Summary Information For: AAV5, FVIII-BDD, Roctavian, NCT03370913 (Phase 3, GENEr8-1 Study)
AAV5, FVIII-BDD, Roctavian, NCT03370913 (Phase 3, GENEr8-1 Study)
Haemophilia A
BioMarin Pharmaceutical
General Study Information
  • ClinicalTrials.gov Identifier: NCT033709131, 2 
  • Phase III, Open-label, multicenter
  • Single-Arm Study, GENEr8-1 Study

Active, not recruiting, Last Update Posted: December 20, 20231

Information regarding the approval status of Roctavian was collected from here1112 and summarised as follows:

  • In June 29,  2023, Roctavian was approved in the USA for the treatment of haemophilia A
  • In August 24, 2024,  Roctavian was approved by the EMA for the treatment of haemophilia A
  • Male ≥18 years of age
  • Base FVIII level ≤ 1 IU/dL2
  • Treated/exposed to FVIII concentrates or cryoprecipitate for a minimum of 150 Eds

 Key exclusion criteria were reported here3 as follows:

  • Anti-AAV5 capsid total binding antibodies
  • HIV infection (added as a criterion after a protocol amendment)
  • Substantial liver dysfunction, substantial liver fibrosis, or liver cirrhosis

AAV5/baculovirus, Spodoptera frugiperda (Sf9) insect-cell production system3 [supplementary appendix]

Codon-optimized expression cassette for the SQ variant of B-domain–deleted humna hFVIII (AAV-HLP-FVIII-SQ)49

HLP is a 251-bp enhancer/promoter fragment containing 

  • a 34-bp core enhancer from the human ApoE-HCR gene 
  • a modified 217-bp gene promoter comprising the distal X and the proximal A1B regulatory domains from SERPINA1 (α-1-antitrypsin)5

The FVIII expression cassette also includes a synthetic polyA signal4 [supplementary material]

    Systemic (peripheral vein infusion)3

Different populations within the same dose cohort were defined here3, 6 as follows:

  • ITT Pop. (N = 134): an intention-to-treat population of 134 pts. that received one infusion of the AAV5-hFVIII-SQ vector (6e13 vg/kg)
  • mITT Pop. (N = 132): a modified intention-to-treat population including the 132 HIV-negative pts.
  • mITT Pop. 2-year3 or mITT Pop. 3-year6 (N= 17): subgroups of mITT Pop. including 17 pts. with infusion ≥2 or ≥3 years before data cutoff
  • RP (N = 112): the rollover population included 112 pts. from mITT Pop. who had ≥ 6 months of prospective data on bleeding and FVIII use from the non-interventional 270-902 study 7
  • Median follow-up was 60.2 weeks (range, 51.1 to 150.4)3 and 110.9 weeks (range, 66.1 to 197.4)
  • As reported here9,  safety and efficacy results included data from the year-3 data cut cutoff36:
    • Mean follow-up was 172.8 (standard deviation [SD], 26.61) weeks
    • Median, 162.4 weeks; range, 66.1–255.0 weeks

    Both OS and CH were carried out23

Efficacy details

The impact of anti-AAV5 TAb and AAV5 TI titers on FVIII activity was reported here9 as follows:

  • 3 pts. who developed detectable anti-AAV5 TAb (titers of < 20, 56, and 91) between screening and day 1 (range, 25–42 days) were treated with valoctocogene roxaparvovec
  • Despite this, they demonstrated effective transduction, with FVIII activity levels between 2.0 and 9.2 IU/dL at week 152 or week 156
  • There was no associated impact on the safety profile
  • At baseline, 11 pts. who tested positive for AAV5 TI exhibited a median FVIII activity at week 104, with values ranging between 1.6 and 78.3 IU/dL
  • None were AAV5 TAb-positive at baseline or screening, although 1 of 11 was AAV5 TAb-positive at day 1
  • At week 156, the mean FVIII activity for these 11 pts. was 22.9 IU/dL and the median was 9.0 IU/dL
  • Compared to the overall ITT Pop., the mean FVIII activity was 18.2 IU/dL and the median was 8.2 IU/dL
  • The median FVIII activity demonstrated no correlation with the peak AAV5 TAb titers at week 104,
    nor with the AAV5 TAb titers measured at week 8
     

Efficacy data on FVIII activity in the mITT Pop. (n = 132) at the end of Year 1 (week 52), 2 (week 104) and 3 (week 156) were
retrieved from Table S36 and Figure 213 and are summarized as follows:

Mean and median FVIII activity (IU/dL) levels per CH and OS in the mITT Pop. (n =132) at the end of years 1, 2 and 3 post infusion 

 

Year 1 (week 52)

Year 2 (week 104)

Year 3 (week 156)

Year 4 (week 208)

FVIII activity (IU/dL) per CH

n = 132

n = 132

n = 132

n = 17

    Mean ±SD

42.8 ± 45.6

23.0 ± 32.9

18.4 ± 30.8

15.2 ± 21.5

    Median (IQR)

23.9 (11.9, 62.3)

11.8 (5.0, 25.7)

8.3 (3.0, 17.2)

7.4 (4.7, 11.9)

FVIII activity (IU/dL) per OS

 

    Mean ±SD

64.0 ± 64.8

36.1 ± 47.3

29.7 ± 43.5

22.1 ± 26.3

    Median (IQR)

40.3 (19.7, 86.9)

21.6 (7.6, 42.2)

16.2 (5.5,31.7)

13.2 (8.6, 20.5)

           


Efficacy data concerning FVIII activity at specific thresholds within the ITT Pop. and mITT Pop. at the end of Year 1, 2 and 3 post-infusion were
presented in Table S56 and Figure S213 as shown below.

Median and meanFVIII activity (IU/dL) levels per CH and OS in the ITT Pop. at the end of years 1 (week 52) and 2 (week 104) post infusion 

 

Year 1 (N = 134)

Year 2 (N = 132a)

Year 3 (N = 132)

 

Median FVIII activity

Mean FVIII activity

FVIII activity (IU/dL) per CH

n (%)

n (%)

n (%)

     <3 IU/dL (LLOQb)

13 (9.7)

18 (13.6)

32 (24.2)

     <5 IU/dL

16 (11.9)

31 (23.5)

12 (9.1)c

     ≥5 and <40 IU/dL

69 (51.5)

81 (61.2)

74 (56.1)d

     ≥40 IU/dL

49 (36.6)

20 (15.2)

14 (1.6)

FVIII activity (IU/dL) per OS

n (%)

n (%)

-

     <1 IU/dL (LLOQ)

2 (1.5)

6 (4.5)

-

     <5 IU/dL

10 (7.5)

18 (13.6)

-

     ≥5 and <40 IU/dL

56 (41.8)

79 (59.8)

-

     ≥40 IU/dL

68 (50.7)

35 (26.5)

-

a Data of 2 pts. who discontinued the study before week 104 were excluded
b LLOQ, lower limit of quantitation
c ≥3 to ≤5 IU/dL
d >5 and <40 IU/dL

Efficacy data related to FVIII activity in the mITT Pop. 4-year (n = 17) at the end of Year 1 (week 52),  2 (week 104), 3 (week 156) and 4 (week 208)
were retrieved from Table S36 and Figure 213 and are summarized as follows:

Mean and median FVIII activity (IU/dL) levels per CH and OS in the mITT Pop. 4-year (n = 17) at the end of Years 1, 2, 3 and 4 post infusion 

 

Year 1 (week 52)

Year 2 (week 104)

Year 3 (week 156)

Year 4 (week 208)

FVIII activity (IU/dL) per CH

 

    Mean ±SD

42.0 ± 51.1

24.5 ± 29.7

16.8 ± 21.1

15.2 ± 21.5

    Median (IQR)

23.9 (11.2, 55.0)

14.7 (6.4, 25.9)

9.3 (4.6, 13.6)

7.4 (4.7, 11.9)

FVIII activity (IU/dL) per OS

 

    Mean ±SD

-

-

-

22.1 ± 26.3

    Median (IQR)

-

-

-

13.2 (8.6, 20.5)

Extrapolated FVIII activity up to 5 years (Week 260) after the gene transfer was presented in Table 1 here6, as shown below:

Estimated mean and median FVIII activity (IU/dL) per CH using a linear mixes effects (LME) model

Time post infusion

Mean

Median (range)

Week 104

22.3 ± 29.7

11.1 (BLQ-171)

Week 156

16.9 ± 25.0

8.9 (BLQ-156)

Week 208

13.6 ± 22.4

7.2 (BLQ–143)

Week 260

11.8 ± 21.0

5.7 (BLQ–131)

      BLQ, below the limit of quantitation

The following statements regarding the extrapolated FVIII activity were outlined here6, as follows:

  • In the present phase 3 study, the mean and median extrapolated FVIII activity levels measured per CH at week 260
  • Among the 7 pts. in the phase 1–2 trial8 who received a dose of 6e13 vg/kg, the relative rate of decrease in FVIII activity
    resembled that observed in this phase 3 study were estimated to be 11.8 and 5.7 IU/dL, respectively

According to Figure 13, peaks of median FVIII activity levels are achieved

  • At 21-32 weeks in the mITT Pop. (n = 132) and  
  • At 29-32 weeks in the mITT Pop. 2-year (n= 17) after vector infusion

Efficacy data regarding the ABR in RP (N = 112) were reported here3, 6, 13 and were obtained from Figure 1A6, 13 , 1B13 and 1C6 and are summarized in tables as follows:

Mean and median annualized rates of Treated bleeding episodesa (Figure 1A)6, 13 in RP (n = 112) using the baseline values from a 6-months prospective study (270-902)

Annualized rates

at Baseline

Year 1 b

Year 2 c

Year 3 d

All Postprophylaxis

mean ± SD

4.8 ± 6.5

0.9

0.7

1.0

0.8

median

2.8

0

0

0

0

mean (95% CI) change from BL in Y3

NA

NA

NA

NA

−4.0 (−5.2 to −2.8) bleeds per year

ABR reduction in Y3

NA

NA

NA

NA

82.9%

 

Mean and median annualized rates of All bleeding eventsa (Figure 1B13, 1C6) in RP (n = 112)

Annualized rates

at Baseline

Year 1 b

Year 2 c

Year 3 d

All Postprophylaxis

mean ± SD

5.4

1.5

1.0

1.4

1.3

median

3.3

0

0

0

0.3

mean (95% CI) change from BL in Y3

NA

NA

NA

NA

−4.1 (−5.4 to −2.8) bleeds per year

ABR reduction in Y3

NA

NA

NA

NA

76.0%


Efficacy data for year 1 through year 4 in mITT Pop. 4-year were extracted from Table S113 and S26 and summarized as follows:

Annualized treated bleeding rate a in mITT Pop. 3-year (N = 17)

 

 

Year 1 b

Year 2 c

Year 3e

Year 4

 

Annualized rates

n=17

n=17

n= 16f

n=16

 

mean ± SD

1.2 ± 3.0

0.5 ± 0.9

0.6 ± 1.7

0.8 ± 1.4

 

median (IQR)

0.0 (0.0, 0.0)

0.0 (0.0, 0.0)

0.0 (0.0, 0.5)

0.0 (0.0, 1.0)

 


The data on reported joint and not-joint bleeds by year of post-prophylaxis follow-up in ITT Pop. (N = 134) were extracted from Figure S6A6
and summarized as presented below:

Joint and not-joint bleeds in the ITT pop. (n = 134) by year of Postprophylaxis

 

All bleeds

Treated bleeds

Percent of participants (n)

Year 1 b

Year 2 c

Year 1 b

Year 2 c

Problem joints

3.7 (5)

3.0 (4)

3.0 (4)

1.5 (2)

Anywhere except problem joints

42.5 (57)

34.3 (46)

20.1 (27)

17.2 (23)

Not in joints

33.6 (45)

24.6 (33)

15.7 (21)

10.4 (14)

a Treated bleeding events were defined as bleeding events followed by the use of standard half-life, extended half-life, or plasma-derived factor VIII products within 72 hours after the event
b Year 1 values included the period beginning either at the start of week 5 or 3 days after the end of factor VIII prophylaxis (whichever was later) and ending at week 5
c Year 2 values included week 53 to week 104
d Year 3 data were based on N = 110 due to participants who discontinued the study
e Year 3 indicates the period from week 105 to 156
f One participant was lost to follow-up at week 66. For year 2, his ABR data through week 66 were and for year 3, no ABR data were included

Data from a post hoc analysis10 assessing the comparative effectiveness of valoctocogene roxaparvovec versus FVIII prophylaxis, using propensity scoring (PS) among participants in the rollover population (RP, n = 112) and a contemporaneous external control group (n=73) from the non-interventional 270-902 trial, are summarized as follows:

  • As shown in Figure 1b, c, compared with the control cohort, participants who received valoctocogene roxaparvovec were significantly more likely to have no treated bleeds and a reduction in all bleeds
    • Mean treated ABR (SD):  4.40 (6.14) vs 0.85 (3.59); P < 0.001
    • All ABR (SD): 5.01 (6.60) vs 1.54 (3.82); P < 0.001;
  • As shown in Figure 2a, b, compared with the control cohort, a significantly higher proportion of participants who received valoctocogene roxaparvovec also had
    • zero treated bleeds: 32.9% (95% CI, 21.8–45.5%) vs 82.1% (95% CI, 74.2–88.6%); P < 0.001
    • zero all bleeds: 28.5% (95% CI, 17.9–41.0%) vs 58.0% (95% CI, 48.6–67.1%); P < 0.001

Early data concerning changes from baseline in AIR in RP (N = 112) were extracted from Figure 1B3 and are summarized as follows:

Mean and median changes from baseline in AIR from W4 after infusion in the RP (N = 112)

AIR

Baseline

starting at W4 post infusion

AIR reduction

median (range)

128.6 (39.5 - 363.8)

0

Mean change, -113.9 (95% CI, -143.0 to -124.3), corresponding to 98.6%

mean ±SD

135.9 ±52.0

2.0


The annualized rates (AR) of FVIII use per year for up to 3 years in RP (N = 112) were obtained from Figure 1B6 and 1C13 and are summarized as follows:

Mean and median AR of FVIII use at baseline (BL) period vs the time W4 after infusion in the RP (N = 112)


Annualized rate of FVIII use


Baseline


Year 1


Year 2


Year 3


All Postprophylaxis

Reduction in AR of FVIII use from BL in comparison to all Postprophylaxis

mean

3961.2

45.4

88.3

228

125

Mean change, -3836.3 (95% CI, -4186.9 to -3503.6, P<0.001), corresponding to 96.8%

median

3754.4

0

0

0

11


The One-time prophylaxis use, which was clinically appropriate based on individual risk, as reported here6, is summarized as follows:

Mean (±SD) and median ARs of one-time use of FVIII prophylaxis in 21 pts. in the ITT Pop. (N = 134)

median (range) IU/kg per year

0.0 (0.0 to 639.2) IU/kg

mean ±SD IU/kg per year

15.5±72.1 IU/kg

 

Safety Details
  • Initially reported Infusion-related reactions (IRR) were defined as AEs occurring within 48 hours after infusion3
    • Commonly reported events were nausea (19 pts., 14.2%), fatigue (10 pts., 7.5%) and headache (8 pts, 6.0%), with most events being mild to moderate
    • The following eventswere reported during or shortly after infusion:
      • 7 pts. (5.2%) experienced systemic hypersensitivity
      • 3 pts. (2.2%) reported serious infusion-related reactions:
        • 1 pt. reported maculopapular rash
        • 1 pt. reported an anaphylactic reaction
        • 1 pt. reported a hypersensitivity reaction
  • Subsequently, AEs occurring within 48 hours after infusion were defined as infusion-associated reactions (IAR), and those occurring during infusion or 6 hours after infusion as IRRs6
  • Total IRRs and total IARs in the ITT Pop. (N = 134) for the 2-year follow-up were extracted from Table 26 and are summarized as follows:
    • IARs were reported in 50 pts. (37.3%)
    • IRRs were reported in 19 pts. (9.0%)

Statements concerning the observed AEs were reported here9  as follow:

  • Through 3 years of follow-up post-administration, no participants developed a clinically meaningful FVIII inhibitor response
  • The most common adverse event, elevated alanine aminotransferase (ALT) levels (≥1.5x baseline or above the upper limit of
    normal [ULN]), was observed in 90.3% of participants through year 3
  • The median time to ALT rise above the ULN was 8.1 weeks. No ALT elevations that emerged after year 2 were managed with immunosuppressants
  • In year 1, 114 (85.1%) study participants experienced an ALT elevation, with incidence declining in years 2 and 3 (40 [29.9%] and 31 [23.7%] participants, respectively).
  • ALT elevations that started after week 52 were not associated with unanticipated drops in FVIII activity; thus, treatment with corticosteroids was not deemed to be beneficial.
  • Cases of infusion-related reactions and systemic hypersensitivity and other safety results for up to 2 years were previously published.

