Allergic reactions

Following Xiapex injection, severe allergic reaction could occur, and patients should be observed for 30 minutes before leaving the clinic in order to monitor for any signs or symptoms of a serious allergic reaction, e.g. wide spread redness or rash, swelling, tightness in the throat or difficulty breathing. Patients should be instructed to consult a doctor immediately if they experience any of these signs or symptoms. Emergency medication for treatment of potential allergic reactions should be available.

An anaphylactic reaction was reported in a post-marketing clinical study in a patient who had previous exposure to Xiapex for the treatment of Dupuytren’s contracture, demonstrating that severe reactions including anaphylaxis can occur following Xiapex injections. Some patients with Dupuytren’s contracture developed IgE-anti-drug antibodies in greater proportions and higher titers with successive Xiapex injections.

In the double-blind portion of the three phase 3 placebo-controlled clinical studies in Dupuytren’s contracture, 17% of Xiapex-treated patients had mild reactions (i.e. pruritus) after up to 3 injections. The incidence of Xiapex-associated pruritus increased after more Xiapex injections in patients with Dupuytren’s contracture.

In the double-blind portion of the two phase 3 placebo-controlled clinical trials in Peyronie’s disease, a greater proportion of Xiapex-treated patients (4%) compared to placebo-treated patients (1%) had localized pruritus after up to 4 treatment cycles (involving up to 8 Xiapex injections). The incidence of Xiapex-associated pruritus was similar after each injection regardless of the number of injections administered.

Tendon rupture or other serious injury to the injected finger/hand in the treatment of Dupuytren’s contracture

Xiapex must only be injected into the Dupuytren’s cord. Because Xiapex lyses collagen, care must be taken to avoid injecting into tendons, nerves, blood vessels, or other collagen-containing structures of the hand. Injection of Xiapex into collagen containing structures may result in damage to those structures, and possible permanent injury such as tendon rupture or ligament damage. Care should be taken when injecting Xiapex into cords contracting the PIP joints as clinical studies indicate an increased risk of tendon rupture and ligament injury associated with treatment of PIP contractures with Xiapex. This is particularly important for cords situated at the PIP joint of the fifth finger. When injecting a cord affecting a PIP joint of the fifth finger, the needle insertion must not be more than 2 to 3 mm in depth and not more than 4 mm distal to the palmar digital crease. Patients should be instructed to comply with the treatment instructions (see section 4.2) and to promptly contact the physician if there is trouble bending the finger after the swelling goes down (symptoms of tendon rupture).

Most patients experiencing tendon/ligament rupture or injury have gone on to have successful surgical repair. Early diagnosis and prompt evaluation and treatment are important because tendon rupture/ligament injury may potentially affect overall hand function.

Patients with Dupuytren’s contractures that adhere to the skin may be at higher risk of skin lesions as a result of the pharmacological effect of Xiapex and the finger extension procedure on the skin overlying the targeted cord.

Cases of skin laceration requiring skin graft after finger extension procedures have been reported postmarketing. Signs or symptoms that may reflect serious injury to the treated finger/hand after injection or manipulation should be promptly evaluated because surgical intervention may be required. A higher rate for skin laceration has been shown following two concurrent injections in the same hand in a controlled post-marketing trial (see also Section 4.8).

Cases of finger necrosis have been reported, which in some cases led to amputation of finger parts. Pre-existing reduced peripheral circulation, e.g. Raynaud syndrome, and the use of epinephrine combined with local anaesthetics in these patients may contribute to this (see also section 4.8).

Cases of digital phalangeal fractures have been reported after finger manipulation procedure. Caution should be exercised when performing finger extension procedures in patients with bone fragility, which may predispose to digital phalangeal fracture (e.g. in patients with osteopenia/osteoporosis). Diagnostic imaging is recommended after manipulation if finger deformity, pain or increased swelling develops (see also section 4.8).

Corporal rupture (fracture of penis) or other serious injury to the penis in the treatment of Peyronie’s disease

Injection of Xiapex into collagen-containing structures such as the corpora cavernosa of the penis may result in damage to those structures and possible injury such as corporal rupture (penile fracture). Therefore, Xiapex must be injected only into the Peyronie’s plaque and care should be taken to avoid injecting into the urethra, nerves, blood vessels, corpora cavernosa or other collagen-containing structures of the penis.

