How long were the pivotal tox studies for approved gene therapies?

“Single-Dose Intravenous Study of PF 06838435 in Monkeys with a 13- or 104-Week Observation Phase”

“A GLP Toxicity Study of -hFIX-Padua by Intravenous Infusion in Monkeys with a 30- or 90- day Recovery Period”

“Overall, these studies demonstrated no increased tumorigenic potential over a period of up to 16 months when WAS LVV-transduced HSPCs were transplanted into WAS deficient mice.”

“No standalone, GLP in vivo pivotal toxicology study has been performed.”

“These studies demonstrated that OAV101 was well tolerated at this dose level up to 12 months post injection, with minor microscopic findings reported 6 weeks post-administration in the dorsal root ganglia (DRG), spinal cord, peripheral nerves, and brain that did not increase in severity or incidence over the 12 month study.”

“A single IT dose of onasemnogene abeparvovec was administered at three dose levels: 1.20 × 10 13 vg/animal (equivalent to the clinical therapeutic dose), 3.0 × 10 13 vg/animal, and 6.0 × 10 13 vg/animal.”

“Scheduled Sacrifice Time Points 52 weeks post-dose”

“Toxicology and tumorigenicity study in ARSA KO mice treated with ARSA-/- HSPCs transduced with ARSA.LV Vector”

“Scheduled Sacrifice Time Points Days 190 (two animals) and 217 (two animals)”

“In these studies, virus was injected subretinally either once only, or once into each eye, and twice into the same eye.”

“A 7- and 27-Week Toxicity and Biodistribution Study Following a Single Intracochlear Injection of DB-OTO in Cynomolgus Monkeys”

“The 2-month Good Laboratory Practice (GLP) study in adult mice, and the 3-month GLP study in juvenile mice, at dose levels up to 1.3 x 1011 vg/ear showed no DB-OTO-related adverse findings, with a no observed adverse effect level (NOAEL) of 1.3 x 1011 vg/ear.”

“No adverse vector-related findings were observed in the 6-month Good Laboratory Practice (GLP) safety and BD study”

“The definitive 3-month GLP safety and BD study investigated the effect of a single IV administration of 5.0x1013 to 2.0x1014 vg/kg FAYUVI in WT C57BL/6 mice.”

“To evaluate potential toxicity of IV DTX401 administration in NHPs with a 6-month recovery period.”

“One 6-month, single-dose toxicology study was conducted in healthy juvenile non-human primates (NHPs)”

“Moreover, the long-term expression of the therapeutic gene has been taken into account by including an extended follow-up period of 6 months in one of the single dose toxicity studies performed with AMT-011.”

“The non-clinical toxicology programme of Glybera included one single dose toxicity study performed with AMT-010 with a 90-day observation period, two single dose toxicity studies performed with AMT-011 with a 180-day and 105-day observation period, respectively, and a combined reproductive toxicology and breeding study performed with AMT-011.”

“At 26 weeks following IV administration of 5x1012 to 9x1013 gc/kg HEMGENIX in NHPs, high levels of vector DNA were detected in a dose-dependent manner in the liver.”

“The single IV dose toxicology studies and the analysis of the safety parameters were performed under GLP compliance.”

“There were no significant adverse findings noted in a 6-month toxicology study in rats administered dose levels ranging from 7.5x108 – 7.5x109 vg/animal.”

“Two single-dose studies were conducted to assess toxicity at 30-days and 6 months.”

“Scheduled Sacrifice Time Points 6 months post-transplant”

“In vivo studies were also conducted to assess the activity and safety of mBMCs transduced with BB305 following primary and secondary transplantation in β-thalassemic and wild-type C57BL/6 mice.”

“In single-dose toxicology studies conducted in adult male :CD1 mice with study durations up to 6 months, the IV administration of ROCTAVIAN at dose levels of 6.53 × 1013 vg/kg and higher resulted in dose-dependent adverse histopathologic findings in the heart”

“Then, two GLP single-dose studies were conducted in normal CD1 mice with observation periods of up to 26 weeks, and with doses ranging from 6E12 to 2E14 vg/kg.”

“No adverse findings were observed up to 6 months following repeat administration of mRP1 (16 total doses; up to 1x106 PFU/animal/injection) in healthy rats.”

