Method of photodynamic therapy (PDT) for bladder cancer

Abstract

This invention relates to a method of photodynamic therapy (PDT) for bladder cancer and its use as an adjuvant or neoadjuvant therapy in the treatment of bladder cancer. The invention provides a composition comprising hexyl 5-ALA ester (HAL) or a pharmaceutically acceptable salt thereof for use in a method of photodynamic therapy for bladder cancer, wherein said composition is instilled into the bladder of a patient in need of such treatment and the inside of said bladder is exposed to blue light having a fluence rate of 1.5 to 12.5 mW/cm2.

Claims

1. A method of photodynamic therapy for bladder cancer comprising the instillation into the bladder of a patient in need of such treatment of a composition in the form of a solution of 2 mg/ml hexyl 5-ALA ester (HAL) hydrochloride in an aqueous buffer comprising disodium phosphate dehydrate, potassium dihydrogen phosphate, sodium chloride, hydrochloric acid, sodium hydroxide and water and exposing the inside of said bladder to blue light having a fluence rate of 1.5 to 12.5 mW/cm.sup.2 and wherein the blue light is provided at a light dose of 0.2 to 15.0 J/cm.sup.2.

2. The method according to claim 1, wherein the inside of the bladder is exposed to blue light having a fluence rate of 2.5 to 7.0 mW/cm.sup.2.

3. The method according to claim 2, wherein the blue light is provided at a light dose of 0.3 to 8.0 J/cm.sup.2.

4. The method according to claim 1, wherein the blue light is provided at a light dose of 0.3 to 8.0 J/cm.sup.2.

5. The method according to claim 1, wherein the inside of said bladder is further exposed to white light having a fluence rate of 3.0 to 22.0 mW/cm.sup.2.

6. The method according to claim 5, wherein said white light is provided at a light dose of 0.4 to 26.5 J/cm.sup.2.

7. The method according to claim 5, wherein said inside of the bladder is exposed to white light having a fluence rate of 5.0 to 12.5 mW/cm.sup.2.

8. The method according to claim 5, wherein said white light is provided at a light dose of 0.6 to 15.0 J/cm.sup.2.

9. The method according to claim 8, wherein said white light is provided at a light dose of 0.6 to 15.0 J/cm.sup.2.

10. The method according to claim 5, wherein said inside of the bladder is first exposed to white light and then to blue light.

11. The method according to claim 5, wherein a blue-light cystoscope is used as a light source to provide said blue light and said white light.

12. The method according to claim 5, wherein the inside of the bladder is exposed to blue light and white light for a period of 2 to 20 minutes.

13. The method according to claim 5, wherein said method of photodynamic therapy is used as adjuvant therapy in the treatment of bladder cancer.

14. The method according to claim 13, wherein said bladder cancer is NMIBC and said method of photodynamic therapy is simultaneously carried out with a transurethral resection of NMIBC.

15. The method according to claim 13, wherein said bladder cancer is NMIBC and said method of photodynamic therapy is carried in a patient having undergone transurethral resection of NMIBC.

16. The method according to claim 13, wherein said method of photodynamic therapy replaces or partially replaces other adjuvant therapies.

17. The method according to claim 16, wherein said other adjuvant therapies are chemotherapy and/or immunotherapy.

18. The method according to claim 17, wherein said other adjuvant therapy is BCG treatment.

19. The method according to claim 5, wherein said method of photodynamic therapy is carried out in BCG refractory patients.

20. The method according claim 5, wherein said method of photodynamic therapy is used as neoadjuvant therapy in a method of treating bladder cancer.

21. The method according to claim 20, wherein said bladder cancer is MIBC.

22. The method according to claim 1, wherein said composition is an aqueous solution of HAL.

23. The method according to claim 22, wherein said composition is a solution of HAL in an aqueous buffer.

24. The method according to claim 22, wherein said composition is a solution of HAL in a phosphate buffer.

25. The method according to claim 22, wherein the pH of said composition is in the range of 4.5 to 7.5.

26. The method according to claim 1, wherein a blue-light cystoscope is used as a light source to provide said blue light.

