Local chemotherapeutic agents for the treatment of ocular malignancies

Safety and efficacy of topical interferon alpha 2B and mitomycin C for localized conjunctival intraepithelial neoplasia: long-term report of their pharmacological safety and efficacy

PURPOSE

Ocular surface squamous neoplasia (OSSN) comprises a wide spectrum of squamous tumors, from which corneal/conjunctival intraepithelial neoplasia (CIN) is the most common one. The classic treatment is complete excision, but recurrence rates are high. Antineoplastic drugs such as mitomycin C (MMC) and interferon alpha 2b (IFNα2b) have been used as adjuvants or as primary treatment. To evaluate the efficacy and safety of topical IFNα2b and MMC in patients with CIN, a phase IIb double-blind clinical trial was performed.

METHODS

Patients diagnosed with localized CIN were evaluated by slit lamp and impression cytology and were randomly given MMC 0.04% or INF2b (1 million IU/mL) 4 times daily until neoplasia resolution. Time of resolution and frequency of adverse effects were analyzed to determine the pharmacological efficacy and safety of both medications.

RESULTS

Seventeen patients were included. Nine patients were treated with MMC and 8 with IFNα2b. All patients responded to treatment. The resolution time in days was 59.11 ± 24.02 in patients treated with MMC and 143.50 ± 47.181 in those treated with IFNα2b (p < 0.001). In the MMC group, one recurrence was reported (11%). There were no recurrences at 2 years of follow-up in the IFNα2b group. Regarding adverse effects, one or more mild adverse reaction occurred in 77% of patients managed with MMC and in 50% of patients managed with IFNα2b (p > 0.05). No serious adverse effects were reported.

CONCLUSIONS

Topical chemotherapy with MMC and IFNα2b demonstrate pharmacological safety and efficacy. Therefore, these drugs could be considered as primary therapies for localized CIN .

Use of interferon alpha 2b to manage conjunctival primary acquired melanosis and conjunctival melanoma

Primary acquired melanosis (PAM) is acquired conjunctival pigmentation that can give rise to conjunctival melanoma (CM), a malignant tumor of the bulbar and palpebral conjunctiva or the caruncle. Surgical excision is the treatment of choice for this neoplasm. Topical chemotherapy is also used for patients with PAM with atypia or CM, hand in patients with recurrent or extensive disease, this may be an important option. Of the several chemotherapeutic drugs used, topical interferon alpha 2b (IFN-α2b) has become popular because of its low toxicity. Clinical evidence from case reports and case series supports the efficacy of IFN-α2b as the preferred adjuvant treatment for PAM and CM. In addition, topical IFN-α2b has been successfully applied to melanocytic tumors refractory to other treatments, such as cryotherapy and topical mitomycin C. In patients with locally advanced CM, the combination of IFN-α2b and systemic immunotherapy may serve as an alternative to exenteration. Given the low frequency of CM, long-term multicenter studies are needed to demonstrate the efficacy of IFN-α2b for preventing local recurrence and distant metastasis.

Fangchinoline suppresses conjunctival melanoma by directly binding FUBP2 and inhibiting the homologous recombination pathway

Conjunctival melanoma (CM) is a rare and fatal ocular tumour with poor prognosis. There is an urgent need of effective therapeutic drugs against CM. Here, we reported the discovery of a novel potential therapeutic target for CM. Through phenotypic screening of our in-house library, fangchinoline was discovered to significantly inhibit the growth of CM cells including CM-AS16, CRMM1, CRMM2 and CM2005.1. Further mechanistic experiments indicated that fangchinoline suppressed the homologous recombination (HR)-directed DNA repair by binding with far upstream element binding protein 2 (FUBP2) and downregulating the expression of HR factors BRCA1 and RAD51. In vitro and in vivo antitumour experiments revealed that fangchinoline increased the efficacy of cisplatin by blocking HR factors and reduced the drug dose and toxicity. In conclusion, our work provides a promising therapeutic strategy for the treatment of CM that is worthy of extensive preclinical investigation.

INTRAVITREAL MELPHALAN FOR TREATMENT OF VITREOUS SEEDING FROM CHOROIDAL MELANOMA

PURPOSE

To report treatment of vitreous seeding of choroidal melanoma with monthly injections of intravitreal melphalan.

METHODS

Case report.

