• ClinicalTrials.gov Identifier: NCT02576795¹
• A Phase 1/2, Dose-Escalation, Safety, Tolerability and Efficacy Study of Valoctocogene Roxaparvovec, 
  an Adenovirus-Associated Virus Vector-Mediated gene transfer of human FVIII in Patients with severe Haemophilia A

• Ongoing development, Active, not recruiting
• Last Update Posted: August 06, 2024¹

• Male ≥18 years of age with base FVIII level ≤ 1 IU/dL
• Treated/exposed to FVIII concentrates or cryoprecipitate for a minimum of 150 Eds

• Detectable pre-existing immunity to the AAV5 capsid^a
• Prior treatment with any vector or gene transfer agent
• Use of systemic immunosuppressive agents or live vaccines within 30 days before the viral infusion

^a Cell-based in vitro transduction-inhibition assay and total antiAAV5 antibody assay

AAV5/baculovirus, Spodoptera frugiperda (Sf9) insect-cell production system²

    Codon-optimized expression cassette encoding the SQ variant of B-domain–deleted human FVIII²

As reported in Reference #3, HLP is a 251-bp enhancer/promoter fragment consisting of:

• a 34-bp core enhancer from the human ApoE-HCR gene upstream of
• a modified 217-bp gene promoter, which includes the distal X and proximal A1B regulatory domains from SERPINA1 (α1-antitrypsin)

As reported in Reference #2 [supplementary material], the FVIII expression cassette also includes a synthetic poly(A) signal

    Systemic (peripheral vein infusion)²

• Co. 1: 6e12 (1)²
• Co. 2: 2e13 (1)²
• Co. 3: 6e13 (7)^2, 4, 5
• Co. 4: 4e13 (6) ^4, 5

    52 weeks², 3 years⁴, 4 years⁵ and 5 years⁶

• FVIII activity levels were assessed by both OS and CH clotting assays^2, 4, 11
• OS FVIII activity levels were approximately 1.6⁴ to 1.65² times as high as the FVIII levels from CH 

Data on FVIII activity levels up to week 52 for the low and intermediate cohorts (Co. 1 and Co. 2) have been reported in reference #2 and are summarized as follows:

FVIII activity at specific thresholds through week 52 in the high dose cohort was published in reference #2  and is summarized as follows:

Multiyear mean and median FVIII activity levels for Co. 3 (4e13 vg/kg) and Co. 4 (6e13 vg/kg) were published in references #4, #5, #6, #9 and #11 and are summarized as follows:

* Missing data from 2/7 pts. in Co. 3 (6e13 vg/kg) that resumed prophylaxis at year 7 are not imputed in the calculation of mean and median FVIII activities
† Missing data from 2/6 pts. in Co. 4 (4e13 vg/kg) are not imputed in the calculation of mean and median FVIII activities

• When including results prior to resuming prophylaxis, respective mean FVIII activity was 12.6 (median, 5.1) IU/dL (n = 7) 
  and 5.2 (median, 4.5) IU/dL (n = 6) for the 6e13 vg/kg and 4e13 vg/kg cohort¹¹

Data concerning the annual absolute % change in mean FVIII activity per CSA were published in reference #11 are summarized below as follows:

As shown in Figure 1 in reference #4, the times to peak response are summarized as follows:

• 20 to 24 weeks in Co. 3 (6e13 vg/kg, n=7) and
• 44 weeks in Co. 4 (4e13 vg/kg, n=6)

Early follow-up efficacy data on ABR in Co. 1–Co. 3 were reported in reference #2 and are summarized below

• Co. 1: not applicable, as the only pt. in this cohort resumed FVIII prophylaxis after W16
• Co. 2: the ABR increased from 3 to 11 events in 1/1 pts. with stable but low FVIII activity level (1 to 3 IU/dL) through W54
• Co. 3: the median ABR dropped from 16 events per year before the study to 1event per year after gene transfer (mean reduction in rate, from 16 to 2 events)

The most recent multiyear follow-up of treated ABRs was reported in reference [11] and is summarized as follows:

Summary of reported reductions from baseline in treated bleeds per year over the course of up to 7 years, as shown below:

* Six of the seven participants were receiving regular FVIII prophylaxis at baseline (one participant was receiving on-demand FVIII prophylaxis
and was excluded). Baseline (n = 6) ABR mean and median were 16.3 and 16.5 bleeds/year, and the mean ABR over the entire study was
0.77 bleeds/year, representing a 95% decrease from baseline.