27. The method according to claim 26, wherein said blue-light cystoscope is a commercially available blue-light cystoscope.

28. The method according to claim 1, wherein the inside of the bladder is exposed to blue light for a period of 2 to 20 minutes.

29. The method according to claim 1, wherein said method of photodynamic therapy is used as adjuvant therapy in the treatment of bladder cancer.

30. The method according to claim 29, wherein said bladder cancer is NMIBC and said method of photodynamic therapy is simultaneously carried out with a transurethral resection of NMIBC.

31. The method according to claim 29, wherein said bladder cancer is NMIBC and said method of photodynamic therapy is carried in a patient having undergone transurethral resection of NMIBC.

32. The method according to claim 29, wherein said method of photodynamic therapy replaces or partially replaces other adjuvant therapies.

33. The method according to claim 32, wherein said other adjuvant therapies are chemotherapy and/or immunotherapy.

34. The method according to claim 33, wherein said other adjuvant therapy is BCG treatment.

35. The method according to claim 1, wherein said method of photodynamic therapy is carried out in BCG refractory patients.

36. The method according claim 1, wherein said method of photodynamic therapy is used as neoadjuvant therapy in a method of treating bladder cancer.

37. The method according to claim 36, wherein said bladder cancer is MIBC.

Description

EXAMPLES

Example 1

(1) Orthotopic Rat Bladder Tumor Model

(2) A rat bladder carcinoma cell line was used in these experiments to establish superficial bladder tumors in Female Fischer rats weighing 150-175 g as described in François, et al., J. Urol. 190(2), 2013, 731-736. The animals were used in the experiments 5 days after tumor cell inoculation.

(3) PDT in Rat Bladders

(4) Lyophilized HAL (in the form of Hexvix® powder) was dissolved in PBS to a final concentration of 2 mg/ml (8 mM). 0.5 ml of the solution was instilled into the rat bladder and was left in the bladder for about 1 hour. After evacuation of the HAL solution, 0.5 ml of PBS was instilled into the bladder and whole bladder irradiation with blue light at a fluence rate of 3.5 or 7.0 mW/cm.sup.2 was performed using a 170 mW Modulight laser model ML 6500-405 delivering light at a wavelength of 401 nm, coupled to a fiber with a cylindrical diffuser (1×5 mm) model RD05/500/800 (Medlight, Ecublens, Switzerland) placed in a central position in the bladder. Rats received a blue light dose of 4.0 J/cm.sup.2 (fluence rate 3.5 mW/cm.sup.2) or 7.5 J/cm.sup.2 (fluence rate 7.0 mW/cm.sup.2)

(5) For control, no Hexvix was instilled and only blue light irradiation was carried out at the aforementioned fluence rates/light doses.

(6) Post PDT Protocol

(7) The rats were sacrificed 48 hours after illumination by an overdose of pentobarbital. Bladders were filled in with formaldehyde (4%), removed from the animals and transferred into a vials with formaldehyde (4%) for a minimum of 4 h. Then the bladder was macroscopically cut into 4 parts and fixed for 48 h. Following different cycles of dehydration with gradients of ethanol and xylene, the bladder tissue was included into paraffin. Paraffin embedded sections of 5 μm were cut and used for histology with haematoxylin/eosin staining.

(8) Results

(9) Bladders of animals in the control group (n=2 for each fluence rate/light dose) showed no inflammation (sign of a PDT effect) but persistent and chorion infiltrating tumors for both fluence rates/light doses.

(10) The bladders of 1 animal (50%) in the 3.5 mW/cm.sup.2/4 J/cm.sup.2 group (n=2) showed no inflammation, persistent and chorion infiltrating tumors while the tumor in the bladder of another animal (50%) looked less compact and the superficial layer of said tumor was destroyed.

(11) Bladders of animals in the 7.0 mW/cm.sup.2/7.5 J/cm.sup.2 group (n=2) showed increased tissue thickness/inflammation (both signs of PDT effect) and disintegrating/less compact tumor tissue.