Corporal rupture was reported as a serious adverse reaction after Xiapex injection in 5 out of 1044 patients (0.5%) in the controlled and uncontrolled clinical trials in Peyronie’s disease. In other Xiapex-treated patients (9 of 1044; 0.9%), a combination of penile ecchymoses or haematoma, sudden penile detumescence, and/or a penile “popping” sound or sensation was reported, and in these cases, a diagnosis of corporal rupture cannot be excluded.

Severe penile haematoma was also reported as an adverse reaction in 39 of 1044 patients (3.7%) in the controlled and uncontrolled clinical studies in Peyronie’s disease.

Physicians should advise the patient to wait for at least 4 weeks after the second injection of a treatment cycle before resuming sexual activity taking care to ensure that any pain and swelling has ceased and to be cautious when resuming sexual activity.

Signs or symptoms that may reflect serious injury to the penis should be promptly evaluated in order to assess for corporal rupture or severe penile haematoma, which may require surgical intervention.

Use in patients with coagulation disorders

Xiapex must be used with caution in patients with coagulation disorders or those taking anticoagulants. In the three double-blind, placebo-controlled phase 3 studies in Dupuytren’s contracture, 73% of Xiapex-treated patients reported an ecchymosis or a contusion and 38% reported a haemorrhage at the injection site. In the two double-blind, placebo-controlled phase 3 studies in Peyronie’s disease, 65.5% of Xiapex-treated patients developed penile haematoma and 14.5% developed penile ecchymosis. The efficacy and safety of Xiapex in patients receiving anticoagulant medicinal products other than up to 150 mg acetylsalicylic acid per day prior to Xiapex administration is not known. Use of Xiapex in patients who have received anticoagulants (with the exception of up to 150 mg acetylsalicylic acid daily) within 7 days prior to receiving an injection of Xiapex is not recommended.

Immunogenicity

As with any non-human protein medicinal product, patients may develop antibodies to the therapeutic protein. During clinical studies, blood samples from patients with Dupuytren’s contracture and Peyronie’s disease were tested at multiple time points for antibodies to the protein components of the medicinal product (AUX-I and AUX-II).

In the Dupuytren’s contracture clinical trials at 30 days post the first injection, 92% of patients had circulating antibodies detected against AUX-I and 86% of patients against AUX-II. At five years after the initial injection of Xiapex, 92.8% and 93.4% of subjects were seropositive for anti-AUX-I and anti-AUX-II respectively.

Almost all patients had positive titers for anti-AUX-I antibodies (97.9%) and anti-AUX-II antibodies (97.5%) 60 days post two concurrent injections.

In the Peyronie’s disease clinical studies, at 6 weeks after the first treatment cycle of Xiapex, approximately 75% of patients had antibodies against AUX-I and approximately 55% of patients had antibodies against AUX-II. Six weeks after the eighth injection (fourth treatment cycle) of Xiapex >99% of Xiapex-treated patients developed high titers of antibodies to both AUX-I and AUX-II. Neutralizing antibodies were assayed for a subset of 70 samples selected to be representative of high and low titer binding antibody responses at week 12 of treatment. For each subject in whom a Week 12 sample was selected, the corresponding Week 6, 18, 24, and 52 samples were assayed if they were also binding antibody positive. Neutralizing antibodies to AUX-I or AUX-II, were detected in 60% and 51.8%, respectively, of patients tested. At five years after the initial injection of Xiapex the majority of subjects (>90%) were seropositive for anti-AUX-I and anti-AUX-II antibodies. In addition, seropositivity for neutralizing anti-AUX-I and anti-AUX-II antibodies was maintained.

In patients treated for these two indications, there was no apparent correlation of antibody frequency, antibody titers, or neutralizing status to clinical response or adverse reactions.

Since the enzymes in Xiapex have some sequence homology with human matrix metalloproteinases (MMPs), anti-drug antibodies (ADA) could theoretically interfere with human MMPs. No safety concerns related to the inhibition of endogenous MMPs have been observed, in particular no adverse events indicating the development or exacerbation of autoimmune diseases or the development of a musculoskeletal syndrome (MSS). Whilst there is no clinical evidence from the current safety data of a musculoskeletal syndrome developing following the administration of Xiapex, the potential for it to occur cannot be excluded. If this syndrome were to develop, it would occur progressively and is characterized by one or more of the following signs and symptoms: arthralgia, myalgia, joint stiffness, stiffness of the shoulders, hand oedema, palmar fibrosis and thickening or nodules forming in the tendons.