Early follow-up efficacy data related to AIR in Co. 1 – Co. 2 were reported in Reference #2 and are summarized as follows:

The most recent multiyear follow-up of AIRs before and after treatment was reported in Reference #11 for in both high dose cohorts and is summarized as follows:

* Six of the seven participants were receiving regular FVIII prophylaxis at baseline (one participant was receiving on-demand FVIII prophylaxis 
and was excluded). Baseline (n = 6) ABR mean and median were 16.3 and 16.5 bleeds/year, and the mean ABR over the entire study was
0.77 bleeds/year, representing a 95% decrease from baseline.

Infusion-related reactions (IRRs) in the high-dose cohorts were reported in Reference #6 as follows:

• Co. 3 (6 × 10¹³ vg/kg, n = 7): IRRs occurred in 3/7 participants (42.9%)
• Co. 4 (4 × 10¹³ vg/kg, n = 6): IRRs occurred in 4/6 participants (66.7%)

Extended follow-up data for Co. 4  (4 × 10¹³ vg/kg, n = 6) were reported in Reference #12:

• No additional IRRs were reported during Years 2–7

Safety data on AEs and SAEs were reported sequentially in References #4, #6, #11, and #12. To avoid duplication across overlapping follow-up periods, the annual incidence data are consolidated below using the most recent available data for each year, including Year 7 data for the 4 × 10¹³ vg/kg cohort (Co. 4) from the final analysis reported in Reference #12

    Table notes:
      Note: Data are presented as n (%)
      ^a Pyrexia on study day 2.
      ^b ALT elevation defined as ALT ≥1.5 × ULN or ALT ≥1.5 × baseline.
      ^c In Y7, one participant experienced a non-treatment-related CTCAE grade 1 ALT elevation at week 336 that was ongoing at database lock.
         This event was not coded as an AE of special interest and therefore is not included in the tabulated ALT-elevation count.
      ^d AEs of liver dysfunction were identified using a MedDRA search strategy with the high-level term “liver function analyses.”
Abbreviation: AE, adverse event; ALT, alanine aminotransferase; CTCAE, Common Terminology Criteria for Adverse Events; MedDRA, Medical Dictionary for Regulatory Activities; SAE, serious AE; ULN, upper limit of normal; Y, year

Data-source annotations for the consolidated table

• Co. 3 (Y1–Y7) and Co. 4 (Y1–Y6) data are based on the latest annual safety summary reported in Reference #11.
• Co. 4, Year 7 data from Reference #12 are summarized below:
  • Two of six participants experienced an AE; no SAEs or treatment-related AEs were reported, and no new safety signals were identified
  • No ALT elevations were classified as AEs of special interest
  • One of six participants experienced an AE of liver dysfunction
  • No potential Hy’s law cases, infusion-related reactions, systemic hypersensitivity, anaphylactic/anaphylactoid reactions, or thromboembolic events were reported

Additional early safety data from Reference #4, including cumulative AE incidence, event numbers, and AE severity grades, are summarized below for Co. 1–3 through 3 years of follow-up and Co. 4 through 2 years of follow-up.

    AE: adverse event , SAE: serious adverse event
    * Adverse events were graded in accordance with the Common Terminology Criteria for Adverse Events, version 4.0.3 (CTCAE)
    † Treated ALT elevations include all ALT elevations that resulted in initiation or modification of glucocorticoid treatment

Additional safety findings reported in References #4  and #6 are summarized as follows:

• The most common AEs associated with valoctocogene roxaparvovec were transient, asymptomatic, mild-to-moderate ALT elevations.
• A treatment-related grade 2 SAE of pyrexia, developed along with myalgia and headache, occurred in one participant (P13, Co. 4) within 24 hours after administration of AAV5-hFVIII-SQ.
  • Symptoms resolved within 48 hours following treatment with acetaminophen.

Not reported 

Early 1-year data on ALT elevations in Co. 1–Co. 3 were reported in Reference #2 and are summarized as follows:

• Co. 1 (low dose, 6 × 10¹² vg/kg, n = 1): ALT elevation occurred in 1/1 participant
• Co. 2 (intermediate dose, 2 × 10¹³ vg/kg, n = 1): No ALT elevation was reported
• Co. 3 (high dose, 6 × 10¹³ vg/kg, n = 7): ALT elevations occurred in 7/7 participants
• Overall, ALT elevations occurred in 8/9 participants:
  • the first observed value above the ULN occurred at Week 3;
  • peak ALT levels ranged from 59 to 128 U/L (normal range, 6–43 U/L)
• All ALT elevations were asymptomatic and resolved without sequelae
• In one participant in Co. 3 (Participant 4), ALT increased between Weeks 28 and 35:
  • peak ALT was 95 U/L
  • the elevation was accompanied by a decline in FVIII activity from 227 to 52 IU/dL