Example 2

(12) HAL/Blue Light Group:

(13) A solution of HAL (Hexvix®) was instilled into the bladder of patients through a catheter and was left in the bladder for about 1 hour. If the patient could not retain the composition for about 1 hour, at least about 1 hour was allowed to pass from the instillation of Hexvix® to the start of exposing the inside of the bladder to light. After evacuation of Hexvix®, a commercially available blue-light cystoscope was inserted into the bladder and a TUR was carried out by exposing the inside of the bladder to white light for the visual inspection, subsequent blue light exposure for fluorescence detection of bladder cancer lesions, resection of the detected lesions under white light and monitoring of the completeness of the resection by use of blue light. Blue light was provided at a fluence rate of 1.5 to 12.5 mW/cm.sup.2 and a light dose of 0.2 to 15.0 J/cm.sup.2 while light was provided at a fluence rate of 3.0 to 22.0 mW/cm.sup.2 and a light dose of 0.4 to 26.5 J/cm.sup.2.

(14) The resected bladder tumors were processed according to methods known in the art and primary cell cultures were established from said patient-derived bladder tumor under appropriate conditions in culture medium. No in vitro primary cell cultures could be established from said resected bladder tumors.

(15) No HAL/White Light Group:

(16) A commercially available white light cystoscope was inserted into the bladder of patients and a TUR was carried out by exposing the inside of the bladder to white light for the visual inspection, detection of bladder cancer lesions, resection of said lesions and monitoring of the completeness of the resection.

(17) Resected bladder tumors were processed identically to those in the HAL/blue light group. In vitro primary cell cultures of such resected bladder tumors could be established.

(18) The fact that no in vitro primary cell cultures could be established from resected bladder tumors in the HAL/blue light patient group points towards a phototoxic effect, i.e. that tumor cells were killed in the applied TUR procedure.

Example 3

(19) A prospective, randomized, comparative, controlled phase III multicenter study was carried out in patients with non-muscle invasive papillary bladder cancer (NMIBC). The study population comprised 551 patients which were randomized into two groups (see below). The groups were similar in age, gender, race, bladder cancer history and prior intravesical therapy.

(20) HAL Group:

(21) 271 patients. The method of the invention was carried out as follows: A solution of HAL (Hexvix®) was instilled into the bladder of patients through a catheter and was left in the bladder for about 1 hour. If the patient could not retain the composition for about 1 hour, at least about 1 hour was allowed to pass from the instillation of Hexvix® to the start of exposing the inside of the bladder to light.

(22) After evacuation of Hexvix®, cystoscopy was carried out with a commercially available cystoscope (blue and white light). The inside of the bladder was first exposed to white light and visually assessed, followed by exposure to blue light to detect cancerous lesions in the bladder. Transurethral resection (TUR) of the detected lesions was carried out under white light and completion of the resection was assessed under blue light.

(23) White Light Group:

(24) 280 patients. Cystoscopy and TUR of bladder cancer under white light only, no HAL.

(25) Patients from both groups with histologically confirmed Ta or T1 lesions were followed up by white light cystoscopy after 3, 6 and 9 months. All tumor recurrences during the 9 months follow-up period were histologically confirmed.

(26) Comparison of Tumor Recurrence in Patients in the White Light Group and the HAL Group According to the Invention

(27) Tumor recurrence was observed during the 9 months follow-up period in 157 of the 280 patients in the white light group (56.1%) and in 128 of 271 patients in the HAL group (42.7%). This difference in tumor recurrence rate is statistically significant and has been explained with improved tumor detection and more complete resection in the HAL group (Stenzl et al., J Urol 184, 2010, 1907-1914).

(28) Comparison of Tumor Recurrence in Patients Who Did/Did not Receive BCG Intravesical Treatment

(29) 50 patients in the HAL group (18.5%) and 55 patients in the white light group (19.6%) received BCG treatment during the 9 months follow-up period. BCG (Bacillus Calmette-Guérin) is an immunotherapy agent for the treatment of bladder cancer. It is usually repeatedly instilled into the bladder. Tumor recurrence rate in both patient groups were determined and the results are displayed in Table 1