RESULTS

A 70-year-old white woman noted floaters in her left eye, and further examination revealed visual acuity of 20/30 in both eyes. Funduscopically, there was a mushroom-shaped choroidal melanoma in her left eye, measuring 9 mm in basal dimension and 4.8 mm in thickness. Notably, there was apical retinal invasion of melanoma with mild vitreous hemorrhage, without vitreous seeding. The tumor was treated with iodine-125 plaque radiotherapy using an apex dose of 70 Gy over 99 hours, designed to include the retinal invasion. The melanoma demonstrated complete regression into a nearly flat scar of 1 mm and remained stable over 4 years. Five years after radiotherapy, there were diffuse vitreous pigmented seeds of presumed melanoma origin, emanating from the site of retinal necrosis. This progressively worsened over the following 18 months, suspicious for viable melanoma cells, as visual acuity concurrently declined to 20/100. Treatment with intravitreal melphalan (10 μg/0.05 mL) was delivered on a monthly basis for 12 cycles, resulting in vitreous seeds regression, and preservation of the eye. Final visual acuity was 20/200. There were no treatment-related complications.

CONCLUSION

Intravitreal melphalan can be considered in cases of vitreous seeding from uveal melanoma.

Ocular surface complications of local anticancer drugs for treatment of ocular tumors

Local chemotherapy is increasingly used, either in combination with surgery or as monotherapy, for management of ocular tumors. Yet many of the local chemotherapeutic agents used for ocular tumors are cytotoxic drugs that are frequently associated with toxicities in normal ocular tissues. Understanding and managing these side effects are important because they affect treatment tolerability, outcome and quality of vision. Herein, we review local anticancer drugs administered for the treatment of ocular tumors, with an emphasis on their toxicities to the ocular surface, adnexa and lacrimal drainage system. We provide the underlying mechanisms and management strategies for the ocular side effects. Recent innovations in anticancer immunotherapy and ocular drug delivery systems also are discussed as new potential therapeutic modalities for alleviation of side effects.

Management Issues in Conjunctival Tumours: Conjunctival Melanoma and Primary Acquired Melanosis

Conjunctival melanoma is a rare malignant condition of the ocular surface. It is potentially lethal, with regional lymph node spread often preceding distant solid-organ metastasis. Due to its rarity and the long latency between treatment and local recurrence or the development of metastases, it is difficult to study. The literature is composed entirely of case series of varying quality, and there is significant variability in the management of this condition. This commentary attempts to distil the evidence base to provide practical management tips for the clinician.

Mitomycin C or interferon as adjuvant therapy to surgery for ocular surface squamous neoplasia: comparative study

Background:

Traditionally, surgical excision has been the treatment of choice for ocular surface squamous neoplasia (OSSN). Recurrences after surgery are high. To reduce the risk of recurrence, adjuvant therapies have been increasingly used.

Purpose:

We compared recurrences and complications of 3 forms of treatment for OSSN: surgical excision (group A), surgical excision plus adjuvant topical mitomycin C (MMC) (group B), and surgical excision plus subconjunctival interferon-α-2b (IFN-α-2b) (group C).

Methods:

A retrospective comparative study was conducted between January 2006 and March 2016 at the Ocular Oncology Service of the Catholic University of Rome. Seventy-nine patients with a confirmed histological diagnosis of OSSN were included: 43 were treated with surgical excision (group A), 16 underwent surgical excision plus topical MMC (group B), and 20 underwent surgical excision plus adjuvant subconjunctival IFN-α-2b (group C).

Results:

The recurrences were different in the 3 groups. Thirty-one recurrences (72%) were seen in group A, 5 (31%) were found in group B, and 3 (15%) were seen in group C. Eight (50%) patients who received MMC 0.02% complained of ocular discomfort, 10 (62.5%) presented conjunctival hyperemia, while conjunctival chemosis and corneal epitheliopathy were noticed in 2 (13%) and 2 (13%) patients, respectively. All patients treated with subconjunctival IFN-α-2b reported flu-like symptoms. Two patients (10%) complained of ocular discomfort.

Conclusions:

Our study revealed that OSSN is not always manageable with simple excision. Adjuvant chemotherapy is strongly advisable after surgery to reduce recurrences. Interferon injections and MMC drops are effective in preventing recurrences and should be administered after surgery.