“Toxicology studies evaluating TUDRIQEV and mRP1 were conducted in tumor-bearing immunocompetent mice and healthy rats, respectively.”

“In a 6-month toxicology study conducted in juvenile non-human primates, single IV administration of onasemnogene abeparvovec at the recommended clinical dose level of 1.1 × 10 14 vg/kg, with or without corticosteroid treatment, resulted in microscopic findings in the dorsal root ganglia (DRG), trigeminal ganglia (TG), spinal cord, brainstem, and liver.”

“The Applicant conducted two 12 weeks and one 24 weeks GLP compliant studies with a single IV Zolgensma administration in neonatal FVB wild type mice as indicated in the table below.”

“Findings observed in the animals that survived to the Month 6 scheduled sacrifice included the following:”

“These in vivo studies (NC-11-002, NC-12-019, B2-15-161 and B2-16-200) were pivotal and combined pharmacology, biodistribution, single-dose toxicity and genotoxicity studies”

“A 6-month good laboratory practice (GLP) toxicology and biodistribution study (Report No. SR-19-050) evaluated single IV administration of 1.33 × 1014 and 4.01 × 1014 vg/kg ELEVIDYS”

“A 3-month GLP toxicology study (Report No. SR-20-015) evaluated single IV administration of ELEVIDYS (manufactured by Process B at Catalent) in neonatal C57BL/6J WT mice administered 1.33 × 1014 and 4.01 × 1014 vg/kg at post-natal day 1.”

“dose levels of 2.5 x 1011 vp/animal (1x1011 vg rAd-IFN/mL in 1 mg/mL Syn3), 1.25 x 1013 vp/animal (5x1011 vg rAd-IFN/mL in 1 mg/mL Syn3), Syn3 alone (1mg/mL), or placebo control on Days 1 and 91, followed by a two month observation period”

“on Days 1 and 91, followed by a two month observation period in a GLP toxicology study.”

“Moreover, combined GLP toxicity and tumorigenicity study has been conducted in NSG mice with a duration of 20 weeks.”

“Both GLP studies were conducted as single-dose studies using the intravenous (IV) route reproducing the clinical use of exa-cel.”

“The observation time to determine survival, engraftment and clinical signs in this combined biodistribution/toxicology study was 16 weeks.”

“In this study, NSG mice (n=10/sex/group) were pre-conditioned with busulfan [40 mg/kg total dose over 2 days; intraperitoneal (IP)] prior to dosing transduced cells”

“A 92-day GLP toxicology study in myeloablated mice evaluated a single administration of 1x106 Lenti-D transduced healthy human CD34+ HSCs/mouse.”

“A 92-day GLP toxicology study in myeloablated mice evaluated a single administration of 1x106 Lenti-D transduced healthy human CD34+ HSCs/mouse.”

“Exploratory and GLP-compliant repeat dose toxicity studies were conducted in Balb/c mice with up to 12 weekly doses.”

“Pivotal repeat-dose toxicology, biodistribution, and embryo-foetal development studies were performed in accordance with Good Laboratory Practice (GLP) regulations.”

“The remaining animals were sacrificed on Day 30 or allowed to recover for an additional 30 days following completion”

“five repeat weekly ID administrations of VYJUVEK in BALB/c mice at 6.9 x 106 or 3.45 x 107 pfu/mouse/administration”

“In the toxicology and biodistribution (BD) study, nonclinical products representative of ZEVASKYN comprised of human acellular dermal matrix and RVV-transduced human keratinocytes (cells alone) were implanted into excisional wounds generated in mice for 4- or 8-weeks.”

“In the toxicology and biodistribution (BD) study, nonclinical products representative of ZEVASKYN comprised of human acellular dermal matrix and RVV-transduced human keratinocytes (cells alone) were implanted into excisional wounds generated in mice for 4- or 8-weeks.”

“Mice were sacrificed 1 month after Chim-CD18-WPRE LV transduced Lin- cell transplantation.”

“A 1-month in vivo toxicology and biodistribution (BD) study was also conducted using recipient mice for safety evaluation of Chim-CD18-WPRE LV transduced Lin- murine HSPCs.”

“Dosing Regimen Once weekly for three weeks, a total of three administrations on Days 0,7, and 14 for all groups.”

“GLP Status No”