(30) TABLE-US-00001 TABLE 1 Tumor recurrence rate by group and BCG treatment Group No BCG Received BCG All White light 61.8% 32.7% 56.1% (n = 280) (139/225) (18/55) (157/280) HAL 49.3% 38.0% 47.2% (n = 271) (109/221) (19/50) (128/271)

(31) As mentioned above, during the 9 months follow-up period in 157 of the 280 patients in the white light group (56.1%) and in 128 of 271 patients in the HAL group (42.7%) had confirmed tumor recurrence (Table 1, right column). This difference is mainly driven by the patients who did not receive BCG (61.8% in the white light group versus 49.3% in the HAL group). The difference in tumor recurrence for patients who received BCG between the groups is much less pronounced (32.7% in the white light group versus 38.0% in the HAL group)

(32) In the white light group the difference in recurrence rate between the patients who received and who did not receive BCG treatment was statistically significant with a p-value<0.001 (32.7% versus 61.8%) which demonstrates the efficacy of BCG in preventing bladder cancer recurrence.

(33) In the HAL group, however, the efficacy of BCG treatment could not be demonstrated, since the difference in recurrence rate between the patients who received and who did not receive BCG was not statistically significant (p-value=0.148, 38.0% versus 49.3%). This absence of significant BCG effect is mainly due to pronounced reduced tumor recurrence rate in patients who did not receive BCG (49.3% versus 61.8%) and this reduction in tumor recurrence rate could possibly be explained by a therapeutic effect of HAL (HAL PDT effect) which results in the prevention of bladder cancer recurrence.

(34) Comparison of Tumor Recurrence Rate in Patients Who Did/Did not Receive BCG and/or Mitomycin Intravesical Treatment

(35) Mitomycin is a chemotherapeutic agent for the treatment of bladder cancer. It may be instilled after TUR (single instillation) to e.g. prevent tumor cell seeding, i.e. re-attachment to the bladder wall of tumor cells which were dislocated during resection. Mitomycin was administered after TUR to 16 patients in the HAL group (5.9%) and to 20 patients in the white light group (7.1%).

(36) Tumor recurrence rate in both patient groups were determined and the results are displayed in Table 2

(37) TABLE-US-00002 TABLE 2 Tumor recurrence rate by group and BCG and/or mitomycin treatment Received no BCG Received BCG Group and/or mitomycin and/or mitomycin All White light 63.1% 36.5% 56.1% (n = 280) (130/206) (27/74) (157/280) HAL 49.0% 41.5% 47.2% (n = 271) (101/206) (27/65) (128/271)

(38) In the white light group the difference in recurrence rate between the patients who received and who did not receive BCG and/or mitomycin treatment was statistically significant with a p-value<0.001 (36.5% versus 63.1%) which demonstrates the efficacy of BCG and/or mitomycin in preventing bladder cancer recurrence.

(39) In the HAL group, however, the efficacy of these treatments could not be demonstrated, since the difference in recurrence rate between the patients who received and who did not receive BCG and/or mitomycin was not statistically significant (p-value=0.291, 41.5% versus 49.0%). This absence of significant BCG and/or mitomycin treatment effect is mainly due to pronounced reduced tumor recurrence rate in patients who did not receive BCG and/or mitomycin (49.0% versus 63.1%) and this reduction in tumor recurrence rate could possibly be explained by a therapeutic effect of HAL (HAL PDT effect) which results in the prevention of bladder cancer recurrence.

(40) Various embodiments of the invention are as follows:

Embodiment 1

(41) Composition comprising hexyl 5-ALA ester (HAL) or a pharmaceutically acceptable salt thereof for use in a method of photodynamic therapy for bladder cancer, wherein said composition is instilled into the bladder of a patient in need of such treatment and the inside of said bladder is exposed to blue light having a fluence rate of 1.5 to 12.5 mW/cm.sup.2.

Embodiment 2

(42) Composition for use according to Embodiment 1, wherein the blue light is provided at a light dose of 0.2 to 15.0 J/cm.sup.2.

Embodiment 3

(43) Composition for use according to Embodiment 1 or 2, wherein the inside of the bladder is exposed to blue light having a fluence rate of 2.5 to 7.0 mW/cm.sup.2.