Post-treatment surgery

The impact of treatment with Xiapex on subsequent surgery, if needed, is not known.

Special penile conditions/diseases not studied in clinical trials

Xiapex treatment in patients having a calcified plaque that could have interfered with the injection technique, chordee in the presence or absence of hypospadias, thrombosis of the dorsal penile artery and/or vein, infiltration by a benign or malignant mass resulting in penile curvature, infiltration by an infectious agent, such as in lymphogranuloma venereum, ventral curvature from any cause and isolated hourglass deformity of the penis has not been studied and treatment in these patients should be avoided.

Excipients

This medicinal product contains less than 1 mmol sodium (23 mg) per dose, that is to say essentially ‘sodium- free’.

No formal medicinal product interaction studies with Xiapex have been performed. There is no quantifiable systemic exposure following a single injection of Xiapex in patients with Dupuytren’s contracture and only minimal and short-lived systemic exposure of Xiapex in patients with Peyronie’s disease.

There were no clinically meaningful differences in the incidence of adverse events following treatment with Xiapex based on the severity of baseline erectile dysfunction or concomitant phosphodiesterase type 5 (PDE5) inhibitor use.

Whilst there is no clinical evidence of an interaction between tetracycline and anthracycline/anthraquinolone antibiotics and anthraquinone derivatives and Xiapex, such derivatives have been shown to inhibit matrix metalloproteinase-mediated collagen degradation at pharmacologically relevant concentrations in vitro. Therefore, use of Xiapex in patients who have received tetracycline antibiotics (e.g., doxycycline) within 14 days prior to receiving an injection of Xiapex is not recommended.

Pregnancy and fertility

For Xiapex no clinical data on exposed pregnancies are available. Animal studies do not indicate direct or indirect harmful effects with respect to fertility, pregnancy, or embryonal/foetal development, (see section 5.3). Parturition or postnatal development studies in animals were not conducted since human pharmacokinetic studies show that Xiapex levels are not quantifiable in the systemic circulation following injection into a Dupuytren’s cord (see section 5.1). Patients develop ADAs after repeated administration, the cross-reactivity of which versus endogenous MMPs involved in pregnancy and labour cannot be excluded. The potential risk for humans on parturition and postnatal development is unknown. Therefore, the use of Xiapex is not recommended in pregnancy and treatment should be postponed until after pregnancy.

Peyronie’s disease occurs exclusively in adult male patients and hence there is no relevant information for use in females. Low levels of Xiapex were quantifiable in the plasma of evaluable male patients for up to 30 minutes following administration of Xiapex into the penile plaque of patients with Peyronie’s disease (see section 5.2).

Breast-feeding

It is not known whether collagenase clostridium histolyticum is excreted in human milk. Caution should be exercised when Xiapex is administered to a breast-feeding woman.

Xiapex may have a major influence on the ability to drive and use machines due to the swelling and pain which may impair the use of the treated hand in Dupuytren’s disease. Other minor influences on the ability to drive and use machines include dizziness, paresthesia, hypoesthesia, and headache that have also been reported following injection of Xiapex. Patients must be instructed to avoid potentially hazardous tasks such as driving or using machines until it is safe to do so or as advised by the physician.

Dupuytren’s contracture

Summary of the safety profile

The most frequently reported adverse reactions during the Xiapex clinical studies (272 of 409 patients received up to three single injections of Xiapex and 775 patients received two concurrent injections in the same hand) were local injection site reactions such as oedema peripheral (local to the injection site), contusion (including ecchymosis), injection site haemorrhage and injection site pain. Injection site reactions were very common, occurring in the vast majority of patients, were mostly mild to moderate in severity and generally subsided within 1-2 weeks post injection. Serious adverse reactions of tendon rupture (6 cases), tendonitis (1 case), other ligament injury (2 cases) and complex regional pain syndrome (1 case) related to the medicinal product were reported. Anaphylactic reaction was reported in a patient previously treated with Xiapex (1 case).

