Pharmacotherapeutic group: Other respiratory system products, ATC code: R07AX33.
Mechanism of action
VNZ and TEZ are CFTR correctors that bind to different sites on the CFTR protein and have an additive effect in facilitating the cellular processing and trafficking of select mutant forms of CFTR (including F508del-CFTR) to increase the amount of CFTR protein delivered to the cell surface compared to either molecule alone. D-IVA potentiates the channel open probability (or gating) of the CFTR protein at the cell surface.
The combined effect of VNZ, TEZ and D-IVA is increased quantity and function of CFTR at the cell surface, resulting in increased CFTR activity as measured both by CFTR mediated chloride transport in vitro and by sweat chloride (SwCl) in people with CF.
CFTR Chloride Transport Assay in Fischer Rat Thyroid (FRT) cells expressing mutant CFTR
The chloride transport response of mutant CFTR protein to D-IVA/TEZ/VNZ was determined in Ussing chamber electrophysiology studies using a panel of FRT cell lines transfected with individual CFTR mutations. D-IVA/TEZ/VNZ increased chloride transport in FRT cells expressing select CFTR mutations.
The in vitro CFTR chloride transport response threshold was designated as a net increase of at least 10% of normal over baseline because it is predictive of clinical benefit. For individual mutations, the magnitude of the net change over baseline in CFTR mediated chloride transport in vitro is not correlated with the magnitude of clinical response.
Clinical outcomes were consistent with in vitro results and indicate that a single responsive allele (including the F508del mutation) is sufficient to result in a significant clinical response.
Table 4 lists responsive CFTR mutations based on clinical and/or in vitro data.
| Table 4: List of CFTR gene mutations that are responsive to Alyftrek |
| 1140-1151dup | A561E | F1052V | G628A | K522Q | P1021T | R516G | T1057R |
| 1341G→A | A566D | F1074L | G628R | K951E | P111L | R516S | T1086A |
| 1461insGAT | A613T | F1078S | G85E | L1011S | P1372T | R553Q | T1086I |
| 1507_1515del9 | A62P | F1099L | G85V | L102R | P140S | R555G | T1246I |
| 1898+3A→G | A72D | F1107L | G91R | L102R;F1016S* | P205S | R560S | T1299I |
| 2055del9 | A872E | F191V | G930E | L1065P | P439S | R560T | T1299K |
| 2183A→G | c.1367_1369dupTTG | F200I | G970D | L1065R | P499A | R600S | T164P |
| 2752-26A→G | C225R | F311del | G970S | L1077P | P574H | R668C | T338I |
| 2789+2insA | C491R | F311L | G970V | L1227S | P5L | R709Q | T351I |
| 2789+5G→A | C590Y | F312del | H1054D | L1324P | P67L | R74Q | T351S |
| 2851A/G | C866Y | F433L | H1079P | L1335P | P750L | R74Q;R297Q* | T351S;R851L* |
| 293A→G | D110E | F508C | H1085P | L137P | P798S | R74Q;V201M;D1270N* | T388M |
| 296+28A→G | D110H | F508C;S1251N* | H1085R | L137R | P988R | R74W | T465I |
| 3007del6 | D110N | F508del | H1375N | L1388P | P99L | R74W;D1270N* | T465N |
| 3041-15T→G | D1152A | F508del;R1438W* | H1375P | L1480P | Q1012P | R74W;R1070W;D1270N* | T501A |
| 3131del15 | D1152H | F575Y | H139L | L159S | Q1100P | R74W;S945L* | T582S |
| 3132T→G | D1270N | F587I | H139R | L15P | Q1209P | R74W;V201M* | T604I |
| 3141del9 | D1270Y | F587L | H146R | L15P;L1253F* | Q1291H | R74W;V201M;D1270N* | T908N |
| 3143del9 | D1312G | F693L(TTG) | H147del | L165S | Q1291R | R74W;V201M;L997F* | T990I |
| 314del9 | D1377H | F87L | H147P | L167R | Q1313K | R751L | V1008D |
| 3195del6 | D1445N | F932S | H199Q | L206W | Q1352H | R75L | V1010D |
| 3199del6 | D192G | G1047D | H199R | L210P | Q151K | R75Q | V1153E |
| 3272-26A→G | D192N | G1047R | H199Y | L293P | Q179K | R75Q;L1065P* | V11I |
| 3331del6 | D373N | G1061R | H609L | L320V | Q237E | R75Q;N1088D* | V1240G |
| 3410T→C | D426N | G1069R | H609R | L327P | Q237H | R75Q;S549N* | V1293G |
| 3523A→G | D443Y | G1123R | H620P | L32P | Q237P | R792G | V1293I |