AEs occurring in the ITT Pop. (N = 134) during a 3-year follow-up after vector infusion were obtained from Table 113 and are summarized as follows:

Summary of the reported AEs observed in the ITT Pop. (n = 134)

 

 

Year 1, n (%)

Year 2, n (%)

Year 3, n (%)

All follow-up, n (%)

Any AE

134 (100)

113 (84.3)

104 (78.8)

134 (100)

Adverse event occurring in ≥30% of participantsa

    ALT increased

-

-

-

121 (90.3)

    Arthralgia

-

-

-

60 (44.8)

    Headache

-

-

-

58 (43.3)

    Nausea

-

-

-

52 (38.8)

    AST increased

-

-

-

49 (36.6)

    Fatigue

-

-

-

41(30.6)

Any SAE

-

-

-

42 (31.3)

Any AEs grade ≥3

21 (15.7)

6 (4.5)

9 (6.8)

32 (23.9)

Any fatal AEs

0

1 (0.7)

1 (0.7)

1 (0.7)

Valoctocogene roxaparvovec-related

     

 

     AEs

123 (91.8)

28 (20.9)

13 (9.8)

123 (91.8)

     SAEs

5 (3.7)

0

0

5 (3.7)

Adverse event related to glucocorticoids

     

 

     AEs

80 (59.7)

9 (6.7)

1 (0.8)

81 (60.4)

     SAEs

3 (2.2)

0

0

3 (2.2)

Nonsteroidal immunosuppressants-related

 

    AEs

12 (9.0)

2 (1.5)

2 (1.5)

16 (11.9)

    SAEs

1 (0.7)

0

0

1 (0.7)

AEs of special interest

     

 

    ALT elevationa

114 (85.1)

40 (29.9)

31 (23.5)

121 (90.3)

    ALT elevation grade ≥3

11 (8.2)

1 (0.7)

0

11 (8.2)

    AEs related to liver function

116 (86.6)

40 (29.9)

32 (24.2)

121 (90.3)

    Potential Hy’s law caseb

0

0

0

0

    Infusion-related reactionc

12 (9.0)

0

0

12 (9.0)

    Infusion-associated reactiond

50 (37.3)

0

0

50 (37.3)

    Systemic hypersensitivity

7 (5.2)

0

0

7 (5.2)

    Anaphylactic or anaphylactoid reaction

3 (2.2)

0

0

3 (2.2)

    Thromboembolic event

0

0

0

0

    Anti–FVIII neutralizing antibodies

0

0

0

0

    Malignancy (except nonmelanoma skin cancer)

0

0

1 (0.8)

1 (0.7)


a The threshold for an AE of special interest of ALT elevation evolved through the trial. First, the threshold was defined as ALT ≥1.5× the upper limit of normal (ULN, 43 U/L),
   then amended to include elevations greater than ULN when ALT was >2× baseline, and then amended again to include elevations greater than ULN or ≥1.5× baseline.
b Hy’s law cases have 3 components: 1) ALT or AST elevation >3× ULN, often much greater (>5× or >10× ULN); 2) total bilirubin elevations >2× ULN, without findings of obstruction
   (such as elevated alkaline phosphatase), malignancy, or impaired glucuronidation capacity; and 3) no other explanation can be found for the combination of increased ALT/AST and
   total bilirubin (eg, viral hepatitis and preexisting liver disease).
c Infusion-related reactions were defined as AEs occurring during infusion or within 6 hours after infusion, irrespective of causal association with valoctocogene roxaparvovec.
d Infusion-associated reactions were defined as AEs occurring within 48 hours after infusion, irrespective of causal association with valoctocogene roxaparvovec.

Data, including a 2-year follow-up of AEs and SAEs related to glucocorticoid treatment, were extracted from Table 26 and are summarized as follows:

Adverse events related to glucocorticoid use

 

Year 1

Year 2

total

Any AE related to glucocorticoids

80 (59.7)

9 (6.7)

81 (60.4)

SAE related to glucocorticoids

3 (2.7)

0

3 (2.7)


Data regarding specific AEs (occurring in ≥5% of pts.) and SAEs related to glucocorticoids during the early follow-up (all 134 pts. > 51 weeks) were obtained from Table S83 and are summarized as follows:

AEs and SAEs deemed related to glucocorticoid use by the investigator

 

ITT Pop. (n = 110)a

Event 

No. (%)

Any AE related to glucocorticoids

79 (71.8%)

AEs related to glucocorticoids occurring in ≥5% of pts.