Embodiment 4

(44) Composition for use according to Embodiment 3, wherein the blue light is provided at a light dose of 0.3 to 8.0 J/cm.sup.2.

Embodiment 5

(45) Composition for use according to any of Embodiments 1 to 4, wherein the inside of said bladder is further exposed to white light having a fluence rate of 3.0 to 22.0 mW/cm.sup.2.

Embodiment 6

(46) Composition for use according to Embodiment 5, wherein said white light is provided at a light dose of 0.4 to 26.5 J/cm.sup.2.

Embodiment 7

(47) Composition for use according to Embodiment 5, wherein said inside of the bladder is exposed to white light having a fluence rate of 5.0 to 12.5 mW/cm.sup.2.

Embodiment 8

(48) Composition for use according to Embodiment 7, wherein said white light is provided at a light dose of 0.6 to 15.0 J/cm.sup.2.

Embodiment 9

(49) Composition for use according to any of Embodiments 1 to 8, wherein said composition is an aqueous solution of HAL, preferably a solution of HAL in an aqueous buffer, more preferably a solution of HAL in a phosphate buffer.

Embodiment 10

(50) Composition for use according to Embodiment 9, wherein the pH of said composition is in the range of 4.5 to 7.5, preferably in the range of 5.7 to 7.2.

Embodiment 11

(51) Composition for use according to any of Embodiments 1 to 10, wherein said composition is a solution of 2 mg/ml HAL hydrochloride in an aqueous buffer comprising disodium phosphate dehydrate, potassium dihydrogen phosphate, sodium chloride, hydrochloric acid, sodium hydroxide and water.

Embodiment 12

(52) Composition for use according to any of Embodiments 5 to 11, wherein said inside of the bladder is first exposed to white light and then to blue light.

Embodiment 13

(53) Composition for use according to any of Embodiments 1 to 12, wherein a blue-light cystoscope is used as a light source to provide and blue light or said blue and white light.

Embodiment 14

(54) Composition for use according to Embodiment 13, wherein said blue-light cystoscope is a commercially available blue-light cystoscope.

Embodiment 15

(55) Composition for use according to any of Embodiments 1 to 14, wherein the inside of the bladder is exposed to blue light or to blue and white light for a period of 2 to 20 minutes.

Embodiment 16

(56) Composition for use according to any of Embodiments 1 to 15 for use in a method of treating bladder cancer wherein said method of photodynamic therapy is used as adjuvant therapy.

Embodiment 17

(57) Composition for use according to Embodiment 16, wherein said bladder cancer is NMIBC and said method of photodynamic therapy is simultaneously carried out with a transurethral resection of NMIBC.

Embodiment 18

(58) Composition for use according to Embodiment 16, wherein said bladder cancer is NMIBC and said method of photodynamic therapy is carried in a patient having undergone transurethral resection of NMIBC.

Embodiment 19

(59) Composition for use according to Embodiments 16-18, wherein said method of photodynamic therapy replaces or partially replaces other adjuvant therapies.

Embodiment 20

(60) Composition for use according to Embodiment 19, wherein said other adjuvant therapies are chemotherapy and/or immunotherapy, preferably BCG treatment.

Embodiment 21

(61) Composition for use according to Embodiment 19, wherein said method of photodynamic therapy is carried out in BCG refractory patients.

Embodiment 22

(62) Composition for use according to any of Embodiments 1 to 15 for use in a method of treating bladder cancer wherein said method of photodynamic therapy is used as neoadjuvant therapy.

Embodiment 23

(63) Composition for use according to Embodiment 22, wherein said bladder cancer is MIBC.

Embodiment 24

(64) Composition for use according to Embodiment 23, wherein said method of photodynamic therapy is carried out prior to a cystectomy.

Embodiment 25

(65) Composition for use according to Embodiment 24, wherein the cystectomy is carried out directly after the method of photodynamic therapy.

Embodiment 26

(66) Method of photodynamic therapy for bladder cancer comprising the instillation into the bladder of a patient in need of such treatment of a composition comprising hexyl 5-ALA ester (HAL) or a pharmaceutically acceptable salt thereof and exposing the inside of said bladder to blue light having a fluence rate of 1.5 to 12.5 mW/cm.sup.2.