| 3600G→A | D443Y;G576A;R668C* | G1173S | H620Q | L333F | Q30P | R792Q | V1415F |
| 3601A→C | D513G | G1237V | H939R | L333H | Q359K/T360K* | R810G | V201M |
| 3761T→G | D529G | G1244E | H939R;H949L* | L346P | Q359R | R851L | V232A |
| 3791C/T | D565G | G1244R | H954P | L441P | Q372H | R933G | V232D |
| 3849+10kbC→T | D567N | G1247R | I1023R | L453S | Q452P | S1045Y | V317A |
| 3849+40A→G | D572N | G1249E | I1027T | L467F | Q493L | S108F | V322M |
| 3849+4A→G | D579G | G1249R | I105N | L558F | Q493R | S1118F | V392G |
| 3850-3T→G | D58H | G1265V | I1139V | L594P | Q552P | S1159F | V456A |
| 3850G→A | D58V | G126D | I1203V | L610S | Q98P | S1159P | V456F |
| 3978G→C | D614G | G1298V | I1234L | L619S | Q98R | S1188L | V520F |
| 4005+2T→C | D651H | G1349D | I1234Vdel6aa | L633P | R1048G | S1235R | V520I |
| 4193T→G | D651N | G149R | I125T | L636P | R1066C | S1251N | V562I |
| 546insCTA | D806G | G149R;G576A;R668C* | I1269N | L88S | R1066G | S1255P | V562I;A1006E* |
| 548insTAC | D836Y | G178E | I1366N | L927P | R1066H | S13F | V562L |
| 5T;TG12 | D924N | G178R | I1366T | L967F;L1096R* | R1066L | S13P | V591A |
| 5T;TG13 | D979A | G194R | I1398S | L967S | R1066M | S158N | V603F |
| 621+3A→G | D979V | G194V | I148L | L973F | R1070P | S182R | V754M |
| 711+3A→G | D985H | G213E | I148N | L997F | R1070Q | S18I | V920L |
| A1006E | D985Y | G213E;R668C* | I148T | M1101K | R1070W | S18N | V920M |
| A1025D | D993A | G213V | I148T;H609R* | M1101R | R1162L | S308P | V93D |
| A1067P | D993G | G226R | I175V | M1137R | R1162Q | S341P | W1098C |
| A1067T | D993Y | G239R | I331N | M1137V | R117C | S364P | W1282G |
| A1067V | E1104K | G253R | I336K | M1210K | R117C;G576A;R668C* | S434P | W1282R |
| A107G | E1104V | G27E | I336L | M150K | R117G | S492F | W202C |
| A1081V | E1126K | G27R | I444S | M150R | R117H | S50P | W361R |
| A1087P | E116K | G314E | I497S | M152L | R117L | S519G | W496R |
| A120T | E116Q | G314R | I502T | M152V | R117L;L997F* | S531P | Y1014C |
| A1319E | E1221V | G424S | I506L | M265R | R117P | S549I | Y1032C |
| A1374D | E1228K | G437D | I506T | M348K | R1239S | S549N | Y1032N |
| A141D | E1409K | G451V | I506V | M394L | R1283G | S549R | Y1073C |
| A1466S | E1433K | G461R | I506V;D1168G* | M469V | R1283M | S557F | Y1092H |
| A155P | E193K | G461V | I521S | M498I | R1283S | S589I | Y109C |
| A234D | E217G | G463V | I530N | M952I | R1438W | S589N | Y109H |
| A234V | E264V | G480C | I556V | M952T | R170H | S624R | Y109N |
| A238V | E282D | G480D | I586V | M961L | R248K | S686Y | Y122C |
| A309D | E292K | G480S | I601F | N1088D | R258G | S737F | Y1381H |
| A349V | E384K | G500D | I601T | N1195T | R297Q | S821G | Y161C |
| A357T | E403D | G545R | I618N | N1303I | R31C | S898R | Y161D |
| A455E | E474K | G551A | I618T | N1303K | R31L | S912L | Y161S |
| A455V | E527G | G551D | I807M | N186K | R334L | S912L;G1244V* | Y301C |
| A457T | E56K | G551R | I86M | N187K | R334Q | S912T | Y517C |
| A462P | E588V | G551S | I980K | N396Y | R334W | S945L | Y563N |
| A46D | E60K | G576A | K1060T | N418S | R347H | S955P | Y569C |
| A534E | E822K | G576A;R668C* | K162E | N900K | R347L | S977F | Y89C |
| A554E | E831X | G576A;S1359Y* | K464E | P1013H | R347P | S977F;R1438W* | Y913C |
| A559T | E92K | G622D | K464N | P1013L | R352Q | T1036N | Y913S |
| A559V | F1016S | G622V | K522E | P1021L | R352W | T1053I | Y919C |
| * Complex/compound mutations where a single allele of the CFTR gene has multiple mutations; these exist independent of the presence of mutations on the other allele. |
Pharmacodynamic effects
Effects on sweat chloride
In study 121-102 (people with CF heterozygous for a F508del and a CFTR mutation that results in a protein that is not responsive to IVA or TEZ/IVA [minimal function mutation]) the treatment difference of Alyftrek compared to IVA/TEZ/ELX for mean absolute change in SwCl from baseline through week 24 was ‑8.4 mmol/L (95% CI: -10.5, -6.3; P < 0.0001).