     Acne

32 (29.1)

     Insomnia 

23 (20.9%)

     Cushingoid

16 (14.5%) 

     Weight increased

16 (14.5%)

     Folliculitis

10 (9.1%) 

     Rash pustular                 

10 (9.1%) 

     Hypertension 

9 (8.2%)

     Mood swings

8 (7.3%)

     Irritability

6 (5.5%) 

     Fatigue

6 (5.5%)

Any SAE related to glucocorticoids

3 (2.7%)

     Rectal hemorrhage

1 (0.9%) 

     Pneumonia

1 (0.9%)b

     Influenza A virus test positive

1 (0.9%)b

Diabetes mellitus

1 (0.9%)c

Steroid diabetes

1 (0.9%)c

Hypertension

1 (0.9%)c


a      Includes pts. who received any glucocorticoids
b, c  2 and 3 AEs occurred in the same pt.

The correlation between ALT levels and anti-AAV5 TAb in the ITT Pop. was described here9 as follows:

  • There was no correlation between the AAV5 TAb titers at week 8 or maximum AAV5 TAb titers at week 104 and peak ALT levels in the ITT Pop.

Safety data regarding ALT elevation levels were reported here3, 6 as follows:

  • In total, 119/134 (88.8%) pts. had an increase in ALT levels (385 events) within the 2-years period following infusion:
    • Of all 385 events, 202 (52.5%) occurred within 26 weeks of infusion
    • 101 (26.2%) occurred between 26 and 52 weeks post infusion
    • 38 (9.9%) occurred between 52 and 78 weeks post infusion
    • 31 (8.1%) occurred between 78 and 104 weeks post infusion
    • 13 (3.4%) occurred after 104 weeks post-infusion
  • The median time to the first elevation in ALT level after infusion was 8.0 weeks and the median duration of elevation was 15 days
  • In total, 11/134 (8.2%) pts. had an ALT level increase of grade 3 (13/385 events [3.4%]) during the period of 2 years post infusion
  • 2 of these 13 ALT elevation events affecting 2 pts. (1.5%) were SAEs leading to intervention with intravenous methylprednisolone
    • 9 occurred within 26 weeks after infusion3
    • 3 occurred during weeks 26 through 36 weeks after infusion3
    • 1 occurred during weeks 52 trough weeks 78 post infusion3
  • No grade 4 or higher elevations in ALT level occurred
  • AST elevation occurrences are listed below in the variable AEs possibly/likely related to Study Agent
  • Peak level and timing of AST elevation was not reported

Data regarding the peaks of AAV5 TAb and AAV5 TI titers were described here9 as follows.:

  • All 127/134 ITT Pop. participants with AAV5 TAb assessments available on week 8, the first time point assessed after dosing, were AAV5 TAb positive
  • Mean AAV5 TAb titers first peaked at week 36 and were generally sustained thereafter
  • Similar to results for AAV5 TAb, all participants were AAV5 TI positive by week 8
  • Mean AAV5 TI titers began to plateau at week 36 and were generally sustained

Data regarding the FVIII TAb and neutralizing antibodies were described here9 as follows:

  • To date, 12/134 (9.0%) ITT Pop. participants have tested positive at least once for FVIII TAb
  • 11/32 (34.4%) of these positive tests occurred prior to dosing (Table 29)
  • FVIII TAb positivity was not associated with ALT elevations above the ULN based on proximal ALT levels
  • At week 104 only 2/12 participants who were FVIII TAb–positive had FVIII activity below the mild hemophilia range (5–40 IU/dL)
  • These sporadic FVIII TAb–positive results were not considered clinically relevant because they are consistent with transient, low-titer FVIII TAb
    that do not typically progress to FVIII neutralizing antibodies (FVIII inhibitors), and none of these participants were positive for FVIII neutralizing inhibitors at any time point
  • A total of 4 participants in the ITT Pop. had single-positive results in a Nijmegen modified Bethesda assay for FVIII neutralizing antibodies before or after day 1 (titer range, 0.7 -4.0 BU; Table S29),
    all of which were negative for FVIII TAb at all available/assessed time points.
  • These results did not meet the specified criteria for clinically meaningful inhibitor responses, which is defined as a positive Bethesda titer ≥0.6 BU in the Nijmegen-modified Bethesda assay confirmed
    with 2 independent samples taken within a 1- to 4-week period
  • Additionally, none of the 4 participants were positive for FVIII TAb at any time point

Data regarding the peaks of AAV5 capsid–specific cellular immune response was described here9 as follows:

