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Table 1 Characteristics of the HPV vaccine industry study programmes and non-industry funded clinical studies

From: Index of the human papillomavirus (HPV) vaccine industry clinical study programmes and non-industry funded studies: a necessary basis to address reporting bias in a systematic review

Study characteristics

Industry HPV vaccine studies

Non-industry funded HPV vaccine studies

P valuek

Total: N = 145

GSK (Cervarix): N = 69

Merck (Gardasil and Gardasil 9): N = 66

Otherj: N = 10

Total: N = 61

Cervarix: N = 6

Gardasil and Gardasil 9: N = 48

Other: N = 7

Type of study

 Randomized clinical trial

96 (67%)

43 (62%)

45 (68%)

8 (80%)

40 (65%)

4 (67%)

33 (69%)

3 (43%)

1.00

 - “Placebo”a comparison

5 of 96

(5%)

0 of 43

(0%)

3 of 45

(7%)

2 of 8

(25%)

12 of 40

(30%)

0 of 4

(0%)

11 of 33

(33%)

1 of 3

(33%)

0.0002

 - Adjuvantb comparison

36 of 96

(39%)

15 of 43

(35%)

19 of 45

(42%)

2 of 8

(25%)

0 of 40

(0%)

0 of 4

(0%)

0 of 33

(0%)

0 of 3

(0%)

<0.0001

 - Vaccinec comparison

51 of 96

(51%)

28 of 43

(65%)

19 of 45

(42%)

4 of 8

(50%)

24 of 40

(60%)

3 of 4

(75%)

19 of 33

(58%)

2 of 3

(67%)

0.57

 - No intervention in control arm

0 of 96

(0%)

0 of 43

(0%)

0 of 45

(0%)

0 of 8

(0%)

3 of 40

(8%)

1 of 4

(25%)

2 of 33

(6%)

0 of 3

(0%)

0.027

 - Unclear

4 of 96

(5%)

0 of 43

(0%)

4 of 45

(9%)

0 of 8

(0%)

1 of 40

(2%)

0 of 4

(0%)

1 of 33

(3%)

0 of 3

(0%)

1.00

 Follow-up to randomized clinical trial

23 (16%)

18 (26%)

5 (8%)

0 (0%)

3 (5%)

0 (0%)

0 (0%)

3 (43%)

0.037

 Non-randomized

24 (16%)

8 (12%)

14 (21%)

2 (20%)

18 (30%)

2 (33%)

15 (31%)

1 (14%)

0.039

 Unclear

2 (1%)

0 (0%)

2 (3%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

1.00

Phase of studyd

 I

8 (5%)

2 (3%)

4 (6%)

2 (20%)

6 (10%)

0 (0%)

2 (4%)

4 (57%)

0.36

 II

32 (22%)

14 (20%)

14 (21%)

4 (40%)

7 (11%)

0 (0%)

6 (13%)

1 (14%)

0.081

 III

79 (55%)

44 (64%)

31 (47%)

4 (40%)

10 (16%)

1 (17%)

9 (19%)

0 (0%)

<0.0001

 IV

9 (6%)

4 (6%)

5 (8%)

0 (0%)

22 (37%)

5 (83%)

17 (35%)

0 (0%)

<0.0001

 Unclear

17 (12%)

5 (7%)

12 (18%)

0 (0%)

16 (26%)

0 (0%)

14 (29%)

2 (29%)

0.013

Type of HPV vaccine used

 Monovalent

5 (3%)

0 (0%)

5 (8%)

0 (0%)

4 (7%)

0 (0%)

0 (0%)

4 (57%)

0.45

 Bivalent (e.g., Cervarix)

76 (52%)

65 (94%)

2 (3%)

9 (90%)

7 (11%)

6 (100%)

0 (0%)

1 (14%)

<0.0001

 Quadrivalent (e.g., Gardasil)

43 (30%)

4 (6%)

38 (57%)

1 (10%)

44 (72%)

0 (0%)

44 (92%)

0 (0%)

<0.0001

 Octavalent

3 (2%)

0 (0%)

3 (5%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

0.56

 Ninevalent (e.g., Gardasil 9)

17 (12%)

0 (0%)

17 (25%)

0 (0%)

4 (7%)

0 (0%)

4 (8%)

0 (0%)

0.45

 Unclear

1 (1%)

0 (0%)

1 (2%)

0 (0%)

2 (3%)

0 (0%)

0 (0%)

2 (29%)

0.21

Funding

 Industry funded study

128

(88%)

69

(100%)

49

(75%)

10

(100%)

0

(0%)

0

(0%)

0

(0%)

0

(0%)

<0.0001

 Industry co-funded study

17 (12%)

0 (0%)

17 (25%)i

0 (0%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

0.004

 Non-industry funded study

0 (0%)

0 (0%)

0 (0%)

0 (0%)

61 (100%)

6 (100%)

48 (100%)

7 (100%)

<0.0001

Study completion status

 Completed

110

(76%)

57

(83%)

49

(75%)

4

(40%)

39

(64%)

3

(50%)

29

(60%)

7

(100%)

0.090

 - Mean study time in monthse

36.9

[2; 140]

34.2

[2; 97]

42.1

[8; 140]

15.8

[8; 30]

