BIAL LTI-291-004 tail, GBA activation table, Questions to BIAL, Gain Therapeutics GT-02287, Fusion Protein anti-TfR1 sdAbs
BIAL LTI-291-004
| Phase | Trial | Population | status | n | design | Tx | Primary | Secondary |
|---|---|---|---|---|---|---|---|---|
| P2 = NL7061 LTI-291-004; LSO882EC-178821; NTR7299 | (LTI-291-004) | GBA+PD (Detail not specified) GBA-PD WT | Inclusion stopped, follow up (?) | 15 | DB, RCT, PLACEBO IMAGING STUDY | 28d, 10 or 60 mg once daily for 28 day, fMRI AND FDG-PET | enhanced brain blood flow by arterial spin labeling, increased brain glucose metabolism by FDG PET, and better functional connectivity in the default mode network on fMRI scans. The effects were similar in all treated patients, but not statistically significant in this small cohort. | (Analysis, by David Eidelberg’s group): (2 placebo and 9 treated), revealed that “anti-Parkinsonian” changes were clearly seen in 2 of patients in the high-dose group. Both of these patients also produced the characteristic peripheral intracellular (PBMC2겠군) GluCer increase at 7 and 14 days. |
GBA activation table
| WT (N370S/4MUG, pH4.7) cell-free assay (reduction by cerezyme is defined as 100%) | L444P iPSC-DaNs (reduction by cerezyme is defined as 100%) | SNCA triplication iPSC NEURONS FROM PATIENTS | |
|---|---|---|---|
| GBA activation | (MICE) 118% at 300 mg/kg Cf) iPS: LTI-177 0.1 μM: 127%, LTI-179: 140% (20150217 Slides, p14) Cf) iPS: 113, 211, 382% @ 0.1/1/10 μM 3% at 300 mg/kg EC350: 5.2 μM | Cf) NIH-758: ~170% (20150217 Slides, p12) ↓ by ~70% | ↓ by ~70% |
| GlcCer / GlcSph | No effect up to 10 μM | ||
| ↓ aSyn | 50% |
Questions to BIAL
- aSyn? → no quantitative correlation between GBA activity & CSF aSyn level
- ALL gba mutation? → effective in at least (L444P, N370S, E326K)
- CSF data, → No positive outcome, should be only effective in confined system (intracellular, particularly membrane)
- GlcSph detectible?
- LYSOSOMAL function, proteolysis?
- Ceramide 도 봤나? 우리 inhouse: ↓ (GD), BUT Guede 2017: ↑ Cer, ↑ LacCer
- GalCer 도 봤나? 우리 inhouse: ↑ (GD), & Guede 2017: ↑ (GalCer + GlcCer)
- LacCer? 우리 inhouse: NA, Guede 2017: ↑ LacCer
Low Effect size → two rationale to go beyond the genetic status difference, i. effect on WT GBA allele ii. aSyn (bi-directional, ↓ spreading)
Gain Therapeutics GT-02287
GBA ALLOSTERIC REGULATOR small molecule
| Phase | Trial design |
|---|---|
| Clinical P1 | a single center, randomized, double-blind, placebo-controlled, (SAD/MAD) study to evaluate the safety and tolerability of GT-02287 administered orally once daily in healthy adults. The secondary objective is to evaluate PK of SAD and MAD dose levels to identify a MTD) and identify recommended doses for further clinical development in the setting of GBA1 Parkinson’s disease. The SAD part of the Phase 1 enrolled 40 healthy participants across five separate cohorts—all of which were completed at the planned dose levels with no premature discontinuations or safety signals. The MAD part was initiated in February in parallel to the last SAD cohorts after approval from the Bellberry Human Research Ethics Committee (HREC) in Australia. We expect to initiate a first-in-patient cohort in the Phase 1 clinical trial in the second half of 2024 that can provide proof of mechanism in patients with PD based on relevant biomarkers. ↓ aSyn |