  • AAV5 capsid–specific enzyme-linked immunosorbent spot (ELISpot) data were available for 124 of 134 (92.5%) ITT Pop. participants, 117 (94.4%) of whom tested positive at 1 or more time points
    through a maximum of 208 weeks of follow-up
  • Following stimulation with AAV5 capsid peptides, positive responses were detected in 5 of 95 (5.3%) baseline samples, and the incidence of positive responses peaked at week 2 (Figure 2 and Table S3)
  • The proportion of positive responses declined over time, with 17 of 74 (23.0%) participants testing positive at week 26 and 10 of 60 (16.7%) at week 52
  • A higher rate of response was observed following stimulation with AAV5 peptide pool 2 (which spans amino acids 1–370) compared with peptide pool 1 (which spans amino acids 371 - 724);
    113 of 125 (90.4%) participants tested had a positive response to AAV5 peptide pool 2 at any time point to date compared with 101 of 125 (80.8%) for peptide pool 1

Statements concerning the reviewed immune responses were reported here9 as follows:

  • Positive responses were detected during periods of corticosteroid use, suggesting that immune suppression with corticosteroids did not prevent detection of
    AAV5 capsid–specific cellular immune responses as assessed in vitro, although it was associated with reductions in ALT.
  • Following initiation of corticosteroid use, the median time to a ≥10 U/L drop in ALT, or ALT returning to or below the ULN, was 8 days (mean [SD], 12.94 [18.92] days) for the ITT Pop.

The subsequent information regarding the duration of steroid treatment and steroid responsiveness was extracted from previous publicatinos3, 6 and summarized as follows:

  • According to Table S93, among the ITT Pop. (n = 134) 39/134 pts. (29.1%) used other immunosuppressants than glucocorticoids due to contraindications, side effects, or a poor/no response to glucocorticoid treatment
  • According to Table S86, the median (IQR) duration of glucocorticoid treatment per participant was 32.9 weeks (3.1, 86.3) in the ITT Pop. (n = 134)

Statements concerning the observed FVIII activity in relation to ALT elevations were reported here9 as follow:

  • ALT elevations that started after week 52 were not associated with unanticipated drops in FVIII activity;
    Thus, treatment with corticosteroids was not deemed to be beneficial


A case of B-cell acute lymphoblastic leukemia (B-ALL) was reported here13 as follows:

  • Almost 3 years after infusion of 6e13 vg/kg valoctocogene roxaparvovec, 1 participant was diagnosed with B-ALL via bone marrow biopsy
  • This serious AE was considered unrelated to the treatment
  • Genetic testing and whole-genome sequencing were performed on enriched populations of leukemic and healthy blood cells
  • A Philadelphia-like chromosomal translocation was detected in 85% of bone marrow cells
  • Extremely low levels of valoctocogene roxaparvovec vector DNA were detected in 5 cell populations:
    • < 1 copy per 100 cells in 5 populations: 2 leukemic cell-enriched and 3 healthy
    • All cell populations underwent genomic analysis by multisite droplet digital PCR, with leukemic cells containing the lowest levels of vector copies
    • No vector-host integration sites were identified by whole-genome sequencing in any samples
  • Based on these analyses, this instance of B-ALL was very likely not related to valoctocogene roxaparvovec
References:
  1. Single-Arm Study To Evaluate The Efficacy and Safety of Valoctocogene Roxaparvovec in Hemophilia A Patients (BMN 270-301) (BMN 270-301).  Available at: Study Details | Single-Arm Study To Evaluate The Efficacy and Safety of Valoctocogene Roxaparvovec in Hemophilia A Patients (BMN 270-301) | ClinicalTrials.gov
  2. Ozelo, C.M., et al., Efficacy and Safety of Valoctocogene Roxaparvovec Adeno-associated Virus Gene Transfer for Severe Hemophilia A: Results from the Phase 3 GENEr8-1 Trial. ISTH 2021 Congress, 2021. Efficacy and Safety of Valoctocogene Roxaparvovec Adeno-associated Virus Gene Transfer for Severe Hemophilia A: Results from the Phase 3 GENEr8-1 Trial - ISTH Congress Abstracts
  3. Ozelo, M.C., et al., Valoctocogene Roxaparvovec Gene Therapy for Hemophilia A. N Engl J Med, 2022. 386(11): p. 1013-1025. Valoctocogene Roxaparvovec Gene Therapy for Hemophilia A | NEJM
  4. Rangarajan, S., et al., AAV5-Factor VIII Gene Transfer in Severe Haemophilia A. N Engl J Med, 2017. 377(26): p. 2519-2530. AAV5–Factor VIII Gene Transfer in Severe Hemophilia A | NEJM
  5. McIntosh, J., et al., Therapeutic levels of FVIII following a single peripheral vein administration of rAAV vector encoding a novel human factor VIII variant. Blood, 2013. 121(17): p. 3335-44. Therapeutic levels of FVIII following a single peripheral vein administration of rAAV vector encoding a novel human factor VIII variant | Blood | American Society of Hematology (ashpublications.org)
  6. Mahlangu, J., et al., Two-Year Outcomes of Valoctocogene Roxaparvovec Therapy for Hemophilia A. N Engl J Med, 2023. 388(8): p. 694-705. Two-Year Outcomes of Valoctocogene Roxaparvovec Therapy for Hemophilia A | NEJM
  7. Kenet, G., et al., Real-World Rates of Bleeding, Factor VIII Use, and Quality of Life in Individuals with Severe Haemophilia A Receiving Prophylaxis in a Prospective, Noninterventional Study. J Clin Med, 2021. 10(24). Real-World Rates of Bleeding, Factor VIII Use, and Quality of Life in Individuals with Severe Haemophilia A Receiving Prophylaxis in a Prospective, Noninterventional Study - PMC (nih.gov)
  8. Pasi KJ, Laffan M, Rangarajan S, Robinson TM, Mitchell N, Lester W, Symington E, Madan B, Yang X, Kim B, Pierce GF, Wong WY. 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. Persistence of haemostatic response following gene therapy with valoctocogene roxaparvovec in severe haemophilia A - PMC (nih.gov)
  9. Long BR, Robinson TM, Day JRS, Yu H, Lau K, Imtiaz U, Patton KS, de Hart G, Henshaw J, Agarwal S, Vettermann C, Zoog SJ, Gupta S. Clinical immunogenicity outcomes from GENEr8-1, a phase 3 study of valoctocogene roxaparvovec, an AAV5-vectored gene therapy for hemophilia A. Mol Ther. 2024 May 24:S1525-0016(24)00335-6. doi: 10.1016/j.ymthe.2024.05.033. Epub ahead of print. PMID: 38796703. S1525-0016(24)00335-6.pdf (cell.com)
  10. Oldenburg J, Chambost H, Liu H, Hawes C, You X, Yang X, Newman V, Robinson TM, Hatswell AJ, Hinds D, Santos S, Ozelo M. Comparative Effectiveness of Valoctocogene Roxaparvovec and Prophylactic Factor VIII Replacement in Severe Hemophilia A. Adv Ther. 2024 Jun;41(6):2267-2281. doi: 10.1007/s12325-024-02834-9. Epub 2024 Apr 15. PMID: 38616241; PMCID: PMC11133144. Comparative Effectiveness of Valoctocogene Roxaparvovec and Prophylactic Factor VIII Replacement in Severe Hemophilia A - PMC (nih.gov)
  11. FDA BLA Approval Document. Available at: June 30, 2023 Approval Letter - ROCTAVIAN (fda.gov)
  12. Roctavian | European Medicines Agency - European Union. Available at: Roctavian | European Medicines Agency (europa.eu)
  13. Madan B, Ozelo MC, Raheja P, Symington E, Quon DV, Leavitt AD, Pipe SW, Lowe G, Kenet G, Reding MT, Mason J, Wang M, von Drygalski A, Klamroth R, Shapiro S, Chambost H, Dunn AL, Oldenburg J, Chou SC, Peyvandi F, Millar CM, Osmond D, Yu H, Dashiell-Aje E, Robinson TM, Mahlangu J. Three-year outcomes of valoctocogene roxaparvovec gene therapy for hemophilia A. J Thromb Haemost. 2024 Jul;22(7):1880-1893. doi: 10.1016/j.jtha.2024.04.001. Epub 2024 Apr 12. PMID: 38614387. Three-year outcomes of valoctocogene roxaparvovec gene therapy for hemophilia A - Journal of Thrombosis and Haemostasis (jthjournal.org)

AAV, Adeno-associated virus; Annualized bleeding rate; AEs: adverse events; AIR, Annualized FVIII/FIX infusion rate; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BU, Bethesda units; BL, baseline; 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; TAb, total binding antibody; TAC, tacrolimus; TI, orthogonal cell-based transduction inhibitor; ULN, upper limit of normal; VCN, vector copy number; vg, vector genomes; W, weeks; WT, wild type; Y, year