Longer-term data on ALT elevations in the high-dose cohorts were reported in Reference #6 and are summarized as follows:

• Co. 3 (6 × 10¹³ vg/kg, n = 7):
  • ALT elevations classified as AEs of special interest occurred in:
    • 6/7 participants (85.7%) in Year 1,
    • 1/7 (14.3%) in Year 4
    • 1/7 (14.3%) in Year 5
  • Year 4: one Grade 1 ALT elevation reached 1.4 × ULN on study day 1389 and resolved by study day 1431 without treatment
  • Year 5: one Grade 1 ALT elevation reached 1.3 × ULN on study day 1626 and resolved by study day 1631
  • Both later ALT elevations were considered not treatment-related, and no glucocorticoids were administered
• Co. 4 (4 × 10¹³ vg/kg, n = 6):
  • ALT elevations classified as AEs of special interest occurred in:
    • 4/6 participants (66.7%) in Year 1
    • 1/6 (16.7%) in Year 3
  • Year 3: one Grade 1 ALT elevation reached 2.1 × ULN on study day 1100 and resolved by study day 1135 without treatment
  • The event was considered not treatment-related
• The later ALT elevations reported in both cohorts were mild, transient, and asymptomatic, required no glucocorticoid treatment, and were not associated with a decrease in FVIII levels

Extended follow-up data for Co. 4 were reported in Reference #12 and are summarized as follows:

• No ALT elevations classified as AEs of special interest were reported during Years 4–7
• In Year 7, one participant experienced a non-treatment-related CTCAE Grade 1 ALT elevation at Week 336
• The ALT elevation was ongoing at database lock, and the participant had a history of fatty liver disease
• This event was not classified as an AE of special interest and was therefore not included in that category in Table 1
• Peak ALT level was not reported for this Year 7 event

3/9 pts. (peak levels and timing not reported)² and 10/15 pts. (peak levels and timing not reported)⁴ 

Data regarding capsid directed T cell activation were reported by different publications as follows:

• 0/9 pts. (peak and timing not reported)² and Sporadic, transient positives in some pts.⁴ 
• All 15 pts. were tested negative for the AAV5-specific IFN-g responses at baseline⁷
• 4 /15 pts. were tested positive (R50 SFU/106 PBMCs) for AAV5-specific IFN-g responses at a single time point ^a post-administration and negative at all subsequent time points tested (Figure 4A) ⁷

^a PBMC samples were collected at baseline and at several time points after administration that varied by cohort but were generally every 2–4 weeks during the first 6 months, 4–8 weeks through the rest of year 1, and every 3 months thereafter

•  Yes, all pts. with elevated ALT levels were steroid responsive (mean duration of steroid treatment was 21 weeks in 7/9 pts.)²
•  Co. 3: Steroid treatment in 2/3 participants did not inhibit ALT elevations (duration not reported)⁴

The association between ALT elevations and decreases in FVIII activity/expression in Co. 3 was reported in References #2 and #4, as follows:

• The increase in ALT levels led to a decline in FVIII activity in 1/9 (11%) participants in Co. 3 [Reference #2].
  • The level in this participant declined from 227 IU/dL to 52 IU/dL in conjunction with an increase in the ALT level from W28 to W35.
  • The FVIII activity level subsequently increased, and no bleeding was reported.
• Elevations in ALT levels appeared to have been temporally associated with decreases in FVIII expression in 4/9 pts. (P4, P5, P7, and P8) in Co. 3 [Reference #4].

 Follow-up data regarding a diagnosed cancer in a pt. were taken from here⁸ and summarized as follows: 

• One SAE in a pt. was diagnosed as salivary gland cancer
• The cancerous mass was removed, and the pt. was monitored
• The study investigator considered the SAE as being unrelated to the treatment
   
• BioMarin announced the findings from genomic analysis from a tissue sample containing the mass, stating that: “The results  showed a comparable pattern of integration between healthy and tumor containing tissues, with no evidence emerging that vector integration contributed to the salivary gland mass.”