| Preclinical | preclinical data presented at WORLDSymposium earlier in February 2024 demonstrated that treatment with GT-02287 completely restored motor function and reduced plasma levels of the emerging neurodegeneration biomarker NfL back to normal levels. In vitro: aSyn PFF rat DA neurons with and without CBE In vivo: - CBE mouse: 8-10 weeks of age male C57BL/6 mice received daily CBE i.p. injections and oral q.d. drug treatment for 14 days. Wirehang test and beam walk test are performed at day 12. Sacrifice on day 14. ↓ glucer (cortex), ↓ aSyn (SN, HIStology), TH+ DA neuron (just TH histology?), NfL (plasma), ↓ dopamine, ↓ cortical neurons (NeuN), IBA-1 (SN) - CBE-treated aSyn pff mouse: ↓ plasma NfL |
Fusion Protein
Anti TfR1 sdAbs (fused N-terminally to GCB)
| required profile | desired profile |
|---|---|
| Humanized (to avoid immunogenicity, and not related to BBB crossing.) | |
| Cross reactivity to NHP required (94.9% homologous) | Cross reactivity to mouse strongly desired (73.5% homologous) Tak: but the affinity may be different, and it would be better to confirm BBB crossing (of direct-labeled PET, what about assest?) using human TfR Tg mouse (not must-have in my understanding though). |
| No Tf competition | |
| VHH, nanobody ~15 kDa | |
| No RBC toxicity |
Progress
- CL-464373 (sdAb-7), CL-463388 (sdAb-13), with cross-reactivity to mouse, cyno, human
- 40117: sdAb 464373 (sdAb7) prioritized and performs better than VHH-A (Vectorus) in iPSC neuronal cells
- One humanized version of 464373 (VH9) performs the same as 464373 in iPSC neuronal cells
- Assessment of TfR binders on erythroid differentiation by DSRE (in vitro) shows similar properties as VHH
- ((Pothin, 2020) VHH is the variable domain of heavy-chain IgG2 and IgG3)
- Concentration dependent increase in viable cell count with TfR binder-GCB fusions for VHH and CL-464373
GCB variants
- WT GCB affects cell morphology (GCB variants not yet tested), cells look less compact, more detached
- Half-life extension safety review if albumin binders may cause AEs in CNS and how best to test such
Generated variants
- Several novel GCB variants with improved stability and activity have been generated, further optimization is ongoing.
- V343T / F347S
- C126T / V343T
- ~50 new variants assessed as single mutations, in silico mapping in context of other mutations is ongoing
- new variants produced for testing in iPSC:
- CL-464373-3x(G4S)_GCB_A318C-L286C-C126T-V343T
- CL-464373-3x(G4S)_GCB_A318C-L286C-C126T-C342S-V343T
- CL-464373-3x(G4S)_GCB_F347S-C126T-V343T
In vitro biochemical and iPSC data supports these variants as promising candidates: F347S; F347S-V343T; A318C-L286C-V343T; A318C-L286C
Mouse in vivo
- Mouse in vivo ongoing includes variant F347S-V343T (and Amicus and Freeline competitor); GCase activity assay transfer is ongoing; GlcSph data expected end / begin of February
- First study with tissue collection after 4 days showed only GlcSph lowering in the liver, not in brain
- CRO cannot get GCase activity assay to work — alternatives are currently evaluated
- Arzeda collaboration is on hold until after pipeline prioritization (April), i.e. probably not useful then as it does not fit with timelines to IND
- Mouse data with 1× injection at 6.25 mg/kg shows promising brain activity for GCB double variant V343T-F347S
Plan for testing additional TfR binders
Plan for testing additional TfR binders in context of one novel GCB to start in April with plasmid order (up to 20)
001 PE preparation — Feedback from PQR 20240501
Team to define the patient benefit more clearly in respect to benefit regarding cognitive and psychiatric symptoms and determine whether the magnitude of target engagement / PD effect is similar or different from that required to address motoric dysfunction.