42.2

[5; 143]

45

[12; 81]

32.6

[6; 66]

56

[5; 143]

NAl

 On going

27 (19%)

7 (10%)

14 (20%)

6 (60%)

19 (31%)

2 (33%)

17 (36%)

0 (0%)

0.066

 Terminated prematurely

5 (3%)

4 (6%)

1 (2%)

0 (0%)

2 (3%)

1 (17%)

1 (2%)

0 (0%)

1.00

 Unclear

3 (2%)

1 (1%)

2 (3%)

0 (0%)

1 (2%)

0 (0%)

1 (2%)

0 (0%)

1.00

Study centre statusf

 Single centre

27 of 106

(25%)

9 of 60

(15%)

11 of 37

(30%)

7 of 9

(78%)

40 of 53

(75%)

6 of 6

(100%)

28 of 41

(68%)

6 of 6

(100%)

<0.0001

 Multicentre

79 of 106 (75%)

51 of 60

(85%)

26 of 37

(70%)

2 of 9

(22%)

13 of 53

(25%)

0 of 6

(0%)

13 of 41

(32%)

0 of 6

(0%)

<0.0001

 - Mean centres per multicentre study

36.5

[2; 105]

35.3

[2; 135]

39.9

[2; 105]

6.0

[2; 10]

21.5

[2; 134]

NA

21.5

[2; 134]

NA

NA

 Unclear

39 (27%)

9 (13%)

29 (44%)

1 (10%)

8 (13%)

0 (0%)

7 (15%)

1 (14%)

0.044

Participants

 Both females and males

22 (16%)

4 (5%)

16 (24%)

2 (20%)

19 (31%)

0 (0%)

14 (29%)

5 (71%)

0.013

 Only females

113

(78%)

64

(93%)

41

(62%)

8

(80%)

38

(62%)

6

(100%)

30

(63%)

2

(29%)

0.025

 Only males

5 (3%)

1 (2%)

4 (6%)

0 (0%)

4 (7%)

0 (0%)

4 (8%)

0 (0%)

0.45

Unclear

5 (3%)

0 (0%)

5 (8%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

0.32

 Total number of enrolled participantsg

522,298

122,323

376,643

23,332

100,707

42,801

47,452

10,454

<0.0001

 - Mean participants per studyg

3602 [2; 189,629]

1773 [2; 34,206]

6726 [24; 189,629]

2592 [90; 12,000]

1767 [12; 24,000]

8560 [200; 24,000]

1054

[12; 20,000]

1493 [45; 10,000]

NA

 - Mean participants per multicentre studyf,g

2388 [20; 34,206]

2073 [20; 34,206]

2692 [67; 14,840]

6450 [900; 12,000]

2745 [75; 20,000]

NA

2745 [75; 20,000]

NA

NA

 - Mean participants per centre in multicentre studiesf,g

66

[2; 1513]

59

[2; 1513]

67

[10; 240]

1075 [450; 1200]

128

[5; 2222]

NA

128

[5; 2222]

NA

NA

 Studies with > 1000 participantsg

51 (35%)

22 (32%)

26 (39%)

3 (30%)

10 (16%)

2 (33%)

7 (15%)

1 (14%)

0.007

 Studies with participants under age 18h

77 (53%)

23 (33%)

49 (75%)

5 (50%)

28 (46%)

4 (67%)

23 (48%)

1 (14%)

0.36

  1. aIf a study reported that it used a ‘placebo’ comparator, but the study did not describe the “placebo” (i.e., as saline), we noted the comparator as ‘placebo’
  2. bAdjuvant comparisons contained, for example, the aluminum adjuvants used in Cervarix and Gardasil/Gardasil 9, i.e., aluminum hydroxide (Al[OH]3) and amorphous aluminum hydroxyphosphate sulfate (AAHS), respectively
  3. cVaccine comparisons included: Adacel, Boostrix, Cervarix (compared with Gardasil or Gardasil 9), Dengvaxia, Engerix, Gardasil (compared with Cervarix or Gardasil 9), Gardasil 9 (compared with Cervarix or Gardasil), Havrix, Infanrix, Menactra, Priorix, Repevax, and Twinrix
  4. dIf a study was both a phase I and a phase II study, we noted the study as the uppermost phase (i.e., phase II)
  5. e105 of the 110 completed industry studies and 33 of the 39 completed non-industry studies had information for mean study time
  6. fThe exact number of study centers could be assessed in 106 of the 145 industry studies and 53 of the 61 non-industry studies
  7. gThe number of participants could be assessed in 140 of 145 industry studies and 57 of 61 non-industry studies (studies that were terminated prematurely were not included)
  8. hThe number of participants under age 18 could be assessed in 140 of the 145 industry studies and 59 of the 61 non-industry studies
  9. i10 Merck studies were co-funded with universities, four with hospitals and three with governmental healthcare institutions
  10. jOther HPV vaccine manufacturers were Shanghai Zerun Biotechnology Co., Ltd. and Xiamen Innovax Biotech Co., Ltd
  11. kP values were calculated for total industry studies vs. total non-industry studies with Fisher’s exact test (http://www.langsrud.com/fisher.htm)
  12. lNot applicable
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Systematic Reviews

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