Embodiment 27

(67) Method according to Embodiment 26, wherein the blue light is provided at a light dose of 0.2 to 15.0 J/cm.sup.2.

Embodiment 28

(68) Method according to Embodiment 26 or 27, wherein the inside of the bladder is exposed to blue light having a fluence rate of 2.5 to 7.0 mW/cm.sup.2.

Embodiment 29

(69) Method according to Embodiment 28, wherein the blue light is provided at a light dose of 0.3 to 8.0 J/cm.sup.2.

Embodiment 30

(70) Method according to any of Embodiments 26 to 29, wherein the inside of said bladder is further exposed to white light having a fluence rate of 3.0 to 22.0 mW/cm.sup.2.

Embodiment 31

(71) Method according to Embodiment 30, wherein said white light is provided at a light dose of 0.4 to 26.5 J/cm.sup.2.

Embodiment 32

(72) Method according to Embodiment 30, wherein said inside of the bladder is exposed to white light having a fluence rate of 5.0 to 12.5 mW/cm.sup.2.

Embodiment 33

(73) Composition for use according to Embodiment 32, wherein said white light is provided at a light dose of 0.6 to 15.0 J/cm.sup.2.

Embodiment 34

(74) Method according to any of Embodiments 26 to 33, wherein said composition is an aqueous solution of HAL, preferably a solution of HAL in an aqueous buffer, more preferably a solution of HAL in a phosphate buffer.

Embodiment 35

(75) Method according to Embodiment 34, wherein the pH of said composition is in the range of 4.5 to 7.5, preferably in the range of 5.7 to 7.2.

Embodiment 36

(76) Method according to any of Embodiments 26 to 35, wherein said composition is a solution of 2 mg/ml HAL hydrochloride in an aqueous buffer comprising disodium phosphate dehydrate, potassium dihydrogen phosphate, sodium chloride, hydrochloric acid, sodium hydroxide and water.

Embodiment 37

(77) Method according to any of Embodiments 30 to 36, wherein said inside of the bladder is first exposed to white light and then to blue light.

Embodiment 38

(78) Method according to any of Embodiments 26 to 37, wherein a blue-light cystoscope is used as a light source to provide and blue light or said blue and white light.

Embodiment 39

(79) Method according to Embodiment 38, wherein said blue-light cystoscope is a commercially available blue-light cystoscope.

Embodiment 40

(80) Method according to any of Embodiments 26 to 39, wherein the inside of the bladder is exposed to blue light or to blue and white light for a period of 2 to 20 minutes.

Embodiment 41

(81) Method according to any of Embodiments 26 to 40 for use in a method of treating bladder cancer wherein said method of photodynamic therapy is used as adjuvant therapy.

Embodiment 42

(82) Method according to Embodiment 41, wherein said bladder cancer is NMIBC and said method of photodynamic therapy is simultaneously carried out with a transurethral resection of NMIBC.

Embodiment 43

(83) Method according to Embodiment 41, wherein said bladder cancer is NMIBC and said method of photodynamic therapy is carried in a patient having undergone transurethral resection of NMIBC.

Embodiment 44

(84) Method according to Embodiments 41 to 43, wherein said method of photodynamic therapy replaces or partially replaces other adjuvant therapies.

Embodiment 45

(85) Method according to Embodiment 44, wherein said other adjuvant therapies are chemotherapy and/or immunotherapy, preferably BCG treatment.

Embodiment 46

(86) Method according to Embodiment 44, wherein said method of photodynamic therapy is carried out in BCG refractory patients.

Embodiment 47

(87) Method according to any of Embodiments 26 to 40 for use in a method of treating bladder cancer wherein said method of photodynamic therapy is used as neoadjuvant therapy.

Embodiment 48

(88) Method according to Embodiment 47, wherein said bladder cancer is MIBC.

Embodiment 49

(89) Method according to Embodiment 48, wherein said method of photodynamic therapy is carried out prior to a cystectomy.

Embodiment 50

(90) Method according to Embodiment 49, wherein the cystectomy is carried out directly after the method of photodynamic therapy.