Pharmacotherapy and Immunotherapy of Conjunctival Tumors

Conjunctiva and cornea tumors represent a large spectrum of conditions ranging from benign lesions to aggressive and life-threatening malignancies. Topical pharmacotherapies and immunotherapies have recently acquired a relevant role in the management of conjunctival tumors and, in the past 2 decades, there has been a shift from surgery alone toward the use of these agents, both as a sole therapy or as adjunct to surgery (before or after surgery). The 3 main agents that have been used for topical medical treatment of conjunctival tumors are mitomycin-C, 5-fluorouracil, and interferon-α2b. Advantages of topical pharmacotherapies and immunotherapies include the ability to treat the entire ocular surface and prevention of surgical side effects and complications. The aim of this review is to summarize the current use of topical pharmacotherapy and immunotherapy in the management of conjunctival tumors.

Periocular Amyloidosis Manifesting as Pseudopemphigoid Treated With Mitomycin C

PURPOSE

To describe an unusual cicatrizing manifestation of periocular amyloid and the utility of adjuvant antimetabolite therapy.

METHODS

This is a case report of a 49-year old woman with progressive bilateral upper lid ptosis, who was found to have bilateral inferior forniceal masses with thickening of the conjunctiva. Conjunctival and eyelid biopsies showed evidence of amyloid deposition. Systemic evaluation did not reveal any evidence of systemic amyloidosis. Her blepharoptosis continued to deteriorate, and she underwent bilateral sequential upper lid ptosis correction surgery and debulking procedures. Subsequently, she developed severe and progressive cicatricial conjunctivitis with extensive symblepharon formation in all 4 fornices and restriction of ocular motility, simulating a clinical picture of ocular mucous membrane pemphigoid.

RESULTS

She was treated surgically by division of symblepharon augmented with application of topical mitomycin C intraoperatively. This has been partially successful in freeing up differential movement between her lid and her eye and consequently improving eye protection and lubrication.

CONCLUSIONS

Pseudopemphigoid represents a rare manifestation of periocular amyloid. Risks and benefits of surgical procedures in this context need to be carefully weighed to minimize the risk of secondary complications. Topical mitomycin C may be considered as a relatively safe adjunct in managing the cicatricial component of the disease.

Advances in the management of conjunctival melanoma

Malignant melanoma of the conjunctiva is a rare but serious condition. Over the last several years, there have been important advances in the classification, diagnosis, and treatment of this condition. Recent cytogenetic and immunohistochemical studies are increasing understanding of its tumorigenesis. Diagnosis, although still made via histopathology, has been aided with imaging techniques such as ultrasound biomicroscopy and anterior segment optical coherence tomography. Primary treatment consists of surgical excision. But adjuvant treatments with cryotherapy, topical chemotherapy, and radiation therapy have shown increased success. Sentinel lymph node biopsy has shown early promise of detecting micro-metastasis. Long term follow-up of patients with conjunctival melanoma with systemic surveillance is necessary to detect recurrences and metastases.

Gene-directed enzyme prodrug therapy for localized chemotherapeutics in allograft and xenograft tumor models

Most chemotherapy regimens rely on systemic administration of drugs leading to a wide array of toxicities. Using viral-vector-mediated gene modification of muscle tissues, we have developed a method for gene-directed enzyme prodrug therapy that allows for localized drug administration. An inactive prodrug of geldanamycin was activated locally for inhibition of tumor growth without systemic toxicities. A recombinant adeno-associated virus (rAAV) was used to deliver β-galactosidase (LacZ) to the treatment group and green fluorescent protein to the control group. After 1 week, both groups received adenocarcinoma cells in the same location as the previous rAAV injection. The geldanamycin prodrug was administered 1 h later via intraperitoneal injection. Tumor growth was significantly suppressed in animals whose muscles were gene modified to express β-galactosidase compared with the control. Serum assay to access hepatotoxicity resulted in no significant differences between the animals treated with the inactive or activated form of geldanamycin, indicating minimal damage to non-target organs. Using gene-directed enzyme prodrug therapy, in combination with novel recombinant AAV vectors, we have developed a method for localized activation of chemotherapeutic agents that limits the toxicities seen with traditional systemic administration of these potent drugs.

Management of conjunctival malignant melanoma: a review and update

Conjunctival malignant melanoma is a pigmented lesion of the ocular surface. It is an uncommon but potentially devastating tumor that may invade the local tissues of the eye, spread systemically through lymphatic drainage and hematogenous spread, and recur in spite of treatment. Despite its severity, the rarity of available cases has limited the evidence for diagnosis and management. This review will provide an overview of the epidemiology, presentation, diagnosis, management, and surveillance of conjunctival melanoma, with an emphasis on recent advances in biological therapies to treat this disease.