1. Gene Therapy Study in Severe Haemophilia A Patients (270-201). ClinicalTrials.gov identifier: NCT02576795. Link
2. Rangarajan S, Walsh L, Lester W, Perry D, Madan B, Laffan M, et al. AAV5-Factor VIII Gene Transfer in Severe Hemophilia A. N Engl J Med. 2017 Dec 28;377(26):2519-2530. doi: 10.1056/NEJMoa1708483. Epub 2017 Dec 9. PMID: 29224506. Link
3. McIntosh J, Lenting PJ, Rosales C, Lee D, Rabbanian S, Raj D, et al. Therapeutic levels of FVIII following a single peripheral vein administration of rAAV vector encoding a novel human factor VIII variant. Blood. 2013 Apr 25;121(17):3335-44. doi: 10.1182/blood-2012-10-462200. Epub 2013 Feb 20. PMID: 23426947; PMCID: PMC3637010. Link
4. Pasi KJ, Rangarajan S, Mitchell N, Lester W, Symington E, Madan B, et al. Multiyear Follow-up of AAV5-hFVIII-SQ Gene Therapy for Hemophilia A. N Engl J Med. 2020 Jan 2;382(1):29-40. doi: 10.1056/NEJMoa1908490. PMID: 31893514. Link
5. Pasi, K., et al., Hemostatic Response is Maintained for up to 5 Years Following Treatment with Valoctocogene Roxaparvovec, an AAV5-hFVIII-SQ Gene Therapy for Severe Hemophilia A [presentation]. ISTH 2021 Congress, 2021. Link
6. Pasi KJ, Laffan M, Rangarajan S, Robinson TM, Mitchell N, Lester W, et al. Persistence of haemostatic response following gene therapy with valoctocogene roxaparvovec in severe haemophilia A. Haemophilia. 2021 Nov;27(6):947-956. doi: 10.1111/hae.14391. Epub 2021 Aug 11. PMID: 34378280; PMCID: PMC9291073. Link
7. Long BR, Veron P, Kuranda K, Hardet R, Mitchell N, Hayes GM, et al. Early Phase Clinical Immunogenicity of Valoctocogene Roxaparvovec, an AAV5-Mediated Gene Therapy for Hemophilia A. Mol Ther. 2021 Feb 3;29(2):597-610. doi: 10.1016/j.ymthe.2020.12.008. Epub 2020 Dec 10. PMID: 33309883; PMCID: PMC7854299. Link
8. BioMarin follows up on previously-reported serious adverse event in its phase I/II gene therapy clinical trial for haemophilia A. 2022, WFH World Federation of Hemophilia. Link
9. Symington E, Rangarajan S, Lester W, Madan B, Pierce GF, Raheja P, et al. Long-term safety and efficacy outcomes of valoctocogene roxaparvovec gene transfer up to 6 years post-treatment. Haemophilia. 2024 Mar;30(2):320-330. doi: 10.1111/hae.14936. Epub 2024 Feb 5. PMID: 38317480. Link
10. Pasi, K., et al., Hemostatic Response is Maintained for up to 5 Years Following Treatment with Valoctocogene Roxaparvovec, an AAV5-hFVIII-SQ Gene Therapy for Severe Hemophilia A. ISTH 2021 Congress, 2021. Abstract Number: OC 67.1. Link
11. Symington E, Rangarajan S, Lester W, Madan B, Pierce GF, Raheja P, et al. Valoctocogene roxaparvovec gene therapy provides durable haemostatic control for up to 7 years for haemophilia A. Haemophilia. 2024 Sep;30(5):1138-1147. doi: 10.1111/hae.15071. Epub 2024 Jul 8. PMID: 38975624. Link
12. Raheja P, Rangarajan S, Lester W, Madan B, Pierce GF, Symington E, Millar C, Osmond D, Li M, Chavele KM. Final Analysis of the Phase 1/2 Trial of Valoctocogene Roxaparvovec for Severe Haemophilia A. Haemophilia. 2026 Jul-Aug;32(4):974-981. doi: 10.1111/hae.70284. Epub 2026 Apr 12. PMID: 41968461; PMCID: PMC13378670. Link

AAV, Adeno-associated virus; ABR, Annualized bleeding rate; AEs: adverse events; AIR, Annualized FVIII/FIX infusion rate; ALT, alanine aminotransferase; AST, aspartate aminotransferase; CH, Chromogenic Assay; Co., cohort; DOACs, Direct oral anticoagulants; D, days; EDs, exposure days; FIX, factor IX; FIX-Padua, gain of function FIX variant; FVIII, factor VIII; gc, genome copies; HEK cells, human embryonic kidney cells; IQR, interquartile range; IRR, Infusion-related reaction; NAbs, neutralizing antibodies; OS, One-stage clotting assay; Pop., population; pt., patient/participant; pts., patients/participants; P1, Participant 1; PI, phase I; PBGD, porphobilinogen deaminase; PBMC, peripheral blood mononuclear cells; SAEs, serious adverse events; SFU, spot-forming units; TAC, tacrolimus; ULN, upper limit of normal; VCN, vector copy number; vg, vector genomes; W, weeks; WT, wild type; Y, year