Table 2.
Outcome clinical data
| Therapeutic tolerance induction | Prophylactic tolerance induction | |||
|---|---|---|---|---|
| Patient 1 | Patient 2 | Patient 3 | Patient 4 | |
| Current age | 56 months | 36 months | 35 months | 22 months |
| rhGAA | 20 mg/kg every 2 weeks | 40 mg/kg every week* | 20 mg/kg every 2 weeks | 20 mg/kg every 2 weeks |
| Ventilation | From 13 months to only at night |
None | None | 3 days at diagnosis |
| LVMI (gm/m2.7) | ||||
| Baseline | 202 | 117 | NA | NA |
| 6 months | 75 | 59** | NA | 389 |
| 12 months | 60 | NA | NA | 273 |
| Last | 31 (48 months) | 44 (30 months) | NA | 194 (15 months) |
| FS | ||||
| Baseline | 40% | 36% | 18% | 7% |
| 6 months | 42% | 35%** | 15% | 10% |
| 12 months | 64% | NA | 26% | 4% |
| Last | 38% (48 months) | 35% (30 months) | 25% (27 months) | 11% (15 months) |
| Cardiomyopathy | Resolved (6 months) | Resolved (3 months) | Improved (14 months) | Ongoing |
| Neuromotor status | Scoots in sitting for independent floor mobility; pulls to stand independently, maintains standing with moderate assistance; fine motor skills advancing; communication impaired by poor intelligibility. |
Age-appropriate gross motor skills, with isolated residual weakness, decreased core strength, myopathic facies, ptosis; no difficulty swallowing. Mild speech delay; low average overall cognitive abilities: gross, fine motor and visual reception— average, language ability— below average. |
Walks and runs independently. No difficulty swallowing. Speaks, but with hypernasal speech as is seen in other children who survive infantile Pompe disease. |
Prop-sit independently, sits briefly without hand support, rolls from supine to side lying, bears weight through lower extremities in supported standing. Swallows solid food and drools less than previously. Age-appropriate hand function and speech. |
| Sits independently | Yes | Yes | Yes | Yes |
| Bears weight through lower extremities |
Yes | Yes | Yes | Yes |
| Independently ambulatory | No | Yes | Yes | No |
| MRI of brain (age in months) | New deep white matter changes (age 54 months) |
Normal (age 31 months) | Normal (age 17 months) | Not done |
| Hearing test | Mild conductive hearing loss—middle to high frequencies (age 56 months) |
PE tubes (age 26 months) | Inconclusive (age 12 months) |
Not done |
ERT, enzyme replacement therapy FS, fractional shortening by m-mode echocardiography; LVMI, left ventricular mass index per height2.7 (gm/m2.7); MRI, magnetic resonance imaging; NA, not available; PE tubes, pressure-equalizing tubes; rhGAA, recombinant human acid α-glucosidase; CPK, creatinine phosphokinase.
*
Patient 2 received rhGAA 20 mg/kg, which was changed to 30 mg/kg after 17 months of ERT and then to 40 mg/kg after 23 months. Frequency was increased to weekly 40 mg/ kg after 29 months of ERT due to increased CPK levels, progression of ptosis, increased fatigue, and decreased stamina, all of which have since improved.
**
Patient 2 echocardiography data are for 9 months of ERT. No data for 6 or 12 months.