In study 121-103 (people with CF homozygous for the F508del mutation, heterozygous for the F508del mutation and either a gating or a residual function mutation, or at least one mutation responsive to IVA/TEZ/ELX with no F508del mutation), the treatment difference of Alyftrek compared to IVA/TEZ/ELX for mean absolute change in SwCl from baseline through week 24 was ‑2.8 mmol/L (95% CI: ‑4.7, ‑0.9; P = 0.0034).
In study 121-105, Cohort B1 (people with CF aged 6 to less than 12 years with at least one mutation that is responsive to IVA/TEZ/ELX), the mean absolute change in SwCl from baseline through week 24 was -8.6 mmol/L (95% CI: -11.0, -6.3).
Cardiovascular effects
Effect on QT interval
At exposures corresponding up to 6 times over those observed with the VNZ maximum recommended dose, and doses up to 3 times over the TEZ and D-IVA maximum recommended doses, the QT/QTc interval in healthy subjects was not prolonged to any clinically relevant extent.
Clinical efficacy and safety
The efficacy of Alyftrek in people with CF aged 12 years and older was evaluated in two, phase 3, randomized, double-blind, IVA/TEZ/ELX-controlled studies (studies 121-102 and 121-103). The pharmacokinetic profile, safety, and efficacy of Alyftrek in people with CF aged 6 to less than 12 years are supported with evidence from studies of Alyftrek in people with CF aged 12 years and older (studies 121-102 and 121-103) and additional data from an open‑label, phase 3 study (study 121-105, Cohort B1).
Studies 121-102 and 121-103
Study 121-102 was a 52‑week, randomized, double‑blind, IVA/TEZ/ELX‑controlled study in people with CF heterozygous for F508del and a CFTR mutation that results in a protein that is not responsive to IVA or TEZ/IVA (minimal function mutation). A total of 398 people with CF aged 12 years and older (mean age 30.8 years) received IVA/TEZ/ELX during a 4‑week run-in period and were then randomized to receive Alyftrek or IVA/TEZ/ELX during the 52‑week treatment period. After the 4‑week run-in, the mean ppFEV1 at baseline was 67.1 percentage points (range: 28.0, 108.6) and the mean SwCl at baseline was 53.9 mmol/L (range: 10.0 mmol/L, 113.5 mmol/L).
Study 121-103 was a 52-week, randomized, double-blind, IVA/TEZ/ELX controlled study in people with CF who had one of the following genotypes: homozygous for the F508del mutation, heterozygous for the F508del mutation and either a gating or a residual function mutation, or at least one mutation responsive to IVA/TEZ/ELX with no F508del mutation. A total of 573 people with CF aged 12 years and older (mean age 33.7 years) received IVA/TEZ/ELX during a 4-week run-in period and were then randomized to receive Alyftrek or IVA/TEZ/ELX during the 52-week treatment period. After the 4-week run-in, the mean ppFEV1 at baseline was 66.8 percentage points (range: 36.4, 112.5) and the mean SwCl at baseline was 42.8 mmol/L (range: 10.0 mmol/L, 113.3 mmol/L).
In both studies, the primary endpoint evaluated non-inferiority in mean absolute change from baseline in ppFEV1 through week 24. Key secondary endpoints evaluated superiority in mean absolute change from baseline in SwCl through week 24, and the proportion of participants achieving SwCl < 60 mmol/L and SwCl < 30 mmol/L through week 24.
