Mark Forman
Analyst · Neena Bitritto-Garg with Citi. Your line is open
Thank you, Chip. First, let me discuss our lead program PBGM01 for GM1 gangliosidosis. GM1 is a fatal neurological lysosomal storage disease caused by a GLB1 gene mutation that results in low activity of the beta-galactosidase enzyme. This leads to a rapid neurological decline and in the most severe form, unfortunately, to mortality within several years. Patients with GM1 are a rare and underserved population and there are no disease modifying therapies for their disorder currently. Our Imagine-1 clinical trial focuses on the early and late infantile forms of GM1, which are the most severe forms of the disease. This global Phase I/II trial is an open-label dose escalation study with PBGM01 enrolling 4 distinct cohorts divided by age and dose level. As a reminder, We were pleased to report updated positive interim safety, biomarker and clinical efficacy data from Cohort 1 at ASGCT in May. These data show that the low dose of PBGM01 was well tolerated and had a favorable safety profile with patient 1 data through 13 months and patient 2 data through 7 months. No serious adverse events, no complications related to ICM administration and no evidence of dorsal root ganglion toxicity were observed in either patient. Both patients showed continued improvement across developmental areas on the Vineland-II, a caregiver assessed scale and Bayley 3, an investigator assessed scale following PBGM01 administration. Patient 1 showed improvement across all developmental areas through the 12-month assessment with notable progression in motor and language domains. Patient two showed improvement across multiple developmental domains despite having severe developmental delay at baseline and a prior history of regression. This patient progressed from standing with support for 5 seconds to standing with support for one to three minutes and walking without support. We were extremely pleased to see continued and meaningful improvement in developmental milestones for these children, including regaining of lost milestones. Volumetric MRI data showed meaningful growth in brain volume for patient 1 who was 15 months of age at gene transfer. Patient two who had severe developmental delay at baseline and was 31 months of age at gene transfer showed a slight decline in brain volume following -- from baseline at 6 months. Longer-term biomarker data for beta-galactosidase enzyme activity in CSF and serum showed functional transgene expression. As Chip mentioned, our Imagine-1 trial has experienced strong momentum. To-date we have dosed a total of five patients in the study, we have completed dosing of Cohorts 1 and 3 low dose in late and early infantile patients, respectively and have dosed the first patient in the high dose late infantile Cohort 2. Following positive review of interim safety data from Cohort 3 by the independent data monitoring committee, we are excited to have now advanced the study to recruitment of patients for Cohort 4 high dose early infantile GM1. This is the final patient cohort in the dose ascending phase of the study. We remain on track to report initial safety and biomarker data from Cohorts 2 and 3 in the second half of 2022. Moving on to our global PBKR03 program GALax-C, which is an open-label dose escalation study in patients with early infantile Krabbe disease. Krabbe disease is a condition that progresses rapidly damaging both the brain and the peripheral nervous system resulting in a life expectancy of only two years in the severe cases. Krabbe disease is a fatal neurological lysosomal storage disease caused by a GALC gene mutation that results in decreased enzyme activity of galactosylceramidase. Like GM1, this is also a pediatric leukodystrophy and lysosomal storage disease with an underserved population and devastating disease progression. Our approach to treating Krabbe is similar to our approach to GM1, utilizing the same proprietary capsid and ICM delivery to potentially address both CNS and peripheral disease manifestations. We have dosed the first patient in the study and are actively recruiting additional patients in Cohort 1. We look forward to reporting initial safety and biomarker data from a subset of Cohort 1 by the end of 2022. Our third clinical program, PBFT02 is for frontotemporal dementia with granular mutations. FTD is a devastating form of early onset dementia affecting patients between the ages of 40 to 65. The form of the disease we are seeking to treat with our therapy is caused by a granulin or GRN gene mutation, which results in a deficiency of progranulin. It's estimated that about 5% to 10% of FTD is caused by a GRN mutation. We are utilizing the AAV1 capsid to deliver the GRN gene via ICM delivery to the CSF. As a reminder, the study design consists of 2 cohorts of 3 patients each receiving 2 different ascending doses of PBFT02 with an optional third cohort treated with a higher dose depending on safety and biomarker data results observed in the first 2 cohorts. We now have 3 active clinical trial sites, including 2 in the US and 1 in Brazil, and activation efforts at additional sites continue. We also continue to employ a variety of patient identification initiatives, including efforts to increase genetic testing among FTD patients. We've now identified prospective patients with a granulin mutation that could dose the first patient in the study shortly. Turning lastly to PBML04, our program for metachromatic leukodystrophy or MLD. Infantile MLD is a fatal inherited disease caused by mutations in the ARSA or the arylsulfatase A gene, MLD is characterized by muscle weakness, rigidity, gait disorder and developmental delays and unfortunately, children typically die by the age of 5. Worldwide incidence is approximately 1 in 100,000 live births. Our approach is similar to our approach to GM1 and Krabbe, utilizing the same proprietary capsid AAVhu68 and ICM delivery to express ARSA and potentially address both central nervous system and peripheral manifestations of this devastating disease. We announced in June that the FDA cleared our IND marking our fourth IND clearance as a company and our third pediatric lysosomal storage disorder program to reach clinical development. We're thrilled to have achieved this milestone and are excited by the promise of our potential therapy. As we continue to evaluate our resources and operating expenses, we' With that, I will now turn the call over to Simona to review our financials.