Tabulated list of adverse reactions

Table 1 presents adverse reactions listed by system organ class and frequency categories, using the following convention: very common (≥1/10), common (≥1/100 to <1/10), and uncommon (≥1/1,000 to <1/100), and not known: cannot be estimated from the available data. Within each frequency group, adverse reactions are presented in order of decreasing seriousness. Adverse reactions reported from the clinical programme are those that occurred in the Phase 3 double blind placebo-controlled studies for the treatment of Dupuytren’s contracture in adult patients with a palpable cord (AUX-CC-857, AUX-CC-859) and the post-marketing clinical studies (AUX-CC-864, AUX-CC-867) for two concurrent injections in the same hand.

Table 1. Tabulated list of adverse reactions:

^a reported with a higher incidence (very common) in patients who received two concurrent injections of Xiapex in the same hand compared with subjects treated with up to three single injections in the Phase 3 placebo-controlled pivotal studies in Dupuytren’s contracture.
^b “skin laceration” includes “injection site laceration” and "laceration"
^c “oedema peripheral” includes “injection site oedema” and "oedema"
^d see also section 4.4

The incidence of skin laceration (29.1%) was higher for subjects treated with two concurrent injections of Xiapex in historically-controlled clinical study AUX-CC-867 compared with subjects treated with up to three single injections in the Phase 3 placebo-controlled pivotal studies in Dupuytren’s contracture (CORD I and CORD II) (8.8%). The majority of the skin lacerations occurred on the manipulation day. A higher incidence of skin laceration may be attributable to more vigorous finger extension procedures in patients after receiving anaesthesia to the hand. In Study AUX-CC-867, most (85%) subjects received local anaesthesia prior to the finger extension procedure. There were no other clinically relevant differences between two concurrent injections of Xiapex in the same hand and up to three single injections of Xiapex in the types of adverse events reported (i.e., most adverse events were local to the treated extremity and of mild or moderate intensity).

The overall safety profile was similar regardless of the timing of the post-injection finger extension procedure (i.e., 24 hours, 48 hours, and ≥72 hours after injection) among patients who received two concurrent injections of Xiapex in Study AUX-CC-867.

Peyronie’s disease

Summary of the safety profile

The overall safety profile was similar in the two Phase 3 double-blind placebo-controlled studies (832 male patients, 551 patients received Xiapex) and in an open-label Phase 3 study (189 male patients) of patients who had previously received placebo in the controlled studies. In the two Phase 3 double-blind placebo-controlled studies, most adverse reactions were local events of the penis and groin and the majority of these events were of mild or moderate severity, and most (79%) resolved within 14 days of the injection. The adverse reaction profile was similar after each injection, regardless of the number of injections administered. The most frequently reported adverse drug reactions (≥25%) during the Xiapex controlled clinical studies were penile haematoma, penile swelling and penile pain. Severe penile haematoma including severe injection site haematoma were reported with the frequency very common.

In the controlled and uncontrolled clinical studies of Xiapex in Peyronie’s disease corporal rupture and other serious penile injury were reported uncommonly (see section 4.4).

A popping noise or popping sensation in the penis, sometimes described as “snapping” or “cracking” and sometimes accompanied by detumescence, haematoma and/or pain, were reported in 73/551 (13.2%) Xiapex-treated patients and 1/281 (0.3%) placebo-treated patients, in Studies 1 and 2 combined.

Tabulated list of adverse reactions

Table 2 presents adverse reactions listed by system organ class and frequency categories, using the following convention: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), and not known: cannot be estimated from the available data. Within each frequency group, adverse reactions are presented in order of decreasing seriousness. Adverse reactions reported from the clinical programme are those that occurred in the Phase 3 double-blind placebo-controlled studies.

Table 2. Tabulated list of adverse reactions:

^a Includes: injection site haematoma and penile haematoma were reported with the verbatim term of penile bruising or injection site bruising in 87% of patients.
^b Includes: injection site swelling, penile oedema, penile swelling, local swelling, scrotal swelling, and injection site oedema.
^c Includes: injection site pain, penile pain, and injection site discomfort.
^d Includes: contusion, ecchymosis, penile haemorrhage, and injection site haemorrhage.
^∗ reported from a post-marketing clinical study in a patient who had previous exposure to Xiapex for the treatment of Dupuytren’s contracture.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system listed in Appendix V.

In the absence of compatibility studies, this medicinal product must not be mixed with other medicinal products except those mentioned in section 6.6.