In study 121-102, treatment with Alyftrek resulted in an LS mean difference of 0.2 percentage points (1-sided P < 0.0001 for non-inferiority; 95% CI: -0.7, 1.1) in absolute change in ppFEV1 from baseline through week 24 compared to IVA/TEZ/ELX. In study 121‑103, treatment with Alyftrek resulted in an LS mean difference of 0.2 percentage points (1‑sided P < 0.0001 for non-inferiority; 95% CI: -0.5, 0.9) in absolute change in ppFEV1 from baseline through week 24 compared to IVA/TEZ/ELX. In studies 121-102 and 121-103, mean absolute change from baseline in ppFEV1 through week 24 was maintained through week 52.
As the lower bounds of the 95% CI of the LS mean difference in absolute change in ppFEV1 from baseline through week 24 was greater than -3.0 percentage points (the pre‑specified non‑inferiority margin) in study 121-102 and study 121-103, these results demonstrate non‑inferiority of Alyftrek compared to IVA/TEZ/ELX.
In studies 121-102 and 121-103, Alyftrek was superior to IVA/TEZ/ELX on all key secondary endpoints. On the first key secondary endpoint, when compared to IVA/TEZ/ELX, treatment with Alyftrek resulted in a reduction of ‑8.4 mmol/L (95% CI: ‑10.5, ‑6.3; P < 0.0001) and ‑2.8 mmol/L (95% CI: ‑4.7, ‑0.9; P = 0.0034) in SwCl through week 24, in studies 121-102 and 121-103, respectively. Absolute change from baseline in SwCl through week 24 was maintained through week 52 in both trials. On the remaining key secondary endpoints, treatment with Alyftrek resulted in 86% of people with CF achieving a SwCl level below 60 mmol/L through week 24, compared to 77% of people treated with IVA/TEZ/ELX (odds ratio 2.21; 95% CI: 1.55, 3.15; P < 0.0001), and 31% of people with CF achieving a SwCl level below 30 mmol/L through week 24, compared to 23% of people treated with IVA/TEZ/ELX (odds ratio 2.87; 95% CI: 2.00, 4.12; P < 0.0001).
Other secondary endpoints (pulmonary exacerbation rate, change in CFQ-R RD score from baseline) demonstrated consistent benefit between Alyftrek and IVA/TEZ/ELX.
See Table 5 for a summary of key efficacy outcomes for studies 121-102 and 121-103.
| Table 5: Efficacy analyses from study 121-102 and study 121-103 |
| Analysis* | Statistic | Study 121-102 | Study 121-103 |
| Alyftrek N = 196 | IVA/TEZ/ELX N = 202 | Alyftrek N = 284 | IVA/TEZ/ELX N = 289 |
| Primary |
| Baseline ppFEV1 (percentage points) | Mean (SD) | 67.0 (15.3) | 67.2 (14.6) | 67.2 (14.6) | 66.4 (14.9) |
| Absolute change from baseline in ppFEV1 through week 24 (percentage points) | n | 187 | 193 | 268 | 276 |
| LS mean (SE) | 0.5 (0.3) | 0.3 (0.3) | 0.2 (0.3) | 0.0 (0.2) |
| LS mean difference, 95% CI | 0.2 (-0.7, 1.1) | 0.2 (-0.5, 0.9) |
| P-value (1-sided) for Non-Inferiority# | < 0.0001 | < 0.0001 |
| Key Secondary |
| Baseline SwCl (mmol/L) | Mean (SD) | 53.6 (17.0) | 54.3 (18.2) | 43.4 (18.5) | 42.1 (17.9) |
| Absolute change from baseline in SwCl through week 24 (mmol/L) | n | 185 | 194 | 270 | 276 |
| LS mean (SE) | -7.5 (0.8) | 0.9 (0.8) | -5.1 (0.7) | -2.3 (0.7) |
| LS mean difference, 95% CI | -8.4 (-10.5, -6.3) | -2.8 (-4.7, -0.9) |
| P-value (2-sided) | < 0.0001 | 0.0034 |
| Proportion of participants with SwCl < 60 mmol/L† through week 24 | n | 465 Alyftrek vs 479 IVA/TEZ/ELX |
| Proportion (%) | 86 Alyftrek vs 77 IVA/TEZ/ELX |
| Odds Ratio, 95% CI¶ | 2.21 (1.55, 3.15) |
| P-value (2-sided) | < 0.0001 |
| Proportion of participants with SwCl < 30 mmol/L§ through week 24 | n | 465 Alyftrek vs 479 IVA/TEZ/ELX |
| Proportion (%) | 31 Alyftrek vs 23 IVA/TEZ/ELX |
| Odds Ratio, 95% CI¶ | 2.87 (2.00, 4.12) |
| P-value (2-sided) | < 0.0001 |
| Other Secondary** |
| Number of pulmonary exacerbations through week 52 | Number of events | 67 | 90 | 86 | 79 |
