712 +/- 843 pg/ml following injection of CRF and 2025 +/- 242 pg/ml after TRH. Contralateral values were 165 +/- 79 pg/ml, 490 +/- 200 pg/ml and 165 +/- 72 pg/ml respectively. Prolactin concentration on the side of the adenoma was 98 +/- 49 ng/ml before stimulation, 236 +/- 62 ng/ml after CRF and 747 +/- 168 ng/ml after TRH. Contralateral concentration was 22 +/- 10 ng/ml, 64 +/- 19 ng/ml respectively. Sampling localised all adenomas correctly, whereas contrast-enhanced MRT diagnosed only four adenomas.

[Computer-assisted diabetes therapy--a challenge for modern medicine]

By the use of computers in the therapy of diabetes new diagnostic and therapeutic possibilities are brought about. The computers open the possibility for a comprehensive data seizing, evaluation of the stored material and possibilities of various abilities for demonstration. Moreover, it becomes possible to regulate the therapy more subtly with the help of self-adapting programs and in its consequence to render it more effective than the own management of therapy is able to do it. This manifests itself significantly in badly or only moderately stabilised diabetics. In very well educated and trained diabetics even the superiority of the management of the computer becomes visible. Here this can no more be shown in the improvement of the stabilisation of diabetes which can no more be improved without risks for the patient. In these patients it is the reduction of the frequency of hyperglycaemia, by means of which can be shown that the stabilisation of diabetes in diabetics who were well stabilised already before can still be improved by the computer therapy. In addition to this the computer seems to cause further positive effects on the learning behaviour of the diabetics.

[Osteoporosis: a case report]

A 56-year-old female patient was admitted to our hospital because she was suffering from severe osteoporosis. The patient had experienced repeated spontaneous fractures for 1.5 years such as serial rib fractures, fractures of the sternum and most recently fracture of the neck of the femur after a minimal trauma. Histology revealed a low-turnover-osteoporosis. Subsequent radiologic examination showed extreme osteoporosis of the skeleton with numerous compression fractures of the vertebral bodies as the most outstanding finding. The bone histology and the relatively short history of spontaneous fractures led us to investigate endogenous hypercortisolism as a possible cause although clinical signs were absent. An attenuated diurnal variation of cortisol levels and lack of suppressibility of cortisol was found. Furthermore, magnetic resonance tomography showed a microadenoma of the pituitary gland. Computerized tomography of the adrenals was normal. Transsphenoidal surgery confirmed the tentative diagnosis and histological examination revealed a bilateral adenoma of the pituitary gland.

Compliance in microcomputer-assisted conventional insulin therapy: computer simulation study results

Compliance in diabetes self-management is a complex issue. It involves the interdependent daily actions of self-measurement of blood glucose and adherence to a prescribed schedule of daily activities. This impacts strongly on lifestyle because it necessitates precise meal timing as well as control of size and carbohydrate content. We sought to identify how strongly relaxing the lifestyle constraints per se would impact the ability to achieve improved metabolic control. To isolate these effects from those that result from poor measurement compliance, we used a computer simulator called OMNI et al. Furthermore, to standardize the "clinical" therapy, a second microprocessor device called an "Insulin Dosage Computer" was used to adjust insulin doses based on the usual clinical practice of four times a day precibal blood glucose measurements. Ten type 1 diabetic patients were stimulated and each followed for 120 simulated days. In each such subject, the simulation was repeated three times to include three different levels of lifestyle compliance ranging from excellent to poor. In all three protocols, starting from a level of poor control of diabetes, mean blood glucose values were significantly improved without significant differences after 120 days of computer-simulated treatment. Only the standard deviations, expressing the fluctuations of blood glucose and hence its stability, increased with decreasing lifestyle compliance. This computer simulation predicts that consistent self-monitoring of four blood glucose values per day is the cornerstone of diabetic self-control and that the use of these data according to a standardized therapeutic algorithm for insulin adjustment may successfully stabilize even patients with poor lifestyle compliance. Clinical studies must follow.

Selective in situ pancreatic perfusion via chronic in vivo celiac artery catheterization

A new technique to catheterize the celiac artery has been developed. This has opened the possibility for direct in vivo, in situ study of pancreatic endocrine cell function in a conscious experimental animal. The catheter is small, soft and placed without arterial ligation so that celiac artery, hepatic, splenic, and pancreatic blood flows were essentially not compromised. Arterial vessel integrity, absence of inflammation, and thrombosis as well as catheter patency were achieved for periods exceeding eight months. Metabolically and hormonally, the presence of the catheter had no effect on the fasting status. However, we found somewhat lower glucose levels and higher insulin levels in the response to oral glucose challenges after catheterization, but these differences were statistically not significant. Glucose loads of 50 mg/kg (0.75 g) administered directly to the pancreas via the celiac artery produced peak insulin levels similar to peripheral glucose loads some tenfold larger. We suggest that this technique may be useful to selectively study the first-pass pancreatic response to a variety of hormones, drugs or metabolic substrates.

[Selective blood sampling from the inferior petrosal sinus using digital subtraction angiography]

Simultaneous bilateral venous sampling of blood from the inferior petrosal sinuses helps in the differentiation between peripheral and central ACTH hypersecretion. One can also locate the site of a hormonally active hypophyseal micro-adenoma that cannot be demonstrated by other methods. The authors have experience with fifteen patients and discuss the indications, technique and problems as well as the advantages of using digital subtraction angiography.

Developmental and application of insulin infusion profiles for therapy of type-I diabetics with portable insulin infusion systems

We studied the insulin requirements of seven insulin-dependent diabetics applying a glucose controlled insulin infusion system. The data were transformed into individually programmed and rectangular profiles. The MAGE, a measure of blood sugar fluctuations, was significantly lower when individually programmed step profiles were used (P less than 0.005) than it was when rectangular profiles were applied: 57.7 +/- 24.8 mg/dl vs 89.0 +/- 42.9 mg/dl. The average of measured blood glucose levels was significantly lower in individually programmed infusion profiles (P less than 0.025). The combination of individually programmed profiles and preprandial insulin bolus significantly reduced the postprandial blood glucose level and increase (P less than 0.001). Our investigations suggest that individually programmed insulin infusion profiles are able to smooth blood glucose fluctuations. When combined with an initial insulin bolus they may lead to a reduced insulin consumption after meals.

Development of individual insulin infusion profiles for open loop infusion systems

A computer controlled syringe-type insulin infusion pump storing up to 254 different infusion rates, eight different meal programs and two different basal rates automatically changeable during 24 h in EPROM was used for insulin infusion applying a wavy step profile. This profile approaching the physiological postprandial insulin secretion of the B-cell was calculated by an algorithm following the biphasic insulin secretion model proposed by E. Cerasi . The computer program for the open loop infusion device simulated the feed-back structure of a closed loop insulin secretion control by an algorithm based upon a theoretical postprandial blood sugar profile. Fifteen unstable juvenile onset insulin requiring diabetics could be well controlled after two to three days of an intravenous open loop insulin infusion program. The programs consisted of two constant basal rates and superimposed wavy step profile programs activated at the beginning of each meal. The preabsorptive bolus or cephalic phase was an additional tool both for improved postprandial blood sugar control and further reduction of insulin consumption. The programmable insulin infusion device proved as a valuable tool for the study of a sophisticated insulin infusion profile suitable as well for open loop as for closed loop insulin infusion systems.