| Event rate per year | 0.32 | 0.42 | 0.29 | 0.26 |
| Rate difference, 95% CI | -0.10 (-0.24, 0.04) | 0.03 (-0.07, 0.13) |
| Absolute change from baseline in CFQ-R RD score through week 24 (points) | n | 186 | 192 | 268 | 270 |
| LS mean (SE) | 0.5 (1.1) | -1.7 (1.0) | -1.2 (0.8) | -1.2 (0.8) |
| LS mean difference, 95% CI | 2.3 (-0.6, 5.2) | -0.1 (-2.3, 2.1) |
| ppFEV1: percent predicted Forced Expiratory Volume in 1 second; CI: Confidence Interval; SE: Standard Error; CFQ‑R RD: Cystic Fibrosis Questionnaire‑Revised (respiratory domain); SwCl: Sweat Chloride Note: Analyses were based on the full analysis set (FAS) unless otherwise noted. FAS was defined as all randomized subjects who carry the intended CFTR allele mutation and received at least 1 dose of study drug. * A 4-week IVA/TEZ/ELX run-in-period was performed to establish an on-treatment baseline. † SwCl ≥ 60 mmol/L meets the diagnostic threshold for CF as evidence of CFTR dysfunction. § Normal SwCl levels are considered < 30 mmol/L. ¶ Odds ratio > 1 favours Alyftrek. # The pre-specified non-inferiority margin was -3.0 percentage points. ** Not controlled for multiplicity. |
Study 121-105
Study 121-105 was multicohort, open‑label study in people with CF with at least one mutation responsive to IVA/TEZ/ELX. Cohort A1 evaluated pharmacokinetic and safety parameters of Alyftrek during a 22‑day treatment period in a total of 17 people with CF aged 6 to less than 12 years of age. Cohort B1 evaluated the safety, tolerability, and efficacy of Alyftrek in a total of 78 people with CF aged 6 to less than 12 years (mean age 9.1 years) during a 24‑week treatment period. In Cohort B1, all participants were on IVA/TEZ/ELX at baseline. The mean ppFEV1 at baseline on IVA/TEZ/ELX was 99.7 percentage points (range: 29.3, 146.0) and the mean SwCl at baseline, on IVA/TEZ/ELX, was 40.4 mmol/L (range: 11.5 mmol/L, 109.5 mmol/L).
In study 121-105, Cohort B1, safety and tolerability were the primary endpoints. Efficacy endpoints included absolute change in ppFEV1, absolute change in SwCl, proportion of participants with SwCl of < 60 mmol/L, proportion of participants with SwCl of < 30 mmol/L, absolute change in CFQ-R respiratory domain score, and number of PEx through week 24.
See Table 6 for a summary of efficacy outcomes.
| Table 6: Efficacy analyses, study 121-105 (Cohort B1) |
| Analysis | Statistic | D-IVA/TEZ/VNZ N = 78 |
| Secondary Efficacy |
| Baseline ppFEV1 | Mean (SD) | 99.7 (15.1) |
| Baseline SwCl | Mean (SD) | 40.4 (20.9) |
| Absolute change in ppFEV1 from baseline through week 24 (percentage points) | LS mean (95% CI) | 0.0 (-2.0, 1.9) |
| Absolute change in SwCl from baseline through week 24 (mmol/L) | LS mean (95% CI) | -8.6 (-11.0, -6.3) |
| Proportion of participants with SwCl <60 mmol/L* through week 24 | Proportion (95% CI) | 95% (87%, 99%) |
| Proportion of participants with SwCl <30 mmol/L† through week 24 | Proportion (95% CI) | 53% (41%, 64%) |
| Absolute change in CFQ-R Respiratory Domain score from baseline through week 24 (points) | LS mean (95% CI) | 3.9 (1.5, 6.3) |
| Number of pulmonary exacerbations through week 24 | Event rate per year | 0.15 |
| CI: Confidence Interval; ppFEV1: percent predicted Forced Expiratory Volume in 1 second; CFQ‑R: Cystic Fibrosis Questionnaire‑Revised * SwCl ≥ 60 mmol/L meets the diagnostic threshold for CF as evidence of CFTR dysfunction. † Normal SwCl levels are considered < 30 mmol/L. |
The Medicines and Healthcare products Regulatory Agency (MHRA) has deferred the obligation to submit the results of studies with Alyftrek in one or more subset of the paediatric population in cystic fibrosis (see section 4.2 for information on paediatric use).